kvm.c

Go to the documentation of this file.

/*
 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
 * Copyright 2010-2011 Freescale Semiconductor, Inc.
 *
 * Authors:
 *     Alexander Graf <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/kvm_host.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/kvm_para.h>
#include <linux/slab.h>
#include <linux/of.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;
static char kvm_tmp[1024 * 1024];
static int kvm_tmp_index;

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

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

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

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

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

    if ((kvm_tmp_index + len) > ARRAY_SIZE(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 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 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 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 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 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 kvm_map_magic_page(void *data)
{
    u32 *features = data;

    ulong in[8];
    ulong out[8];

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

    kvm_hypercall(in, out, HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE);

    *features = out[0];
}

static void 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_BOOK3E_MMU
    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_BOOK3E_MMU */

    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_BOOK3E_MMU
    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_BOOK3E_MMU */

    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
    }

    switch (inst_no_rt & ~KVM_MASK_RB) {
#ifdef CONFIG_PPC_BOOK3S_32
    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;
        break;
#endif
    }

    switch (_inst) {
#ifdef CONFIG_BOOKE
    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 kvm_use_magic_page(void)
{
    u32 *p;
    u32 *start, *end;
    u32 tmp;
    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 (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
        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");
}

unsigned long kvm_hypercall(unsigned long *in,
                unsigned long *out,
                unsigned long nr)
{
    unsigned long register r0 asm("r0");
    unsigned long register r3 asm("r3") = in[0];
    unsigned long register r4 asm("r4") = in[1];
    unsigned long register r5 asm("r5") = in[2];
    unsigned long register r6 asm("r6") = in[3];
    unsigned long register r7 asm("r7") = in[4];
    unsigned long register r8 asm("r8") = in[5];
    unsigned long register r9 asm("r9") = in[6];
    unsigned long register r10 asm("r10") = in[7];
    unsigned long register r11 asm("r11") = nr;
    unsigned long register r12 asm("r12");

    asm volatile("bl    epapr_hypercall_start"
             : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
               "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
               "=r"(r12)
             : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
               "r"(r9), "r"(r10), "r"(r11)
             : "memory", "cc", "xer", "ctr", "lr");

    out[0] = r4;
    out[1] = r5;
    out[2] = r6;
    out[3] = r7;
    out[4] = r8;
    out[5] = r9;
    out[6] = r10;
    out[7] = r11;

    return r3;
}
EXPORT_SYMBOL_GPL(kvm_hypercall);

static __init void kvm_free_tmp(void)
{
    unsigned long start, end;

    start = (ulong)&kvm_tmp[kvm_tmp_index + (PAGE_SIZE - 1)] & PAGE_MASK;
    end = (ulong)&kvm_tmp[ARRAY_SIZE(kvm_tmp)] & PAGE_MASK;

    /* Free the tmp space we don't need */
    for (; start < end; start += PAGE_SIZE) {
        ClearPageReserved(virt_to_page(start));
        init_page_count(virt_to_page(start));
        free_page(start);
        totalram_pages++;
    }
}

static int __init kvm_guest_init(void)
{
    if (!kvm_para_available())
        goto free_tmp;

    if (!epapr_paravirt_enabled)
        goto free_tmp;

    if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
        kvm_use_magic_page();

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

free_tmp:
    kvm_free_tmp();

    return 0;
}

postcore_initcall(kvm_guest_init);