text: // 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;
  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] = {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 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;
  #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 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_pages_readable((const char *)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 __init void kvm_free_tmp(void)
  {
  	/*
  	 * Inform kmemleak about the hole in the .bss section since the
  	 * corresponding pages will be unmapped with DEBUG_PAGEALLOC=y.
  	 */
  	kmemleak_free_part(&kvm_tmp[kvm_tmp_index],
  			   ARRAY_SIZE(kvm_tmp) - kvm_tmp_index);
  	free_reserved_area(&kvm_tmp[kvm_tmp_index],
  			   &kvm_tmp[ARRAY_SIZE(kvm_tmp)], -1, NULL);
  }
  
  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);
  