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Commit b7ebfb05 authored by Sheng Yang's avatar Sheng Yang Committed by Avi Kivity
Browse files

KVM: VMX: Prepare an identity page table for EPT in real mode 



[aliguory: plug leak]

Signed-off-by: default avatarSheng Yang <sheng.yang@intel.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 0d150298

arch/x86/kvm/vmx.c

+76 −3
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) 
	return container_of(vcpu, struct vcpu_vmx, vcpu);

}



static int init_rmode_tss(struct kvm *kvm);

static int init_rmode(struct kvm *kvm);



static DEFINE_PER_CPU(struct vmcs *, vmxarea);

static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -1304,7 +1304,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu) 
	fix_rmode_seg(VCPU_SREG_FS, &vcpu->arch.rmode.fs);



	kvm_mmu_reset_context(vcpu);

	init_rmode_tss(vcpu->kvm);

	init_rmode(vcpu->kvm);

}



#ifdef CONFIG_X86_64
@@ -1578,6 +1578,41 @@ static int init_rmode_tss(struct kvm *kvm) 
	return ret;

}



static int init_rmode_identity_map(struct kvm *kvm)

{

	int i, r, ret;

	pfn_t identity_map_pfn;

	u32 tmp;



	if (!vm_need_ept())

		return 1;

	if (unlikely(!kvm->arch.ept_identity_pagetable)) {

		printk(KERN_ERR "EPT: identity-mapping pagetable "

			"haven't been allocated!\n");

		return 0;

	}

	if (likely(kvm->arch.ept_identity_pagetable_done))

		return 1;

	ret = 0;

	identity_map_pfn = VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT;

	r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);

	if (r < 0)

		goto out;

	/* Set up identity-mapping pagetable for EPT in real mode */

	for (i = 0; i < PT32_ENT_PER_PAGE; i++) {

		tmp = (i << 22) + (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER |

			_PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_PSE);

		r = kvm_write_guest_page(kvm, identity_map_pfn,

				&tmp, i * sizeof(tmp), sizeof(tmp));

		if (r < 0)

			goto out;

	}

	kvm->arch.ept_identity_pagetable_done = true;

	ret = 1;

out:

	return ret;

}



static void seg_setup(int seg)

{

	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
@@ -1612,6 +1647,31 @@ static int alloc_apic_access_page(struct kvm *kvm) 
	return r;

}



static int alloc_identity_pagetable(struct kvm *kvm)

{

	struct kvm_userspace_memory_region kvm_userspace_mem;

	int r = 0;



	down_write(&kvm->slots_lock);

	if (kvm->arch.ept_identity_pagetable)

		goto out;

	kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;

	kvm_userspace_mem.flags = 0;

	kvm_userspace_mem.guest_phys_addr = VMX_EPT_IDENTITY_PAGETABLE_ADDR;

	kvm_userspace_mem.memory_size = PAGE_SIZE;

	r = __kvm_set_memory_region(kvm, &kvm_userspace_mem, 0);

	if (r)

		goto out;



	down_read(&current->mm->mmap_sem);

	kvm->arch.ept_identity_pagetable = gfn_to_page(kvm,

			VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT);

	up_read(&current->mm->mmap_sem);

out:

	up_write(&kvm->slots_lock);

	return r;

}



static void allocate_vpid(struct vcpu_vmx *vmx)

{

	int vpid;
@@ -1775,6 +1835,15 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) 
	return 0;

}



static int init_rmode(struct kvm *kvm)

{

	if (!init_rmode_tss(kvm))

		return 0;

	if (!init_rmode_identity_map(kvm))

		return 0;

	return 1;

}



static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -1782,7 +1851,7 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu) 
	int ret;



	down_read(&vcpu->kvm->slots_lock);

	if (!init_rmode_tss(vmx->vcpu.kvm)) {

	if (!init_rmode(vmx->vcpu.kvm)) {

		ret = -ENOMEM;

		goto out;

	}
@@ -2759,6 +2828,10 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) 
		if (alloc_apic_access_page(kvm) != 0)

			goto free_vmcs;



	if (vm_need_ept())

		if (alloc_identity_pagetable(kvm) != 0)

			goto free_vmcs;



	return &vmx->vcpu;



free_vmcs:

arch/x86/kvm/vmx.h

+3 −0
Original line number Diff line number Diff line
@@ -340,6 +340,7 @@ enum vmcs_field { 
#define MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED  0x4



#define APIC_ACCESS_PAGE_PRIVATE_MEMSLOT	9

#define IDENTITY_PAGETABLE_PRIVATE_MEMSLOT	10



#define VMX_NR_VPIDS				(1 << 16)

#define VMX_VPID_EXTENT_SINGLE_CONTEXT		1
@@ -353,4 +354,6 @@ enum vmcs_field { 
#define VMX_EPT_EXTENT_GLOBAL_BIT		(1ull << 26)

#define VMX_EPT_DEFAULT_GAW			3



#define VMX_EPT_IDENTITY_PAGETABLE_ADDR		0xfffbc000ul



#endif

arch/x86/kvm/x86.c

+2 −0
Original line number Diff line number Diff line
@@ -3909,6 +3909,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm) 
	kvm_free_physmem(kvm);

	if (kvm->arch.apic_access_page)

		put_page(kvm->arch.apic_access_page);

	if (kvm->arch.ept_identity_pagetable)

		put_page(kvm->arch.ept_identity_pagetable);

	kfree(kvm);

}

include/asm-x86/kvm_host.h

+3 −0
Original line number Diff line number Diff line
@@ -314,6 +314,9 @@ struct kvm_arch{ 
	struct page *apic_access_page;



	gpa_t wall_clock;



	struct page *ept_identity_pagetable;

	bool ept_identity_pagetable_done;

};



struct kvm_vm_stat {