// SPDX-License-Identifier: GPL-2.0-only
/*
 * intel_pt_decoder.c: Intel Processor Trace support
 * Copyright (c) 2013-2014, Intel Corporation.
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <inttypes.h>
#include <linux/compiler.h>
#include <linux/string.h>
#include <linux/zalloc.h>

#include "../auxtrace.h"

#include "intel-pt-insn-decoder.h"
#include "intel-pt-pkt-decoder.h"
#include "intel-pt-decoder.h"
#include "intel-pt-log.h"

#define BITULL(x) (1ULL << (x))

/* IA32_RTIT_CTL MSR bits */
#define INTEL_PT_CYC_ENABLE             BITULL(1)
#define INTEL_PT_CYC_THRESHOLD          (BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))
#define INTEL_PT_CYC_THRESHOLD_SHIFT    19

#define INTEL_PT_BLK_SIZE 1024

#define BIT63 (((uint64_t)1 << 63))

#define SEVEN_BYTES 0xffffffffffffffULL

#define NO_VMCS 0xffffffffffULL

#define INTEL_PT_RETURN 1

/*
 * Default maximum number of loops with no packets consumed i.e. stuck in a
 * loop.
 */
#define INTEL_PT_MAX_LOOPS 100000

struct intel_pt_blk {
        struct intel_pt_blk *prev;
        uint64_t ip[INTEL_PT_BLK_SIZE];
};

struct intel_pt_stack {
        struct intel_pt_blk *blk;
        struct intel_pt_blk *spare;
        int pos;
};

enum intel_pt_p_once {
        INTEL_PT_PRT_ONCE_UNK_VMCS,
        INTEL_PT_PRT_ONCE_ERANGE,
};

enum intel_pt_pkt_state {
        INTEL_PT_STATE_NO_PSB,
        INTEL_PT_STATE_NO_IP,
        INTEL_PT_STATE_ERR_RESYNC,
        INTEL_PT_STATE_IN_SYNC,
        INTEL_PT_STATE_TNT_CONT,
        INTEL_PT_STATE_TNT,
        INTEL_PT_STATE_TIP,
        INTEL_PT_STATE_TIP_PGD,
        INTEL_PT_STATE_FUP,
        INTEL_PT_STATE_FUP_NO_TIP,
        INTEL_PT_STATE_FUP_IN_PSB,
        INTEL_PT_STATE_RESAMPLE,
        INTEL_PT_STATE_VM_TIME_CORRELATION,
};

static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
{
        switch (pkt_state) {
        case INTEL_PT_STATE_NO_PSB:
        case INTEL_PT_STATE_NO_IP:
        case INTEL_PT_STATE_ERR_RESYNC:
        case INTEL_PT_STATE_IN_SYNC:
        case INTEL_PT_STATE_TNT_CONT:
        case INTEL_PT_STATE_RESAMPLE:
        case INTEL_PT_STATE_VM_TIME_CORRELATION:
                return true;
        case INTEL_PT_STATE_TNT:
        case INTEL_PT_STATE_TIP:
        case INTEL_PT_STATE_TIP_PGD:
        case INTEL_PT_STATE_FUP:
        case INTEL_PT_STATE_FUP_NO_TIP:
        case INTEL_PT_STATE_FUP_IN_PSB:
                return false;
        default:
                return true;
        };
}

#ifdef INTEL_PT_STRICT
#define INTEL_PT_STATE_ERR1     INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_NO_PSB
#define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_NO_PSB
#else
#define INTEL_PT_STATE_ERR1     (decoder->pkt_state)
#define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_IP
#define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_ERR_RESYNC
#define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_IN_SYNC
#endif

struct intel_pt_decoder {
        int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
        int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
                         uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
                         uint64_t max_insn_cnt, void *data);
        bool (*pgd_ip)(uint64_t ip, void *data);
        int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data);
        struct intel_pt_vmcs_info *(*findnew_vmcs_info)(void *data, uint64_t vmcs);
        void *data;
        struct intel_pt_state state;
        const unsigned char *buf;
        size_t len;
        bool return_compression;
        bool branch_enable;
        bool mtc_insn;
        bool pge;
        bool have_tma;
        bool have_cyc;
        bool fixup_last_mtc;
        bool have_last_ip;
        bool in_psb;
        bool hop;
        bool leap;
        bool emulated_ptwrite;
        bool vm_time_correlation;
        bool vm_tm_corr_dry_run;
        bool vm_tm_corr_reliable;
        bool vm_tm_corr_same_buf;
        bool vm_tm_corr_continuous;
        bool nr;
        bool next_nr;
        bool iflag;
        bool next_iflag;
        enum intel_pt_param_flags flags;
        uint64_t pos;
        uint64_t last_ip;
        uint64_t ip;
        uint64_t pip_payload;
        uint64_t timestamp;
        uint64_t tsc_timestamp;
        uint64_t ref_timestamp;
        uint64_t buf_timestamp;
        uint64_t sample_timestamp;
        uint64_t ret_addr;
        uint64_t ctc_timestamp;
        uint64_t ctc_delta;
        uint64_t cycle_cnt;
        uint64_t cyc_ref_timestamp;
        uint64_t first_timestamp;
        uint64_t last_reliable_timestamp;
        uint64_t vmcs;
        uint64_t print_once;
        uint64_t last_ctc;
        uint32_t last_mtc;
        uint32_t tsc_ctc_ratio_n;
        uint32_t tsc_ctc_ratio_d;
        uint32_t tsc_ctc_mult;
        uint32_t tsc_slip;
        uint32_t ctc_rem_mask;
        int mtc_shift;
        struct intel_pt_stack stack;
        enum intel_pt_pkt_state pkt_state;
        enum intel_pt_pkt_ctx pkt_ctx;
        enum intel_pt_pkt_ctx prev_pkt_ctx;
        enum intel_pt_blk_type blk_type;
        int blk_type_pos;
        struct intel_pt_pkt packet;
        struct intel_pt_pkt tnt;
        int pkt_step;
        int pkt_len;
        int last_packet_type;
        unsigned int cbr;
        unsigned int cbr_seen;
        unsigned int max_non_turbo_ratio;
        double max_non_turbo_ratio_fp;
        double cbr_cyc_to_tsc;
        double calc_cyc_to_tsc;
        bool have_calc_cyc_to_tsc;
        int exec_mode;
        unsigned int insn_bytes;
        uint64_t period;
        enum intel_pt_period_type period_type;
        uint64_t tot_insn_cnt;
        uint64_t period_insn_cnt;
        uint64_t period_mask;
        uint64_t period_ticks;
        uint64_t last_masked_timestamp;
        uint64_t tot_cyc_cnt;
        uint64_t sample_tot_cyc_cnt;
        uint64_t base_cyc_cnt;
        uint64_t cyc_cnt_timestamp;
        uint64_t ctl;
        uint64_t cyc_threshold;
        double tsc_to_cyc;
        bool continuous_period;
        bool overflow;
        bool set_fup_tx_flags;
        bool set_fup_ptw;
        bool set_fup_mwait;
        bool set_fup_pwre;
        bool set_fup_exstop;
        bool set_fup_bep;
        bool set_fup_cfe_ip;
        bool set_fup_cfe;
        bool set_fup_mode_exec;
        bool sample_cyc;
        unsigned int fup_tx_flags;
        unsigned int tx_flags;
        uint64_t fup_ptw_payload;
        uint64_t fup_mwait_payload;
        uint64_t fup_pwre_payload;
        uint64_t cbr_payload;
        uint64_t timestamp_insn_cnt;
        uint64_t sample_insn_cnt;
        uint64_t stuck_ip;
        struct intel_pt_pkt fup_cfe_pkt;
        int max_loops;
        int no_progress;
        int stuck_ip_prd;
        int stuck_ip_cnt;
        uint64_t psb_ip;
        const unsigned char *next_buf;
        size_t next_len;
        unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
        int evd_cnt;
        struct intel_pt_evd evd[INTEL_PT_MAX_EVDS];
};

static uint64_t intel_pt_lower_power_of_2(uint64_t x)
{
        int i;

        for (i = 0; x != 1; i++)
                x >>= 1;

        return x << i;
}

__printf(1, 2)
static void p_log(const char *fmt, ...)
{
        char buf[512];
        va_list args;

        va_start(args, fmt);
        vsnprintf(buf, sizeof(buf), fmt, args);
        va_end(args);

        fprintf(stderr, "%s\n", buf);
        intel_pt_log("%s\n", buf);
}

static bool intel_pt_print_once(struct intel_pt_decoder *decoder,
                                enum intel_pt_p_once id)
{
        uint64_t bit = 1ULL << id;

        if (decoder->print_once & bit)
                return false;
        decoder->print_once |= bit;
        return true;
}

static uint64_t intel_pt_cyc_threshold(uint64_t ctl)
{
        if (!(ctl & INTEL_PT_CYC_ENABLE))
                return 0;

        return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;
}

static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
{
        if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
                uint64_t period;

                period = intel_pt_lower_power_of_2(decoder->period);
                decoder->period_mask  = ~(period - 1);
                decoder->period_ticks = period;
        }
}

static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
{
        if (!d)
                return 0;
        return (t / d) * n + ((t % d) * n) / d;
}

struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
{
        struct intel_pt_decoder *decoder;

        if (!params->get_trace || !params->walk_insn)
                return NULL;

        decoder = zalloc(sizeof(struct intel_pt_decoder));
        if (!decoder)
                return NULL;

        decoder->get_trace          = params->get_trace;
        decoder->walk_insn          = params->walk_insn;
        decoder->pgd_ip             = params->pgd_ip;
        decoder->lookahead          = params->lookahead;
        decoder->findnew_vmcs_info  = params->findnew_vmcs_info;
        decoder->data               = params->data;
        decoder->return_compression = params->return_compression;
        decoder->branch_enable      = params->branch_enable;
        decoder->hop                = params->quick >= 1;
        decoder->leap               = params->quick >= 2;
        decoder->vm_time_correlation = params->vm_time_correlation;
        decoder->vm_tm_corr_dry_run = params->vm_tm_corr_dry_run;
        decoder->first_timestamp    = params->first_timestamp;
        decoder->last_reliable_timestamp = params->first_timestamp;
        decoder->max_loops          = params->max_loops ? params->max_loops : INTEL_PT_MAX_LOOPS;

        decoder->flags              = params->flags;

        decoder->ctl                = params->ctl;
        decoder->period             = params->period;
        decoder->period_type        = params->period_type;

        decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
        decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;

        decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);

        intel_pt_setup_period(decoder);

        decoder->mtc_shift = params->mtc_period;
        decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;

        decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
        decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;

        if (!decoder->tsc_ctc_ratio_n)
                decoder->tsc_ctc_ratio_d = 0;

        if (decoder->tsc_ctc_ratio_d) {
                if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
                        decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
                                                decoder->tsc_ctc_ratio_d;
        }

        /*
         * A TSC packet can slip past MTC packets so that the timestamp appears
         * to go backwards. One estimate is that can be up to about 40 CPU
         * cycles, which is certainly less than 0x1000 TSC ticks, but accept
         * slippage an order of magnitude more to be on the safe side.
         */
        decoder->tsc_slip = 0x10000;

        intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
        intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
        intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
        intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
        intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);

        if (decoder->hop)
                intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n");

        return decoder;
}

void intel_pt_set_first_timestamp(struct intel_pt_decoder *decoder,
                                  uint64_t first_timestamp)
{
        decoder->first_timestamp = first_timestamp;
}

static void intel_pt_pop_blk(struct intel_pt_stack *stack)
{
        struct intel_pt_blk *blk = stack->blk;

        stack->blk = blk->prev;
        if (!stack->spare)
                stack->spare = blk;
        else
                free(blk);
}

static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
{
        if (!stack->pos) {
                if (!stack->blk)
                        return 0;
                intel_pt_pop_blk(stack);
                if (!stack->blk)
                        return 0;
                stack->pos = INTEL_PT_BLK_SIZE;
        }
        return stack->blk->ip[--stack->pos];
}

static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
{
        struct intel_pt_blk *blk;

        if (stack->spare) {
                blk = stack->spare;
                stack->spare = NULL;
        } else {
                blk = malloc(sizeof(struct intel_pt_blk));
                if (!blk)
                        return -ENOMEM;
        }

        blk->prev = stack->blk;
        stack->blk = blk;
        stack->pos = 0;
        return 0;
}

static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
{
        int err;

        if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
                err = intel_pt_alloc_blk(stack);
                if (err)
                        return err;
        }

        stack->blk->ip[stack->pos++] = ip;
        return 0;
}

static void intel_pt_clear_stack(struct intel_pt_stack *stack)
{
        while (stack->blk)
                intel_pt_pop_blk(stack);
        stack->pos = 0;
}

static void intel_pt_free_stack(struct intel_pt_stack *stack)
{
        intel_pt_clear_stack(stack);
        zfree(&stack->blk);
        zfree(&stack->spare);
}

void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
{
        intel_pt_free_stack(&decoder->stack);
        free(decoder);
}

static int intel_pt_ext_err(int code)
{
        switch (code) {
        case -ENOMEM:
                return INTEL_PT_ERR_NOMEM;
        case -ENOSYS:
                return INTEL_PT_ERR_INTERN;
        case -EBADMSG:
                return INTEL_PT_ERR_BADPKT;
        case -ENODATA:
                return INTEL_PT_ERR_NODATA;
        case -EILSEQ:
                return INTEL_PT_ERR_NOINSN;
        case -ENOENT:
                return INTEL_PT_ERR_MISMAT;
        case -EOVERFLOW:
                return INTEL_PT_ERR_OVR;
        case -ENOSPC:
                return INTEL_PT_ERR_LOST;
        case -ELOOP:
                return INTEL_PT_ERR_NELOOP;
        case -ECONNRESET:
                return INTEL_PT_ERR_EPTW;
        default:
                return INTEL_PT_ERR_UNK;
        }
}

static const char *intel_pt_err_msgs[] = {
        [INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
        [INTEL_PT_ERR_INTERN] = "Internal error",
        [INTEL_PT_ERR_BADPKT] = "Bad packet",
        [INTEL_PT_ERR_NODATA] = "No more data",
        [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
        [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
        [INTEL_PT_ERR_OVR]    = "Overflow packet",
        [INTEL_PT_ERR_LOST]   = "Lost trace data",
        [INTEL_PT_ERR_UNK]    = "Unknown error!",
        [INTEL_PT_ERR_NELOOP] = "Never-ending loop (refer perf config intel-pt.max-loops)",
        [INTEL_PT_ERR_EPTW]   = "Broken emulated ptwrite",
};

int intel_pt__strerror(int code, char *buf, size_t buflen)
{
        if (code < 1 || code >= INTEL_PT_ERR_MAX)
                code = INTEL_PT_ERR_UNK;
        strlcpy(buf, intel_pt_err_msgs[code], buflen);
        return 0;
}

static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
                                 uint64_t last_ip)
{
        uint64_t ip;

        switch (packet->count) {
        case 1:
                ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
                     packet->payload;
                break;
        case 2:
                ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
                     packet->payload;
                break;
        case 3:
                ip = packet->payload;
                /* Sign-extend 6-byte ip */
                if (ip & (uint64_t)0x800000000000ULL)
                        ip |= (uint64_t)0xffff000000000000ULL;
                break;
        case 4:
                ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
                     packet->payload;
                break;
        case 6:
                ip = packet->payload;
                break;
        default:
                return 0;
        }

        return ip;
}

static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
{
        decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
        decoder->have_last_ip = true;
}

static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
{
        intel_pt_set_last_ip(decoder);
        decoder->ip = decoder->last_ip;
}

static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
{
        intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
                            decoder->buf);
}

static int intel_pt_bug(struct intel_pt_decoder *decoder)
{
        intel_pt_log("ERROR: Internal error\n");
        decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
        return -ENOSYS;
}

static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
{
        decoder->tx_flags = 0;
}

static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
{
        decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
}

static inline void intel_pt_update_pip(struct intel_pt_decoder *decoder)
{
        decoder->pip_payload = decoder->packet.payload;
}

static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder)
{
        decoder->next_nr = decoder->pip_payload & 1;
}

static inline void intel_pt_set_nr(struct intel_pt_decoder *decoder)
{
        decoder->nr = decoder->pip_payload & 1;
        decoder->next_nr = decoder->nr;
}

static inline void intel_pt_set_pip(struct intel_pt_decoder *decoder)
{
        intel_pt_update_pip(decoder);
        intel_pt_set_nr(decoder);
}

static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
{
        intel_pt_clear_tx_flags(decoder);
        decoder->have_tma = false;
        decoder->pkt_len = 1;
        decoder->pkt_step = 1;
        intel_pt_decoder_log_packet(decoder);
        if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
                intel_pt_log("ERROR: Bad packet\n");
                decoder->pkt_state = INTEL_PT_STATE_ERR1;
        }
        return -EBADMSG;
}

static inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder)
{
        decoder->sample_timestamp = decoder->timestamp;
        decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
        decoder->state.cycles = decoder->tot_cyc_cnt;
}

static void intel_pt_reposition(struct intel_pt_decoder *decoder)
{
        decoder->ip = 0;
        decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
        decoder->timestamp = 0;
        decoder->have_tma = false;
}

static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition)
{
        struct intel_pt_buffer buffer = { .buf = 0, };
        int ret;

        decoder->pkt_step = 0;

        intel_pt_log("Getting more data\n");
        ret = decoder->get_trace(&buffer, decoder->data);
        if (ret)
                return ret;
        decoder->buf = buffer.buf;
        decoder->len = buffer.len;
        if (!decoder->len) {
                intel_pt_log("No more data\n");
                return -ENODATA;
        }
        decoder->buf_timestamp = buffer.ref_timestamp;
        if (!buffer.consecutive || reposition) {
                intel_pt_reposition(decoder);
                decoder->ref_timestamp = buffer.ref_timestamp;
                decoder->state.trace_nr = buffer.trace_nr;
                decoder->vm_tm_corr_same_buf = false;
                intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
                             decoder->ref_timestamp);
                return -ENOLINK;
        }

        return 0;
}

static int intel_pt_get_next_data(struct intel_pt_decoder *decoder,
                                  bool reposition)
{
        if (!decoder->next_buf)
                return intel_pt_get_data(decoder, reposition);

        decoder->buf = decoder->next_buf;
        decoder->len = decoder->next_len;
        decoder->next_buf = 0;
        decoder->next_len = 0;
        return 0;
}

static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
{
        unsigned char *buf = decoder->temp_buf;
        size_t old_len, len, n;
        int ret;

        old_len = decoder->len;
        len = decoder->len;
        memcpy(buf, decoder->buf, len);

        ret = intel_pt_get_data(decoder, false);
        if (ret) {
                decoder->pos += old_len;
                return ret < 0 ? ret : -EINVAL;
        }

        n = INTEL_PT_PKT_MAX_SZ - len;
        if (n > decoder->len)
                n = decoder->len;
        memcpy(buf + len, decoder->buf, n);
        len += n;

        decoder->prev_pkt_ctx = decoder->pkt_ctx;
        ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
        if (ret < (int)old_len) {
                decoder->next_buf = decoder->buf;
                decoder->next_len = decoder->len;
                decoder->buf = buf;
                decoder->len = old_len;
                return intel_pt_bad_packet(decoder);
        }

        decoder->next_buf = decoder->buf + (ret - old_len);
        decoder->next_len = decoder->len - (ret - old_len);

        decoder->buf = buf;
        decoder->len = ret;

        return ret;
}

struct intel_pt_pkt_info {
        struct intel_pt_decoder   *decoder;
        struct intel_pt_pkt       packet;
        uint64_t                  pos;
        int                       pkt_len;
        int                       last_packet_type;
        void                      *data;
};

typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);

/* Lookahead packets in current buffer */
static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
                                  intel_pt_pkt_cb_t cb, void *data)
{
        struct intel_pt_pkt_info pkt_info;
        const unsigned char *buf = decoder->buf;
        enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
        size_t len = decoder->len;
        int ret;

        pkt_info.decoder          = decoder;
        pkt_info.pos              = decoder->pos;
        pkt_info.pkt_len          = decoder->pkt_step;
        pkt_info.last_packet_type = decoder->last_packet_type;
        pkt_info.data             = data;

        while (1) {
                do {
                        pkt_info.pos += pkt_info.pkt_len;
                        buf          += pkt_info.pkt_len;
                        len          -= pkt_info.pkt_len;

                        if (!len)
                                return INTEL_PT_NEED_MORE_BYTES;

                        ret = intel_pt_get_packet(buf, len, &pkt_info.packet,
                                                  &pkt_ctx);
                        if (!ret)
                                return INTEL_PT_NEED_MORE_BYTES;
                        if (ret < 0)
                                return ret;

                        pkt_info.pkt_len = ret;
                } while (pkt_info.packet.type == INTEL_PT_PAD);

                ret = cb(&pkt_info);
                if (ret)
                        return 0;

                pkt_info.last_packet_type = pkt_info.packet.type;
        }
}

struct intel_pt_calc_cyc_to_tsc_info {
        uint64_t        cycle_cnt;
        unsigned int    cbr;
        uint32_t        last_mtc;
        uint64_t        ctc_timestamp;
        uint64_t        ctc_delta;
        uint64_t        tsc_timestamp;
        uint64_t        timestamp;
        bool            have_tma;
        bool            fixup_last_mtc;
        bool            from_mtc;
        double          cbr_cyc_to_tsc;
};

/*
 * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
 * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
 * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
 * packet by copying the missing bits from the current MTC assuming the least
 * difference between the two, and that the current MTC comes after last_mtc.
 */
static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
                                    uint32_t *last_mtc)
{
        uint32_t first_missing_bit = 1U << (16 - mtc_shift);
        uint32_t mask = ~(first_missing_bit - 1);

        *last_mtc |= mtc & mask;
        if (*last_mtc >= mtc) {
                *last_mtc -= first_missing_bit;
                *last_mtc &= 0xff;
        }
}

static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct intel_pt_decoder *decoder = pkt_info->decoder;
        struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
        uint64_t timestamp;
        double cyc_to_tsc;
        unsigned int cbr;
        uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;

        switch (pkt_info->packet.type) {
        case INTEL_PT_TNT:
        case INTEL_PT_TIP_PGE:
        case INTEL_PT_TIP:
        case INTEL_PT_FUP:
        case INTEL_PT_PSB:
        case INTEL_PT_PIP:
        case INTEL_PT_MODE_EXEC:
        case INTEL_PT_MODE_TSX:
        case INTEL_PT_PSBEND:
        case INTEL_PT_PAD:
        case INTEL_PT_VMCS:
        case INTEL_PT_MNT:
        case INTEL_PT_PTWRITE:
        case INTEL_PT_PTWRITE_IP:
        case INTEL_PT_BBP:
        case INTEL_PT_BIP:
        case INTEL_PT_BEP:
        case INTEL_PT_BEP_IP:
        case INTEL_PT_CFE:
        case INTEL_PT_CFE_IP:
        case INTEL_PT_EVD:
                return 0;

        case INTEL_PT_MTC:
                if (!data->have_tma)
                        return 0;

                mtc = pkt_info->packet.payload;
                if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
                        data->fixup_last_mtc = false;
                        intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
                                                &data->last_mtc);
                }
                if (mtc > data->last_mtc)
                        mtc_delta = mtc - data->last_mtc;
                else
                        mtc_delta = mtc + 256 - data->last_mtc;
                data->ctc_delta += mtc_delta << decoder->mtc_shift;
                data->last_mtc = mtc;

                if (decoder->tsc_ctc_mult) {
                        timestamp = data->ctc_timestamp +
                                data->ctc_delta * decoder->tsc_ctc_mult;
                } else {
                        timestamp = data->ctc_timestamp +
                                multdiv(data->ctc_delta,
                                        decoder->tsc_ctc_ratio_n,
                                        decoder->tsc_ctc_ratio_d);
                }

                if (timestamp < data->timestamp)
                        return 1;

                if (pkt_info->last_packet_type != INTEL_PT_CYC) {
                        data->timestamp = timestamp;
                        return 0;
                }

                break;

        case INTEL_PT_TSC:
                /*
                 * For now, do not support using TSC packets - refer
                 * intel_pt_calc_cyc_to_tsc().
                 */
                if (data->from_mtc)
                        return 1;
                timestamp = pkt_info->packet.payload |
                            (data->timestamp & (0xffULL << 56));
                if (data->from_mtc && timestamp < data->timestamp &&
                    data->timestamp - timestamp < decoder->tsc_slip)
                        return 1;
                if (timestamp < data->timestamp)
                        timestamp += (1ULL << 56);
                if (pkt_info->last_packet_type != INTEL_PT_CYC) {
                        if (data->from_mtc)
                                return 1;
                        data->tsc_timestamp = timestamp;
                        data->timestamp = timestamp;
                        return 0;
                }
                break;

        case INTEL_PT_TMA:
                if (data->from_mtc)
                        return 1;

                if (!decoder->tsc_ctc_ratio_d)
                        return 0;

                ctc = pkt_info->packet.payload;
                fc = pkt_info->packet.count;
                ctc_rem = ctc & decoder->ctc_rem_mask;

                data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;

                data->ctc_timestamp = data->tsc_timestamp - fc;
                if (decoder->tsc_ctc_mult) {
                        data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
                } else {
                        data->ctc_timestamp -=
                                multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
                                        decoder->tsc_ctc_ratio_d);
                }

                data->ctc_delta = 0;
                data->have_tma = true;
                data->fixup_last_mtc = true;

                return 0;

        case INTEL_PT_CYC:
                data->cycle_cnt += pkt_info->packet.payload;
                return 0;

        case INTEL_PT_CBR:
                cbr = pkt_info->packet.payload;
                if (data->cbr && data->cbr != cbr)
                        return 1;
                data->cbr = cbr;
                data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
                return 0;

        case INTEL_PT_TIP_PGD:
        case INTEL_PT_TRACESTOP:
        case INTEL_PT_EXSTOP:
        case INTEL_PT_EXSTOP_IP:
        case INTEL_PT_MWAIT:
        case INTEL_PT_PWRE:
        case INTEL_PT_PWRX:
        case INTEL_PT_OVF:
        case INTEL_PT_BAD: /* Does not happen */
        default:
                return 1;
        }

        if (!data->cbr && decoder->cbr) {
                data->cbr = decoder->cbr;
                data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
        }

        if (!data->cycle_cnt)
                return 1;

        cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;

        if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
            cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
                             cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
                return 1;
        }

        decoder->calc_cyc_to_tsc = cyc_to_tsc;
        decoder->have_calc_cyc_to_tsc = true;

        if (data->cbr) {
                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
                             cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
        } else {
                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
                             cyc_to_tsc, pkt_info->pos);
        }

        return 1;
}

static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
                                     bool from_mtc)
{
        struct intel_pt_calc_cyc_to_tsc_info data = {
                .cycle_cnt      = 0,
                .cbr            = 0,
                .last_mtc       = decoder->last_mtc,
                .ctc_timestamp  = decoder->ctc_timestamp,
                .ctc_delta      = decoder->ctc_delta,
                .tsc_timestamp  = decoder->tsc_timestamp,
                .timestamp      = decoder->timestamp,
                .have_tma       = decoder->have_tma,
                .fixup_last_mtc = decoder->fixup_last_mtc,
                .from_mtc       = from_mtc,
                .cbr_cyc_to_tsc = 0,
        };

        /*
         * For now, do not support using TSC packets for at least the reasons:
         * 1) timing might have stopped
         * 2) TSC packets within PSB+ can slip against CYC packets
         */
        if (!from_mtc)
                return;

        intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
}

static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
{
        int ret;

        decoder->last_packet_type = decoder->packet.type;

        do {
                decoder->pos += decoder->pkt_step;
                decoder->buf += decoder->pkt_step;
                decoder->len -= decoder->pkt_step;

                if (!decoder->len) {
                        ret = intel_pt_get_next_data(decoder, false);
                        if (ret)
                                return ret;
                }

                decoder->prev_pkt_ctx = decoder->pkt_ctx;
                ret = intel_pt_get_packet(decoder->buf, decoder->len,
                                          &decoder->packet, &decoder->pkt_ctx);
                if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
                    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
                        ret = intel_pt_get_split_packet(decoder);
                        if (ret < 0)
                                return ret;
                }
                if (ret <= 0)
                        return intel_pt_bad_packet(decoder);

                decoder->pkt_len = ret;
                decoder->pkt_step = ret;
                intel_pt_decoder_log_packet(decoder);
        } while (decoder->packet.type == INTEL_PT_PAD);

        return 0;
}

static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
{
        uint64_t timestamp, masked_timestamp;

        timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
        masked_timestamp = timestamp & decoder->period_mask;
        if (decoder->continuous_period) {
                if (masked_timestamp > decoder->last_masked_timestamp)
                        return 1;
        } else {
                timestamp += 1;
                masked_timestamp = timestamp & decoder->period_mask;
                if (masked_timestamp > decoder->last_masked_timestamp) {
                        decoder->last_masked_timestamp = masked_timestamp;
                        decoder->continuous_period = true;
                }
        }

        if (masked_timestamp < decoder->last_masked_timestamp)
                return decoder->period_ticks;

        return decoder->period_ticks - (timestamp - masked_timestamp);
}

static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
{
        switch (decoder->period_type) {
        case INTEL_PT_PERIOD_INSTRUCTIONS:
                return decoder->period - decoder->period_insn_cnt;
        case INTEL_PT_PERIOD_TICKS:
                return intel_pt_next_period(decoder);
        case INTEL_PT_PERIOD_NONE:
        case INTEL_PT_PERIOD_MTC:
        default:
                return 0;
        }
}

static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
{
        uint64_t timestamp, masked_timestamp;

        switch (decoder->period_type) {
        case INTEL_PT_PERIOD_INSTRUCTIONS:
                decoder->period_insn_cnt = 0;
                break;
        case INTEL_PT_PERIOD_TICKS:
                timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
                masked_timestamp = timestamp & decoder->period_mask;
                if (masked_timestamp > decoder->last_masked_timestamp)
                        decoder->last_masked_timestamp = masked_timestamp;
                else
                        decoder->last_masked_timestamp += decoder->period_ticks;
                break;
        case INTEL_PT_PERIOD_NONE:
        case INTEL_PT_PERIOD_MTC:
        default:
                break;
        }

        decoder->state.type |= INTEL_PT_INSTRUCTION;
}

/*
 * Sample FUP instruction at the same time as reporting the FUP event, so the
 * instruction sample gets the same flags as the FUP event.
 */
static void intel_pt_sample_fup_insn(struct intel_pt_decoder *decoder)
{
        struct intel_pt_insn intel_pt_insn;
        uint64_t max_insn_cnt, insn_cnt = 0;
        int err;

        decoder->state.insn_op = INTEL_PT_OP_OTHER;
        decoder->state.insn_len = 0;

        if (!decoder->branch_enable || !decoder->pge || decoder->hop ||
            decoder->ip != decoder->last_ip)
                return;

        if (!decoder->mtc_insn)
                decoder->mtc_insn = true;

        max_insn_cnt = intel_pt_next_sample(decoder);
        if (max_insn_cnt != 1)
                return;

        err = decoder->walk_insn(&intel_pt_insn, &insn_cnt, &decoder->ip,
                                 0, max_insn_cnt, decoder->data);
        /* Ignore error, it will be reported next walk anyway */
        if (err)
                return;

        if (intel_pt_insn.branch != INTEL_PT_BR_NO_BRANCH) {
                intel_pt_log_at("ERROR: Unexpected branch at FUP instruction", decoder->ip);
                return;
        }

        decoder->tot_insn_cnt += insn_cnt;
        decoder->timestamp_insn_cnt += insn_cnt;
        decoder->sample_insn_cnt += insn_cnt;
        decoder->period_insn_cnt += insn_cnt;

        intel_pt_sample_insn(decoder);

        decoder->state.type |= INTEL_PT_INSTRUCTION;
        decoder->ip += intel_pt_insn.length;
}

static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
                              struct intel_pt_insn *intel_pt_insn, uint64_t ip)
{
        uint64_t max_insn_cnt, insn_cnt = 0;
        int err;

        if (!decoder->mtc_insn)
                decoder->mtc_insn = true;

        max_insn_cnt = intel_pt_next_sample(decoder);

        err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
                                 max_insn_cnt, decoder->data);

        decoder->tot_insn_cnt += insn_cnt;
        decoder->timestamp_insn_cnt += insn_cnt;
        decoder->sample_insn_cnt += insn_cnt;
        decoder->period_insn_cnt += insn_cnt;

        if (err) {
                decoder->no_progress = 0;
                decoder->pkt_state = INTEL_PT_STATE_ERR2;
                intel_pt_log_at("ERROR: Failed to get instruction",
                                decoder->ip);
                if (err == -ENOENT)
                        return -ENOLINK;
                return -EILSEQ;
        }

        if (ip && decoder->ip == ip) {
                err = -EAGAIN;
                goto out;
        }

        if (max_insn_cnt && insn_cnt >= max_insn_cnt)
                intel_pt_sample_insn(decoder);

        if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
                decoder->state.type = INTEL_PT_INSTRUCTION;
                decoder->state.from_ip = decoder->ip;
                decoder->state.to_ip = 0;
                decoder->ip += intel_pt_insn->length;
                err = INTEL_PT_RETURN;
                goto out;
        }

        if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
                /* Zero-length calls are excluded */
                if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
                    intel_pt_insn->rel) {
                        err = intel_pt_push(&decoder->stack, decoder->ip +
                                            intel_pt_insn->length);
                        if (err)
                                goto out;
                }
        } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
                decoder->ret_addr = intel_pt_pop(&decoder->stack);
        }

        if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
                int cnt = decoder->no_progress++;

                decoder->state.from_ip = decoder->ip;
                decoder->ip += intel_pt_insn->length +
                                intel_pt_insn->rel;
                decoder->state.to_ip = decoder->ip;
                err = INTEL_PT_RETURN;

                /*
                 * Check for being stuck in a loop.  This can happen if a
                 * decoder error results in the decoder erroneously setting the
                 * ip to an address that is itself in an infinite loop that
                 * consumes no packets.  When that happens, there must be an
                 * unconditional branch.
                 */
                if (cnt) {
                        if (cnt == 1) {
                                decoder->stuck_ip = decoder->state.to_ip;
                                decoder->stuck_ip_prd = 1;
                                decoder->stuck_ip_cnt = 1;
                        } else if (cnt > decoder->max_loops ||
                                   decoder->state.to_ip == decoder->stuck_ip) {
                                intel_pt_log_at("ERROR: Never-ending loop",
                                                decoder->state.to_ip);
                                decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
                                err = -ELOOP;
                                goto out;
                        } else if (!--decoder->stuck_ip_cnt) {
                                decoder->stuck_ip_prd += 1;
                                decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
                                decoder->stuck_ip = decoder->state.to_ip;
                        }
                }
                goto out_no_progress;
        }
out:
        decoder->no_progress = 0;
out_no_progress:
        decoder->state.insn_op = intel_pt_insn->op;
        decoder->state.insn_len = intel_pt_insn->length;
        memcpy(decoder->state.insn, intel_pt_insn->buf,
               INTEL_PT_INSN_BUF_SZ);

        if (decoder->tx_flags & INTEL_PT_IN_TX)
                decoder->state.flags |= INTEL_PT_IN_TX;

        return err;
}

static void intel_pt_mode_exec_status(struct intel_pt_decoder *decoder)
{
        bool iflag = decoder->packet.count & INTEL_PT_IFLAG;

        decoder->exec_mode = decoder->packet.payload;
        decoder->iflag = iflag;
        decoder->next_iflag = iflag;
        decoder->state.from_iflag = iflag;
        decoder->state.to_iflag = iflag;
}

static void intel_pt_mode_exec(struct intel_pt_decoder *decoder)
{
        bool iflag = decoder->packet.count & INTEL_PT_IFLAG;

        decoder->exec_mode = decoder->packet.payload;
        decoder->next_iflag = iflag;
}

static void intel_pt_sample_iflag(struct intel_pt_decoder *decoder)
{
        decoder->state.type |= INTEL_PT_IFLAG_CHG;
        decoder->state.from_iflag = decoder->iflag;
        decoder->state.to_iflag = decoder->next_iflag;
        decoder->iflag = decoder->next_iflag;
}

static void intel_pt_sample_iflag_chg(struct intel_pt_decoder *decoder)
{
        if (decoder->iflag != decoder->next_iflag)
                intel_pt_sample_iflag(decoder);
}

static void intel_pt_clear_fup_event(struct intel_pt_decoder *decoder)
{
        decoder->set_fup_tx_flags = false;
        decoder->set_fup_ptw = false;
        decoder->set_fup_mwait = false;
        decoder->set_fup_pwre = false;
        decoder->set_fup_exstop = false;
        decoder->set_fup_bep = false;
        decoder->set_fup_cfe_ip = false;
        decoder->set_fup_cfe = false;
        decoder->evd_cnt = 0;
        decoder->set_fup_mode_exec = false;
        decoder->iflag = decoder->next_iflag;
}

static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
{
        enum intel_pt_sample_type type = decoder->state.type;
        bool sample_fup_insn = false;
        bool ret = false;

        decoder->state.type &= ~INTEL_PT_BRANCH;
        decoder->state.insn_op = INTEL_PT_OP_OTHER;
        decoder->state.insn_len = 0;

        if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
                bool ip = decoder->set_fup_cfe_ip;

                decoder->set_fup_cfe_ip = false;
                decoder->set_fup_cfe = false;
                decoder->state.type |= INTEL_PT_EVT;
                if (!ip && decoder->pge)
                        decoder->state.type |= INTEL_PT_BRANCH;
                decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
                decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
                decoder->state.evd_cnt = decoder->evd_cnt;
                decoder->state.evd = decoder->evd;
                decoder->evd_cnt = 0;
                if (ip || decoder->pge)
                        decoder->state.flags |= INTEL_PT_FUP_IP;
                ret = true;
        }
        if (decoder->set_fup_mode_exec) {
                decoder->set_fup_mode_exec = false;
                intel_pt_sample_iflag(decoder);
                sample_fup_insn = no_tip;
                ret = true;
        }
        if (decoder->set_fup_tx_flags) {
                decoder->set_fup_tx_flags = false;
                decoder->tx_flags = decoder->fup_tx_flags;
                decoder->state.type |= INTEL_PT_TRANSACTION;
                if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
                        decoder->state.type |= INTEL_PT_BRANCH;
                decoder->state.flags = decoder->fup_tx_flags;
                ret = true;
        }
        if (decoder->set_fup_ptw) {
                decoder->set_fup_ptw = false;
                decoder->state.type |= INTEL_PT_PTW;
                decoder->state.flags |= INTEL_PT_FUP_IP;
                decoder->state.ptw_payload = decoder->fup_ptw_payload;
                ret = true;
        }
        if (decoder->set_fup_mwait) {
                decoder->set_fup_mwait = false;
                decoder->state.type |= INTEL_PT_MWAIT_OP;
                decoder->state.mwait_payload = decoder->fup_mwait_payload;
                ret = true;
        }
        if (decoder->set_fup_pwre) {
                decoder->set_fup_pwre = false;
                decoder->state.type |= INTEL_PT_PWR_ENTRY;
                decoder->state.pwre_payload = decoder->fup_pwre_payload;
                ret = true;
        }
        if (decoder->set_fup_exstop) {
                decoder->set_fup_exstop = false;
                decoder->state.type |= INTEL_PT_EX_STOP;
                decoder->state.flags |= INTEL_PT_FUP_IP;
                ret = true;
        }
        if (decoder->set_fup_bep) {
                decoder->set_fup_bep = false;
                decoder->state.type |= INTEL_PT_BLK_ITEMS;
                ret = true;
        }
        if (decoder->overflow) {
                decoder->overflow = false;
                if (!ret && !decoder->pge) {
                        if (decoder->hop) {
                                decoder->state.type = 0;
                                decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
                        }
                        decoder->pge = true;
                        decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
                        decoder->state.from_ip = 0;
                        decoder->state.to_ip = decoder->ip;
                        return true;
                }
        }
        if (ret) {
                decoder->state.from_ip = decoder->ip;
                decoder->state.to_ip = 0;
                if (sample_fup_insn)
                        intel_pt_sample_fup_insn(decoder);
        } else {
                decoder->state.type = type;
        }
        return ret;
}

static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
                                          struct intel_pt_insn *intel_pt_insn,
                                          uint64_t ip, int err)
{
        return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
               intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
               ip == decoder->ip + intel_pt_insn->length;
}

static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
{
        struct intel_pt_insn intel_pt_insn;
        uint64_t ip;
        int err;

        ip = decoder->last_ip;

        while (1) {
                err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
                if (err == INTEL_PT_RETURN)
                        return 0;
                if (err == -EAGAIN ||
                    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
                        bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;

                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        if (intel_pt_fup_event(decoder, no_tip) && no_tip)
                                return 0;
                        return -EAGAIN;
                }
                decoder->set_fup_tx_flags = false;
                if (err)
                        return err;

                if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
                        intel_pt_log_at("ERROR: Unexpected indirect branch",
                                        decoder->ip);
                        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
                        return -ENOENT;
                }

                if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
                        intel_pt_log_at("ERROR: Unexpected conditional branch",
                                        decoder->ip);
                        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
                        return -ENOENT;
                }

                intel_pt_bug(decoder);
        }
}

static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
{
        struct intel_pt_insn intel_pt_insn;
        int err;

        err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
        if (err == INTEL_PT_RETURN &&
            decoder->pgd_ip &&
            decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
            (decoder->state.type & INTEL_PT_BRANCH) &&
            decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
                /* Unconditional branch leaving filter region */
                decoder->no_progress = 0;
                decoder->pge = false;
                decoder->continuous_period = false;
                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                decoder->state.type |= INTEL_PT_TRACE_END;
                intel_pt_update_nr(decoder);
                return 0;
        }
        if (err == INTEL_PT_RETURN)
                return 0;
        if (err)
                return err;

        intel_pt_update_nr(decoder);
        intel_pt_sample_iflag_chg(decoder);

        if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
                if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        decoder->state.from_ip = decoder->ip;
                        if (decoder->packet.count == 0) {
                                decoder->state.to_ip = 0;
                        } else {
                                decoder->state.to_ip = decoder->last_ip;
                                decoder->ip = decoder->last_ip;
                        }
                        decoder->state.type |= INTEL_PT_TRACE_END;
                } else {
                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        decoder->state.from_ip = decoder->ip;
                        if (decoder->packet.count == 0) {
                                decoder->state.to_ip = 0;
                        } else {
                                decoder->state.to_ip = decoder->last_ip;
                                decoder->ip = decoder->last_ip;
                        }
                }
                return 0;
        }

        if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
                uint64_t to_ip = decoder->ip + intel_pt_insn.length +
                                 intel_pt_insn.rel;

                if (decoder->pgd_ip &&
                    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
                    decoder->pgd_ip(to_ip, decoder->data)) {
                        /* Conditional branch leaving filter region */
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        decoder->ip = to_ip;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = to_ip;
                        decoder->state.type |= INTEL_PT_TRACE_END;
                        return 0;
                }
                intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
                                decoder->ip);
                decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
                return -ENOENT;
        }

        return intel_pt_bug(decoder);
}

struct eptw_data {
        int bit_countdown;
        uint64_t payload;
};

static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct eptw_data *data = pkt_info->data;
        int nr_bits;

        switch (pkt_info->packet.type) {
        case INTEL_PT_PAD:
        case INTEL_PT_MNT:
        case INTEL_PT_MODE_EXEC:
        case INTEL_PT_MODE_TSX:
        case INTEL_PT_MTC:
        case INTEL_PT_FUP:
        case INTEL_PT_CYC:
        case INTEL_PT_CBR:
        case INTEL_PT_TSC:
        case INTEL_PT_TMA:
        case INTEL_PT_PIP:
        case INTEL_PT_VMCS:
        case INTEL_PT_PSB:
        case INTEL_PT_PSBEND:
        case INTEL_PT_PTWRITE:
        case INTEL_PT_PTWRITE_IP:
        case INTEL_PT_EXSTOP:
        case INTEL_PT_EXSTOP_IP:
        case INTEL_PT_MWAIT:
        case INTEL_PT_PWRE:
        case INTEL_PT_PWRX:
        case INTEL_PT_BBP:
        case INTEL_PT_BIP:
        case INTEL_PT_BEP:
        case INTEL_PT_BEP_IP:
        case INTEL_PT_CFE:
        case INTEL_PT_CFE_IP:
        case INTEL_PT_EVD:
                break;

        case INTEL_PT_TNT:
                nr_bits = data->bit_countdown;
                if (nr_bits > pkt_info->packet.count)
                        nr_bits = pkt_info->packet.count;
                data->payload <<= nr_bits;
                data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
                data->bit_countdown -= nr_bits;
                return !data->bit_countdown;

        case INTEL_PT_TIP_PGE:
        case INTEL_PT_TIP_PGD:
        case INTEL_PT_TIP:
        case INTEL_PT_BAD:
        case INTEL_PT_OVF:
        case INTEL_PT_TRACESTOP:
        default:
                return 1;
        }

        return 0;
}

static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
{
        int n = 64 - decoder->tnt.count;
        struct eptw_data data = {
                .bit_countdown = n,
                .payload = decoder->tnt.payload >> n,
        };

        decoder->emulated_ptwrite = false;
        intel_pt_log("Emulated ptwrite detected\n");

        intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
        if (data.bit_countdown)
                return -ECONNRESET;

        decoder->state.type = INTEL_PT_PTW;
        decoder->state.from_ip = decoder->ip;
        decoder->state.to_ip = 0;
        decoder->state.ptw_payload = data.payload;
        return 0;
}

static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
{
        struct intel_pt_insn intel_pt_insn;
        int err;

        while (1) {
                if (decoder->emulated_ptwrite)
                        return intel_pt_emulated_ptwrite(decoder);
                err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
                if (err == INTEL_PT_RETURN) {
                        decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
                        return 0;
                }
                if (err) {
                        decoder->emulated_ptwrite = false;
                        return err;
                }

                if (intel_pt_insn.op == INTEL_PT_OP_RET) {
                        if (!decoder->return_compression) {
                                intel_pt_log_at("ERROR: RET when expecting conditional branch",
                                                decoder->ip);
                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                                return -ENOENT;
                        }
                        if (!decoder->ret_addr) {
                                intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
                                                decoder->ip);
                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                                return -ENOENT;
                        }
                        if (!(decoder->tnt.payload & BIT63)) {
                                intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
                                                decoder->ip);
                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                                return -ENOENT;
                        }
                        decoder->tnt.count -= 1;
                        if (decoder->tnt.count)
                                decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
                        else
                                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        decoder->tnt.payload <<= 1;
                        decoder->state.from_ip = decoder->ip;
                        decoder->ip = decoder->ret_addr;
                        decoder->state.to_ip = decoder->ip;
                        return 0;
                }

                if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
                        /* Handle deferred TIPs */
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type != INTEL_PT_TIP ||
                            decoder->packet.count == 0) {
                                intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
                                                decoder->ip);
                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                                decoder->pkt_step = 0;
                                return -ENOENT;
                        }
                        intel_pt_set_last_ip(decoder);
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = decoder->last_ip;
                        decoder->ip = decoder->last_ip;
                        intel_pt_update_nr(decoder);
                        intel_pt_sample_iflag_chg(decoder);
                        return 0;
                }

                if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
                        decoder->tnt.count -= 1;
                        if (decoder->tnt.count)
                                decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
                        else
                                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                        if (decoder->tnt.payload & BIT63) {
                                decoder->tnt.payload <<= 1;
                                decoder->state.from_ip = decoder->ip;
                                decoder->ip += intel_pt_insn.length +
                                               intel_pt_insn.rel;
                                decoder->state.to_ip = decoder->ip;
                                return 0;
                        }
                        /* Instruction sample for a non-taken branch */
                        if (decoder->state.type & INTEL_PT_INSTRUCTION) {
                                decoder->tnt.payload <<= 1;
                                decoder->state.type = INTEL_PT_INSTRUCTION;
                                decoder->state.from_ip = decoder->ip;
                                decoder->state.to_ip = 0;
                                decoder->ip += intel_pt_insn.length;
                                return 0;
                        }
                        decoder->sample_cyc = false;
                        decoder->ip += intel_pt_insn.length;
                        if (!decoder->tnt.count) {
                                intel_pt_update_sample_time(decoder);
                                return -EAGAIN;
                        }
                        decoder->tnt.payload <<= 1;
                        continue;
                }

                return intel_pt_bug(decoder);
        }
}

static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
{
        unsigned int fup_tx_flags;
        int err;

        fup_tx_flags = decoder->packet.payload &
                       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
        err = intel_pt_get_next_packet(decoder);
        if (err)
                return err;
        if (decoder->packet.type == INTEL_PT_FUP) {
                decoder->fup_tx_flags = fup_tx_flags;
                decoder->set_fup_tx_flags = true;
                if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
                        *no_tip = true;
        } else {
                intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
                                decoder->pos);
                intel_pt_update_in_tx(decoder);
        }
        return 0;
}

static int intel_pt_evd(struct intel_pt_decoder *decoder)
{
        if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
                intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
                return -ENOSYS;
        }
        decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
                .type = decoder->packet.count,
                .payload = decoder->packet.payload,
        };
        return 0;
}

static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
{
        timestamp |= (ref_timestamp & (0xffULL << 56));

        if (timestamp < ref_timestamp) {
                if (ref_timestamp - timestamp > (1ULL << 55))
                        timestamp += (1ULL << 56);
        } else {
                if (timestamp - ref_timestamp > (1ULL << 55))
                        timestamp -= (1ULL << 56);
        }

        return timestamp;
}

/* For use only when decoder->vm_time_correlation is true */
static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
                                   uint64_t timestamp)
{
        uint64_t max_timestamp = decoder->buf_timestamp;

        if (!max_timestamp) {
                max_timestamp = decoder->last_reliable_timestamp +
                                0x400000000ULL;
        }
        return timestamp >= decoder->last_reliable_timestamp &&
               timestamp < decoder->buf_timestamp;
}

static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
{
        uint64_t timestamp;
        bool bad = false;

        decoder->have_tma = false;

        if (decoder->ref_timestamp) {
                timestamp = intel_pt_8b_tsc(decoder->packet.payload,
                                            decoder->ref_timestamp);
                decoder->tsc_timestamp = timestamp;
                decoder->timestamp = timestamp;
                decoder->ref_timestamp = 0;
                decoder->timestamp_insn_cnt = 0;
        } else if (decoder->timestamp) {
                timestamp = decoder->packet.payload |
                            (decoder->timestamp & (0xffULL << 56));
                decoder->tsc_timestamp = timestamp;
                if (timestamp < decoder->timestamp &&
                    decoder->timestamp - timestamp < decoder->tsc_slip) {
                        intel_pt_log_to("Suppressing backwards timestamp",
                                        timestamp);
                        timestamp = decoder->timestamp;
                }
                if (timestamp < decoder->timestamp) {
                        if (!decoder->buf_timestamp ||
                            (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
                                intel_pt_log_to("Wraparound timestamp", timestamp);
                                timestamp += (1ULL << 56);
                                decoder->tsc_timestamp = timestamp;
                        } else {
                                intel_pt_log_to("Suppressing bad timestamp", timestamp);
                                timestamp = decoder->timestamp;
                                bad = true;
                        }
                }
                if (decoder->vm_time_correlation &&
                    (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
                    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
                        p_log("Timestamp out of range");
                decoder->timestamp = timestamp;
                decoder->timestamp_insn_cnt = 0;
        }

        if (decoder->last_packet_type == INTEL_PT_CYC) {
                decoder->cyc_ref_timestamp = decoder->timestamp;
                decoder->cycle_cnt = 0;
                decoder->have_calc_cyc_to_tsc = false;
                intel_pt_calc_cyc_to_tsc(decoder, false);
        }

        intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

static int intel_pt_overflow(struct intel_pt_decoder *decoder)
{
        intel_pt_log("ERROR: Buffer overflow\n");
        intel_pt_clear_tx_flags(decoder);
        intel_pt_set_nr(decoder);
        decoder->timestamp_insn_cnt = 0;
        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
        decoder->state.from_ip = decoder->ip;
        decoder->ip = 0;
        decoder->pge = false;
        intel_pt_clear_fup_event(decoder);
        decoder->overflow = true;
        return -EOVERFLOW;
}

static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
{
        if (decoder->have_cyc)
                return;

        decoder->cyc_cnt_timestamp = decoder->timestamp;
        decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
}

static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
{
        decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;

        if (decoder->pge)
                intel_pt_mtc_cyc_cnt_pge(decoder);
}

static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
{
        uint64_t tot_cyc_cnt, tsc_delta;

        if (decoder->have_cyc)
                return;

        decoder->sample_cyc = true;

        if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
                return;

        tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
        tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;

        if (tot_cyc_cnt > decoder->tot_cyc_cnt)
                decoder->tot_cyc_cnt = tot_cyc_cnt;
}

static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
{
        uint32_t ctc = decoder->packet.payload;
        uint32_t fc = decoder->packet.count;
        uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;

        if (!decoder->tsc_ctc_ratio_d)
                return;

        if (decoder->pge && !decoder->in_psb)
                intel_pt_mtc_cyc_cnt_pge(decoder);
        else
                intel_pt_mtc_cyc_cnt_upd(decoder);

        decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
        decoder->last_ctc = ctc - ctc_rem;
        decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
        if (decoder->tsc_ctc_mult) {
                decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
        } else {
                decoder->ctc_timestamp -= multdiv(ctc_rem,
                                                  decoder->tsc_ctc_ratio_n,
                                                  decoder->tsc_ctc_ratio_d);
        }
        decoder->ctc_delta = 0;
        decoder->have_tma = true;
        decoder->fixup_last_mtc = true;
        intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
                     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
}

static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
{
        uint64_t timestamp;
        uint32_t mtc, mtc_delta;

        if (!decoder->have_tma)
                return;

        mtc = decoder->packet.payload;

        if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
                decoder->fixup_last_mtc = false;
                intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
                                        &decoder->last_mtc);
        }

        if (mtc > decoder->last_mtc)
                mtc_delta = mtc - decoder->last_mtc;
        else
                mtc_delta = mtc + 256 - decoder->last_mtc;

        decoder->ctc_delta += mtc_delta << decoder->mtc_shift;

        if (decoder->tsc_ctc_mult) {
                timestamp = decoder->ctc_timestamp +
                            decoder->ctc_delta * decoder->tsc_ctc_mult;
        } else {
                timestamp = decoder->ctc_timestamp +
                            multdiv(decoder->ctc_delta,
                                    decoder->tsc_ctc_ratio_n,
                                    decoder->tsc_ctc_ratio_d);
        }

        if (timestamp < decoder->timestamp)
                intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
                             timestamp, decoder->timestamp);
        else
                decoder->timestamp = timestamp;

        intel_pt_mtc_cyc_cnt_upd(decoder);

        decoder->timestamp_insn_cnt = 0;
        decoder->last_mtc = mtc;

        if (decoder->last_packet_type == INTEL_PT_CYC) {
                decoder->cyc_ref_timestamp = decoder->timestamp;
                decoder->cycle_cnt = 0;
                decoder->have_calc_cyc_to_tsc = false;
                intel_pt_calc_cyc_to_tsc(decoder, true);
        }

        intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
{
        unsigned int cbr = decoder->packet.payload & 0xff;

        decoder->cbr_payload = decoder->packet.payload;

        if (decoder->cbr == cbr)
                return;

        decoder->cbr = cbr;
        decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
        decoder->cyc_ref_timestamp = decoder->timestamp;
        decoder->cycle_cnt = 0;

        intel_pt_mtc_cyc_cnt_cbr(decoder);
}

static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
{
        uint64_t timestamp = decoder->cyc_ref_timestamp;

        decoder->have_cyc = true;

        decoder->cycle_cnt += decoder->packet.payload;
        if (decoder->pge)
                decoder->tot_cyc_cnt += decoder->packet.payload;
        decoder->sample_cyc = true;

        if (!decoder->cyc_ref_timestamp)
                return;

        if (decoder->have_calc_cyc_to_tsc)
                timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
        else if (decoder->cbr)
                timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
        else
                return;

        if (timestamp < decoder->timestamp)
                intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
                             timestamp, decoder->timestamp);
        else
                decoder->timestamp = timestamp;

        decoder->timestamp_insn_cnt = 0;

        intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

static void intel_pt_bbp(struct intel_pt_decoder *decoder)
{
        if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
                memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
                decoder->state.items.is_32_bit = false;
        }
        decoder->blk_type = decoder->packet.payload;
        decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
        if (decoder->blk_type == INTEL_PT_GP_REGS)
                decoder->state.items.is_32_bit = decoder->packet.count;
        if (decoder->blk_type_pos < 0) {
                intel_pt_log("WARNING: Unknown block type %u\n",
                             decoder->blk_type);
        } else if (decoder->state.items.mask[decoder->blk_type_pos]) {
                intel_pt_log("WARNING: Duplicate block type %u\n",
                             decoder->blk_type);
        }
}

static void intel_pt_bip(struct intel_pt_decoder *decoder)
{
        uint32_t id = decoder->packet.count;
        uint32_t bit = 1 << id;
        int pos = decoder->blk_type_pos;

        if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
                intel_pt_log("WARNING: Unknown block item %u type %d\n",
                             id, decoder->blk_type);
                return;
        }

        if (decoder->state.items.mask[pos] & bit) {
                intel_pt_log("WARNING: Duplicate block item %u type %d\n",
                             id, decoder->blk_type);
        }

        decoder->state.items.mask[pos] |= bit;
        decoder->state.items.val[pos][id] = decoder->packet.payload;
}

/* Walk PSB+ packets when already in sync. */
static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
{
        int err;

        decoder->in_psb = true;

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err)
                        goto out;

                switch (decoder->packet.type) {
                case INTEL_PT_PSBEND:
                        err = 0;
                        goto out;

                case INTEL_PT_TIP_PGD:
                case INTEL_PT_TIP_PGE:
                case INTEL_PT_TIP:
                case INTEL_PT_TNT:
                case INTEL_PT_TRACESTOP:
                case INTEL_PT_BAD:
                case INTEL_PT_PSB:
                case INTEL_PT_PTWRITE:
                case INTEL_PT_PTWRITE_IP:
                case INTEL_PT_EXSTOP:
                case INTEL_PT_EXSTOP_IP:
                case INTEL_PT_MWAIT:
                case INTEL_PT_PWRE:
                case INTEL_PT_PWRX:
                case INTEL_PT_BBP:
                case INTEL_PT_BIP:
                case INTEL_PT_BEP:
                case INTEL_PT_BEP_IP:
                case INTEL_PT_CFE:
                case INTEL_PT_CFE_IP:
                case INTEL_PT_EVD:
                        decoder->have_tma = false;
                        intel_pt_log("ERROR: Unexpected packet\n");
                        err = -EAGAIN;
                        goto out;

                case INTEL_PT_OVF:
                        err = intel_pt_overflow(decoder);
                        goto out;

                case INTEL_PT_TSC:
                        intel_pt_calc_tsc_timestamp(decoder);
                        break;

                case INTEL_PT_TMA:
                        intel_pt_calc_tma(decoder);
                        break;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        break;

                case INTEL_PT_MODE_EXEC:
                        intel_pt_mode_exec_status(decoder);
                        break;

                case INTEL_PT_PIP:
                        intel_pt_set_pip(decoder);
                        break;

                case INTEL_PT_FUP:
                        decoder->pge = true;
                        if (decoder->packet.count) {
                                intel_pt_set_last_ip(decoder);
                                decoder->psb_ip = decoder->last_ip;
                        }
                        break;

                case INTEL_PT_MODE_TSX:
                        intel_pt_update_in_tx(decoder);
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        if (decoder->period_type == INTEL_PT_PERIOD_MTC)
                                decoder->state.type |= INTEL_PT_INSTRUCTION;
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_VMCS:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                default:
                        break;
                }
        }
out:
        decoder->in_psb = false;

        return err;
}

static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
{
        int err;

        if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
                decoder->tx_flags = 0;
                decoder->state.flags &= ~INTEL_PT_IN_TX;
                decoder->state.flags |= INTEL_PT_ABORT_TX;
        } else {
                decoder->state.flags |= INTEL_PT_ASYNC;
        }

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err)
                        return err;

                switch (decoder->packet.type) {
                case INTEL_PT_TNT:
                case INTEL_PT_FUP:
                case INTEL_PT_TRACESTOP:
                case INTEL_PT_PSB:
                case INTEL_PT_TSC:
                case INTEL_PT_TMA:
                case INTEL_PT_MODE_TSX:
                case INTEL_PT_BAD:
                case INTEL_PT_PSBEND:
                case INTEL_PT_PTWRITE:
                case INTEL_PT_PTWRITE_IP:
                case INTEL_PT_EXSTOP:
                case INTEL_PT_EXSTOP_IP:
                case INTEL_PT_MWAIT:
                case INTEL_PT_PWRE:
                case INTEL_PT_PWRX:
                case INTEL_PT_BBP:
                case INTEL_PT_BIP:
                case INTEL_PT_BEP:
                case INTEL_PT_BEP_IP:
                case INTEL_PT_CFE:
                case INTEL_PT_CFE_IP:
                case INTEL_PT_EVD:
                        intel_pt_log("ERROR: Missing TIP after FUP\n");
                        decoder->pkt_state = INTEL_PT_STATE_ERR3;
                        decoder->pkt_step = 0;
                        return -ENOENT;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        break;

                case INTEL_PT_OVF:
                        return intel_pt_overflow(decoder);

                case INTEL_PT_TIP_PGD:
                        decoder->state.from_ip = decoder->ip;
                        if (decoder->packet.count == 0) {
                                decoder->state.to_ip = 0;
                        } else {
                                intel_pt_set_ip(decoder);
                                decoder->state.to_ip = decoder->ip;
                        }
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        decoder->state.type |= INTEL_PT_TRACE_END;
                        intel_pt_update_nr(decoder);
                        return 0;

                case INTEL_PT_TIP_PGE:
                        decoder->pge = true;
                        intel_pt_log("Omitting PGE ip " x64_fmt "\n",
                                     decoder->ip);
                        decoder->state.from_ip = 0;
                        if (decoder->packet.count == 0) {
                                decoder->state.to_ip = 0;
                        } else {
                                intel_pt_set_ip(decoder);
                                decoder->state.to_ip = decoder->ip;
                        }
                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
                        intel_pt_mtc_cyc_cnt_pge(decoder);
                        intel_pt_set_nr(decoder);
                        return 0;

                case INTEL_PT_TIP:
                        decoder->state.from_ip = decoder->ip;
                        if (decoder->packet.count == 0) {
                                decoder->state.to_ip = 0;
                        } else {
                                intel_pt_set_ip(decoder);
                                decoder->state.to_ip = decoder->ip;
                        }
                        intel_pt_update_nr(decoder);
                        intel_pt_sample_iflag_chg(decoder);
                        return 0;

                case INTEL_PT_PIP:
                        intel_pt_update_pip(decoder);
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        if (decoder->period_type == INTEL_PT_PERIOD_MTC)
                                decoder->state.type |= INTEL_PT_INSTRUCTION;
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_MODE_EXEC:
                        intel_pt_mode_exec(decoder);
                        break;

                case INTEL_PT_VMCS:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                        break;

                default:
                        return intel_pt_bug(decoder);
                }
        }
}

static int intel_pt_resample(struct intel_pt_decoder *decoder)
{
        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
        decoder->state.type = INTEL_PT_INSTRUCTION;
        decoder->state.from_ip = decoder->ip;
        decoder->state.to_ip = 0;
        return 0;
}

struct intel_pt_vm_tsc_info {
        struct intel_pt_pkt pip_packet;
        struct intel_pt_pkt vmcs_packet;
        struct intel_pt_pkt tma_packet;
        bool tsc, pip, vmcs, tma, psbend;
        uint64_t ctc_delta;
        uint64_t last_ctc;
        int max_lookahead;
};

/* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct intel_pt_vm_tsc_info *data = pkt_info->data;

        switch (pkt_info->packet.type) {
        case INTEL_PT_PAD:
        case INTEL_PT_MNT:
        case INTEL_PT_MODE_EXEC:
        case INTEL_PT_MODE_TSX:
        case INTEL_PT_MTC:
        case INTEL_PT_FUP:
        case INTEL_PT_CYC:
        case INTEL_PT_CBR:
                break;

        case INTEL_PT_TSC:
                data->tsc = true;
                break;

        case INTEL_PT_TMA:
                data->tma_packet = pkt_info->packet;
                data->tma = true;
                break;

        case INTEL_PT_PIP:
                data->pip_packet = pkt_info->packet;
                data->pip = true;
                break;

        case INTEL_PT_VMCS:
                data->vmcs_packet = pkt_info->packet;
                data->vmcs = true;
                break;

        case INTEL_PT_PSBEND:
                data->psbend = true;
                return 1;

        case INTEL_PT_TIP_PGE:
        case INTEL_PT_PTWRITE:
        case INTEL_PT_PTWRITE_IP:
        case INTEL_PT_EXSTOP:
        case INTEL_PT_EXSTOP_IP:
        case INTEL_PT_MWAIT:
        case INTEL_PT_PWRE:
        case INTEL_PT_PWRX:
        case INTEL_PT_BBP:
        case INTEL_PT_BIP:
        case INTEL_PT_BEP:
        case INTEL_PT_BEP_IP:
        case INTEL_PT_OVF:
        case INTEL_PT_BAD:
        case INTEL_PT_TNT:
        case INTEL_PT_TIP_PGD:
        case INTEL_PT_TIP:
        case INTEL_PT_PSB:
        case INTEL_PT_TRACESTOP:
        case INTEL_PT_CFE:
        case INTEL_PT_CFE_IP:
        case INTEL_PT_EVD:
        default:
                return 1;
        }

        return 0;
}

struct intel_pt_ovf_fup_info {
        int max_lookahead;
        bool found;
};

/* Lookahead to detect a FUP packet after OVF */
static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct intel_pt_ovf_fup_info *data = pkt_info->data;

        if (pkt_info->packet.type == INTEL_PT_CYC ||
            pkt_info->packet.type == INTEL_PT_MTC ||
            pkt_info->packet.type == INTEL_PT_TSC)
                return !--(data->max_lookahead);
        data->found = pkt_info->packet.type == INTEL_PT_FUP;
        return 1;
}

static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
{
        struct intel_pt_ovf_fup_info data = {
                .max_lookahead = 16,
                .found = false,
        };

        intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
        return data.found;
}

/* Lookahead and get the TMA packet after TSC */
static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct intel_pt_vm_tsc_info *data = pkt_info->data;

        if (pkt_info->packet.type == INTEL_PT_CYC ||
            pkt_info->packet.type == INTEL_PT_MTC)
                return !--(data->max_lookahead);

        if (pkt_info->packet.type == INTEL_PT_TMA) {
                data->tma_packet = pkt_info->packet;
                data->tma = true;
        }
        return 1;
}

static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
{
        if (decoder->tsc_ctc_mult)
                return ctc * decoder->tsc_ctc_mult;
        else
                return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
}

static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
                                           uint32_t ctc,
                                           uint32_t fc,
                                           uint64_t last_ctc_timestamp,
                                           uint64_t ctc_delta,
                                           uint32_t last_ctc)
{
        /* Number of CTC ticks from last_ctc_timestamp to last_mtc */
        uint64_t last_mtc_ctc = last_ctc + ctc_delta;
        /*
         * Number of CTC ticks from there until current TMA packet. We would
         * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
         * past an MTC, so a sign-extended value is used.
         */
        uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
        /* Total CTC ticks from last_ctc_timestamp to current TMA packet */
        uint64_t new_ctc_delta = ctc_delta + delta;
        uint64_t expected_tsc;

        /*
         * Convert CTC ticks to TSC ticks, add the starting point
         * (last_ctc_timestamp) and the fast counter from the TMA packet.
         */
        expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;

        if (intel_pt_enable_logging) {
                intel_pt_log_x64(last_mtc_ctc);
                intel_pt_log_x32(last_ctc);
                intel_pt_log_x64(ctc_delta);
                intel_pt_log_x64(delta);
                intel_pt_log_x32(ctc);
                intel_pt_log_x64(new_ctc_delta);
                intel_pt_log_x64(last_ctc_timestamp);
                intel_pt_log_x32(fc);
                intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
                intel_pt_log_x64(expected_tsc);
        }

        return expected_tsc;
}

static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
                                      struct intel_pt_vm_tsc_info *data)
{
        uint32_t ctc = data->tma_packet.payload;
        uint32_t fc = data->tma_packet.count;

        return intel_pt_calc_expected_tsc(decoder, ctc, fc,
                                          decoder->ctc_timestamp,
                                          data->ctc_delta, data->last_ctc);
}

static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
                                      struct intel_pt_vmcs_info *vmcs_info)
{
        uint64_t payload = decoder->packet.payload;

        /* VMX adds the TSC Offset, so subtract to get host TSC */
        decoder->packet.payload -= vmcs_info->tsc_offset;
        /* TSC packet has only 7 bytes */
        decoder->packet.payload &= SEVEN_BYTES;

        /*
         * The buffer is mmapped from the data file, so this also updates the
         * data file.
         */
        if (!decoder->vm_tm_corr_dry_run)
                memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);

        intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
                     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
                     payload, decoder->packet.payload, vmcs_info->vmcs,
                     vmcs_info->tsc_offset);
}

static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
                                             uint64_t tsc_offset)
{
        struct intel_pt_vmcs_info vmcs_info = {
                .vmcs = NO_VMCS,
                .tsc_offset = tsc_offset
        };

        intel_pt_translate_vm_tsc(decoder, &vmcs_info);
}

static inline bool in_vm(uint64_t pip_payload)
{
        return pip_payload & 1;
}

static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
{
        return pip_packet->payload & 1;
}

static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
{
        p_log("VMCS: %#" PRIx64 "  TSC Offset %#" PRIx64,
              vmcs_info->vmcs, vmcs_info->tsc_offset);
}

static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
                                    struct intel_pt_vm_tsc_info *data)
{
        memset(data, 0, sizeof(*data));
        data->ctc_delta = decoder->ctc_delta;
        data->last_ctc = decoder->last_ctc;
        intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
        if (data->tsc && !data->psbend)
                p_log("ERROR: PSB without PSBEND");
        decoder->in_psb = data->psbend;
}

static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
                                          struct intel_pt_vm_tsc_info *data,
                                          struct intel_pt_vmcs_info *vmcs_info,
                                          uint64_t host_tsc)
{
        if (!decoder->in_psb) {
                /* Can't happen */
                p_log("ERROR: First TSC is not in PSB+");
        }

        if (data->pip) {
                if (pip_in_vm(&data->pip_packet)) { /* Guest */
                        if (vmcs_info && vmcs_info->tsc_offset) {
                                intel_pt_translate_vm_tsc(decoder, vmcs_info);
                                decoder->vm_tm_corr_reliable = true;
                        } else {
                                p_log("ERROR: First TSC, unknown TSC Offset");
                        }
                } else { /* Host */
                        decoder->vm_tm_corr_reliable = true;
                }
        } else { /* Host or Guest */
                decoder->vm_tm_corr_reliable = false;
                if (intel_pt_time_in_range(decoder, host_tsc)) {
                        /* Assume Host */
                } else {
                        /* Assume Guest */
                        if (vmcs_info && vmcs_info->tsc_offset)
                                intel_pt_translate_vm_tsc(decoder, vmcs_info);
                        else
                                p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
                }
        }
}

static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
                                    struct intel_pt_vm_tsc_info *data)
{
        struct intel_pt_vmcs_info *vmcs_info;
        uint64_t tsc_offset = 0;
        uint64_t vmcs;
        bool reliable = true;
        uint64_t expected_tsc;
        uint64_t host_tsc;
        uint64_t ref_timestamp;

        bool assign = false;
        bool assign_reliable = false;

        /* Already have 'data' for the in_psb case */
        if (!decoder->in_psb) {
                memset(data, 0, sizeof(*data));
                data->ctc_delta = decoder->ctc_delta;
                data->last_ctc = decoder->last_ctc;
                data->max_lookahead = 16;
                intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
                if (decoder->pge) {
                        data->pip = true;
                        data->pip_packet.payload = decoder->pip_payload;
                }
        }

        /* Calculations depend on having TMA packets */
        if (!data->tma) {
                p_log("ERROR: TSC without TMA");
                return;
        }

        vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
        if (vmcs == NO_VMCS)
                vmcs = 0;

        vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);

        ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
        host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);

        if (!decoder->ctc_timestamp) {
                intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
                return;
        }

        expected_tsc = intel_pt_expected_tsc(decoder, data);

        tsc_offset = host_tsc - expected_tsc;

        /* Determine if TSC is from Host or Guest */
        if (data->pip) {
                if (pip_in_vm(&data->pip_packet)) { /* Guest */
                        if (!vmcs_info) {
                                /* PIP NR=1 without VMCS cannot happen */
                                p_log("ERROR: Missing VMCS");
                                intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
                                decoder->vm_tm_corr_reliable = false;
                                return;
                        }
                } else { /* Host */
                        decoder->last_reliable_timestamp = host_tsc;
                        decoder->vm_tm_corr_reliable = true;
                        return;
                }
        } else { /* Host or Guest */
                reliable = false; /* Host/Guest is a guess, so not reliable */
                if (decoder->in_psb) {
                        if (!tsc_offset)
                                return; /* Zero TSC Offset, assume Host */
                        /*
                         * TSC packet has only 7 bytes of TSC. We have no
                         * information about the Guest's 8th byte, but it
                         * doesn't matter because we only need 7 bytes.
                         * Here, since the 8th byte is unreliable and
                         * irrelevant, compare only 7 byes.
                         */
                        if (vmcs_info &&
                            (tsc_offset & SEVEN_BYTES) ==
                            (vmcs_info->tsc_offset & SEVEN_BYTES)) {
                                /* Same TSC Offset as last VMCS, assume Guest */
                                goto guest;
                        }
                }
                /*
                 * Check if the host_tsc is within the expected range.
                 * Note, we could narrow the range more by looking ahead for
                 * the next host TSC in the same buffer, but we don't bother to
                 * do that because this is probably good enough.
                 */
                if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
                        /* Within expected range for Host TSC, assume Host */
                        decoder->vm_tm_corr_reliable = false;
                        return;
                }
        }

guest: /* Assuming Guest */

        /* Determine whether to assign TSC Offset */
        if (vmcs_info && vmcs_info->vmcs) {
                if (vmcs_info->tsc_offset && vmcs_info->reliable) {
                        assign = false;
                } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
                           decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
                        /* Continuous tracing, TSC in a PSB is not a time loss */
                        assign = true;
                        assign_reliable = true;
                } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
                        /*
                         * Unlikely to be a time loss TSC in a PSB which is not
                         * at the start of a buffer.
                         */
                        assign = true;
                        assign_reliable = false;
                }
        }

        /* Record VMCS TSC Offset */
        if (assign && (vmcs_info->tsc_offset != tsc_offset ||
                       vmcs_info->reliable != assign_reliable)) {
                bool print = vmcs_info->tsc_offset != tsc_offset;

                vmcs_info->tsc_offset = tsc_offset;
                vmcs_info->reliable = assign_reliable;
                if (print)
                        intel_pt_print_vmcs_info(vmcs_info);
        }

        /* Determine what TSC Offset to use */
        if (vmcs_info && vmcs_info->tsc_offset) {
                if (!vmcs_info->reliable)
                        reliable = false;
                intel_pt_translate_vm_tsc(decoder, vmcs_info);
        } else {
                reliable = false;
                if (vmcs_info) {
                        if (!vmcs_info->error_printed) {
                                p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
                                      vmcs_info->vmcs);
                                vmcs_info->error_printed = true;
                        }
                } else {
                        if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
                                p_log("ERROR: Unknown VMCS");
                }
                intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
        }

        decoder->vm_tm_corr_reliable = reliable;
}

static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
{
        uint64_t host_tsc = decoder->packet.payload;
        uint64_t guest_tsc = decoder->packet.payload;
        struct intel_pt_vmcs_info *vmcs_info;
        uint64_t vmcs;

        vmcs = decoder->vmcs;
        if (vmcs == NO_VMCS)
                vmcs = 0;

        vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);

        if (decoder->pge) {
                if (in_vm(decoder->pip_payload)) { /* Guest */
                        if (!vmcs_info) {
                                /* PIP NR=1 without VMCS cannot happen */
                                p_log("ERROR: Missing VMCS");
                        }
                } else { /* Host */
                        return;
                }
        } else { /* Host or Guest */
                if (intel_pt_time_in_range(decoder, host_tsc)) {
                        /* Within expected range for Host TSC, assume Host */
                        return;
                }
        }

        if (vmcs_info) {
                /* Translate Guest TSC to Host TSC */
                host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
                host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
                intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
                             "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
                             guest_tsc, host_tsc, vmcs_info->vmcs,
                             vmcs_info->tsc_offset);
                if (!intel_pt_time_in_range(decoder, host_tsc) &&
                    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
                        p_log("Timestamp out of range");
        } else {
                if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
                        p_log("ERROR: Unknown VMCS");
                host_tsc = decoder->timestamp;
        }

        decoder->packet.payload = host_tsc;

        if (!decoder->vm_tm_corr_dry_run)
                memcpy((void *)decoder->buf + 1, &host_tsc, 8);
}

static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
{
        struct intel_pt_vm_tsc_info data = { .psbend = false };
        bool pge;
        int err;

        if (decoder->in_psb)
                intel_pt_vm_tm_corr_psb(decoder, &data);

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err == -ENOLINK)
                        continue;
                if (err)
                        break;

                switch (decoder->packet.type) {
                case INTEL_PT_TIP_PGD:
                        decoder->pge = false;
                        decoder->vm_tm_corr_continuous = false;
                        break;

                case INTEL_PT_TNT:
                case INTEL_PT_TIP:
                case INTEL_PT_TIP_PGE:
                        decoder->pge = true;
                        break;

                case INTEL_PT_OVF:
                        decoder->in_psb = false;
                        pge = decoder->pge;
                        decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
                        if (pge != decoder->pge)
                                intel_pt_log("Surprising PGE change in OVF!");
                        if (!decoder->pge)
                                decoder->vm_tm_corr_continuous = false;
                        break;

                case INTEL_PT_FUP:
                        if (decoder->in_psb)
                                decoder->pge = true;
                        break;

                case INTEL_PT_TRACESTOP:
                        decoder->pge = false;
                        decoder->vm_tm_corr_continuous = false;
                        decoder->have_tma = false;
                        break;

                case INTEL_PT_PSB:
                        intel_pt_vm_tm_corr_psb(decoder, &data);
                        break;

                case INTEL_PT_PIP:
                        decoder->pip_payload = decoder->packet.payload;
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        break;

                case INTEL_PT_TSC:
                        intel_pt_vm_tm_corr_tsc(decoder, &data);
                        intel_pt_calc_tsc_timestamp(decoder);
                        decoder->vm_tm_corr_same_buf = true;
                        decoder->vm_tm_corr_continuous = decoder->pge;
                        break;

                case INTEL_PT_TMA:
                        intel_pt_calc_tma(decoder);
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        break;

                case INTEL_PT_PSBEND:
                        decoder->in_psb = false;
                        data.psbend = false;
                        break;

                case INTEL_PT_VMCS:
                        if (decoder->packet.payload != NO_VMCS)
                                decoder->vmcs = decoder->packet.payload;
                        break;

                case INTEL_PT_BBP:
                        decoder->blk_type = decoder->packet.payload;
                        break;

                case INTEL_PT_BIP:
                        if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
                            decoder->packet.count == 2)
                                intel_pt_vm_tm_corr_pebs_tsc(decoder);
                        break;

                case INTEL_PT_BEP:
                case INTEL_PT_BEP_IP:
                        decoder->blk_type = 0;
                        break;

                case INTEL_PT_CFE:
                case INTEL_PT_CFE_IP:
                case INTEL_PT_EVD:
                case INTEL_PT_MODE_EXEC:
                case INTEL_PT_MODE_TSX:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                case INTEL_PT_PTWRITE_IP:
                case INTEL_PT_PTWRITE:
                case INTEL_PT_MWAIT:
                case INTEL_PT_PWRE:
                case INTEL_PT_EXSTOP_IP:
                case INTEL_PT_EXSTOP:
                case INTEL_PT_PWRX:
                case INTEL_PT_BAD: /* Does not happen */
                default:
                        break;
                }
        }

        return err;
}

#define HOP_PROCESS     0
#define HOP_IGNORE      1
#define HOP_RETURN      2
#define HOP_AGAIN       3

static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);

/* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
{
        *err = 0;

        /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
        if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
                *err = intel_pt_scan_for_psb(decoder);
                if (*err)
                        return HOP_RETURN;
        }

        switch (decoder->packet.type) {
        case INTEL_PT_TNT:
                return HOP_IGNORE;

        case INTEL_PT_TIP_PGD:
                decoder->pge = false;
                if (!decoder->packet.count) {
                        intel_pt_set_nr(decoder);
                        return HOP_IGNORE;
                }
                intel_pt_set_ip(decoder);
                decoder->state.type |= INTEL_PT_TRACE_END;
                decoder->state.from_ip = 0;
                decoder->state.to_ip = decoder->ip;
                intel_pt_update_nr(decoder);
                return HOP_RETURN;

        case INTEL_PT_TIP:
                if (!decoder->packet.count) {
                        intel_pt_set_nr(decoder);
                        return HOP_IGNORE;
                }
                intel_pt_set_ip(decoder);
                decoder->state.type = INTEL_PT_INSTRUCTION;
                decoder->state.from_ip = decoder->ip;
                decoder->state.to_ip = 0;
                intel_pt_update_nr(decoder);
                intel_pt_sample_iflag_chg(decoder);
                return HOP_RETURN;

        case INTEL_PT_FUP:
                if (!decoder->packet.count)
                        return HOP_IGNORE;
                intel_pt_set_ip(decoder);
                if (decoder->set_fup_mwait || decoder->set_fup_pwre)
                        *no_tip = true;
                if (!decoder->branch_enable || !decoder->pge)
                        *no_tip = true;
                if (*no_tip) {
                        decoder->state.type = INTEL_PT_INSTRUCTION;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        intel_pt_fup_event(decoder, *no_tip);
                        return HOP_RETURN;
                }
                intel_pt_fup_event(decoder, *no_tip);
                decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
                *err = intel_pt_walk_fup_tip(decoder);
                if (!*err && decoder->state.to_ip)
                        decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
                return HOP_RETURN;

        case INTEL_PT_PSB:
                decoder->state.psb_offset = decoder->pos;
                decoder->psb_ip = 0;
                decoder->last_ip = 0;
                decoder->have_last_ip = true;
                *err = intel_pt_walk_psbend(decoder);
                if (*err == -EAGAIN)
                        return HOP_AGAIN;
                if (*err)
                        return HOP_RETURN;
                decoder->state.type = INTEL_PT_PSB_EVT;
                if (decoder->psb_ip) {
                        decoder->state.type |= INTEL_PT_INSTRUCTION;
                        decoder->ip = decoder->psb_ip;
                }
                decoder->state.from_ip = decoder->psb_ip;
                decoder->state.to_ip = 0;
                return HOP_RETURN;

        case INTEL_PT_BAD:
        case INTEL_PT_PAD:
        case INTEL_PT_TIP_PGE:
        case INTEL_PT_TSC:
        case INTEL_PT_TMA:
        case INTEL_PT_MODE_EXEC:
        case INTEL_PT_MODE_TSX:
        case INTEL_PT_MTC:
        case INTEL_PT_CYC:
        case INTEL_PT_VMCS:
        case INTEL_PT_PSBEND:
        case INTEL_PT_CBR:
        case INTEL_PT_TRACESTOP:
        case INTEL_PT_PIP:
        case INTEL_PT_OVF:
        case INTEL_PT_MNT:
        case INTEL_PT_PTWRITE:
        case INTEL_PT_PTWRITE_IP:
        case INTEL_PT_EXSTOP:
        case INTEL_PT_EXSTOP_IP:
        case INTEL_PT_MWAIT:
        case INTEL_PT_PWRE:
        case INTEL_PT_PWRX:
        case INTEL_PT_BBP:
        case INTEL_PT_BIP:
        case INTEL_PT_BEP:
        case INTEL_PT_BEP_IP:
        case INTEL_PT_CFE:
        case INTEL_PT_CFE_IP:
        case INTEL_PT_EVD:
        default:
                return HOP_PROCESS;
        }
}

struct intel_pt_psb_info {
        struct intel_pt_pkt fup_packet;
        bool fup;
        int after_psbend;
};

/* Lookahead and get the FUP packet from PSB+ */
static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
        struct intel_pt_psb_info *data = pkt_info->data;

        switch (pkt_info->packet.type) {
        case INTEL_PT_PAD:
        case INTEL_PT_MNT:
        case INTEL_PT_TSC:
        case INTEL_PT_TMA:
        case INTEL_PT_MODE_EXEC:
        case INTEL_PT_MODE_TSX:
        case INTEL_PT_MTC:
        case INTEL_PT_CYC:
        case INTEL_PT_VMCS:
        case INTEL_PT_CBR:
        case INTEL_PT_PIP:
                if (data->after_psbend) {
                        data->after_psbend -= 1;
                        if (!data->after_psbend)
                                return 1;
                }
                break;

        case INTEL_PT_FUP:
                if (data->after_psbend)
                        return 1;
                if (data->fup || pkt_info->packet.count == 0)
                        return 1;
                data->fup_packet = pkt_info->packet;
                data->fup = true;
                break;

        case INTEL_PT_PSBEND:
                if (!data->fup)
                        return 1;
                /* Keep going to check for a TIP.PGE */
                data->after_psbend = 6;
                break;

        case INTEL_PT_TIP_PGE:
                /* Ignore FUP in PSB+ if followed by TIP.PGE */
                if (data->after_psbend)
                        data->fup = false;
                return 1;

        case INTEL_PT_PTWRITE:
        case INTEL_PT_PTWRITE_IP:
        case INTEL_PT_EXSTOP:
        case INTEL_PT_EXSTOP_IP:
        case INTEL_PT_MWAIT:
        case INTEL_PT_PWRE:
        case INTEL_PT_PWRX:
        case INTEL_PT_BBP:
        case INTEL_PT_BIP:
        case INTEL_PT_BEP:
        case INTEL_PT_BEP_IP:
        case INTEL_PT_CFE:
        case INTEL_PT_CFE_IP:
        case INTEL_PT_EVD:
                if (data->after_psbend) {
                        data->after_psbend -= 1;
                        if (!data->after_psbend)
                                return 1;
                        break;
                }
                return 1;

        case INTEL_PT_OVF:
        case INTEL_PT_BAD:
        case INTEL_PT_TNT:
        case INTEL_PT_TIP_PGD:
        case INTEL_PT_TIP:
        case INTEL_PT_PSB:
        case INTEL_PT_TRACESTOP:
        default:
                return 1;
        }

        return 0;
}

static int intel_pt_psb(struct intel_pt_decoder *decoder)
{
        int err;

        decoder->last_ip = 0;
        decoder->psb_ip = 0;
        decoder->have_last_ip = true;
        intel_pt_clear_stack(&decoder->stack);
        err = intel_pt_walk_psbend(decoder);
        if (err)
                return err;
        decoder->state.type = INTEL_PT_PSB_EVT;
        decoder->state.from_ip = decoder->psb_ip;
        decoder->state.to_ip = 0;
        return 0;
}

static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
{
        int err;

        if (decoder->ip != decoder->last_ip) {
                err = intel_pt_walk_fup(decoder);
                if (!err || err != -EAGAIN)
                        return err;
        }

        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
        err = intel_pt_psb(decoder);
        if (err) {
                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                return -ENOENT;
        }

        return 0;
}

static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
{
        struct intel_pt_psb_info data = { .fup = false };

        if (!decoder->branch_enable)
                return false;

        intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
        if (!data.fup)
                return false;

        decoder->packet = data.fup_packet;
        intel_pt_set_last_ip(decoder);
        decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;

        *err = intel_pt_fup_in_psb(decoder);

        return true;
}

static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
{
        int last_packet_type = INTEL_PT_PAD;
        bool no_tip = false;
        int err;

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err)
                        return err;
next:
                err = 0;
                if (decoder->cyc_threshold) {
                        if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
                                decoder->sample_cyc = false;
                        last_packet_type = decoder->packet.type;
                }

                if (decoder->hop) {
                        switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
                        case HOP_IGNORE:
                                continue;
                        case HOP_RETURN:
                                return err;
                        case HOP_AGAIN:
                                goto next;
                        default:
                                break;
                        }
                }

                switch (decoder->packet.type) {
                case INTEL_PT_TNT:
                        if (!decoder->packet.count)
                                break;
                        decoder->tnt = decoder->packet;
                        decoder->pkt_state = INTEL_PT_STATE_TNT;
                        err = intel_pt_walk_tnt(decoder);
                        if (err == -EAGAIN)
                                break;
                        return err;

                case INTEL_PT_TIP_PGD:
                        if (decoder->packet.count != 0)
                                intel_pt_set_last_ip(decoder);
                        decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
                        return intel_pt_walk_tip(decoder);

                case INTEL_PT_TIP_PGE: {
                        decoder->pge = true;
                        decoder->overflow = false;
                        intel_pt_mtc_cyc_cnt_pge(decoder);
                        intel_pt_set_nr(decoder);
                        if (decoder->packet.count == 0) {
                                intel_pt_log_at("Skipping zero TIP.PGE",
                                                decoder->pos);
                                break;
                        }
                        intel_pt_sample_iflag_chg(decoder);
                        intel_pt_set_ip(decoder);
                        decoder->state.from_ip = 0;
                        decoder->state.to_ip = decoder->ip;
                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
                        /*
                         * In hop mode, resample to get the to_ip as an
                         * "instruction" sample.
                         */
                        if (decoder->hop)
                                decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
                        return 0;
                }

                case INTEL_PT_OVF:
                        return intel_pt_overflow(decoder);

                case INTEL_PT_TIP:
                        if (decoder->packet.count != 0)
                                intel_pt_set_last_ip(decoder);
                        decoder->pkt_state = INTEL_PT_STATE_TIP;
                        return intel_pt_walk_tip(decoder);

                case INTEL_PT_FUP:
                        if (decoder->packet.count == 0) {
                                intel_pt_log_at("Skipping zero FUP",
                                                decoder->pos);
                                no_tip = false;
                                break;
                        }
                        intel_pt_set_last_ip(decoder);
                        if (!decoder->branch_enable || !decoder->pge) {
                                decoder->ip = decoder->last_ip;
                                if (intel_pt_fup_event(decoder, no_tip))
                                        return 0;
                                no_tip = false;
                                break;
                        }
                        if (decoder->set_fup_mwait)
                                no_tip = true;
                        if (no_tip)
                                decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
                        else
                                decoder->pkt_state = INTEL_PT_STATE_FUP;
                        err = intel_pt_walk_fup(decoder);
                        if (err != -EAGAIN)
                                return err;
                        if (no_tip) {
                                no_tip = false;
                                break;
                        }
                        return intel_pt_walk_fup_tip(decoder);

                case INTEL_PT_TRACESTOP:
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        intel_pt_clear_tx_flags(decoder);
                        decoder->have_tma = false;
                        break;

                case INTEL_PT_PSB:
                        decoder->state.psb_offset = decoder->pos;
                        decoder->psb_ip = 0;
                        if (intel_pt_psb_with_fup(decoder, &err))
                                return err;
                        err = intel_pt_psb(decoder);
                        if (err == -EAGAIN)
                                goto next;
                        return err;

                case INTEL_PT_PIP:
                        intel_pt_update_pip(decoder);
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        if (decoder->period_type != INTEL_PT_PERIOD_MTC)
                                break;
                        /*
                         * Ensure that there has been an instruction since the
                         * last MTC.
                         */
                        if (!decoder->mtc_insn)
                                break;
                        decoder->mtc_insn = false;
                        /* Ensure that there is a timestamp */
                        if (!decoder->timestamp)
                                break;
                        decoder->state.type = INTEL_PT_INSTRUCTION;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        decoder->mtc_insn = false;
                        return 0;

                case INTEL_PT_TSC:
                        intel_pt_calc_tsc_timestamp(decoder);
                        break;

                case INTEL_PT_TMA:
                        intel_pt_calc_tma(decoder);
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        if (decoder->cbr != decoder->cbr_seen) {
                                decoder->state.type = 0;
                                return 0;
                        }
                        break;

                case INTEL_PT_MODE_EXEC:
                        intel_pt_mode_exec(decoder);
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type == INTEL_PT_FUP) {
                                decoder->set_fup_mode_exec = true;
                                no_tip = true;
                        }
                        goto next;

                case INTEL_PT_MODE_TSX:
                        /* MODE_TSX need not be followed by FUP */
                        if (!decoder->pge || decoder->in_psb) {
                                intel_pt_update_in_tx(decoder);
                                break;
                        }
                        err = intel_pt_mode_tsx(decoder, &no_tip);
                        if (err)
                                return err;
                        goto next;

                case INTEL_PT_BAD: /* Does not happen */
                        return intel_pt_bug(decoder);

                case INTEL_PT_PSBEND:
                case INTEL_PT_VMCS:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                        break;

                case INTEL_PT_PTWRITE_IP:
                        decoder->fup_ptw_payload = decoder->packet.payload;
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type == INTEL_PT_FUP) {
                                decoder->set_fup_ptw = true;
                                no_tip = true;
                        } else {
                                intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
                                                decoder->pos);
                        }
                        goto next;

                case INTEL_PT_PTWRITE:
                        decoder->state.type = INTEL_PT_PTW;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        decoder->state.ptw_payload = decoder->packet.payload;
                        return 0;

                case INTEL_PT_MWAIT:
                        decoder->fup_mwait_payload = decoder->packet.payload;
                        decoder->set_fup_mwait = true;
                        break;

                case INTEL_PT_PWRE:
                        if (decoder->set_fup_mwait) {
                                decoder->fup_pwre_payload =
                                                        decoder->packet.payload;
                                decoder->set_fup_pwre = true;
                                break;
                        }
                        decoder->state.type = INTEL_PT_PWR_ENTRY;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        decoder->state.pwrx_payload = decoder->packet.payload;
                        return 0;

                case INTEL_PT_EXSTOP_IP:
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type == INTEL_PT_FUP) {
                                decoder->set_fup_exstop = true;
                                no_tip = true;
                        } else {
                                intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
                                                decoder->pos);
                        }
                        goto next;

                case INTEL_PT_EXSTOP:
                        decoder->state.type = INTEL_PT_EX_STOP;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        return 0;

                case INTEL_PT_PWRX:
                        decoder->state.type = INTEL_PT_PWR_EXIT;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        decoder->state.pwrx_payload = decoder->packet.payload;
                        return 0;

                case INTEL_PT_BBP:
                        intel_pt_bbp(decoder);
                        break;

                case INTEL_PT_BIP:
                        intel_pt_bip(decoder);
                        break;

                case INTEL_PT_BEP:
                        decoder->state.type = INTEL_PT_BLK_ITEMS;
                        decoder->state.from_ip = decoder->ip;
                        decoder->state.to_ip = 0;
                        return 0;

                case INTEL_PT_BEP_IP:
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type == INTEL_PT_FUP) {
                                decoder->set_fup_bep = true;
                                no_tip = true;
                        } else {
                                intel_pt_log_at("ERROR: Missing FUP after BEP",
                                                decoder->pos);
                        }
                        goto next;

                case INTEL_PT_CFE:
                        decoder->fup_cfe_pkt = decoder->packet;
                        decoder->set_fup_cfe = true;
                        if (!decoder->pge) {
                                intel_pt_fup_event(decoder, true);
                                return 0;
                        }
                        break;

                case INTEL_PT_CFE_IP:
                        decoder->fup_cfe_pkt = decoder->packet;
                        err = intel_pt_get_next_packet(decoder);
                        if (err)
                                return err;
                        if (decoder->packet.type == INTEL_PT_FUP) {
                                decoder->set_fup_cfe_ip = true;
                                no_tip = true;
                        } else {
                                intel_pt_log_at("ERROR: Missing FUP after CFE",
                                                decoder->pos);
                        }
                        goto next;

                case INTEL_PT_EVD:
                        err = intel_pt_evd(decoder);
                        if (err)
                                return err;
                        break;

                default:
                        return intel_pt_bug(decoder);
                }
        }
}

static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
{
        return decoder->packet.count &&
               (decoder->have_last_ip || decoder->packet.count == 3 ||
                decoder->packet.count == 6);
}

/* Walk PSB+ packets to get in sync. */
static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
{
        int err;

        decoder->in_psb = true;

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err)
                        goto out;

                switch (decoder->packet.type) {
                case INTEL_PT_TIP_PGD:
                        decoder->continuous_period = false;
                        fallthrough;
                case INTEL_PT_TIP_PGE:
                case INTEL_PT_TIP:
                case INTEL_PT_PTWRITE:
                case INTEL_PT_PTWRITE_IP:
                case INTEL_PT_EXSTOP:
                case INTEL_PT_EXSTOP_IP:
                case INTEL_PT_MWAIT:
                case INTEL_PT_PWRE:
                case INTEL_PT_PWRX:
                case INTEL_PT_BBP:
                case INTEL_PT_BIP:
                case INTEL_PT_BEP:
                case INTEL_PT_BEP_IP:
                case INTEL_PT_CFE:
                case INTEL_PT_CFE_IP:
                case INTEL_PT_EVD:
                        intel_pt_log("ERROR: Unexpected packet\n");
                        err = -ENOENT;
                        goto out;

                case INTEL_PT_FUP:
                        decoder->pge = true;
                        if (intel_pt_have_ip(decoder)) {
                                uint64_t current_ip = decoder->ip;

                                intel_pt_set_ip(decoder);
                                decoder->psb_ip = decoder->ip;
                                if (current_ip)
                                        intel_pt_log_to("Setting IP",
                                                        decoder->ip);
                        }
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        break;

                case INTEL_PT_TSC:
                        intel_pt_calc_tsc_timestamp(decoder);
                        break;

                case INTEL_PT_TMA:
                        intel_pt_calc_tma(decoder);
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        break;

                case INTEL_PT_PIP:
                        intel_pt_set_pip(decoder);
                        break;

                case INTEL_PT_MODE_EXEC:
                        intel_pt_mode_exec_status(decoder);
                        break;

                case INTEL_PT_MODE_TSX:
                        intel_pt_update_in_tx(decoder);
                        break;

                case INTEL_PT_TRACESTOP:
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        intel_pt_clear_tx_flags(decoder);
                        fallthrough;

                case INTEL_PT_TNT:
                        decoder->have_tma = false;
                        intel_pt_log("ERROR: Unexpected packet\n");
                        if (decoder->ip)
                                decoder->pkt_state = INTEL_PT_STATE_ERR4;
                        else
                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
                        err = -ENOENT;
                        goto out;

                case INTEL_PT_BAD: /* Does not happen */
                        err = intel_pt_bug(decoder);
                        goto out;

                case INTEL_PT_OVF:
                        err = intel_pt_overflow(decoder);
                        goto out;

                case INTEL_PT_PSBEND:
                        err = 0;
                        goto out;

                case INTEL_PT_PSB:
                case INTEL_PT_VMCS:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                default:
                        break;
                }
        }
out:
        decoder->in_psb = false;

        return err;
}

static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
{
        int err;

        while (1) {
                err = intel_pt_get_next_packet(decoder);
                if (err)
                        return err;

                switch (decoder->packet.type) {
                case INTEL_PT_TIP_PGD:
                        decoder->continuous_period = false;
                        decoder->pge = false;
                        if (intel_pt_have_ip(decoder))
                                intel_pt_set_ip(decoder);
                        if (!decoder->ip)
                                break;
                        decoder->state.type |= INTEL_PT_TRACE_END;
                        return 0;

                case INTEL_PT_TIP_PGE:
                        decoder->pge = true;
                        intel_pt_mtc_cyc_cnt_pge(decoder);
                        if (intel_pt_have_ip(decoder))
                                intel_pt_set_ip(decoder);
                        if (!decoder->ip)
                                break;
                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
                        return 0;

                case INTEL_PT_TIP:
                        decoder->pge = true;
                        if (intel_pt_have_ip(decoder))
                                intel_pt_set_ip(decoder);
                        if (!decoder->ip)
                                break;
                        return 0;

                case INTEL_PT_FUP:
                        if (intel_pt_have_ip(decoder))
                                intel_pt_set_ip(decoder);
                        if (decoder->ip)
                                return 0;
                        break;

                case INTEL_PT_MTC:
                        intel_pt_calc_mtc_timestamp(decoder);
                        break;

                case INTEL_PT_TSC:
                        intel_pt_calc_tsc_timestamp(decoder);
                        break;

                case INTEL_PT_TMA:
                        intel_pt_calc_tma(decoder);
                        break;

                case INTEL_PT_CYC:
                        intel_pt_calc_cyc_timestamp(decoder);
                        break;

                case INTEL_PT_CBR:
                        intel_pt_calc_cbr(decoder);
                        break;

                case INTEL_PT_PIP:
                        intel_pt_set_pip(decoder);
                        break;

                case INTEL_PT_MODE_EXEC:
                        intel_pt_mode_exec_status(decoder);
                        break;

                case INTEL_PT_MODE_TSX:
                        intel_pt_update_in_tx(decoder);
                        break;

                case INTEL_PT_OVF:
                        return intel_pt_overflow(decoder);

                case INTEL_PT_BAD: /* Does not happen */
                        return intel_pt_bug(decoder);

                case INTEL_PT_TRACESTOP:
                        decoder->pge = false;
                        decoder->continuous_period = false;
                        intel_pt_clear_tx_flags(decoder);
                        decoder->have_tma = false;
                        break;

                case INTEL_PT_PSB:
                        decoder->state.psb_offset = decoder->pos;
                        decoder->psb_ip = 0;
                        decoder->last_ip = 0;
                        decoder->have_last_ip = true;
                        intel_pt_clear_stack(&decoder->stack);
                        err = intel_pt_walk_psb(decoder);
                        if (err)
                                return err;
                        decoder->state.type = INTEL_PT_PSB_EVT;
                        decoder->state.from_ip = decoder->psb_ip;
                        decoder->state.to_ip = 0;
                        return 0;

                case INTEL_PT_TNT:
                case INTEL_PT_PSBEND:
                case INTEL_PT_VMCS:
                case INTEL_PT_MNT:
                case INTEL_PT_PAD:
                case INTEL_PT_PTWRITE:
                case INTEL_PT_PTWRITE_IP:
                case INTEL_PT_EXSTOP:
                case INTEL_PT_EXSTOP_IP:
                case INTEL_PT_MWAIT:
                case INTEL_PT_PWRE:
                case INTEL_PT_PWRX:
                case INTEL_PT_BBP:
                case INTEL_PT_BIP:
                case INTEL_PT_BEP:
                case INTEL_PT_BEP_IP:
                case INTEL_PT_CFE:
                case INTEL_PT_CFE_IP:
                case INTEL_PT_EVD:
                default:
                        break;
                }
        }
}

static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
{
        int err;

        intel_pt_clear_fup_event(decoder);
        decoder->overflow = false;

        if (!decoder->branch_enable) {
                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
                decoder->state.type = 0; /* Do not have a sample */
                return 0;
        }

        intel_pt_log("Scanning for full IP\n");
        err = intel_pt_walk_to_ip(decoder);
        if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
                return err;

        /* In hop mode, resample to get the to_ip as an "instruction" sample */
        if (decoder->hop)
                decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
        else
                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;

        decoder->state.from_ip = 0;
        decoder->state.to_ip = decoder->ip;
        intel_pt_log_to("Setting IP", decoder->ip);

        return 0;
}

static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
{
        const unsigned char *end = decoder->buf + decoder->len;
        size_t i;

        for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
                if (i > decoder->len)
                        continue;
                if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
                        return i;
        }
        return 0;
}

static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
{
        size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
        const char *psb = INTEL_PT_PSB_STR;

        if (rest_psb > decoder->len ||
            memcmp(decoder->buf, psb + part_psb, rest_psb))
                return 0;

        return rest_psb;
}

static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
                                  int part_psb)
{
        int rest_psb, ret;

        decoder->pos += decoder->len;
        decoder->len = 0;

        ret = intel_pt_get_next_data(decoder, false);
        if (ret)
                return ret;

        rest_psb = intel_pt_rest_psb(decoder, part_psb);
        if (!rest_psb)
                return 0;

        decoder->pos -= part_psb;
        decoder->next_buf = decoder->buf + rest_psb;
        decoder->next_len = decoder->len - rest_psb;
        memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
        decoder->buf = decoder->temp_buf;
        decoder->len = INTEL_PT_PSB_LEN;

        return 0;
}

static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
{
        unsigned char *next;
        int ret;

        intel_pt_log("Scanning for PSB\n");
        while (1) {
                if (!decoder->len) {
                        ret = intel_pt_get_next_data(decoder, false);
                        if (ret)
                                return ret;
                }

                next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
                              INTEL_PT_PSB_LEN);
                if (!next) {
                        int part_psb;

                        part_psb = intel_pt_part_psb(decoder);
                        if (part_psb) {
                                ret = intel_pt_get_split_psb(decoder, part_psb);
                                if (ret)
                                        return ret;
                        } else {
                                decoder->pos += decoder->len;
                                decoder->len = 0;
                        }
                        continue;
                }

                decoder->pkt_step = next - decoder->buf;
                return intel_pt_get_next_packet(decoder);
        }
}

static int intel_pt_sync(struct intel_pt_decoder *decoder)
{
        int err;

        decoder->pge = false;
        decoder->continuous_period = false;
        decoder->have_last_ip = false;
        decoder->last_ip = 0;
        decoder->psb_ip = 0;
        decoder->ip = 0;
        intel_pt_clear_stack(&decoder->stack);

        err = intel_pt_scan_for_psb(decoder);
        if (err)
                return err;

        if (decoder->vm_time_correlation) {
                decoder->in_psb = true;
                if (!decoder->timestamp)
                        decoder->timestamp = 1;
                decoder->state.type = 0;
                decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
                return 0;
        }

        decoder->have_last_ip = true;
        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;

        err = intel_pt_walk_psb(decoder);
        if (err)
                return err;

        decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
        decoder->state.from_ip = decoder->psb_ip;
        decoder->state.to_ip = 0;

        if (decoder->ip) {
                /*
                 * In hop mode, resample to get the PSB FUP ip as an
                 * "instruction" sample.
                 */
                if (decoder->hop)
                        decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
                else
                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
        }

        return 0;
}

static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
{
        uint64_t est = decoder->sample_insn_cnt << 1;

        if (!decoder->cbr || !decoder->max_non_turbo_ratio)
                goto out;

        est *= decoder->max_non_turbo_ratio;
        est /= decoder->cbr;
out:
        return decoder->sample_timestamp + est;
}

const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
{
        int err;

        do {
                decoder->state.type = INTEL_PT_BRANCH;
                decoder->state.flags = 0;

                switch (decoder->pkt_state) {
                case INTEL_PT_STATE_NO_PSB:
                        err = intel_pt_sync(decoder);
                        break;
                case INTEL_PT_STATE_NO_IP:
                        decoder->have_last_ip = false;
                        decoder->last_ip = 0;
                        decoder->ip = 0;
                        fallthrough;
                case INTEL_PT_STATE_ERR_RESYNC:
                        err = intel_pt_sync_ip(decoder);
                        break;
                case INTEL_PT_STATE_IN_SYNC:
                        err = intel_pt_walk_trace(decoder);
                        break;
                case INTEL_PT_STATE_TNT:
                case INTEL_PT_STATE_TNT_CONT:
                        err = intel_pt_walk_tnt(decoder);
                        if (err == -EAGAIN)
                                err = intel_pt_walk_trace(decoder);
                        break;
                case INTEL_PT_STATE_TIP:
                case INTEL_PT_STATE_TIP_PGD:
                        err = intel_pt_walk_tip(decoder);
                        break;
                case INTEL_PT_STATE_FUP:
                        err = intel_pt_walk_fup(decoder);
                        if (err == -EAGAIN)
                                err = intel_pt_walk_fup_tip(decoder);
                        break;
                case INTEL_PT_STATE_FUP_NO_TIP:
                        err = intel_pt_walk_fup(decoder);
                        if (err == -EAGAIN)
                                err = intel_pt_walk_trace(decoder);
                        break;
                case INTEL_PT_STATE_FUP_IN_PSB:
                        err = intel_pt_fup_in_psb(decoder);
                        break;
                case INTEL_PT_STATE_RESAMPLE:
                        err = intel_pt_resample(decoder);
                        break;
                case INTEL_PT_STATE_VM_TIME_CORRELATION:
                        err = intel_pt_vm_time_correlation(decoder);
                        break;
                default:
                        err = intel_pt_bug(decoder);
                        break;
                }
        } while (err == -ENOLINK);

        if (err) {
                decoder->state.err = intel_pt_ext_err(err);
                if (err != -EOVERFLOW)
                        decoder->state.from_ip = decoder->ip;
                intel_pt_update_sample_time(decoder);
                decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
                intel_pt_set_nr(decoder);
        } else {
                decoder->state.err = 0;
                if (decoder->cbr != decoder->cbr_seen) {
                        decoder->cbr_seen = decoder->cbr;
                        if (!decoder->state.type) {
                                decoder->state.from_ip = decoder->ip;
                                decoder->state.to_ip = 0;
                        }
                        decoder->state.type |= INTEL_PT_CBR_CHG;
                        decoder->state.cbr_payload = decoder->cbr_payload;
                        decoder->state.cbr = decoder->cbr;
                }
                if (intel_pt_sample_time(decoder->pkt_state)) {
                        intel_pt_update_sample_time(decoder);
                        if (decoder->sample_cyc) {
                                decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
                                decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
                                decoder->sample_cyc = false;
                        }
                }
                /*
                 * When using only TSC/MTC to compute cycles, IPC can be
                 * sampled as soon as the cycle count changes.
                 */
                if (!decoder->have_cyc)
                        decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
        }

         /* Let PSB event always have TSC timestamp */
        if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
                decoder->sample_timestamp = decoder->tsc_timestamp;

        decoder->state.from_nr = decoder->nr;
        decoder->state.to_nr = decoder->next_nr;
        decoder->nr = decoder->next_nr;

        decoder->state.timestamp = decoder->sample_timestamp;
        decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
        decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
        decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;

        return &decoder->state;
}

/**
 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
 * @buf: pointer to buffer pointer
 * @len: size of buffer
 *
 * Updates the buffer pointer to point to the start of the next PSB packet if
 * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
 * @len is adjusted accordingly.
 *
 * Return: %true if a PSB packet is found, %false otherwise.
 */
static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
{
        unsigned char *next;

        next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
        if (next) {
                *len -= next - *buf;
                *buf = next;
                return true;
        }
        return false;
}

/**
 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
 *                     packet.
 * @buf: pointer to buffer pointer
 * @len: size of buffer
 *
 * Updates the buffer pointer to point to the start of the following PSB packet
 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
 * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
 *
 * Return: %true if a PSB packet is found, %false otherwise.
 */
static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
{
        unsigned char *next;

        if (!*len)
                return false;

        next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
        if (next) {
                *len -= next - *buf;
                *buf = next;
                return true;
        }
        return false;
}

/**
 * intel_pt_last_psb - find the last PSB packet in a buffer.
 * @buf: buffer
 * @len: size of buffer
 *
 * This function finds the last PSB in a buffer.
 *
 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
 */
static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
{
        const char *n = INTEL_PT_PSB_STR;
        unsigned char *p;
        size_t k;

        if (len < INTEL_PT_PSB_LEN)
                return NULL;

        k = len - INTEL_PT_PSB_LEN + 1;
        while (1) {
                p = memrchr(buf, n[0], k);
                if (!p)
                        return NULL;
                if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
                        return p;
                k = p - buf;
                if (!k)
                        return NULL;
        }
}

/**
 * intel_pt_next_tsc - find and return next TSC.
 * @buf: buffer
 * @len: size of buffer
 * @tsc: TSC value returned
 * @rem: returns remaining size when TSC is found
 *
 * Find a TSC packet in @buf and return the TSC value.  This function assumes
 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
 * PSBEND packet is found.
 *
 * Return: %true if TSC is found, false otherwise.
 */
static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
                              size_t *rem)
{
        enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
        struct intel_pt_pkt packet;
        int ret;

        while (len) {
                ret = intel_pt_get_packet(buf, len, &packet, &ctx);
                if (ret <= 0)
                        return false;
                if (packet.type == INTEL_PT_TSC) {
                        *tsc = packet.payload;
                        *rem = len;
                        return true;
                }
                if (packet.type == INTEL_PT_PSBEND)
                        return false;
                buf += ret;
                len -= ret;
        }
        return false;
}

/**
 * intel_pt_tsc_cmp - compare 7-byte TSCs.
 * @tsc1: first TSC to compare
 * @tsc2: second TSC to compare
 *
 * This function compares 7-byte TSC values allowing for the possibility that
 * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
 * around so for that purpose this function assumes the absolute difference is
 * less than half the maximum difference.
 *
 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
 * after @tsc2.
 */
static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
{
        const uint64_t halfway = (1ULL << 55);

        if (tsc1 == tsc2)
                return 0;

        if (tsc1 < tsc2) {
                if (tsc2 - tsc1 < halfway)
                        return -1;
                else
                        return 1;
        } else {
                if (tsc1 - tsc2 < halfway)
                        return 1;
                else
                        return -1;
        }
}

#define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)

/**
 * adj_for_padding - adjust overlap to account for padding.
 * @buf_b: second buffer
 * @buf_a: first buffer
 * @len_a: size of first buffer
 *
 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
 * accordingly.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts
 */
static unsigned char *adj_for_padding(unsigned char *buf_b,
                                      unsigned char *buf_a, size_t len_a)
{
        unsigned char *p = buf_b - MAX_PADDING;
        unsigned char *q = buf_a + len_a - MAX_PADDING;
        int i;

        for (i = MAX_PADDING; i; i--, p++, q++) {
                if (*p != *q)
                        break;
        }

        return p;
}

/**
 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
 *                             using TSC.
 * @buf_a: first buffer
 * @len_a: size of first buffer
 * @buf_b: second buffer
 * @len_b: size of second buffer
 * @consecutive: returns true if there is data in buf_b that is consecutive
 *               to buf_a
 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
 *
 * If the trace contains TSC we can look at the last TSC of @buf_a and the
 * first TSC of @buf_b in order to determine if the buffers overlap, and then
 * walk forward in @buf_b until a later TSC is found.  A precondition is that
 * @buf_a and @buf_b are positioned at a PSB.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts, or
 * @buf_b + @len_b if there is no non-overlapped data.
 */
static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
                                                size_t len_a,
                                                unsigned char *buf_b,
                                                size_t len_b, bool *consecutive,
                                                bool ooo_tsc)
{
        uint64_t tsc_a, tsc_b;
        unsigned char *p;
        size_t len, rem_a, rem_b;

        p = intel_pt_last_psb(buf_a, len_a);
        if (!p)
                return buf_b; /* No PSB in buf_a => no overlap */

        len = len_a - (p - buf_a);
        if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
                /* The last PSB+ in buf_a is incomplete, so go back one more */
                len_a -= len;
                p = intel_pt_last_psb(buf_a, len_a);
                if (!p)
                        return buf_b; /* No full PSB+ => assume no overlap */
                len = len_a - (p - buf_a);
                if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
                        return buf_b; /* No TSC in buf_a => assume no overlap */
        }

        while (1) {
                /* Ignore PSB+ with no TSC */
                if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
                        int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);

                        /* Same TSC, so buffers are consecutive */
                        if (!cmp && rem_b >= rem_a) {
                                unsigned char *start;

                                *consecutive = true;
                                start = buf_b + len_b - (rem_b - rem_a);
                                return adj_for_padding(start, buf_a, len_a);
                        }
                        if (cmp < 0 && !ooo_tsc)
                                return buf_b; /* tsc_a < tsc_b => no overlap */
                }

                if (!intel_pt_step_psb(&buf_b, &len_b))
                        return buf_b + len_b; /* No PSB in buf_b => no data */
        }
}

/**
 * intel_pt_find_overlap - determine start of non-overlapped trace data.
 * @buf_a: first buffer
 * @len_a: size of first buffer
 * @buf_b: second buffer
 * @len_b: size of second buffer
 * @have_tsc: can use TSC packets to detect overlap
 * @consecutive: returns true if there is data in buf_b that is consecutive
 *               to buf_a
 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
 *
 * When trace samples or snapshots are recorded there is the possibility that
 * the data overlaps.  Note that, for the purposes of decoding, data is only
 * useful if it begins with a PSB packet.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts, or
 * @buf_b + @len_b if there is no non-overlapped data.
 */
unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
                                     unsigned char *buf_b, size_t len_b,
                                     bool have_tsc, bool *consecutive,
                                     bool ooo_tsc)
{
        unsigned char *found;

        /* Buffer 'b' must start at PSB so throw away everything before that */
        if (!intel_pt_next_psb(&buf_b, &len_b))
                return buf_b + len_b; /* No PSB */

        if (!intel_pt_next_psb(&buf_a, &len_a))
                return buf_b; /* No overlap */

        if (have_tsc) {
                found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
                                                  consecutive, ooo_tsc);
                if (found)
                        return found;
        }

        /*
         * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
         * we can ignore the first part of buffer 'a'.
         */
        while (len_b < len_a) {
                if (!intel_pt_step_psb(&buf_a, &len_a))
                        return buf_b; /* No overlap */
        }

        /* Now len_b >= len_a */
        while (1) {
                /* Potential overlap so check the bytes */
                found = memmem(buf_a, len_a, buf_b, len_a);
                if (found) {
                        *consecutive = true;
                        return adj_for_padding(buf_b + len_a, buf_a, len_a);
                }

                /* Try again at next PSB in buffer 'a' */
                if (!intel_pt_step_psb(&buf_a, &len_a))
                        return buf_b; /* No overlap */
        }
}

/**
 * struct fast_forward_data - data used by intel_pt_ff_cb().
 * @timestamp: timestamp to fast forward towards
 * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
 *                 the fast forward timestamp.
 */
struct fast_forward_data {
        uint64_t timestamp;
        uint64_t buf_timestamp;
};

/**
 * intel_pt_ff_cb - fast forward lookahead callback.
 * @buffer: Intel PT trace buffer
 * @data: opaque pointer to fast forward data (struct fast_forward_data)
 *
 * Determine if @buffer trace is past the fast forward timestamp.
 *
 * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
 *         timestamp, and 0 otherwise.
 */
static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
{
        struct fast_forward_data *d = data;
        unsigned char *buf;
        uint64_t tsc;
        size_t rem;
        size_t len;

        buf = (unsigned char *)buffer->buf;
        len = buffer->len;

        if (!intel_pt_next_psb(&buf, &len) ||
            !intel_pt_next_tsc(buf, len, &tsc, &rem))
                return 0;

        tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);

        intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
                     tsc, buffer->ref_timestamp);

        /*
         * If the buffer contains a timestamp earlier that the fast forward
         * timestamp, then record it, else stop.
         */
        if (tsc < d->timestamp)
                d->buf_timestamp = buffer->ref_timestamp;
        else
                return 1;

        return 0;
}

/**
 * intel_pt_fast_forward - reposition decoder forwards.
 * @decoder: Intel PT decoder
 * @timestamp: timestamp to fast forward towards
 *
 * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
 *
 * Return: 0 on success or negative error code on failure.
 */
int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
{
        struct fast_forward_data d = { .timestamp = timestamp };
        unsigned char *buf;
        size_t len;
        int err;

        intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);

        /* Find buffer timestamp of buffer to fast forward to */
        err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
        if (err < 0)
                return err;

        /* Walk to buffer with same buffer timestamp */
        if (d.buf_timestamp) {
                do {
                        decoder->pos += decoder->len;
                        decoder->len = 0;
                        err = intel_pt_get_next_data(decoder, true);
                        /* -ENOLINK means non-consecutive trace */
                        if (err && err != -ENOLINK)
                                return err;
                } while (decoder->buf_timestamp != d.buf_timestamp);
        }

        if (!decoder->buf)
                return 0;

        buf = (unsigned char *)decoder->buf;
        len = decoder->len;

        if (!intel_pt_next_psb(&buf, &len))
                return 0;

        /*
         * Walk PSBs while the PSB timestamp is less than the fast forward
         * timestamp.
         */
        do {
                uint64_t tsc;
                size_t rem;

                if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
                        break;
                tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
                /*
                 * A TSC packet can slip past MTC packets but, after fast
                 * forward, decoding starts at the TSC timestamp. That means
                 * the timestamps may not be exactly the same as the timestamps
                 * that would have been decoded without fast forward.
                 */
                if (tsc < timestamp) {
                        intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
                        decoder->pos += decoder->len - len;
                        decoder->buf = buf;
                        decoder->len = len;
                        intel_pt_reposition(decoder);
                } else {
                        break;
                }
        } while (intel_pt_step_psb(&buf, &len));

        return 0;
}