svm.c

/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * AMD SVM support
 *
 * Copyright (C) 2006 Qumranet, Inc.
 *
 * Authors:
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *   Avi Kivity   <avi@qumranet.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */
#include <linux/kvm_host.h>

#include "irq.h"
#include "mmu.h"
#include "kvm_cache_regs.h"
#include "x86.h"

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/ftrace_event.h>
#include <linux/slab.h>

#include <asm/desc.h>

#include <asm/virtext.h>
#include "trace.h"

#define __ex(x) __kvm_handle_fault_on_reboot(x)

MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

#define IOPM_ALLOC_ORDER 2
#define MSRPM_ALLOC_ORDER 1

#define SEG_TYPE_LDT 2
#define SEG_TYPE_BUSY_TSS16 3

#define SVM_FEATURE_NPT  (1 << 0)
#define SVM_FEATURE_LBRV (1 << 1)
#define SVM_FEATURE_SVML (1 << 2)
#define SVM_FEATURE_PAUSE_FILTER (1 << 10)

#define NESTED_EXIT_HOST	0	/* Exit handled on host level */
#define NESTED_EXIT_DONE	1	/* Exit caused nested vmexit  */
#define NESTED_EXIT_CONTINUE	2	/* Further checks needed      */

#define DEBUGCTL_RESERVED_BITS (~(0x3fULL))

static const u32 host_save_user_msrs[] = {
#ifdef CONFIG_X86_64
	MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE,
	MSR_FS_BASE,
#endif
	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
};

#define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs)

struct kvm_vcpu;

struct nested_state {
	struct vmcb *hsave;
	u64 hsave_msr;
	u64 vmcb;

	/* These are the merged vectors */
	u32 *msrpm;

	/* gpa pointers to the real vectors */
	u64 vmcb_msrpm;

	/* A VMEXIT is required but not yet emulated */
	bool exit_required;

	/* cache for intercepts of the guest */
	u16 intercept_cr_read;
	u16 intercept_cr_write;
	u16 intercept_dr_read;
	u16 intercept_dr_write;
	u32 intercept_exceptions;
	u64 intercept;

};

struct vcpu_svm {
	struct kvm_vcpu vcpu;
	struct vmcb *vmcb;
	unsigned long vmcb_pa;
	struct svm_cpu_data *svm_data;
	uint64_t asid_generation;
	uint64_t sysenter_esp;
	uint64_t sysenter_eip;

	u64 next_rip;

	u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS];
	u64 host_gs_base;

	u32 *msrpm;

	struct nested_state nested;

	bool nmi_singlestep;
};

/* enable NPT for AMD64 and X86 with PAE */
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
static bool npt_enabled = true;
#else
static bool npt_enabled = false;
#endif
static int npt = 1;

module_param(npt, int, S_IRUGO);

static int nested = 1;
module_param(nested, int, S_IRUGO);

static void svm_flush_tlb(struct kvm_vcpu *vcpu);
static void svm_complete_interrupts(struct vcpu_svm *svm);

static int nested_svm_exit_handled(struct vcpu_svm *svm);
static int nested_svm_intercept(struct vcpu_svm *svm);
static int nested_svm_vmexit(struct vcpu_svm *svm);
static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
				      bool has_error_code, u32 error_code);

static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
{
	return container_of(vcpu, struct vcpu_svm, vcpu);
}

static inline bool is_nested(struct vcpu_svm *svm)
{
	return svm->nested.vmcb;
}

static inline void enable_gif(struct vcpu_svm *svm)
{
	svm->vcpu.arch.hflags |= HF_GIF_MASK;
}

static inline void disable_gif(struct vcpu_svm *svm)
{
	svm->vcpu.arch.hflags &= ~HF_GIF_MASK;
}

static inline bool gif_set(struct vcpu_svm *svm)
{
	return !!(svm->vcpu.arch.hflags & HF_GIF_MASK);
}

static unsigned long iopm_base;

struct kvm_ldttss_desc {
	u16 limit0;
	u16 base0;
	unsigned base1 : 8, type : 5, dpl : 2, p : 1;
	unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
	u32 base3;
	u32 zero1;
} __attribute__((packed));

struct svm_cpu_data {
	int cpu;

	u64 asid_generation;
	u32 max_asid;
	u32 next_asid;
	struct kvm_ldttss_desc *tss_desc;

	struct page *save_area;
};

static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
static uint32_t svm_features;

struct svm_init_data {
	int cpu;
	int r;
};

static u32 msrpm_ranges[] = {0, 0xc0000000, 0xc0010000};

#define NUM_MSR_MAPS ARRAY_SIZE(msrpm_ranges)
#define MSRS_RANGE_SIZE 2048
#define MSRS_IN_RANGE (MSRS_RANGE_SIZE * 8 / 2)

#define MAX_INST_SIZE 15

static inline u32 svm_has(u32 feat)
{
	return svm_features & feat;
}

static inline void clgi(void)
{
	asm volatile (__ex(SVM_CLGI));
}

static inline void stgi(void)
{
	asm volatile (__ex(SVM_STGI));
}

static inline void invlpga(unsigned long addr, u32 asid)
{
	asm volatile (__ex(SVM_INVLPGA) :: "a"(addr), "c"(asid));
}

static inline void force_new_asid(struct kvm_vcpu *vcpu)
{
	to_svm(vcpu)->asid_generation--;
}

static inline void flush_guest_tlb(struct kvm_vcpu *vcpu)
{
	force_new_asid(vcpu);
}

static void svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
	if (!npt_enabled && !(efer & EFER_LMA))
		efer &= ~EFER_LME;

	to_svm(vcpu)->vmcb->save.efer = efer | EFER_SVME;
	vcpu->arch.efer = efer;
}

static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
				bool has_error_code, u32 error_code)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	/* If we are within a nested VM we'd better #VMEXIT and let the
	   guest handle the exception */
	if (nested_svm_check_exception(svm, nr, has_error_code, error_code))
		return;

	svm->vmcb->control.event_inj = nr
		| SVM_EVTINJ_VALID
		| (has_error_code ? SVM_EVTINJ_VALID_ERR : 0)
		| SVM_EVTINJ_TYPE_EXEPT;
	svm->vmcb->control.event_inj_err = error_code;
}

static int is_external_interrupt(u32 info)
{
	info &= SVM_EVTINJ_TYPE_MASK | SVM_EVTINJ_VALID;
	return info == (SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR);
}

static u32 svm_get_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	u32 ret = 0;

	if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK)
		ret |= X86_SHADOW_INT_STI | X86_SHADOW_INT_MOV_SS;
	return ret & mask;
}

static void svm_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (mask == 0)
		svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK;
	else
		svm->vmcb->control.int_state |= SVM_INTERRUPT_SHADOW_MASK;

}

static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (!svm->next_rip) {
		if (emulate_instruction(vcpu, 0, 0, EMULTYPE_SKIP) !=
				EMULATE_DONE)
			printk(KERN_DEBUG "%s: NOP\n", __func__);
		return;
	}
	if (svm->next_rip - kvm_rip_read(vcpu) > MAX_INST_SIZE)
		printk(KERN_ERR "%s: ip 0x%lx next 0x%llx\n",
		       __func__, kvm_rip_read(vcpu), svm->next_rip);

	kvm_rip_write(vcpu, svm->next_rip);
	svm_set_interrupt_shadow(vcpu, 0);
}

static int has_svm(void)
{
	const char *msg;

	if (!cpu_has_svm(&msg)) {
		printk(KERN_INFO "has_svm: %s\n", msg);
		return 0;
	}

	return 1;
}

static void svm_hardware_disable(void *garbage)
{
	cpu_svm_disable();
}

static int svm_hardware_enable(void *garbage)
{

	struct svm_cpu_data *sd;
	uint64_t efer;
	struct desc_ptr gdt_descr;
	struct desc_struct *gdt;
	int me = raw_smp_processor_id();

	rdmsrl(MSR_EFER, efer);
	if (efer & EFER_SVME)
		return -EBUSY;

	if (!has_svm()) {
		printk(KERN_ERR "svm_hardware_enable: err EOPNOTSUPP on %d\n",
		       me);
		return -EINVAL;
	}
	sd = per_cpu(svm_data, me);

	if (!sd) {
		printk(KERN_ERR "svm_hardware_enable: svm_data is NULL on %d\n",
		       me);
		return -EINVAL;
	}

	sd->asid_generation = 1;
	sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
	sd->next_asid = sd->max_asid + 1;

	kvm_get_gdt(&gdt_descr);
	gdt = (struct desc_struct *)gdt_descr.address;
	sd->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS);

	wrmsrl(MSR_EFER, efer | EFER_SVME);

	wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(sd->save_area) << PAGE_SHIFT);

	return 0;
}

static void svm_cpu_uninit(int cpu)
{
	struct svm_cpu_data *sd = per_cpu(svm_data, raw_smp_processor_id());

	if (!sd)
		return;

	per_cpu(svm_data, raw_smp_processor_id()) = NULL;
	__free_page(sd->save_area);
	kfree(sd);
}

static int svm_cpu_init(int cpu)
{
	struct svm_cpu_data *sd;
	int r;

	sd = kzalloc(sizeof(struct svm_cpu_data), GFP_KERNEL);
	if (!sd)
		return -ENOMEM;
	sd->cpu = cpu;
	sd->save_area = alloc_page(GFP_KERNEL);
	r = -ENOMEM;
	if (!sd->save_area)
		goto err_1;

	per_cpu(svm_data, cpu) = sd;

	return 0;

err_1:
	kfree(sd);
	return r;

}

static void set_msr_interception(u32 *msrpm, unsigned msr,
				 int read, int write)
{
	int i;

	for (i = 0; i < NUM_MSR_MAPS; i++) {
		if (msr >= msrpm_ranges[i] &&
		    msr < msrpm_ranges[i] + MSRS_IN_RANGE) {
			u32 msr_offset = (i * MSRS_IN_RANGE + msr -
					  msrpm_ranges[i]) * 2;

			u32 *base = msrpm + (msr_offset / 32);
			u32 msr_shift = msr_offset % 32;
			u32 mask = ((write) ? 0 : 2) | ((read) ? 0 : 1);
			*base = (*base & ~(0x3 << msr_shift)) |
				(mask << msr_shift);
			return;
		}
	}
	BUG();
}

static void svm_vcpu_init_msrpm(u32 *msrpm)
{
	memset(msrpm, 0xff, PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER));

#ifdef CONFIG_X86_64
	set_msr_interception(msrpm, MSR_GS_BASE, 1, 1);
	set_msr_interception(msrpm, MSR_FS_BASE, 1, 1);
	set_msr_interception(msrpm, MSR_KERNEL_GS_BASE, 1, 1);
	set_msr_interception(msrpm, MSR_LSTAR, 1, 1);
	set_msr_interception(msrpm, MSR_CSTAR, 1, 1);
	set_msr_interception(msrpm, MSR_SYSCALL_MASK, 1, 1);
#endif
	set_msr_interception(msrpm, MSR_K6_STAR, 1, 1);
	set_msr_interception(msrpm, MSR_IA32_SYSENTER_CS, 1, 1);
}

static void svm_enable_lbrv(struct vcpu_svm *svm)
{
	u32 *msrpm = svm->msrpm;

	svm->vmcb->control.lbr_ctl = 1;
	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1);
	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1);
	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 1, 1);
	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 1, 1);
}

static void svm_disable_lbrv(struct vcpu_svm *svm)
{
	u32 *msrpm = svm->msrpm;

	svm->vmcb->control.lbr_ctl = 0;
	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 0, 0);
	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 0, 0);
	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 0, 0);
	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 0, 0);
}

static __init int svm_hardware_setup(void)
{
	int cpu;
	struct page *iopm_pages;
	void *iopm_va;
	int r;

	iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER);

	if (!iopm_pages)
		return -ENOMEM;

	iopm_va = page_address(iopm_pages);
	memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER));
	iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;

	if (boot_cpu_has(X86_FEATURE_NX))
		kvm_enable_efer_bits(EFER_NX);

	if (boot_cpu_has(X86_FEATURE_FXSR_OPT))
		kvm_enable_efer_bits(EFER_FFXSR);

	if (nested) {
		printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
		kvm_enable_efer_bits(EFER_SVME);
	}

	for_each_possible_cpu(cpu) {
		r = svm_cpu_init(cpu);
		if (r)
			goto err;
	}

	svm_features = cpuid_edx(SVM_CPUID_FUNC);

	if (!svm_has(SVM_FEATURE_NPT))
		npt_enabled = false;

	if (npt_enabled && !npt) {
		printk(KERN_INFO "kvm: Nested Paging disabled\n");
		npt_enabled = false;
	}

	if (npt_enabled) {
		printk(KERN_INFO "kvm: Nested Paging enabled\n");
		kvm_enable_tdp();
	} else
		kvm_disable_tdp();

	return 0;

err:
	__free_pages(iopm_pages, IOPM_ALLOC_ORDER);
	iopm_base = 0;
	return r;
}

static __exit void svm_hardware_unsetup(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		svm_cpu_uninit(cpu);

	__free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT), IOPM_ALLOC_ORDER);
	iopm_base = 0;
}

static void init_seg(struct vmcb_seg *seg)
{
	seg->selector = 0;
	seg->attrib = SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK |
		SVM_SELECTOR_WRITE_MASK; /* Read/Write Data Segment */
	seg->limit = 0xffff;
	seg->base = 0;
}

static void init_sys_seg(struct vmcb_seg *seg, uint32_t type)
{
	seg->selector = 0;
	seg->attrib = SVM_SELECTOR_P_MASK | type;
	seg->limit = 0xffff;
	seg->base = 0;
}

static void init_vmcb(struct vcpu_svm *svm)
{
	struct vmcb_control_area *control = &svm->vmcb->control;
	struct vmcb_save_area *save = &svm->vmcb->save;

	svm->vcpu.fpu_active = 1;

	control->intercept_cr_read = 	INTERCEPT_CR0_MASK |
					INTERCEPT_CR3_MASK |
					INTERCEPT_CR4_MASK;

	control->intercept_cr_write = 	INTERCEPT_CR0_MASK |
					INTERCEPT_CR3_MASK |
					INTERCEPT_CR4_MASK |
					INTERCEPT_CR8_MASK;

	control->intercept_dr_read = 	INTERCEPT_DR0_MASK |
					INTERCEPT_DR1_MASK |
					INTERCEPT_DR2_MASK |
					INTERCEPT_DR3_MASK |
					INTERCEPT_DR4_MASK |
					INTERCEPT_DR5_MASK |
					INTERCEPT_DR6_MASK |
					INTERCEPT_DR7_MASK;

	control->intercept_dr_write = 	INTERCEPT_DR0_MASK |
					INTERCEPT_DR1_MASK |
					INTERCEPT_DR2_MASK |
					INTERCEPT_DR3_MASK |
					INTERCEPT_DR4_MASK |
					INTERCEPT_DR5_MASK |
					INTERCEPT_DR6_MASK |
					INTERCEPT_DR7_MASK;

	control->intercept_exceptions = (1 << PF_VECTOR) |
					(1 << UD_VECTOR) |
					(1 << MC_VECTOR);


	control->intercept = 	(1ULL << INTERCEPT_INTR) |
				(1ULL << INTERCEPT_NMI) |
				(1ULL << INTERCEPT_SMI) |
				(1ULL << INTERCEPT_SELECTIVE_CR0) |
				(1ULL << INTERCEPT_CPUID) |
				(1ULL << INTERCEPT_INVD) |
				(1ULL << INTERCEPT_HLT) |
				(1ULL << INTERCEPT_INVLPG) |
				(1ULL << INTERCEPT_INVLPGA) |
				(1ULL << INTERCEPT_IOIO_PROT) |
				(1ULL << INTERCEPT_MSR_PROT) |
				(1ULL << INTERCEPT_TASK_SWITCH) |
				(1ULL << INTERCEPT_SHUTDOWN) |
				(1ULL << INTERCEPT_VMRUN) |
				(1ULL << INTERCEPT_VMMCALL) |
				(1ULL << INTERCEPT_VMLOAD) |
				(1ULL << INTERCEPT_VMSAVE) |
				(1ULL << INTERCEPT_STGI) |
				(1ULL << INTERCEPT_CLGI) |
				(1ULL << INTERCEPT_SKINIT) |
				(1ULL << INTERCEPT_WBINVD) |
				(1ULL << INTERCEPT_MONITOR) |
				(1ULL << INTERCEPT_MWAIT);

	control->iopm_base_pa = iopm_base;
	control->msrpm_base_pa = __pa(svm->msrpm);
	control->tsc_offset = 0;
	control->int_ctl = V_INTR_MASKING_MASK;

	init_seg(&save->es);
	init_seg(&save->ss);
	init_seg(&save->ds);
	init_seg(&save->fs);
	init_seg(&save->gs);

	save->cs.selector = 0xf000;
	/* Executable/Readable Code Segment */
	save->cs.attrib = SVM_SELECTOR_READ_MASK | SVM_SELECTOR_P_MASK |
		SVM_SELECTOR_S_MASK | SVM_SELECTOR_CODE_MASK;
	save->cs.limit = 0xffff;
	/*
	 * cs.base should really be 0xffff0000, but vmx can't handle that, so
	 * be consistent with it.
	 *
	 * Replace when we have real mode working for vmx.
	 */
	save->cs.base = 0xf0000;

	save->gdtr.limit = 0xffff;
	save->idtr.limit = 0xffff;

	init_sys_seg(&save->ldtr, SEG_TYPE_LDT);
	init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16);

	save->efer = EFER_SVME;
	save->dr6 = 0xffff0ff0;
	save->dr7 = 0x400;
	save->rflags = 2;
	save->rip = 0x0000fff0;
	svm->vcpu.arch.regs[VCPU_REGS_RIP] = save->rip;

	/* This is the guest-visible cr0 value.
	 * svm_set_cr0() sets PG and WP and clears NW and CD on save->cr0.
	 */
	svm->vcpu.arch.cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
	kvm_set_cr0(&svm->vcpu, svm->vcpu.arch.cr0);

	save->cr4 = X86_CR4_PAE;
	/* rdx = ?? */

	if (npt_enabled) {
		/* Setup VMCB for Nested Paging */
		control->nested_ctl = 1;
		control->intercept &= ~((1ULL << INTERCEPT_TASK_SWITCH) |
					(1ULL << INTERCEPT_INVLPG));
		control->intercept_exceptions &= ~(1 << PF_VECTOR);
		control->intercept_cr_read &= ~INTERCEPT_CR3_MASK;
		control->intercept_cr_write &= ~INTERCEPT_CR3_MASK;
		save->g_pat = 0x0007040600070406ULL;
		save->cr3 = 0;
		save->cr4 = 0;
	}
	force_new_asid(&svm->vcpu);

	svm->nested.vmcb = 0;
	svm->vcpu.arch.hflags = 0;

	if (svm_has(SVM_FEATURE_PAUSE_FILTER)) {
		control->pause_filter_count = 3000;
		control->intercept |= (1ULL << INTERCEPT_PAUSE);
	}

	enable_gif(svm);
}

static int svm_vcpu_reset(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	init_vmcb(svm);

	if (!kvm_vcpu_is_bsp(vcpu)) {
		kvm_rip_write(vcpu, 0);
		svm->vmcb->save.cs.base = svm->vcpu.arch.sipi_vector << 12;
		svm->vmcb->save.cs.selector = svm->vcpu.arch.sipi_vector << 8;
	}
	vcpu->arch.regs_avail = ~0;
	vcpu->arch.regs_dirty = ~0;

	return 0;
}

static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
{
	struct vcpu_svm *svm;
	struct page *page;
	struct page *msrpm_pages;
	struct page *hsave_page;
	struct page *nested_msrpm_pages;
	int err;

	svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
	if (!svm) {
		err = -ENOMEM;
		goto out;
	}

	err = kvm_vcpu_init(&svm->vcpu, kvm, id);
	if (err)
		goto free_svm;

	err = -ENOMEM;
	page = alloc_page(GFP_KERNEL);
	if (!page)
		goto uninit;

	msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
	if (!msrpm_pages)
		goto free_page1;

	nested_msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
	if (!nested_msrpm_pages)
		goto free_page2;

	hsave_page = alloc_page(GFP_KERNEL);
	if (!hsave_page)
		goto free_page3;

	svm->nested.hsave = page_address(hsave_page);

	svm->msrpm = page_address(msrpm_pages);
	svm_vcpu_init_msrpm(svm->msrpm);

	svm->nested.msrpm = page_address(nested_msrpm_pages);

	svm->vmcb = page_address(page);
	clear_page(svm->vmcb);
	svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
	svm->asid_generation = 0;
	init_vmcb(svm);

	fx_init(&svm->vcpu);
	svm->vcpu.arch.apic_base = 0xfee00000 | MSR_IA32_APICBASE_ENABLE;
	if (kvm_vcpu_is_bsp(&svm->vcpu))
		svm->vcpu.arch.apic_base |= MSR_IA32_APICBASE_BSP;

	return &svm->vcpu;

free_page3:
	__free_pages(nested_msrpm_pages, MSRPM_ALLOC_ORDER);
free_page2:
	__free_pages(msrpm_pages, MSRPM_ALLOC_ORDER);
free_page1:
	__free_page(page);
uninit:
	kvm_vcpu_uninit(&svm->vcpu);
free_svm:
	kmem_cache_free(kvm_vcpu_cache, svm);
out:
	return ERR_PTR(err);
}

static void svm_free_vcpu(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	__free_page(pfn_to_page(svm->vmcb_pa >> PAGE_SHIFT));
	__free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
	__free_page(virt_to_page(svm->nested.hsave));
	__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
	kvm_vcpu_uninit(vcpu);
	kmem_cache_free(kvm_vcpu_cache, svm);
}

static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	int i;

	if (unlikely(cpu != vcpu->cpu)) {
		u64 delta;

		if (check_tsc_unstable()) {
			/*
			 * Make sure that the guest sees a monotonically
			 * increasing TSC.
			 */
			delta = vcpu->arch.host_tsc - native_read_tsc();
			svm->vmcb->control.tsc_offset += delta;
			if (is_nested(svm))
				svm->nested.hsave->control.tsc_offset += delta;
		}
		vcpu->cpu = cpu;
		kvm_migrate_timers(vcpu);
		svm->asid_generation = 0;
	}

	for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
		rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
}

static void svm_vcpu_put(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	int i;

	++vcpu->stat.host_state_reload;
	for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
		wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);

	vcpu->arch.host_tsc = native_read_tsc();
}

static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
{
	return to_svm(vcpu)->vmcb->save.rflags;
}

static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
	to_svm(vcpu)->vmcb->save.rflags = rflags;
}

static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
{
	switch (reg) {
	case VCPU_EXREG_PDPTR:
		BUG_ON(!npt_enabled);
		load_pdptrs(vcpu, vcpu->arch.cr3);
		break;
	default:
		BUG();
	}
}

static void svm_set_vintr(struct vcpu_svm *svm)
{
	svm->vmcb->control.intercept |= 1ULL << INTERCEPT_VINTR;
}

static void svm_clear_vintr(struct vcpu_svm *svm)
{
	svm->vmcb->control.intercept &= ~(1ULL << INTERCEPT_VINTR);
}

static struct vmcb_seg *svm_seg(struct kvm_vcpu *vcpu, int seg)
{
	struct vmcb_save_area *save = &to_svm(vcpu)->vmcb->save;

	switch (seg) {
	case VCPU_SREG_CS: return &save->cs;
	case VCPU_SREG_DS: return &save->ds;
	case VCPU_SREG_ES: return &save->es;
	case VCPU_SREG_FS: return &save->fs;
	case VCPU_SREG_GS: return &save->gs;
	case VCPU_SREG_SS: return &save->ss;
	case VCPU_SREG_TR: return &save->tr;
	case VCPU_SREG_LDTR: return &save->ldtr;
	}
	BUG();
	return NULL;
}

static u64 svm_get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
	struct vmcb_seg *s = svm_seg(vcpu, seg);

	return s->base;
}

static void svm_get_segment(struct kvm_vcpu *vcpu,
			    struct kvm_segment *var, int seg)
{
	struct vmcb_seg *s = svm_seg(vcpu, seg);

	var->base = s->base;
	var->limit = s->limit;
	var->selector = s->selector;
	var->type = s->attrib & SVM_SELECTOR_TYPE_MASK;
	var->s = (s->attrib >> SVM_SELECTOR_S_SHIFT) & 1;
	var->dpl = (s->attrib >> SVM_SELECTOR_DPL_SHIFT) & 3;
	var->present = (s->attrib >> SVM_SELECTOR_P_SHIFT) & 1;
	var->avl = (s->attrib >> SVM_SELECTOR_AVL_SHIFT) & 1;
	var->l = (s->attrib >> SVM_SELECTOR_L_SHIFT) & 1;
	var->db = (s->attrib >> SVM_SELECTOR_DB_SHIFT) & 1;
	var->g = (s->attrib >> SVM_SELECTOR_G_SHIFT) & 1;

	/* AMD's VMCB does not have an explicit unusable field, so emulate it
	 * for cross vendor migration purposes by "not present"
	 */
	var->unusable = !var->present || (var->type == 0);

	switch (seg) {
	case VCPU_SREG_CS:
		/*
		 * SVM always stores 0 for the 'G' bit in the CS selector in
		 * the VMCB on a VMEXIT. This hurts cross-vendor migration:
		 * Intel's VMENTRY has a check on the 'G' bit.
		 */
		var->g = s->limit > 0xfffff;
		break;
	case VCPU_SREG_TR:
		/*
		 * Work around a bug where the busy flag in the tr selector
		 * isn't exposed
		 */
		var->type |= 0x2;
		break;
	case VCPU_SREG_DS:
	case VCPU_SREG_ES:
	case VCPU_SREG_FS:
	case VCPU_SREG_GS:
		/*
		 * The accessed bit must always be set in the segment
		 * descriptor cache, although it can be cleared in the
		 * descriptor, the cached bit always remains at 1. Since
		 * Intel has a check on this, set it here to support
		 * cross-vendor migration.
		 */
		if (!var->unusable)
			var->type |= 0x1;
		break;
	case VCPU_SREG_SS:
		/* On AMD CPUs sometimes the DB bit in the segment
		 * descriptor is left as 1, although the whole segment has
		 * been made unusable. Clear it here to pass an Intel VMX
		 * entry check when cross vendor migrating.
		 */
		if (var->unusable)
			var->db = 0;
		break;
	}
}

static int svm_get_cpl(struct kvm_vcpu *vcpu)
{
	struct vmcb_save_area *save = &to_svm(vcpu)->vmcb->save;

	return save->cpl;
}

static void svm_get_idt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	dt->size = svm->vmcb->save.idtr.limit;
	dt->address = svm->vmcb->save.idtr.base;
}

static void svm_set_idt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	svm->vmcb->save.idtr.limit = dt->size;
	svm->vmcb->save.idtr.base = dt->address ;
}

static void svm_get_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	dt->size = svm->vmcb->save.gdtr.limit;
	dt->address = svm->vmcb->save.gdtr.base;
}

static void svm_set_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	svm->vmcb->save.gdtr.limit = dt->size;
	svm->vmcb->save.gdtr.base = dt->address ;
}

static void svm_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
{
}

static void svm_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
}

static void update_cr0_intercept(struct vcpu_svm *svm)
{
	ulong gcr0 = svm->vcpu.arch.cr0;
	u64 *hcr0 = &svm->vmcb->save.cr0;

	if (!svm->vcpu.fpu_active)
		*hcr0 |= SVM_CR0_SELECTIVE_MASK;
	else
		*hcr0 = (*hcr0 & ~SVM_CR0_SELECTIVE_MASK)
			| (gcr0 & SVM_CR0_SELECTIVE_MASK);


	if (gcr0 == *hcr0 && svm->vcpu.fpu_active) {
		svm->vmcb->control.intercept_cr_read &= ~INTERCEPT_CR0_MASK;
		svm->vmcb->control.intercept_cr_write &= ~INTERCEPT_CR0_MASK;
	} else {
		svm->vmcb->control.intercept_cr_read |= INTERCEPT_CR0_MASK;
		svm->vmcb->control.intercept_cr_write |= INTERCEPT_CR0_MASK;
	}
}

static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
	struct vcpu_svm *svm = to_svm(vcpu);

#ifdef CONFIG_X86_64
	if (vcpu->arch.efer & EFER_LME) {
		if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
			vcpu->arch.efer |= EFER_LMA;
			svm->vmcb->save.efer |= EFER_LMA | EFER_LME;
		}

		if (is_paging(vcpu) && !(cr0 & X86_CR0_PG)) {
			vcpu->arch.efer &= ~EFER_LMA;
			svm->vmcb->save.efer &= ~(EFER_LMA | EFER_LME);
		}
	}
#endif
	vcpu->arch.cr0 = cr0;

	if (!npt_enabled)
		cr0 |= X86_CR0_PG | X86_CR0_WP;

	if (!vcpu->fpu_active)
		cr0 |= X86_CR0_TS;
	/*
	 * re-enable caching here because the QEMU bios
	 * does not do it - this results in some delay at
	 * reboot
	 */
	cr0 &= ~(X86_CR0_CD | X86_CR0_NW);
	svm->vmcb->save.cr0 = cr0;
	update_cr0_intercept(svm);
}

static void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
	unsigned long host_cr4_mce = read_cr4() & X86_CR4_MCE;
	unsigned long old_cr4 = to_svm(vcpu)->vmcb->save.cr4;

	if (npt_enabled && ((old_cr4 ^ cr4) & X86_CR4_PGE))
		force_new_asid(vcpu);

	vcpu->arch.cr4 = cr4;
	if (!npt_enabled)
		cr4 |= X86_CR4_PAE;
	cr4 |= host_cr4_mce;
	to_svm(vcpu)->vmcb->save.cr4 = cr4;
}

static void svm_set_segment(struct kvm_vcpu *vcpu,
			    struct kvm_segment *var, int seg)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	struct vmcb_seg *s = svm_seg(vcpu, seg);

	s->base = var->base;
	s->limit = var->limit;
	s->selector = var->selector;
	if (var->unusable)
		s->attrib = 0;
	else {
		s->attrib = (var->type & SVM_SELECTOR_TYPE_MASK);
		s->attrib |= (var->s & 1) << SVM_SELECTOR_S_SHIFT;
		s->attrib |= (var->dpl & 3) << SVM_SELECTOR_DPL_SHIFT;
		s->attrib |= (var->present & 1) << SVM_SELECTOR_P_SHIFT;
		s->attrib |= (var->avl & 1) << SVM_SELECTOR_AVL_SHIFT;
		s->attrib |= (var->l & 1) << SVM_SELECTOR_L_SHIFT;
		s->attrib |= (var->db & 1) << SVM_SELECTOR_DB_SHIFT;
		s->attrib |= (var->g & 1) << SVM_SELECTOR_G_SHIFT;
	}
	if (seg == VCPU_SREG_CS)
		svm->vmcb->save.cpl
			= (svm->vmcb->save.cs.attrib
			   >> SVM_SELECTOR_DPL_SHIFT) & 3;

}

static void update_db_intercept(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	svm->vmcb->control.intercept_exceptions &=
		~((1 << DB_VECTOR) | (1 << BP_VECTOR));

	if (svm->nmi_singlestep)
		svm->vmcb->control.intercept_exceptions |= (1 << DB_VECTOR);

	if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) {
		if (vcpu->guest_debug &
		    (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
			svm->vmcb->control.intercept_exceptions |=
				1 << DB_VECTOR;
		if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
			svm->vmcb->control.intercept_exceptions |=
				1 << BP_VECTOR;
	} else
		vcpu->guest_debug = 0;
}

static void svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
		svm->vmcb->save.dr7 = dbg->arch.debugreg[7];
	else
		svm->vmcb->save.dr7 = vcpu->arch.dr7;

	update_db_intercept(vcpu);
}

static void load_host_msrs(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
	wrmsrl(MSR_GS_BASE, to_svm(vcpu)->host_gs_base);
#endif
}

static void save_host_msrs(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
	rdmsrl(MSR_GS_BASE, to_svm(vcpu)->host_gs_base);
#endif
}

static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
{
	if (sd->next_asid > sd->max_asid) {
		++sd->asid_generation;
		sd->next_asid = 1;
		svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID;
	}

	svm->asid_generation = sd->asid_generation;
	svm->vmcb->control.asid = sd->next_asid++;
}

static int svm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *dest)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	switch (dr) {
	case 0 ... 3:
		*dest = vcpu->arch.db[dr];
		break;
	case 4:
		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
			return EMULATE_FAIL; /* will re-inject UD */
		/* fall through */
	case 6:
		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
			*dest = vcpu->arch.dr6;
		else
			*dest = svm->vmcb->save.dr6;
		break;
	case 5:
		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
			return EMULATE_FAIL; /* will re-inject UD */
		/* fall through */
	case 7:
		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
			*dest = vcpu->arch.dr7;
		else
			*dest = svm->vmcb->save.dr7;
		break;
	}

	return EMULATE_DONE;
}

static int svm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long value)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	switch (dr) {
	case 0 ... 3:
		vcpu->arch.db[dr] = value;
		if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
			vcpu->arch.eff_db[dr] = value;
		break;
	case 4:
		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
			return EMULATE_FAIL; /* will re-inject UD */
		/* fall through */
	case 6:
		vcpu->arch.dr6 = (value & DR6_VOLATILE) | DR6_FIXED_1;
		break;
	case 5:
		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
			return EMULATE_FAIL; /* will re-inject UD */
		/* fall through */
	case 7:
		vcpu->arch.dr7 = (value & DR7_VOLATILE) | DR7_FIXED_1;
		if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
			svm->vmcb->save.dr7 = vcpu->arch.dr7;
			vcpu->arch.switch_db_regs = (value & DR7_BP_EN_MASK);
		}
		break;
	}

	return EMULATE_DONE;
}

static int pf_interception(struct vcpu_svm *svm)
{
	u64 fault_address;
	u32 error_code;

	fault_address  = svm->vmcb->control.exit_info_2;
	error_code = svm->vmcb->control.exit_info_1;

	trace_kvm_page_fault(fault_address, error_code);
	if (!npt_enabled && kvm_event_needs_reinjection(&svm->vcpu))
		kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
	return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code);
}

static int db_interception(struct vcpu_svm *svm)
{
	struct kvm_run *kvm_run = svm->vcpu.run;

	if (!(svm->vcpu.guest_debug &
	      (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) &&
		!svm->nmi_singlestep) {
		kvm_queue_exception(&svm->vcpu, DB_VECTOR);
		return 1;
	}

	if (svm->nmi_singlestep) {
		svm->nmi_singlestep = false;
		if (!(svm->vcpu.guest_debug & KVM_GUESTDBG_SINGLESTEP))
			svm->vmcb->save.rflags &=
				~(X86_EFLAGS_TF | X86_EFLAGS_RF);
		update_db_intercept(&svm->vcpu);
	}

	if (svm->vcpu.guest_debug &
	    (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)){
		kvm_run->exit_reason = KVM_EXIT_DEBUG;
		kvm_run->debug.arch.pc =
			svm->vmcb->save.cs.base + svm->vmcb->save.rip;
		kvm_run->debug.arch.exception = DB_VECTOR;
		return 0;
	}

	return 1;
}

static int bp_interception(struct vcpu_svm *svm)
{
	struct kvm_run *kvm_run = svm->vcpu.run;

	kvm_run->exit_reason = KVM_EXIT_DEBUG;
	kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip;
	kvm_run->debug.arch.exception = BP_VECTOR;
	return 0;
}

static int ud_interception(struct vcpu_svm *svm)
{
	int er;

	er = emulate_instruction(&svm->vcpu, 0, 0, EMULTYPE_TRAP_UD);
	if (er != EMULATE_DONE)
		kvm_queue_exception(&svm->vcpu, UD_VECTOR);
	return 1;
}

static void svm_fpu_activate(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR);
	svm->vcpu.fpu_active = 1;
	update_cr0_intercept(svm);
}

static int nm_interception(struct vcpu_svm *svm)
{
	svm_fpu_activate(&svm->vcpu);
	return 1;
}

static int mc_interception(struct vcpu_svm *svm)
{
	/*
	 * On an #MC intercept the MCE handler is not called automatically in
	 * the host. So do it by hand here.
	 */
	asm volatile (
		"int $0x12\n");
	/* not sure if we ever come back to this point */

	return 1;
}

static int shutdown_interception(struct vcpu_svm *svm)
{
	struct kvm_run *kvm_run = svm->vcpu.run;

	/*
	 * VMCB is undefined after a SHUTDOWN intercept
	 * so reinitialize it.
	 */
	clear_page(svm->vmcb);
	init_vmcb(svm);

	kvm_run->exit_reason = KVM_EXIT_SHUTDOWN;
	return 0;
}

static int io_interception(struct vcpu_svm *svm)
{
	u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */
	int size, in, string;
	unsigned port;

	++svm->vcpu.stat.io_exits;

	svm->next_rip = svm->vmcb->control.exit_info_2;

	string = (io_info & SVM_IOIO_STR_MASK) != 0;

	if (string) {
		if (emulate_instruction(&svm->vcpu,
					0, 0, 0) == EMULATE_DO_MMIO)
			return 0;
		return 1;
	}

	in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
	port = io_info >> 16;
	size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;

	skip_emulated_instruction(&svm->vcpu);
	return kvm_emulate_pio(&svm->vcpu, in, size, port);
}

static int nmi_interception(struct vcpu_svm *svm)
{
	return 1;
}

static int intr_interception(struct vcpu_svm *svm)
{
	++svm->vcpu.stat.irq_exits;
	return 1;
}

static int nop_on_interception(struct vcpu_svm *svm)
{
	return 1;
}

static int halt_interception(struct vcpu_svm *svm)
{
	svm->next_rip = kvm_rip_read(&svm->vcpu) + 1;
	skip_emulated_instruction(&svm->vcpu);
	return kvm_emulate_halt(&svm->vcpu);
}

static int vmmcall_interception(struct vcpu_svm *svm)
{
	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);
	kvm_emulate_hypercall(&svm->vcpu);
	return 1;
}

static int nested_svm_check_permissions(struct vcpu_svm *svm)
{
	if (!(svm->vcpu.arch.efer & EFER_SVME)
	    || !is_paging(&svm->vcpu)) {
		kvm_queue_exception(&svm->vcpu, UD_VECTOR);
		return 1;
	}

	if (svm->vmcb->save.cpl) {
		kvm_inject_gp(&svm->vcpu, 0);
		return 1;
	}

       return 0;
}

static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
				      bool has_error_code, u32 error_code)
{
	int vmexit;

	if (!is_nested(svm))
		return 0;

	svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr;
	svm->vmcb->control.exit_code_hi = 0;
	svm->vmcb->control.exit_info_1 = error_code;
	svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;

	vmexit = nested_svm_intercept(svm);
	if (vmexit == NESTED_EXIT_DONE)
		svm->nested.exit_required = true;

	return vmexit;
}

static inline int nested_svm_intr(struct vcpu_svm *svm)
{
	if (!is_nested(svm))
		return 0;

	if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
		return 0;

	if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
		return 0;

	svm->vmcb->control.exit_code = SVM_EXIT_INTR;

	if (svm->nested.intercept & 1ULL) {
		/*
		 * The #vmexit can't be emulated here directly because this
		 * code path runs with irqs and preemtion disabled. A
		 * #vmexit emulation might sleep. Only signal request for
		 * the #vmexit here.
		 */
		svm->nested.exit_required = true;
		trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
		return 1;
	}

	return 0;
}

static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
{
	struct page *page;

	page = gfn_to_page(svm->vcpu.kvm, gpa >> PAGE_SHIFT);
	if (is_error_page(page))
		goto error;

	*_page = page;

	return kmap(page);

error:
	kvm_release_page_clean(page);
	kvm_inject_gp(&svm->vcpu, 0);

	return NULL;
}

static void nested_svm_unmap(struct page *page)
{
	kunmap(page);
	kvm_release_page_dirty(page);
}

static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
{
	u32 param = svm->vmcb->control.exit_info_1 & 1;
	u32 msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
	struct page *page;
	bool ret = false;
	u32 t0, t1;
	u8 *msrpm;

	if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
		return false;

	msrpm = nested_svm_map(svm, svm->nested.vmcb_msrpm, &page);

	if (!msrpm)
		goto out;

	switch (msr) {
	case 0 ... 0x1fff:
		t0 = (msr * 2) % 8;
		t1 = msr / 8;
		break;
	case 0xc0000000 ... 0xc0001fff:
		t0 = (8192 + msr - 0xc0000000) * 2;
		t1 = (t0 / 8);
		t0 %= 8;
		break;
	case 0xc0010000 ... 0xc0011fff:
		t0 = (16384 + msr - 0xc0010000) * 2;
		t1 = (t0 / 8);
		t0 %= 8;
		break;
	default:
		ret = true;
		goto out;
	}

	ret = msrpm[t1] & ((1 << param) << t0);

out:
	nested_svm_unmap(page);

	return ret;
}

static int nested_svm_exit_special(struct vcpu_svm *svm)
{
	u32 exit_code = svm->vmcb->control.exit_code;

	switch (exit_code) {
	case SVM_EXIT_INTR:
	case SVM_EXIT_NMI:
		return NESTED_EXIT_HOST;
		/* For now we are always handling NPFs when using them */
	case SVM_EXIT_NPF:
		if (npt_enabled)
			return NESTED_EXIT_HOST;
		break;
	/* When we're shadowing, trap PFs */
	case SVM_EXIT_EXCP_BASE + PF_VECTOR:
		if (!npt_enabled)
			return NESTED_EXIT_HOST;
		break;
	default:
		break;
	}

	return NESTED_EXIT_CONTINUE;
}

/*
 * If this function returns true, this #vmexit was already handled
 */
static int nested_svm_intercept(struct vcpu_svm *svm)
{
	u32 exit_code = svm->vmcb->control.exit_code;
	int vmexit = NESTED_EXIT_HOST;

	switch (exit_code) {
	case SVM_EXIT_MSR:
		vmexit = nested_svm_exit_handled_msr(svm);
		break;
	case SVM_EXIT_READ_CR0 ... SVM_EXIT_READ_CR8: {
		u32 cr_bits = 1 << (exit_code - SVM_EXIT_READ_CR0);
		if (svm->nested.intercept_cr_read & cr_bits)
			vmexit = NESTED_EXIT_DONE;
		break;
	}
	case SVM_EXIT_WRITE_CR0 ... SVM_EXIT_WRITE_CR8: {
		u32 cr_bits = 1 << (exit_code - SVM_EXIT_WRITE_CR0);
		if (svm->nested.intercept_cr_write & cr_bits)
			vmexit = NESTED_EXIT_DONE;
		break;
	}
	case SVM_EXIT_READ_DR0 ... SVM_EXIT_READ_DR7: {
		u32 dr_bits = 1 << (exit_code - SVM_EXIT_READ_DR0);
		if (svm->nested.intercept_dr_read & dr_bits)
			vmexit = NESTED_EXIT_DONE;
		break;
	}
	case SVM_EXIT_WRITE_DR0 ... SVM_EXIT_WRITE_DR7: {
		u32 dr_bits = 1 << (exit_code - SVM_EXIT_WRITE_DR0);
		if (svm->nested.intercept_dr_write & dr_bits)
			vmexit = NESTED_EXIT_DONE;
		break;
	}
	case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
		u32 excp_bits = 1 << (exit_code - SVM_EXIT_EXCP_BASE);
		if (svm->nested.intercept_exceptions & excp_bits)
			vmexit = NESTED_EXIT_DONE;
		break;
	}
	default: {
		u64 exit_bits = 1ULL << (exit_code - SVM_EXIT_INTR);
		if (svm->nested.intercept & exit_bits)
			vmexit = NESTED_EXIT_DONE;
	}
	}

	return vmexit;
}

static int nested_svm_exit_handled(struct vcpu_svm *svm)
{
	int vmexit;

	vmexit = nested_svm_intercept(svm);

	if (vmexit == NESTED_EXIT_DONE)
		nested_svm_vmexit(svm);

	return vmexit;
}

static inline void copy_vmcb_control_area(struct vmcb *dst_vmcb, struct vmcb *from_vmcb)
{
	struct vmcb_control_area *dst  = &dst_vmcb->control;
	struct vmcb_control_area *from = &from_vmcb->control;

	dst->intercept_cr_read    = from->intercept_cr_read;
	dst->intercept_cr_write   = from->intercept_cr_write;
	dst->intercept_dr_read    = from->intercept_dr_read;
	dst->intercept_dr_write   = from->intercept_dr_write;
	dst->intercept_exceptions = from->intercept_exceptions;
	dst->intercept            = from->intercept;
	dst->iopm_base_pa         = from->iopm_base_pa;
	dst->msrpm_base_pa        = from->msrpm_base_pa;
	dst->tsc_offset           = from->tsc_offset;
	dst->asid                 = from->asid;
	dst->tlb_ctl              = from->tlb_ctl;
	dst->int_ctl              = from->int_ctl;
	dst->int_vector           = from->int_vector;
	dst->int_state            = from->int_state;
	dst->exit_code            = from->exit_code;
	dst->exit_code_hi         = from->exit_code_hi;
	dst->exit_info_1          = from->exit_info_1;
	dst->exit_info_2          = from->exit_info_2;
	dst->exit_int_info        = from->exit_int_info;
	dst->exit_int_info_err    = from->exit_int_info_err;
	dst->nested_ctl           = from->nested_ctl;
	dst->event_inj            = from->event_inj;
	dst->event_inj_err        = from->event_inj_err;
	dst->nested_cr3           = from->nested_cr3;
	dst->lbr_ctl              = from->lbr_ctl;
}

static int nested_svm_vmexit(struct vcpu_svm *svm)
{
	struct vmcb *nested_vmcb;
	struct vmcb *hsave = svm->nested.hsave;
	struct vmcb *vmcb = svm->vmcb;
	struct page *page;

	trace_kvm_nested_vmexit_inject(vmcb->control.exit_code,
				       vmcb->control.exit_info_1,
				       vmcb->control.exit_info_2,
				       vmcb->control.exit_int_info,
				       vmcb->control.exit_int_info_err);

	nested_vmcb = nested_svm_map(svm, svm->nested.vmcb, &page);
	if (!nested_vmcb)
		return 1;

	/* Give the current vmcb to the guest */
	disable_gif(svm);

	nested_vmcb->save.es     = vmcb->save.es;
	nested_vmcb->save.cs     = vmcb->save.cs;
	nested_vmcb->save.ss     = vmcb->save.ss;
	nested_vmcb->save.ds     = vmcb->save.ds;
	nested_vmcb->save.gdtr   = vmcb->save.gdtr;
	nested_vmcb->save.idtr   = vmcb->save.idtr;
	nested_vmcb->save.cr0    = kvm_read_cr0(&svm->vcpu);
	if (npt_enabled)
		nested_vmcb->save.cr3    = vmcb->save.cr3;
	else
		nested_vmcb->save.cr3    = svm->vcpu.arch.cr3;
	nested_vmcb->save.cr2    = vmcb->save.cr2;
	nested_vmcb->save.cr4    = svm->vcpu.arch.cr4;
	nested_vmcb->save.rflags = vmcb->save.rflags;
	nested_vmcb->save.rip    = vmcb->save.rip;
	nested_vmcb->save.rsp    = vmcb->save.rsp;
	nested_vmcb->save.rax    = vmcb->save.rax;
	nested_vmcb->save.dr7    = vmcb->save.dr7;
	nested_vmcb->save.dr6    = vmcb->save.dr6;
	nested_vmcb->save.cpl    = vmcb->save.cpl;

	nested_vmcb->control.int_ctl           = vmcb->control.int_ctl;
	nested_vmcb->control.int_vector        = vmcb->control.int_vector;
	nested_vmcb->control.int_state         = vmcb->control.int_state;
	nested_vmcb->control.exit_code         = vmcb->control.exit_code;
	nested_vmcb->control.exit_code_hi      = vmcb->control.exit_code_hi;
	nested_vmcb->control.exit_info_1       = vmcb->control.exit_info_1;
	nested_vmcb->control.exit_info_2       = vmcb->control.exit_info_2;
	nested_vmcb->control.exit_int_info     = vmcb->control.exit_int_info;
	nested_vmcb->control.exit_int_info_err = vmcb->control.exit_int_info_err;

	/*
	 * If we emulate a VMRUN/#VMEXIT in the same host #vmexit cycle we have
	 * to make sure that we do not lose injected events. So check event_inj
	 * here and copy it to exit_int_info if it is valid.
	 * Exit_int_info and event_inj can't be both valid because the case
	 * below only happens on a VMRUN instruction intercept which has
	 * no valid exit_int_info set.
	 */
	if (vmcb->control.event_inj & SVM_EVTINJ_VALID) {
		struct vmcb_control_area *nc = &nested_vmcb->control;

		nc->exit_int_info     = vmcb->control.event_inj;
		nc->exit_int_info_err = vmcb->control.event_inj_err;
	}

	nested_vmcb->control.tlb_ctl           = 0;
	nested_vmcb->control.event_inj         = 0;
	nested_vmcb->control.event_inj_err     = 0;

	/* We always set V_INTR_MASKING and remember the old value in hflags */
	if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
		nested_vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;

	/* Restore the original control entries */
	copy_vmcb_control_area(vmcb, hsave);

	kvm_clear_exception_queue(&svm->vcpu);
	kvm_clear_interrupt_queue(&svm->vcpu);

	/* Restore selected save entries */
	svm->vmcb->save.es = hsave->save.es;
	svm->vmcb->save.cs = hsave->save.cs;
	svm->vmcb->save.ss = hsave->save.ss;
	svm->vmcb->save.ds = hsave->save.ds;
	svm->vmcb->save.gdtr = hsave->save.gdtr;
	svm->vmcb->save.idtr = hsave->save.idtr;
	svm->vmcb->save.rflags = hsave->save.rflags;
	svm_set_efer(&svm->vcpu, hsave->save.efer);
	svm_set_cr0(&svm->vcpu, hsave->save.cr0 | X86_CR0_PE);
	svm_set_cr4(&svm->vcpu, hsave->save.cr4);
	if (npt_enabled) {
		svm->vmcb->save.cr3 = hsave->save.cr3;
		svm->vcpu.arch.cr3 = hsave->save.cr3;
	} else {
		kvm_set_cr3(&svm->vcpu, hsave->save.cr3);
	}
	kvm_register_write(&svm->vcpu, VCPU_REGS_RAX, hsave->save.rax);
	kvm_register_write(&svm->vcpu, VCPU_REGS_RSP, hsave->save.rsp);
	kvm_register_write(&svm->vcpu, VCPU_REGS_RIP, hsave->save.rip);
	svm->vmcb->save.dr7 = 0;
	svm->vmcb->save.cpl = 0;
	svm->vmcb->control.exit_int_info = 0;

	/* Exit nested SVM mode */
	svm->nested.vmcb = 0;

	nested_svm_unmap(page);

	kvm_mmu_reset_context(&svm->vcpu);
	kvm_mmu_load(&svm->vcpu);

	return 0;
}

static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
{
	u32 *nested_msrpm;
	struct page *page;
	int i;

	nested_msrpm = nested_svm_map(svm, svm->nested.vmcb_msrpm, &page);
	if (!nested_msrpm)
		return false;

	for (i=0; i< PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER) / 4; i++)
		svm->nested.msrpm[i] = svm->msrpm[i] | nested_msrpm[i];

	svm->vmcb->control.msrpm_base_pa = __pa(svm->nested.msrpm);

	nested_svm_unmap(page);

	return true;
}

static bool nested_svm_vmrun(struct vcpu_svm *svm)
{
	struct vmcb *nested_vmcb;
	struct vmcb *hsave = svm->nested.hsave;
	struct vmcb *vmcb = svm->vmcb;
	struct page *page;

	nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
	if (!nested_vmcb)
		return false;

	/* nested_vmcb is our indicator if nested SVM is activated */
	svm->nested.vmcb = svm->vmcb->save.rax;

	trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, svm->nested.vmcb,
			       nested_vmcb->save.rip,
			       nested_vmcb->control.int_ctl,
			       nested_vmcb->control.event_inj,
			       nested_vmcb->control.nested_ctl);

	/* Clear internal status */
	kvm_clear_exception_queue(&svm->vcpu);
	kvm_clear_interrupt_queue(&svm->vcpu);

	/* Save the old vmcb, so we don't need to pick what we save, but
	   can restore everything when a VMEXIT occurs */
	hsave->save.es     = vmcb->save.es;
	hsave->save.cs     = vmcb->save.cs;
	hsave->save.ss     = vmcb->save.ss;
	hsave->save.ds     = vmcb->save.ds;
	hsave->save.gdtr   = vmcb->save.gdtr;
	hsave->save.idtr   = vmcb->save.idtr;
	hsave->save.efer   = svm->vcpu.arch.efer;
	hsave->save.cr0    = kvm_read_cr0(&svm->vcpu);
	hsave->save.cr4    = svm->vcpu.arch.cr4;
	hsave->save.rflags = vmcb->save.rflags;
	hsave->save.rip    = svm->next_rip;
	hsave->save.rsp    = vmcb->save.rsp;
	hsave->save.rax    = vmcb->save.rax;
	if (npt_enabled)
		hsave->save.cr3    = vmcb->save.cr3;
	else
		hsave->save.cr3    = svm->vcpu.arch.cr3;

	copy_vmcb_control_area(hsave, vmcb);

	if (svm->vmcb->save.rflags & X86_EFLAGS_IF)
		svm->vcpu.arch.hflags |= HF_HIF_MASK;
	else
		svm->vcpu.arch.hflags &= ~HF_HIF_MASK;

	/* Load the nested guest state */
	svm->vmcb->save.es = nested_vmcb->save.es;
	svm->vmcb->save.cs = nested_vmcb->save.cs;
	svm->vmcb->save.ss = nested_vmcb->save.ss;
	svm->vmcb->save.ds = nested_vmcb->save.ds;
	svm->vmcb->save.gdtr = nested_vmcb->save.gdtr;
	svm->vmcb->save.idtr = nested_vmcb->save.idtr;
	svm->vmcb->save.rflags = nested_vmcb->save.rflags;
	svm_set_efer(&svm->vcpu, nested_vmcb->save.efer);
	svm_set_cr0(&svm->vcpu, nested_vmcb->save.cr0);
	svm_set_cr4(&svm->vcpu, nested_vmcb->save.cr4);
	if (npt_enabled) {
		svm->vmcb->save.cr3 = nested_vmcb->save.cr3;
		svm->vcpu.arch.cr3 = nested_vmcb->save.cr3;
	} else {
		kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);
		kvm_mmu_reset_context(&svm->vcpu);
	}
	svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = nested_vmcb->save.cr2;
	kvm_register_write(&svm->vcpu, VCPU_REGS_RAX, nested_vmcb->save.rax);
	kvm_register_write(&svm->vcpu, VCPU_REGS_RSP, nested_vmcb->save.rsp);
	kvm_register_write(&svm->vcpu, VCPU_REGS_RIP, nested_vmcb->save.rip);
	/* In case we don't even reach vcpu_run, the fields are not updated */
	svm->vmcb->save.rax = nested_vmcb->save.rax;
	svm->vmcb->save.rsp = nested_vmcb->save.rsp;
	svm->vmcb->save.rip = nested_vmcb->save.rip;
	svm->vmcb->save.dr7 = nested_vmcb->save.dr7;
	svm->vmcb->save.dr6 = nested_vmcb->save.dr6;
	svm->vmcb->save.cpl = nested_vmcb->save.cpl;

	/* We don't want a nested guest to be more powerful than the guest,
	   so all intercepts are ORed */
	svm->vmcb->control.intercept_cr_read |=
		nested_vmcb->control.intercept_cr_read;
	svm->vmcb->control.intercept_cr_write |=
		nested_vmcb->control.intercept_cr_write;
	svm->vmcb->control.intercept_dr_read |=
		nested_vmcb->control.intercept_dr_read;
	svm->vmcb->control.intercept_dr_write |=
		nested_vmcb->control.intercept_dr_write;
	svm->vmcb->control.intercept_exceptions |=
		nested_vmcb->control.intercept_exceptions;

	svm->vmcb->control.intercept |= nested_vmcb->control.intercept;

	svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa;

	/* cache intercepts */
	svm->nested.intercept_cr_read    = nested_vmcb->control.intercept_cr_read;
	svm->nested.intercept_cr_write   = nested_vmcb->control.intercept_cr_write;
	svm->nested.intercept_dr_read    = nested_vmcb->control.intercept_dr_read;
	svm->nested.intercept_dr_write   = nested_vmcb->control.intercept_dr_write;
	svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
	svm->nested.intercept            = nested_vmcb->control.intercept;

	force_new_asid(&svm->vcpu);
	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
	if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
		svm->vcpu.arch.hflags |= HF_VINTR_MASK;
	else
		svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;

	svm->vmcb->control.int_vector = nested_vmcb->control.int_vector;
	svm->vmcb->control.int_state = nested_vmcb->control.int_state;
	svm->vmcb->control.tsc_offset += nested_vmcb->control.tsc_offset;
	svm->vmcb->control.event_inj = nested_vmcb->control.event_inj;
	svm->vmcb->control.event_inj_err = nested_vmcb->control.event_inj_err;

	nested_svm_unmap(page);

	enable_gif(svm);

	return true;
}

static void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb)
{
	to_vmcb->save.fs = from_vmcb->save.fs;
	to_vmcb->save.gs = from_vmcb->save.gs;
	to_vmcb->save.tr = from_vmcb->save.tr;
	to_vmcb->save.ldtr = from_vmcb->save.ldtr;
	to_vmcb->save.kernel_gs_base = from_vmcb->save.kernel_gs_base;
	to_vmcb->save.star = from_vmcb->save.star;
	to_vmcb->save.lstar = from_vmcb->save.lstar;
	to_vmcb->save.cstar = from_vmcb->save.cstar;
	to_vmcb->save.sfmask = from_vmcb->save.sfmask;
	to_vmcb->save.sysenter_cs = from_vmcb->save.sysenter_cs;
	to_vmcb->save.sysenter_esp = from_vmcb->save.sysenter_esp;
	to_vmcb->save.sysenter_eip = from_vmcb->save.sysenter_eip;
}

static int vmload_interception(struct vcpu_svm *svm)
{
	struct vmcb *nested_vmcb;
	struct page *page;

	if (nested_svm_check_permissions(svm))
		return 1;

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);

	nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
	if (!nested_vmcb)
		return 1;

	nested_svm_vmloadsave(nested_vmcb, svm->vmcb);
	nested_svm_unmap(page);

	return 1;
}

static int vmsave_interception(struct vcpu_svm *svm)
{
	struct vmcb *nested_vmcb;
	struct page *page;

	if (nested_svm_check_permissions(svm))
		return 1;

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);

	nested_vmcb = nested_svm_map(svm, svm->vmcb->save.rax, &page);
	if (!nested_vmcb)
		return 1;

	nested_svm_vmloadsave(svm->vmcb, nested_vmcb);
	nested_svm_unmap(page);

	return 1;
}

static int vmrun_interception(struct vcpu_svm *svm)
{
	if (nested_svm_check_permissions(svm))
		return 1;

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);

	if (!nested_svm_vmrun(svm))
		return 1;

	if (!nested_svm_vmrun_msrpm(svm))
		goto failed;

	return 1;

failed:

	svm->vmcb->control.exit_code    = SVM_EXIT_ERR;
	svm->vmcb->control.exit_code_hi = 0;
	svm->vmcb->control.exit_info_1  = 0;
	svm->vmcb->control.exit_info_2  = 0;

	nested_svm_vmexit(svm);

	return 1;
}

static int stgi_interception(struct vcpu_svm *svm)
{
	if (nested_svm_check_permissions(svm))
		return 1;

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);

	enable_gif(svm);

	return 1;
}

static int clgi_interception(struct vcpu_svm *svm)
{
	if (nested_svm_check_permissions(svm))
		return 1;

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);

	disable_gif(svm);

	/* After a CLGI no interrupts should come */
	svm_clear_vintr(svm);
	svm->vmcb->control.int_ctl &= ~V_IRQ_MASK;

	return 1;
}

static int invlpga_interception(struct vcpu_svm *svm)
{
	struct kvm_vcpu *vcpu = &svm->vcpu;

	trace_kvm_invlpga(svm->vmcb->save.rip, vcpu->arch.regs[VCPU_REGS_RCX],
			  vcpu->arch.regs[VCPU_REGS_RAX]);

	/* Let's treat INVLPGA the same as INVLPG (can be optimized!) */
	kvm_mmu_invlpg(vcpu, vcpu->arch.regs[VCPU_REGS_RAX]);

	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
	skip_emulated_instruction(&svm->vcpu);
	return 1;
}

static int skinit_interception(struct vcpu_svm *svm)
{
	trace_kvm_skinit(svm->vmcb->save.rip, svm->vcpu.arch.regs[VCPU_REGS_RAX]);

	kvm_queue_exception(&svm->vcpu, UD_VECTOR);
	return 1;
}

static int invalid_op_interception(struct vcpu_svm *svm)
{
	kvm_queue_exception(&svm->vcpu, UD_VECTOR);
	return 1;
}

static int task_switch_interception(struct vcpu_svm *svm)
{
	u16 tss_selector;
	int reason;
	int int_type = svm->vmcb->control.exit_int_info &
		SVM_EXITINTINFO_TYPE_MASK;
	int int_vec = svm->vmcb->control.exit_int_info & SVM_EVTINJ_VEC_MASK;
	uint32_t type =
		svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_TYPE_MASK;
	uint32_t idt_v =
		svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID;

	tss_selector = (u16)svm->vmcb->control.exit_info_1;

	if (svm->vmcb->control.exit_info_2 &
	    (1ULL << SVM_EXITINFOSHIFT_TS_REASON_IRET))
		reason = TASK_SWITCH_IRET;
	else if (svm->vmcb->control.exit_info_2 &
		 (1ULL << SVM_EXITINFOSHIFT_TS_REASON_JMP))
		reason = TASK_SWITCH_JMP;
	else if (idt_v)
		reason = TASK_SWITCH_GATE;
	else
		reason = TASK_SWITCH_CALL;

	if (reason == TASK_SWITCH_GATE) {
		switch (type) {
		case SVM_EXITINTINFO_TYPE_NMI:
			svm->vcpu.arch.nmi_injected = false;
			break;
		case SVM_EXITINTINFO_TYPE_EXEPT:
			kvm_clear_exception_queue(&svm->vcpu);
			break;
		case SVM_EXITINTINFO_TYPE_INTR:
			kvm_clear_interrupt_queue(&svm->vcpu);
			break;
		default:
			break;
		}
	}

	if (reason != TASK_SWITCH_GATE ||
	    int_type == SVM_EXITINTINFO_TYPE_SOFT ||
	    (int_type == SVM_EXITINTINFO_TYPE_EXEPT &&
	     (int_vec == OF_VECTOR || int_vec == BP_VECTOR)))
		skip_emulated_instruction(&svm->vcpu);

	return kvm_task_switch(&svm->vcpu, tss_selector, reason);
}

static int cpuid_interception(struct vcpu_svm *svm)
{
	svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
	kvm_emulate_cpuid(&svm->vcpu);
	return 1;
}

static int iret_interception(struct vcpu_svm *svm)
{
	++svm->vcpu.stat.nmi_window_exits;
	svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET);
	svm->vcpu.arch.hflags |= HF_IRET_MASK;
	return 1;
}

static int invlpg_interception(struct vcpu_svm *svm)
{
	if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE)
		pr_unimpl(&svm->vcpu, "%s: failed\n", __func__);
	return 1;
}

static int emulate_on_interception(struct vcpu_svm *svm)
{
	if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE)
		pr_unimpl(&svm->vcpu, "%s: failed\n", __func__);
	return 1;
}

static int cr8_write_interception(struct vcpu_svm *svm)
{
	struct kvm_run *kvm_run = svm->vcpu.run;

	u8 cr8_prev = kvm_get_cr8(&svm->vcpu);
	/* instruction emulation calls kvm_set_cr8() */
	emulate_instruction(&svm->vcpu, 0, 0, 0);
	if (irqchip_in_kernel(svm->vcpu.kvm)) {
		svm->vmcb->control.intercept_cr_write &= ~INTERCEPT_CR8_MASK;
		return 1;
	}
	if (cr8_prev <= kvm_get_cr8(&svm->vcpu))
		return 1;
	kvm_run->exit_reason = KVM_EXIT_SET_TPR;
	return 0;
}

static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	switch (ecx) {
	case MSR_IA32_TSC: {
		u64 tsc_offset;

		if (is_nested(svm))
			tsc_offset = svm->nested.hsave->control.tsc_offset;
		else
			tsc_offset = svm->vmcb->control.tsc_offset;

		*data = tsc_offset + native_read_tsc();
		break;
	}
	case MSR_K6_STAR:
		*data = svm->vmcb->save.star;
		break;
#ifdef CONFIG_X86_64
	case MSR_LSTAR:
		*data = svm->vmcb->save.lstar;
		break;
	case MSR_CSTAR:
		*data = svm->vmcb->save.cstar;
		break;
	case MSR_KERNEL_GS_BASE:
		*data = svm->vmcb->save.kernel_gs_base;
		break;
	case MSR_SYSCALL_MASK:
		*data = svm->vmcb->save.sfmask;
		break;
#endif
	case MSR_IA32_SYSENTER_CS:
		*data = svm->vmcb->save.sysenter_cs;
		break;
	case MSR_IA32_SYSENTER_EIP:
		*data = svm->sysenter_eip;
		break;
	case MSR_IA32_SYSENTER_ESP:
		*data = svm->sysenter_esp;
		break;
	/* Nobody will change the following 5 values in the VMCB so
	   we can safely return them on rdmsr. They will always be 0
	   until LBRV is implemented. */
	case MSR_IA32_DEBUGCTLMSR:
		*data = svm->vmcb->save.dbgctl;
		break;
	case MSR_IA32_LASTBRANCHFROMIP:
		*data = svm->vmcb->save.br_from;
		break;
	case MSR_IA32_LASTBRANCHTOIP:
		*data = svm->vmcb->save.br_to;
		break;
	case MSR_IA32_LASTINTFROMIP:
		*data = svm->vmcb->save.last_excp_from;
		break;
	case MSR_IA32_LASTINTTOIP:
		*data = svm->vmcb->save.last_excp_to;
		break;
	case MSR_VM_HSAVE_PA:
		*data = svm->nested.hsave_msr;
		break;
	case MSR_VM_CR:
		*data = 0;
		break;
	case MSR_IA32_UCODE_REV:
		*data = 0x01000065;
		break;
	default:
		return kvm_get_msr_common(vcpu, ecx, data);
	}
	return 0;
}

static int rdmsr_interception(struct vcpu_svm *svm)
{
	u32 ecx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
	u64 data;

	if (svm_get_msr(&svm->vcpu, ecx, &data)) {
		trace_kvm_msr_read_ex(ecx);
		kvm_inject_gp(&svm->vcpu, 0);
	} else {
		trace_kvm_msr_read(ecx, data);

		svm->vcpu.arch.regs[VCPU_REGS_RAX] = data & 0xffffffff;
		svm->vcpu.arch.regs[VCPU_REGS_RDX] = data >> 32;
		svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
		skip_emulated_instruction(&svm->vcpu);
	}
	return 1;
}

static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	switch (ecx) {
	case MSR_IA32_TSC: {
		u64 tsc_offset = data - native_read_tsc();
		u64 g_tsc_offset = 0;

		if (is_nested(svm)) {
			g_tsc_offset = svm->vmcb->control.tsc_offset -
				       svm->nested.hsave->control.tsc_offset;
			svm->nested.hsave->control.tsc_offset = tsc_offset;
		}

		svm->vmcb->control.tsc_offset = tsc_offset + g_tsc_offset;

		break;
	}
	case MSR_K6_STAR:
		svm->vmcb->save.star = data;
		break;
#ifdef CONFIG_X86_64
	case MSR_LSTAR:
		svm->vmcb->save.lstar = data;
		break;
	case MSR_CSTAR:
		svm->vmcb->save.cstar = data;
		break;
	case MSR_KERNEL_GS_BASE:
		svm->vmcb->save.kernel_gs_base = data;
		break;
	case MSR_SYSCALL_MASK:
		svm->vmcb->save.sfmask = data;
		break;
#endif
	case MSR_IA32_SYSENTER_CS:
		svm->vmcb->save.sysenter_cs = data;
		break;
	case MSR_IA32_SYSENTER_EIP:
		svm->sysenter_eip = data;
		svm->vmcb->save.sysenter_eip = data;
		break;
	case MSR_IA32_SYSENTER_ESP:
		svm->sysenter_esp = data;
		svm->vmcb->save.sysenter_esp = data;
		break;
	case MSR_IA32_DEBUGCTLMSR:
		if (!svm_has(SVM_FEATURE_LBRV)) {
			pr_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTL 0x%llx, nop\n",
					__func__, data);
			break;
		}
		if (data & DEBUGCTL_RESERVED_BITS)
			return 1;

		svm->vmcb->save.dbgctl = data;
		if (data & (1ULL<<0))
			svm_enable_lbrv(svm);
		else
			svm_disable_lbrv(svm);
		break;
	case MSR_VM_HSAVE_PA:
		svm->nested.hsave_msr = data;
		break;
	case MSR_VM_CR:
	case MSR_VM_IGNNE:
		pr_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
		break;
	default:
		return kvm_set_msr_common(vcpu, ecx, data);
	}
	return 0;
}

static int wrmsr_interception(struct vcpu_svm *svm)
{
	u32 ecx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
	u64 data = (svm->vcpu.arch.regs[VCPU_REGS_RAX] & -1u)
		| ((u64)(svm->vcpu.arch.regs[VCPU_REGS_RDX] & -1u) << 32);


	svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
	if (svm_set_msr(&svm->vcpu, ecx, data)) {
		trace_kvm_msr_write_ex(ecx, data);
		kvm_inject_gp(&svm->vcpu, 0);
	} else {
		trace_kvm_msr_write(ecx, data);
		skip_emulated_instruction(&svm->vcpu);
	}
	return 1;
}

static int msr_interception(struct vcpu_svm *svm)
{
	if (svm->vmcb->control.exit_info_1)
		return wrmsr_interception(svm);
	else
		return rdmsr_interception(svm);
}

static int interrupt_window_interception(struct vcpu_svm *svm)
{
	struct kvm_run *kvm_run = svm->vcpu.run;

	svm_clear_vintr(svm);
	svm->vmcb->control.int_ctl &= ~V_IRQ_MASK;
	/*
	 * If the user space waits to inject interrupts, exit as soon as
	 * possible
	 */
	if (!irqchip_in_kernel(svm->vcpu.kvm) &&
	    kvm_run->request_interrupt_window &&
	    !kvm_cpu_has_interrupt(&svm->vcpu)) {
		++svm->vcpu.stat.irq_window_exits;
		kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
		return 0;
	}

	return 1;
}

static int pause_interception(struct vcpu_svm *svm)
{
	kvm_vcpu_on_spin(&(svm->vcpu));
	return 1;
}

static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
	[SVM_EXIT_READ_CR0]           		= emulate_on_interception,
	[SVM_EXIT_READ_CR3]           		= emulate_on_interception,
	[SVM_EXIT_READ_CR4]           		= emulate_on_interception,
	[SVM_EXIT_READ_CR8]           		= emulate_on_interception,
	[SVM_EXIT_CR0_SEL_WRITE]		= emulate_on_interception,
	[SVM_EXIT_WRITE_CR0]          		= emulate_on_interception,
	[SVM_EXIT_WRITE_CR3]          		= emulate_on_interception,
	[SVM_EXIT_WRITE_CR4]          		= emulate_on_interception,
	[SVM_EXIT_WRITE_CR8]          		= cr8_write_interception,
	[SVM_EXIT_READ_DR0] 			= emulate_on_interception,
	[SVM_EXIT_READ_DR1]			= emulate_on_interception,
	[SVM_EXIT_READ_DR2]			= emulate_on_interception,
	[SVM_EXIT_READ_DR3]			= emulate_on_interception,
	[SVM_EXIT_READ_DR4]			= emulate_on_interception,
	[SVM_EXIT_READ_DR5]			= emulate_on_interception,
	[SVM_EXIT_READ_DR6]			= emulate_on_interception,
	[SVM_EXIT_READ_DR7]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR0]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR1]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR2]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR3]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR4]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR5]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR6]			= emulate_on_interception,
	[SVM_EXIT_WRITE_DR7]			= emulate_on_interception,
	[SVM_EXIT_EXCP_BASE + DB_VECTOR]	= db_interception,
	[SVM_EXIT_EXCP_BASE + BP_VECTOR]	= bp_interception,
	[SVM_EXIT_EXCP_BASE + UD_VECTOR]	= ud_interception,
	[SVM_EXIT_EXCP_BASE + PF_VECTOR] 	= pf_interception,
	[SVM_EXIT_EXCP_BASE + NM_VECTOR] 	= nm_interception,
	[SVM_EXIT_EXCP_BASE + MC_VECTOR] 	= mc_interception,
	[SVM_EXIT_INTR] 			= intr_interception,
	[SVM_EXIT_NMI]				= nmi_interception,
	[SVM_EXIT_SMI]				= nop_on_interception,
	[SVM_EXIT_INIT]				= nop_on_interception,
	[SVM_EXIT_VINTR]			= interrupt_window_interception,
	/* [SVM_EXIT_CR0_SEL_WRITE]		= emulate_on_interception, */
	[SVM_EXIT_CPUID]			= cpuid_interception,
	[SVM_EXIT_IRET]                         = iret_interception,
	[SVM_EXIT_INVD]                         = emulate_on_interception,
	[SVM_EXIT_PAUSE]			= pause_interception,
	[SVM_EXIT_HLT]				= halt_interception,
	[SVM_EXIT_INVLPG]			= invlpg_interception,
	[SVM_EXIT_INVLPGA]			= invlpga_interception,
	[SVM_EXIT_IOIO] 		  	= io_interception,
	[SVM_EXIT_MSR]				= msr_interception,
	[SVM_EXIT_TASK_SWITCH]			= task_switch_interception,
	[SVM_EXIT_SHUTDOWN]			= shutdown_interception,
	[SVM_EXIT_VMRUN]			= vmrun_interception,
	[SVM_EXIT_VMMCALL]			= vmmcall_interception,
	[SVM_EXIT_VMLOAD]			= vmload_interception,
	[SVM_EXIT_VMSAVE]			= vmsave_interception,
	[SVM_EXIT_STGI]				= stgi_interception,
	[SVM_EXIT_CLGI]				= clgi_interception,
	[SVM_EXIT_SKINIT]			= skinit_interception,
	[SVM_EXIT_WBINVD]                       = emulate_on_interception,
	[SVM_EXIT_MONITOR]			= invalid_op_interception,
	[SVM_EXIT_MWAIT]			= invalid_op_interception,
	[SVM_EXIT_NPF]				= pf_interception,
};

static int handle_exit(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	struct kvm_run *kvm_run = vcpu->run;
	u32 exit_code = svm->vmcb->control.exit_code;

	trace_kvm_exit(exit_code, svm->vmcb->save.rip);

	if (unlikely(svm->nested.exit_required)) {
		nested_svm_vmexit(svm);
		svm->nested.exit_required = false;

		return 1;
	}

	if (is_nested(svm)) {
		int vmexit;

		trace_kvm_nested_vmexit(svm->vmcb->save.rip, exit_code,
					svm->vmcb->control.exit_info_1,
					svm->vmcb->control.exit_info_2,
					svm->vmcb->control.exit_int_info,
					svm->vmcb->control.exit_int_info_err);

		vmexit = nested_svm_exit_special(svm);

		if (vmexit == NESTED_EXIT_CONTINUE)
			vmexit = nested_svm_exit_handled(svm);

		if (vmexit == NESTED_EXIT_DONE)
			return 1;
	}

	svm_complete_interrupts(svm);

	if (!(svm->vmcb->control.intercept_cr_write & INTERCEPT_CR0_MASK))
		vcpu->arch.cr0 = svm->vmcb->save.cr0;
	if (npt_enabled)
		vcpu->arch.cr3 = svm->vmcb->save.cr3;

	if (svm->vmcb->control.exit_code == SVM_EXIT_ERR) {
		kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
		kvm_run->fail_entry.hardware_entry_failure_reason
			= svm->vmcb->control.exit_code;
		return 0;
	}

	if (is_external_interrupt(svm->vmcb->control.exit_int_info) &&
	    exit_code != SVM_EXIT_EXCP_BASE + PF_VECTOR &&
	    exit_code != SVM_EXIT_NPF && exit_code != SVM_EXIT_TASK_SWITCH)
		printk(KERN_ERR "%s: unexpected exit_ini_info 0x%x "
		       "exit_code 0x%x\n",
		       __func__, svm->vmcb->control.exit_int_info,
		       exit_code);

	if (exit_code >= ARRAY_SIZE(svm_exit_handlers)
	    || !svm_exit_handlers[exit_code]) {
		kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
		kvm_run->hw.hardware_exit_reason = exit_code;
		return 0;
	}

	return svm_exit_handlers[exit_code](svm);
}

static void reload_tss(struct kvm_vcpu *vcpu)
{
	int cpu = raw_smp_processor_id();

	struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
	sd->tss_desc->type = 9; /* available 32/64-bit TSS */
	load_TR_desc();
}

static void pre_svm_run(struct vcpu_svm *svm)
{
	int cpu = raw_smp_processor_id();

	struct svm_cpu_data *sd = per_cpu(svm_data, cpu);

	svm->vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
	/* FIXME: handle wraparound of asid_generation */
	if (svm->asid_generation != sd->asid_generation)
		new_asid(svm, sd);
}

static void svm_inject_nmi(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	svm->vmcb->control.event_inj = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;
	vcpu->arch.hflags |= HF_NMI_MASK;
	svm->vmcb->control.intercept |= (1UL << INTERCEPT_IRET);
	++vcpu->stat.nmi_injections;
}

static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
{
	struct vmcb_control_area *control;

	trace_kvm_inj_virq(irq);

	++svm->vcpu.stat.irq_injections;
	control = &svm->vmcb->control;
	control->int_vector = irq;
	control->int_ctl &= ~V_INTR_PRIO_MASK;
	control->int_ctl |= V_IRQ_MASK |
		((/*control->int_vector >> 4*/ 0xf) << V_INTR_PRIO_SHIFT);
}

static void svm_set_irq(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	BUG_ON(!(gif_set(svm)));

	svm->vmcb->control.event_inj = vcpu->arch.interrupt.nr |
		SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
}

static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (irr == -1)
		return;

	if (tpr >= irr)
		svm->vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
}

static int svm_nmi_allowed(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	struct vmcb *vmcb = svm->vmcb;
	return !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
		!(svm->vcpu.arch.hflags & HF_NMI_MASK);
}

static bool svm_get_nmi_mask(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	return !!(svm->vcpu.arch.hflags & HF_NMI_MASK);
}

static void svm_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (masked) {
		svm->vcpu.arch.hflags |= HF_NMI_MASK;
		svm->vmcb->control.intercept |= (1UL << INTERCEPT_IRET);
	} else {
		svm->vcpu.arch.hflags &= ~HF_NMI_MASK;
		svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET);
	}
}

static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	struct vmcb *vmcb = svm->vmcb;
	int ret;

	if (!gif_set(svm) ||
	     (vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK))
		return 0;

	ret = !!(vmcb->save.rflags & X86_EFLAGS_IF);

	if (is_nested(svm))
		return ret && !(svm->vcpu.arch.hflags & HF_VINTR_MASK);

	return ret;
}

static void enable_irq_window(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	nested_svm_intr(svm);

	/* In case GIF=0 we can't rely on the CPU to tell us when
	 * GIF becomes 1, because that's a separate STGI/VMRUN intercept.
	 * The next time we get that intercept, this function will be
	 * called again though and we'll get the vintr intercept. */
	if (gif_set(svm)) {
		svm_set_vintr(svm);
		svm_inject_irq(svm, 0x0);
	}
}

static void enable_nmi_window(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if ((svm->vcpu.arch.hflags & (HF_NMI_MASK | HF_IRET_MASK))
	    == HF_NMI_MASK)
		return; /* IRET will cause a vm exit */

	/* Something prevents NMI from been injected. Single step over
	   possible problem (IRET or exception injection or interrupt
	   shadow) */
	svm->nmi_singlestep = true;
	svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
	update_db_intercept(vcpu);
}

static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
{
	return 0;
}

static void svm_flush_tlb(struct kvm_vcpu *vcpu)
{
	force_new_asid(vcpu);
}

static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu)
{
}

static inline void sync_cr8_to_lapic(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (!(svm->vmcb->control.intercept_cr_write & INTERCEPT_CR8_MASK)) {
		int cr8 = svm->vmcb->control.int_ctl & V_TPR_MASK;
		kvm_set_cr8(vcpu, cr8);
	}
}

static inline void sync_lapic_to_cr8(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	u64 cr8;

	cr8 = kvm_get_cr8(vcpu);
	svm->vmcb->control.int_ctl &= ~V_TPR_MASK;
	svm->vmcb->control.int_ctl |= cr8 & V_TPR_MASK;
}

static void svm_complete_interrupts(struct vcpu_svm *svm)
{
	u8 vector;
	int type;
	u32 exitintinfo = svm->vmcb->control.exit_int_info;

	if (svm->vcpu.arch.hflags & HF_IRET_MASK)
		svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK);

	svm->vcpu.arch.nmi_injected = false;
	kvm_clear_exception_queue(&svm->vcpu);
	kvm_clear_interrupt_queue(&svm->vcpu);

	if (!(exitintinfo & SVM_EXITINTINFO_VALID))
		return;

	vector = exitintinfo & SVM_EXITINTINFO_VEC_MASK;
	type = exitintinfo & SVM_EXITINTINFO_TYPE_MASK;

	switch (type) {
	case SVM_EXITINTINFO_TYPE_NMI:
		svm->vcpu.arch.nmi_injected = true;
		break;
	case SVM_EXITINTINFO_TYPE_EXEPT:
		/* In case of software exception do not reinject an exception
		   vector, but re-execute and instruction instead */
		if (is_nested(svm))
			break;
		if (kvm_exception_is_soft(vector))
			break;
		if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {
			u32 err = svm->vmcb->control.exit_int_info_err;
			kvm_queue_exception_e(&svm->vcpu, vector, err);

		} else
			kvm_queue_exception(&svm->vcpu, vector);
		break;
	case SVM_EXITINTINFO_TYPE_INTR:
		kvm_queue_interrupt(&svm->vcpu, vector, false);
		break;
	default:
		break;
	}
}

#ifdef CONFIG_X86_64
#define R "r"
#else
#define R "e"
#endif

static void svm_vcpu_run(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);
	u16 fs_selector;
	u16 gs_selector;
	u16 ldt_selector;

	/*
	 * A vmexit emulation is required before the vcpu can be executed
	 * again.
	 */
	if (unlikely(svm->nested.exit_required))
		return;

	svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];
	svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
	svm->vmcb->save.rip = vcpu->arch.regs[VCPU_REGS_RIP];

	pre_svm_run(svm);

	sync_lapic_to_cr8(vcpu);

	save_host_msrs(vcpu);
	fs_selector = kvm_read_fs();
	gs_selector = kvm_read_gs();
	ldt_selector = kvm_read_ldt();
	svm->vmcb->save.cr2 = vcpu->arch.cr2;
	/* required for live migration with NPT */
	if (npt_enabled)
		svm->vmcb->save.cr3 = vcpu->arch.cr3;

	clgi();

	local_irq_enable();

	asm volatile (
		"push %%"R"bp; \n\t"
		"mov %c[rbx](%[svm]), %%"R"bx \n\t"
		"mov %c[rcx](%[svm]), %%"R"cx \n\t"
		"mov %c[rdx](%[svm]), %%"R"dx \n\t"
		"mov %c[rsi](%[svm]), %%"R"si \n\t"
		"mov %c[rdi](%[svm]), %%"R"di \n\t"
		"mov %c[rbp](%[svm]), %%"R"bp \n\t"
#ifdef CONFIG_X86_64
		"mov %c[r8](%[svm]),  %%r8  \n\t"
		"mov %c[r9](%[svm]),  %%r9  \n\t"
		"mov %c[r10](%[svm]), %%r10 \n\t"
		"mov %c[r11](%[svm]), %%r11 \n\t"
		"mov %c[r12](%[svm]), %%r12 \n\t"
		"mov %c[r13](%[svm]), %%r13 \n\t"
		"mov %c[r14](%[svm]), %%r14 \n\t"
		"mov %c[r15](%[svm]), %%r15 \n\t"
#endif

		/* Enter guest mode */
		"push %%"R"ax \n\t"
		"mov %c[vmcb](%[svm]), %%"R"ax \n\t"
		__ex(SVM_VMLOAD) "\n\t"
		__ex(SVM_VMRUN) "\n\t"
		__ex(SVM_VMSAVE) "\n\t"
		"pop %%"R"ax \n\t"

		/* Save guest registers, load host registers */
		"mov %%"R"bx, %c[rbx](%[svm]) \n\t"
		"mov %%"R"cx, %c[rcx](%[svm]) \n\t"
		"mov %%"R"dx, %c[rdx](%[svm]) \n\t"
		"mov %%"R"si, %c[rsi](%[svm]) \n\t"
		"mov %%"R"di, %c[rdi](%[svm]) \n\t"
		"mov %%"R"bp, %c[rbp](%[svm]) \n\t"
#ifdef CONFIG_X86_64
		"mov %%r8,  %c[r8](%[svm]) \n\t"
		"mov %%r9,  %c[r9](%[svm]) \n\t"
		"mov %%r10, %c[r10](%[svm]) \n\t"
		"mov %%r11, %c[r11](%[svm]) \n\t"
		"mov %%r12, %c[r12](%[svm]) \n\t"
		"mov %%r13, %c[r13](%[svm]) \n\t"
		"mov %%r14, %c[r14](%[svm]) \n\t"
		"mov %%r15, %c[r15](%[svm]) \n\t"
#endif
		"pop %%"R"bp"
		:
		: [svm]"a"(svm),
		  [vmcb]"i"(offsetof(struct vcpu_svm, vmcb_pa)),
		  [rbx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RBX])),
		  [rcx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RCX])),
		  [rdx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RDX])),
		  [rsi]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RSI])),
		  [rdi]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RDI])),
		  [rbp]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RBP]))
#ifdef CONFIG_X86_64
		  , [r8]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R8])),
		  [r9]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R9])),
		  [r10]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R10])),
		  [r11]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R11])),
		  [r12]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R12])),
		  [r13]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R13])),
		  [r14]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R14])),
		  [r15]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R15]))
#endif
		: "cc", "memory"
		, R"bx", R"cx", R"dx", R"si", R"di"
#ifdef CONFIG_X86_64
		, "r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15"
#endif
		);

	vcpu->arch.cr2 = svm->vmcb->save.cr2;
	vcpu->arch.regs[VCPU_REGS_RAX] = svm->vmcb->save.rax;
	vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp;
	vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;

	kvm_load_fs(fs_selector);
	kvm_load_gs(gs_selector);
	kvm_load_ldt(ldt_selector);
	load_host_msrs(vcpu);

	reload_tss(vcpu);

	local_irq_disable();

	stgi();

	sync_cr8_to_lapic(vcpu);

	svm->next_rip = 0;

	if (npt_enabled) {
		vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
		vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
	}
}

#undef R

static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	if (npt_enabled) {
		svm->vmcb->control.nested_cr3 = root;
		force_new_asid(vcpu);
		return;
	}

	svm->vmcb->save.cr3 = root;
	force_new_asid(vcpu);
}

static int is_disabled(void)
{
	u64 vm_cr;

	rdmsrl(MSR_VM_CR, vm_cr);
	if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE))
		return 1;

	return 0;
}

static void
svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
{
	/*
	 * Patch in the VMMCALL instruction:
	 */
	hypercall[0] = 0x0f;
	hypercall[1] = 0x01;
	hypercall[2] = 0xd9;
}

static void svm_check_processor_compat(void *rtn)
{
	*(int *)rtn = 0;
}

static bool svm_cpu_has_accelerated_tpr(void)
{
	return false;
}

static int get_npt_level(void)
{
#ifdef CONFIG_X86_64
	return PT64_ROOT_LEVEL;
#else
	return PT32E_ROOT_LEVEL;
#endif
}

static u64 svm_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
{
	return 0;
}

static void svm_cpuid_update(struct kvm_vcpu *vcpu)
{
}

static const struct trace_print_flags svm_exit_reasons_str[] = {
	{ SVM_EXIT_READ_CR0,           		"read_cr0" },
	{ SVM_EXIT_READ_CR3,	      		"read_cr3" },
	{ SVM_EXIT_READ_CR4,	      		"read_cr4" },
	{ SVM_EXIT_READ_CR8,  	      		"read_cr8" },
	{ SVM_EXIT_WRITE_CR0,          		"write_cr0" },
	{ SVM_EXIT_WRITE_CR3,	      		"write_cr3" },
	{ SVM_EXIT_WRITE_CR4,          		"write_cr4" },
	{ SVM_EXIT_WRITE_CR8, 	      		"write_cr8" },
	{ SVM_EXIT_READ_DR0, 	      		"read_dr0" },
	{ SVM_EXIT_READ_DR1,	      		"read_dr1" },
	{ SVM_EXIT_READ_DR2,	      		"read_dr2" },
	{ SVM_EXIT_READ_DR3,	      		"read_dr3" },
	{ SVM_EXIT_WRITE_DR0,	      		"write_dr0" },
	{ SVM_EXIT_WRITE_DR1,	      		"write_dr1" },
	{ SVM_EXIT_WRITE_DR2,	      		"write_dr2" },
	{ SVM_EXIT_WRITE_DR3,	      		"write_dr3" },
	{ SVM_EXIT_WRITE_DR5,	      		"write_dr5" },
	{ SVM_EXIT_WRITE_DR7,	      		"write_dr7" },
	{ SVM_EXIT_EXCP_BASE + DB_VECTOR,	"DB excp" },
	{ SVM_EXIT_EXCP_BASE + BP_VECTOR,	"BP excp" },
	{ SVM_EXIT_EXCP_BASE + UD_VECTOR,	"UD excp" },
	{ SVM_EXIT_EXCP_BASE + PF_VECTOR,	"PF excp" },
	{ SVM_EXIT_EXCP_BASE + NM_VECTOR,	"NM excp" },
	{ SVM_EXIT_EXCP_BASE + MC_VECTOR,	"MC excp" },
	{ SVM_EXIT_INTR,			"interrupt" },
	{ SVM_EXIT_NMI,				"nmi" },
	{ SVM_EXIT_SMI,				"smi" },
	{ SVM_EXIT_INIT,			"init" },
	{ SVM_EXIT_VINTR,			"vintr" },
	{ SVM_EXIT_CPUID,			"cpuid" },
	{ SVM_EXIT_INVD,			"invd" },
	{ SVM_EXIT_HLT,				"hlt" },
	{ SVM_EXIT_INVLPG,			"invlpg" },
	{ SVM_EXIT_INVLPGA,			"invlpga" },
	{ SVM_EXIT_IOIO,			"io" },
	{ SVM_EXIT_MSR,				"msr" },
	{ SVM_EXIT_TASK_SWITCH,			"task_switch" },
	{ SVM_EXIT_SHUTDOWN,			"shutdown" },
	{ SVM_EXIT_VMRUN,			"vmrun" },
	{ SVM_EXIT_VMMCALL,			"hypercall" },
	{ SVM_EXIT_VMLOAD,			"vmload" },
	{ SVM_EXIT_VMSAVE,			"vmsave" },
	{ SVM_EXIT_STGI,			"stgi" },
	{ SVM_EXIT_CLGI,			"clgi" },
	{ SVM_EXIT_SKINIT,			"skinit" },
	{ SVM_EXIT_WBINVD,			"wbinvd" },
	{ SVM_EXIT_MONITOR,			"monitor" },
	{ SVM_EXIT_MWAIT,			"mwait" },
	{ SVM_EXIT_NPF,				"npf" },
	{ -1, NULL }
};

static int svm_get_lpage_level(void)
{
	return PT_PDPE_LEVEL;
}

static bool svm_rdtscp_supported(void)
{
	return false;
}

static void svm_fpu_deactivate(struct kvm_vcpu *vcpu)
{
	struct vcpu_svm *svm = to_svm(vcpu);

	update_cr0_intercept(svm);
	svm->vmcb->control.intercept_exceptions |= 1 << NM_VECTOR;
}

static struct kvm_x86_ops svm_x86_ops = {
	.cpu_has_kvm_support = has_svm,
	.disabled_by_bios = is_disabled,
	.hardware_setup = svm_hardware_setup,
	.hardware_unsetup = svm_hardware_unsetup,
	.check_processor_compatibility = svm_check_processor_compat,
	.hardware_enable = svm_hardware_enable,
	.hardware_disable = svm_hardware_disable,
	.cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,

	.vcpu_create = svm_create_vcpu,
	.vcpu_free = svm_free_vcpu,
	.vcpu_reset = svm_vcpu_reset,

	.prepare_guest_switch = svm_prepare_guest_switch,
	.vcpu_load = svm_vcpu_load,
	.vcpu_put = svm_vcpu_put,

	.set_guest_debug = svm_guest_debug,
	.get_msr = svm_get_msr,
	.set_msr = svm_set_msr,
	.get_segment_base = svm_get_segment_base,
	.get_segment = svm_get_segment,
	.set_segment = svm_set_segment,
	.get_cpl = svm_get_cpl,
	.get_cs_db_l_bits = kvm_get_cs_db_l_bits,
	.decache_cr0_guest_bits = svm_decache_cr0_guest_bits,
	.decache_cr4_guest_bits = svm_decache_cr4_guest_bits,
	.set_cr0 = svm_set_cr0,
	.set_cr3 = svm_set_cr3,
	.set_cr4 = svm_set_cr4,
	.set_efer = svm_set_efer,
	.get_idt = svm_get_idt,
	.set_idt = svm_set_idt,
	.get_gdt = svm_get_gdt,
	.set_gdt = svm_set_gdt,
	.get_dr = svm_get_dr,
	.set_dr = svm_set_dr,
	.cache_reg = svm_cache_reg,
	.get_rflags = svm_get_rflags,
	.set_rflags = svm_set_rflags,
	.fpu_activate = svm_fpu_activate,
	.fpu_deactivate = svm_fpu_deactivate,

	.tlb_flush = svm_flush_tlb,

	.run = svm_vcpu_run,
	.handle_exit = handle_exit,
	.skip_emulated_instruction = skip_emulated_instruction,
	.set_interrupt_shadow = svm_set_interrupt_shadow,
	.get_interrupt_shadow = svm_get_interrupt_shadow,
	.patch_hypercall = svm_patch_hypercall,
	.set_irq = svm_set_irq,
	.set_nmi = svm_inject_nmi,
	.queue_exception = svm_queue_exception,
	.interrupt_allowed = svm_interrupt_allowed,
	.nmi_allowed = svm_nmi_allowed,
	.get_nmi_mask = svm_get_nmi_mask,
	.set_nmi_mask = svm_set_nmi_mask,
	.enable_nmi_window = enable_nmi_window,
	.enable_irq_window = enable_irq_window,
	.update_cr8_intercept = update_cr8_intercept,

	.set_tss_addr = svm_set_tss_addr,
	.get_tdp_level = get_npt_level,
	.get_mt_mask = svm_get_mt_mask,

	.exit_reasons_str = svm_exit_reasons_str,
	.get_lpage_level = svm_get_lpage_level,

	.cpuid_update = svm_cpuid_update,

	.rdtscp_supported = svm_rdtscp_supported,
};

static int __init svm_init(void)
{
	return kvm_init(&svm_x86_ops, sizeof(struct vcpu_svm),
			      THIS_MODULE);
}

static void __exit svm_exit(void)
{
	kvm_exit();
}

module_init(svm_init)
module_exit(svm_exit)