// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
 * Copyright 2010-2011 Freescale Semiconductor, Inc.
 *
 * Authors:
 *     Alexander Graf <agraf@suse.de>
 */

#include <linux/kvm_host.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/kmemleak.h>
#include <linux/kvm_para.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/pagemap.h>

#include <asm/reg.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/disassemble.h>
#include <asm/ppc-opcode.h>
#include <asm/epapr_hcalls.h>

#define KVM_MAGIC_PAGE          (-4096L)
#define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)

#define KVM_INST_LWZ            0x80000000
#define KVM_INST_STW            0x90000000
#define KVM_INST_LD             0xe8000000
#define KVM_INST_STD            0xf8000000
#define KVM_INST_NOP            0x60000000
#define KVM_INST_B              0x48000000
#define KVM_INST_B_MASK         0x03ffffff
#define KVM_INST_B_MAX          0x01ffffff
#define KVM_INST_LI             0x38000000

#define KVM_MASK_RT             0x03e00000
#define KVM_RT_30               0x03c00000
#define KVM_MASK_RB             0x0000f800
#define KVM_INST_MFMSR          0x7c0000a6

#define SPR_FROM                0
#define SPR_TO                  0x100

#define KVM_INST_SPR(sprn, moveto) (0x7c0002a6 | \
                                    (((sprn) & 0x1f) << 16) | \
                                    (((sprn) & 0x3e0) << 6) | \
                                    (moveto))

#define KVM_INST_MFSPR(sprn)    KVM_INST_SPR(sprn, SPR_FROM)
#define KVM_INST_MTSPR(sprn)    KVM_INST_SPR(sprn, SPR_TO)

#define KVM_INST_TLBSYNC        0x7c00046c
#define KVM_INST_MTMSRD_L0      0x7c000164
#define KVM_INST_MTMSRD_L1      0x7c010164
#define KVM_INST_MTMSR          0x7c000124

#define KVM_INST_WRTEE          0x7c000106
#define KVM_INST_WRTEEI_0       0x7c000146
#define KVM_INST_WRTEEI_1       0x7c008146

#define KVM_INST_MTSRIN         0x7c0001e4

static bool kvm_patching_worked = true;
extern char kvm_tmp[];
extern char kvm_tmp_end[];
static int kvm_tmp_index;

static void __init kvm_patch_ins(u32 *inst, u32 new_inst)
{
        *inst = new_inst;
        flush_icache_range((ulong)inst, (ulong)inst + 4);
}

static void __init kvm_patch_ins_ll(u32 *inst, long addr, u32 rt)
{
#ifdef CONFIG_64BIT
        kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
#else
        kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
#endif
}

static void __init kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
{
#ifdef CONFIG_64BIT
        kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
#else
        kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
#endif
}

static void __init kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
{
        kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
}

static void __init kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
{
#ifdef CONFIG_64BIT
        kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
#else
        kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
#endif
}

static void __init kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
{
        kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
}

static void __init kvm_patch_ins_nop(u32 *inst)
{
        kvm_patch_ins(inst, KVM_INST_NOP);
}

static void __init kvm_patch_ins_b(u32 *inst, int addr)
{
#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC_BOOK3S)
        /* On relocatable kernels interrupts handlers and our code
           can be in different regions, so we don't patch them */

        if ((ulong)inst < (ulong)&__end_interrupts)
                return;
#endif

        kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
}

static u32 * __init kvm_alloc(int len)
{
        u32 *p;

        if ((kvm_tmp_index + len) > (kvm_tmp_end - kvm_tmp)) {
                printk(KERN_ERR "KVM: No more space (%d + %d)\n",
                                kvm_tmp_index, len);
                kvm_patching_worked = false;
                return NULL;
        }

        p = (void*)&kvm_tmp[kvm_tmp_index];
        kvm_tmp_index += len;

        return p;
}

extern u32 kvm_emulate_mtmsrd_branch_offs;
extern u32 kvm_emulate_mtmsrd_reg_offs;
extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
extern u32 kvm_emulate_mtmsrd_len;
extern u32 kvm_emulate_mtmsrd[];

static void __init kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
{
        u32 *p;
        int distance_start;
        int distance_end;
        ulong next_inst;

        p = kvm_alloc(kvm_emulate_mtmsrd_len * 4);
        if (!p)
                return;

        /* Find out where we are and put everything there */
        distance_start = (ulong)p - (ulong)inst;
        next_inst = ((ulong)inst + 4);
        distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsrd_branch_offs];

        /* Make sure we only write valid b instructions */
        if (distance_start > KVM_INST_B_MAX) {
                kvm_patching_worked = false;
                return;
        }

        /* Modify the chunk to fit the invocation */
        memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
        p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
        switch (get_rt(rt)) {
        case 30:
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
                                 magic_var(scratch2), KVM_RT_30);
                break;
        case 31:
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
                                 magic_var(scratch1), KVM_RT_30);
                break;
        default:
                p[kvm_emulate_mtmsrd_reg_offs] |= rt;
                break;
        }

        p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
        flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);

        /* Patch the invocation */
        kvm_patch_ins_b(inst, distance_start);
}

extern u32 kvm_emulate_mtmsr_branch_offs;
extern u32 kvm_emulate_mtmsr_reg1_offs;
extern u32 kvm_emulate_mtmsr_reg2_offs;
extern u32 kvm_emulate_mtmsr_orig_ins_offs;
extern u32 kvm_emulate_mtmsr_len;
extern u32 kvm_emulate_mtmsr[];

static void __init kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
{
        u32 *p;
        int distance_start;
        int distance_end;
        ulong next_inst;

        p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
        if (!p)
                return;

        /* Find out where we are and put everything there */
        distance_start = (ulong)p - (ulong)inst;
        next_inst = ((ulong)inst + 4);
        distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];

        /* Make sure we only write valid b instructions */
        if (distance_start > KVM_INST_B_MAX) {
                kvm_patching_worked = false;
                return;
        }

        /* Modify the chunk to fit the invocation */
        memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
        p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;

        /* Make clobbered registers work too */
        switch (get_rt(rt)) {
        case 30:
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
                                 magic_var(scratch2), KVM_RT_30);
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
                                 magic_var(scratch2), KVM_RT_30);
                break;
        case 31:
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
                                 magic_var(scratch1), KVM_RT_30);
                kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
                                 magic_var(scratch1), KVM_RT_30);
                break;
        default:
                p[kvm_emulate_mtmsr_reg1_offs] |= rt;
                p[kvm_emulate_mtmsr_reg2_offs] |= rt;
                break;
        }

        p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
        flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);

        /* Patch the invocation */
        kvm_patch_ins_b(inst, distance_start);
}

#ifdef CONFIG_BOOKE

extern u32 kvm_emulate_wrtee_branch_offs;
extern u32 kvm_emulate_wrtee_reg_offs;
extern u32 kvm_emulate_wrtee_orig_ins_offs;
extern u32 kvm_emulate_wrtee_len;
extern u32 kvm_emulate_wrtee[];

static void __init kvm_patch_ins_wrtee(u32 *inst, u32 rt, int imm_one)
{
        u32 *p;
        int distance_start;
        int distance_end;
        ulong next_inst;

        p = kvm_alloc(kvm_emulate_wrtee_len * 4);
        if (!p)
                return;

        /* Find out where we are and put everything there */
        distance_start = (ulong)p - (ulong)inst;
        next_inst = ((ulong)inst + 4);
        distance_end = next_inst - (ulong)&p[kvm_emulate_wrtee_branch_offs];

        /* Make sure we only write valid b instructions */
        if (distance_start > KVM_INST_B_MAX) {
                kvm_patching_worked = false;
                return;
        }

        /* Modify the chunk to fit the invocation */
        memcpy(p, kvm_emulate_wrtee, kvm_emulate_wrtee_len * 4);
        p[kvm_emulate_wrtee_branch_offs] |= distance_end & KVM_INST_B_MASK;

        if (imm_one) {
                p[kvm_emulate_wrtee_reg_offs] =
                        KVM_INST_LI | __PPC_RT(R30) | MSR_EE;
        } else {
                /* Make clobbered registers work too */
                switch (get_rt(rt)) {
                case 30:
                        kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
                                         magic_var(scratch2), KVM_RT_30);
                        break;
                case 31:
                        kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
                                         magic_var(scratch1), KVM_RT_30);
                        break;
                default:
                        p[kvm_emulate_wrtee_reg_offs] |= rt;
                        break;
                }
        }

        p[kvm_emulate_wrtee_orig_ins_offs] = *inst;
        flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrtee_len * 4);

        /* Patch the invocation */
        kvm_patch_ins_b(inst, distance_start);
}

extern u32 kvm_emulate_wrteei_0_branch_offs;
extern u32 kvm_emulate_wrteei_0_len;
extern u32 kvm_emulate_wrteei_0[];

static void __init kvm_patch_ins_wrteei_0(u32 *inst)
{
        u32 *p;
        int distance_start;
        int distance_end;
        ulong next_inst;

        p = kvm_alloc(kvm_emulate_wrteei_0_len * 4);
        if (!p)
                return;

        /* Find out where we are and put everything there */
        distance_start = (ulong)p - (ulong)inst;
        next_inst = ((ulong)inst + 4);
        distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_0_branch_offs];

        /* Make sure we only write valid b instructions */
        if (distance_start > KVM_INST_B_MAX) {
                kvm_patching_worked = false;
                return;
        }

        memcpy(p, kvm_emulate_wrteei_0, kvm_emulate_wrteei_0_len * 4);
        p[kvm_emulate_wrteei_0_branch_offs] |= distance_end & KVM_INST_B_MASK;
        flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_0_len * 4);

        /* Patch the invocation */
        kvm_patch_ins_b(inst, distance_start);
}

#endif

#ifdef CONFIG_PPC_BOOK3S_32

extern u32 kvm_emulate_mtsrin_branch_offs;
extern u32 kvm_emulate_mtsrin_reg1_offs;
extern u32 kvm_emulate_mtsrin_reg2_offs;
extern u32 kvm_emulate_mtsrin_orig_ins_offs;
extern u32 kvm_emulate_mtsrin_len;
extern u32 kvm_emulate_mtsrin[];

static void __init kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
{
        u32 *p;
        int distance_start;
        int distance_end;
        ulong next_inst;

        p = kvm_alloc(kvm_emulate_mtsrin_len * 4);
        if (!p)
                return;

        /* Find out where we are and put everything there */
        distance_start = (ulong)p - (ulong)inst;
        next_inst = ((ulong)inst + 4);
        distance_end = next_inst - (ulong)&p[kvm_emulate_mtsrin_branch_offs];

        /* Make sure we only write valid b instructions */
        if (distance_start > KVM_INST_B_MAX) {
                kvm_patching_worked = false;
                return;
        }

        /* Modify the chunk to fit the invocation */
        memcpy(p, kvm_emulate_mtsrin, kvm_emulate_mtsrin_len * 4);
        p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
        p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
        p[kvm_emulate_mtsrin_reg2_offs] |= rt;
        p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
        flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);

        /* Patch the invocation */
        kvm_patch_ins_b(inst, distance_start);
}

#endif

static void __init kvm_map_magic_page(void *data)
{
        u32 *features = data;

        ulong in[8] = {0};
        ulong out[8];

        in[0] = KVM_MAGIC_PAGE;
        in[1] = KVM_MAGIC_PAGE | MAGIC_PAGE_FLAG_NOT_MAPPED_NX;

        epapr_hypercall(in, out, KVM_HCALL_TOKEN(KVM_HC_PPC_MAP_MAGIC_PAGE));

        *features = out[0];
}

static void __init kvm_check_ins(u32 *inst, u32 features)
{
        u32 _inst = *inst;
        u32 inst_no_rt = _inst & ~KVM_MASK_RT;
        u32 inst_rt = _inst & KVM_MASK_RT;

        switch (inst_no_rt) {
        /* Loads */
        case KVM_INST_MFMSR:
                kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG0):
                kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG1):
                kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG2):
                kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG3):
                kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SRR0):
                kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SRR1):
                kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
                break;
#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_DEAR):
#else
        case KVM_INST_MFSPR(SPRN_DAR):
#endif
                kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_DSISR):
                kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
                break;

#ifdef CONFIG_PPC_E500
        case KVM_INST_MFSPR(SPRN_MAS0):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas0), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS1):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas1), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS2):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_ld(inst, magic_var(mas2), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS3):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas7_3) + 4, inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS4):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas4), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS6):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas6), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_MAS7):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(mas7_3), inst_rt);
                break;
#endif /* CONFIG_PPC_E500 */

        case KVM_INST_MFSPR(SPRN_SPRG4):
#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_SPRG4R):
#endif
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_ld(inst, magic_var(sprg4), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG5):
#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_SPRG5R):
#endif
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_ld(inst, magic_var(sprg5), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG6):
#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_SPRG6R):
#endif
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_ld(inst, magic_var(sprg6), inst_rt);
                break;
        case KVM_INST_MFSPR(SPRN_SPRG7):
#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_SPRG7R):
#endif
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_ld(inst, magic_var(sprg7), inst_rt);
                break;

#ifdef CONFIG_BOOKE
        case KVM_INST_MFSPR(SPRN_ESR):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(esr), inst_rt);
                break;
#endif

        case KVM_INST_MFSPR(SPRN_PIR):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_lwz(inst, magic_var(pir), inst_rt);
                break;


        /* Stores */
        case KVM_INST_MTSPR(SPRN_SPRG0):
                kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG1):
                kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG2):
                kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG3):
                kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SRR0):
                kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SRR1):
                kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
                break;
#ifdef CONFIG_BOOKE
        case KVM_INST_MTSPR(SPRN_DEAR):
#else
        case KVM_INST_MTSPR(SPRN_DAR):
#endif
                kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_DSISR):
                kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
                break;
#ifdef CONFIG_PPC_E500
        case KVM_INST_MTSPR(SPRN_MAS0):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas0), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS1):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas1), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS2):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_std(inst, magic_var(mas2), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS3):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas7_3) + 4, inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS4):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas4), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS6):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas6), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_MAS7):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(mas7_3), inst_rt);
                break;
#endif /* CONFIG_PPC_E500 */

        case KVM_INST_MTSPR(SPRN_SPRG4):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_std(inst, magic_var(sprg4), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG5):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_std(inst, magic_var(sprg5), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG6):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_std(inst, magic_var(sprg6), inst_rt);
                break;
        case KVM_INST_MTSPR(SPRN_SPRG7):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_std(inst, magic_var(sprg7), inst_rt);
                break;

#ifdef CONFIG_BOOKE
        case KVM_INST_MTSPR(SPRN_ESR):
                if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
                        kvm_patch_ins_stw(inst, magic_var(esr), inst_rt);
                break;
#endif

        /* Nops */
        case KVM_INST_TLBSYNC:
                kvm_patch_ins_nop(inst);
                break;

        /* Rewrites */
        case KVM_INST_MTMSRD_L1:
                kvm_patch_ins_mtmsrd(inst, inst_rt);
                break;
        case KVM_INST_MTMSR:
        case KVM_INST_MTMSRD_L0:
                kvm_patch_ins_mtmsr(inst, inst_rt);
                break;
#ifdef CONFIG_BOOKE
        case KVM_INST_WRTEE:
                kvm_patch_ins_wrtee(inst, inst_rt, 0);
                break;
#endif
        }

#ifdef CONFIG_PPC_BOOK3S_32
        switch (inst_no_rt & ~KVM_MASK_RB) {
        case KVM_INST_MTSRIN:
                if (features & KVM_MAGIC_FEAT_SR) {
                        u32 inst_rb = _inst & KVM_MASK_RB;
                        kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
                }
                break;
        }
#endif

#ifdef CONFIG_BOOKE
        switch (_inst) {
        case KVM_INST_WRTEEI_0:
                kvm_patch_ins_wrteei_0(inst);
                break;

        case KVM_INST_WRTEEI_1:
                kvm_patch_ins_wrtee(inst, 0, 1);
                break;
        }
#endif
}

extern u32 kvm_template_start[];
extern u32 kvm_template_end[];

static void __init kvm_use_magic_page(void)
{
        u32 *p;
        u32 *start, *end;
        u32 features;

        /* Tell the host to map the magic page to -4096 on all CPUs */
        on_each_cpu(kvm_map_magic_page, &features, 1);

        /* Quick self-test to see if the mapping works */
        if (fault_in_readable((const char __user *)KVM_MAGIC_PAGE,
                              sizeof(u32))) {
                kvm_patching_worked = false;
                return;
        }

        /* Now loop through all code and find instructions */
        start = (void*)_stext;
        end = (void*)_etext;

        /*
         * Being interrupted in the middle of patching would
         * be bad for SPRG4-7, which KVM can't keep in sync
         * with emulated accesses because reads don't trap.
         */
        local_irq_disable();

        for (p = start; p < end; p++) {
                /* Avoid patching the template code */
                if (p >= kvm_template_start && p < kvm_template_end) {
                        p = kvm_template_end - 1;
                        continue;
                }
                kvm_check_ins(p, features);
        }

        local_irq_enable();

        printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
                         kvm_patching_worked ? "worked" : "failed");
}

static int __init kvm_guest_init(void)
{
        if (!kvm_para_available())
                return 0;

        if (!epapr_paravirt_enabled)
                return 0;

        if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
                kvm_use_magic_page();

#ifdef CONFIG_PPC_BOOK3S_64
        /* Enable napping */
        powersave_nap = 1;
#endif

        return 0;
}

postcore_initcall(kvm_guest_init);