// SPDX-License-Identifier: GPL-2.0
/*
 * steal/stolen time test
 *
 * Copyright (C) 2020, Red Hat, Inc.
 */
#include <stdio.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>
#include <linux/kernel.h>
#include <asm/kvm.h>
#ifdef __riscv
#include "sbi.h"
#else
#include <asm/kvm_para.h>
#endif

#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
#include "ucall_common.h"

#define NR_VCPUS                4
#define ST_GPA_BASE             (1 << 30)

static void *st_gva[NR_VCPUS];
static uint64_t guest_stolen_time[NR_VCPUS];

#if defined(__x86_64__)

/* steal_time must have 64-byte alignment */
#define STEAL_TIME_SIZE         ((sizeof(struct kvm_steal_time) + 63) & ~63)

static void check_status(struct kvm_steal_time *st)
{
        GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
        GUEST_ASSERT_EQ(READ_ONCE(st->flags), 0);
        GUEST_ASSERT_EQ(READ_ONCE(st->preempted), 0);
}

static void guest_code(int cpu)
{
        struct kvm_steal_time *st = st_gva[cpu];
        uint32_t version;

        GUEST_ASSERT_EQ(rdmsr(MSR_KVM_STEAL_TIME), ((uint64_t)st_gva[cpu] | KVM_MSR_ENABLED));

        memset(st, 0, sizeof(*st));
        GUEST_SYNC(0);

        check_status(st);
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        version = READ_ONCE(st->version);
        check_status(st);
        GUEST_SYNC(1);

        check_status(st);
        GUEST_ASSERT(version < READ_ONCE(st->version));
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        check_status(st);
        GUEST_DONE();
}

static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
        return kvm_cpu_has(X86_FEATURE_KVM_STEAL_TIME);
}

static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
        int ret;

        /* ST_GPA_BASE is identity mapped */
        st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
        sync_global_to_guest(vcpu->vm, st_gva[i]);

        ret = _vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME,
                            (ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK);
        TEST_ASSERT(ret == 0, "Bad GPA didn't fail");

        vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
}

static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
        struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);

        ksft_print_msg("VCPU%d:\n", vcpu_idx);
        ksft_print_msg("    steal:     %lld\n", st->steal);
        ksft_print_msg("    version:   %d\n", st->version);
        ksft_print_msg("    flags:     %d\n", st->flags);
        ksft_print_msg("    preempted: %d\n", st->preempted);
        ksft_print_msg("    u8_pad:    %d %d %d\n",
                        st->u8_pad[0], st->u8_pad[1], st->u8_pad[2]);
        ksft_print_msg("    pad:       %d %d %d %d %d %d %d %d %d %d %d\n",
                        st->pad[0], st->pad[1], st->pad[2], st->pad[3],
                        st->pad[4], st->pad[5], st->pad[6], st->pad[7],
                        st->pad[8], st->pad[9], st->pad[10]);
}

#elif defined(__aarch64__)

/* PV_TIME_ST must have 64-byte alignment */
#define STEAL_TIME_SIZE         ((sizeof(struct st_time) + 63) & ~63)

#define SMCCC_ARCH_FEATURES     0x80000001
#define PV_TIME_FEATURES        0xc5000020
#define PV_TIME_ST              0xc5000021

struct st_time {
        uint32_t rev;
        uint32_t attr;
        uint64_t st_time;
};

static int64_t smccc(uint32_t func, uint64_t arg)
{
        struct arm_smccc_res res;

        do_smccc(func, arg, 0, 0, 0, 0, 0, 0, &res);
        return res.a0;
}

static void check_status(struct st_time *st)
{
        GUEST_ASSERT_EQ(READ_ONCE(st->rev), 0);
        GUEST_ASSERT_EQ(READ_ONCE(st->attr), 0);
}

static void guest_code(int cpu)
{
        struct st_time *st;
        int64_t status;

        status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES);
        GUEST_ASSERT_EQ(status, 0);
        status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES);
        GUEST_ASSERT_EQ(status, 0);
        status = smccc(PV_TIME_FEATURES, PV_TIME_ST);
        GUEST_ASSERT_EQ(status, 0);

        status = smccc(PV_TIME_ST, 0);
        GUEST_ASSERT_NE(status, -1);
        GUEST_ASSERT_EQ(status, (ulong)st_gva[cpu]);

        st = (struct st_time *)status;
        GUEST_SYNC(0);

        check_status(st);
        WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
        GUEST_SYNC(1);

        check_status(st);
        WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
        GUEST_DONE();
}

static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
        struct kvm_device_attr dev = {
                .group = KVM_ARM_VCPU_PVTIME_CTRL,
                .attr = KVM_ARM_VCPU_PVTIME_IPA,
        };

        return !__vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
}

static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
        struct kvm_vm *vm = vcpu->vm;
        uint64_t st_ipa;
        int ret;

        struct kvm_device_attr dev = {
                .group = KVM_ARM_VCPU_PVTIME_CTRL,
                .attr = KVM_ARM_VCPU_PVTIME_IPA,
                .addr = (uint64_t)&st_ipa,
        };

        vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);

        /* ST_GPA_BASE is identity mapped */
        st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
        sync_global_to_guest(vm, st_gva[i]);

        st_ipa = (ulong)st_gva[i] | 1;
        ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
        TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL");

        st_ipa = (ulong)st_gva[i];
        vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);

        ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
        TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST");
}

static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
        struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);

        ksft_print_msg("VCPU%d:\n", vcpu_idx);
        ksft_print_msg("    rev:     %d\n", st->rev);
        ksft_print_msg("    attr:    %d\n", st->attr);
        ksft_print_msg("    st_time: %ld\n", st->st_time);
}

#elif defined(__riscv)

/* SBI STA shmem must have 64-byte alignment */
#define STEAL_TIME_SIZE         ((sizeof(struct sta_struct) + 63) & ~63)

static vm_paddr_t st_gpa[NR_VCPUS];

struct sta_struct {
        uint32_t sequence;
        uint32_t flags;
        uint64_t steal;
        uint8_t preempted;
        uint8_t pad[47];
} __packed;

static void sta_set_shmem(vm_paddr_t gpa, unsigned long flags)
{
        unsigned long lo = (unsigned long)gpa;
#if __riscv_xlen == 32
        unsigned long hi = (unsigned long)(gpa >> 32);
#else
        unsigned long hi = gpa == -1 ? -1 : 0;
#endif
        struct sbiret ret = sbi_ecall(SBI_EXT_STA, 0, lo, hi, flags, 0, 0, 0);

        GUEST_ASSERT(ret.value == 0 && ret.error == 0);
}

static void check_status(struct sta_struct *st)
{
        GUEST_ASSERT(!(READ_ONCE(st->sequence) & 1));
        GUEST_ASSERT(READ_ONCE(st->flags) == 0);
        GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
}

static void guest_code(int cpu)
{
        struct sta_struct *st = st_gva[cpu];
        uint32_t sequence;
        long out_val = 0;
        bool probe;

        probe = guest_sbi_probe_extension(SBI_EXT_STA, &out_val);
        GUEST_ASSERT(probe && out_val == 1);

        sta_set_shmem(st_gpa[cpu], 0);
        GUEST_SYNC(0);

        check_status(st);
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        sequence = READ_ONCE(st->sequence);
        check_status(st);
        GUEST_SYNC(1);

        check_status(st);
        GUEST_ASSERT(sequence < READ_ONCE(st->sequence));
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        check_status(st);
        GUEST_DONE();
}

static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
        uint64_t id = RISCV_SBI_EXT_REG(KVM_RISCV_SBI_EXT_STA);
        unsigned long enabled = vcpu_get_reg(vcpu, id);

        TEST_ASSERT(enabled == 0 || enabled == 1, "Expected boolean result");

        return enabled;
}

static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
        /* ST_GPA_BASE is identity mapped */
        st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
        st_gpa[i] = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)st_gva[i]);
        sync_global_to_guest(vcpu->vm, st_gva[i]);
        sync_global_to_guest(vcpu->vm, st_gpa[i]);
}

static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
        struct sta_struct *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
        int i;

        pr_info("VCPU%d:\n", vcpu_idx);
        pr_info("    sequence:  %d\n", st->sequence);
        pr_info("    flags:     %d\n", st->flags);
        pr_info("    steal:     %"PRIu64"\n", st->steal);
        pr_info("    preempted: %d\n", st->preempted);
        pr_info("    pad:      ");
        for (i = 0; i < 47; ++i)
                pr_info("%d", st->pad[i]);
        pr_info("\n");
}

#elif defined(__loongarch__)

/* steal_time must have 64-byte alignment */
#define STEAL_TIME_SIZE         ((sizeof(struct kvm_steal_time) + 63) & ~63)
#define KVM_STEAL_PHYS_VALID    BIT_ULL(0)

struct kvm_steal_time {
        __u64 steal;
        __u32 version;
        __u32 flags;
        __u8  preempted;
        __u8  pad[47];
};

static void check_status(struct kvm_steal_time *st)
{
        GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
        GUEST_ASSERT_EQ(READ_ONCE(st->flags), 0);
        GUEST_ASSERT_EQ(READ_ONCE(st->preempted), 0);
}

static void guest_code(int cpu)
{
        uint32_t version;
        struct kvm_steal_time *st = st_gva[cpu];

        memset(st, 0, sizeof(*st));
        GUEST_SYNC(0);

        check_status(st);
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        version = READ_ONCE(st->version);
        check_status(st);
        GUEST_SYNC(1);

        check_status(st);
        GUEST_ASSERT(version < READ_ONCE(st->version));
        WRITE_ONCE(guest_stolen_time[cpu], st->steal);
        check_status(st);
        GUEST_DONE();
}

static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
        int err;
        uint64_t val;
        struct kvm_device_attr attr = {
                .group = KVM_LOONGARCH_VCPU_CPUCFG,
                .attr = CPUCFG_KVM_FEATURE,
                .addr = (uint64_t)&val,
        };

        err = __vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &attr);
        if (err)
                return false;

        err = __vcpu_ioctl(vcpu, KVM_GET_DEVICE_ATTR, &attr);
        if (err)
                return false;

        return val & BIT(KVM_FEATURE_STEAL_TIME);
}

static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
        int err;
        uint64_t st_gpa;
        struct kvm_vm *vm = vcpu->vm;
        struct kvm_device_attr attr = {
                .group = KVM_LOONGARCH_VCPU_PVTIME_CTRL,
                .attr = KVM_LOONGARCH_VCPU_PVTIME_GPA,
                .addr = (uint64_t)&st_gpa,
        };

        /* ST_GPA_BASE is identity mapped */
        st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
        sync_global_to_guest(vm, st_gva[i]);

        err = __vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &attr);
        TEST_ASSERT(err == 0, "No PV stealtime Feature");

        st_gpa = (unsigned long)st_gva[i] | KVM_STEAL_PHYS_VALID;
        err = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &attr);
        TEST_ASSERT(err == 0, "Fail to set PV stealtime GPA");
}

static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
        struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);

        ksft_print_msg("VCPU%d:\n", vcpu_idx);
        ksft_print_msg("    steal:     %lld\n", st->steal);
        ksft_print_msg("    flags:     %d\n", st->flags);
        ksft_print_msg("    version:   %d\n", st->version);
        ksft_print_msg("    preempted: %d\n", st->preempted);
}
#endif

static void *do_steal_time(void *arg)
{
        struct timespec ts, stop;

        clock_gettime(CLOCK_MONOTONIC, &ts);
        stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS);

        while (1) {
                clock_gettime(CLOCK_MONOTONIC, &ts);
                if (timespec_to_ns(timespec_sub(ts, stop)) >= 0)
                        break;
        }

        return NULL;
}

static void run_vcpu(struct kvm_vcpu *vcpu)
{
        struct ucall uc;

        vcpu_run(vcpu);

        switch (get_ucall(vcpu, &uc)) {
        case UCALL_SYNC:
        case UCALL_DONE:
                break;
        case UCALL_ABORT:
                REPORT_GUEST_ASSERT(uc);
        default:
                TEST_ASSERT(false, "Unexpected exit: %s",
                            exit_reason_str(vcpu->run->exit_reason));
        }
}

int main(int ac, char **av)
{
        struct kvm_vcpu *vcpus[NR_VCPUS];
        struct kvm_vm *vm;
        pthread_attr_t attr;
        pthread_t thread;
        cpu_set_t cpuset;
        unsigned int gpages;
        long stolen_time;
        long run_delay;
        bool verbose;
        int i;

        verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));

        /* Set CPU affinity so we can force preemption of the VCPU */
        CPU_ZERO(&cpuset);
        CPU_SET(0, &cpuset);
        pthread_attr_init(&attr);
        pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
        pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);

        /* Create a VM and an identity mapped memslot for the steal time structure */
        vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus);
        gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS);
        vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);
        virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages);

        ksft_print_header();
        TEST_REQUIRE(is_steal_time_supported(vcpus[0]));
        ksft_set_plan(NR_VCPUS);

        /* Run test on each VCPU */
        for (i = 0; i < NR_VCPUS; ++i) {
                steal_time_init(vcpus[i], i);

                vcpu_args_set(vcpus[i], 1, i);

                /* First VCPU run initializes steal-time */
                run_vcpu(vcpus[i]);

                /* Second VCPU run, expect guest stolen time to be <= run_delay */
                run_vcpu(vcpus[i]);
                sync_global_from_guest(vm, guest_stolen_time[i]);
                stolen_time = guest_stolen_time[i];
                run_delay = get_run_delay();
                TEST_ASSERT(stolen_time <= run_delay,
                            "Expected stolen time <= %ld, got %ld",
                            run_delay, stolen_time);

                /* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */
                run_delay = get_run_delay();
                pthread_create(&thread, &attr, do_steal_time, NULL);
                do
                        sched_yield();
                while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
                pthread_join(thread, NULL);
                run_delay = get_run_delay() - run_delay;
                TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
                            "Expected run_delay >= %ld, got %ld",
                            MIN_RUN_DELAY_NS, run_delay);

                /* Run VCPU again to confirm stolen time is consistent with run_delay */
                run_vcpu(vcpus[i]);
                sync_global_from_guest(vm, guest_stolen_time[i]);
                stolen_time = guest_stolen_time[i] - stolen_time;
                TEST_ASSERT(stolen_time >= run_delay,
                            "Expected stolen time >= %ld, got %ld",
                            run_delay, stolen_time);

                if (verbose) {
                        ksft_print_msg("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld%s\n",
                                       i, guest_stolen_time[i], stolen_time,
                                       stolen_time == run_delay ?
                                       " (BONUS: guest test-stolen-time even exactly matches test-run_delay)" : "");
                        steal_time_dump(vm, i);
                }
                ksft_test_result_pass("vcpu%d\n", i);
        }

        /* Print results and exit() accordingly */
        ksft_finished();
}