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Commit 1c53da3f authored by Junaid Shahid's avatar Junaid Shahid Committed by Paolo Bonzini
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kvm: x86: Support resetting the MMU context without resetting roots 



This adds support for re-initializing the MMU context in a different
mode while preserving the active root_hpa and the prev_root.

Signed-off-by: default avatarJunaid Shahid <junaids@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0aab33e4

arch/x86/kvm/mmu.c

+9 −17
Original line number Diff line number Diff line
@@ -4032,8 +4032,6 @@ static void nonpaging_init_context(struct kvm_vcpu *vcpu, 
	context->update_pte = nonpaging_update_pte;

	context->root_level = 0;

	context->shadow_root_level = PT32E_ROOT_LEVEL;

	context->root_hpa = INVALID_PAGE;

	context->prev_root = KVM_MMU_ROOT_INFO_INVALID;

	context->direct_map = true;

	context->nx = false;

}
@@ -4568,8 +4566,6 @@ static void paging64_init_context_common(struct kvm_vcpu *vcpu, 
	context->invlpg = paging64_invlpg;

	context->update_pte = paging64_update_pte;

	context->shadow_root_level = level;

	context->root_hpa = INVALID_PAGE;

	context->prev_root = KVM_MMU_ROOT_INFO_INVALID;

	context->direct_map = false;

}
@@ -4599,8 +4595,6 @@ static void paging32_init_context(struct kvm_vcpu *vcpu, 
	context->invlpg = paging32_invlpg;

	context->update_pte = paging32_update_pte;

	context->shadow_root_level = PT32E_ROOT_LEVEL;

	context->root_hpa = INVALID_PAGE;

	context->prev_root = KVM_MMU_ROOT_INFO_INVALID;

	context->direct_map = false;

}
@@ -4636,8 +4630,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) 
	context->invlpg = nonpaging_invlpg;

	context->update_pte = nonpaging_update_pte;

	context->shadow_root_level = kvm_x86_ops->get_tdp_level(vcpu);

	context->root_hpa = INVALID_PAGE;

	context->prev_root = KVM_MMU_ROOT_INFO_INVALID;

	context->direct_map = true;

	context->set_cr3 = kvm_x86_ops->set_tdp_cr3;

	context->get_cr3 = get_cr3;
@@ -4703,8 +4695,6 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu) 
{

	struct kvm_mmu *context = &vcpu->arch.mmu;



	MMU_WARN_ON(VALID_PAGE(context->root_hpa));



	if (!is_paging(vcpu))

		nonpaging_init_context(vcpu, context);

	else if (is_long_mode(vcpu))
@@ -4741,8 +4731,6 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 
	union kvm_mmu_page_role root_page_role =

		kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty);



	MMU_WARN_ON(VALID_PAGE(context->root_hpa));



	context->shadow_root_level = PT64_ROOT_4LEVEL;



	context->nx = true;
@@ -4753,8 +4741,6 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, 
	context->invlpg = ept_invlpg;

	context->update_pte = ept_update_pte;

	context->root_level = PT64_ROOT_4LEVEL;

	context->root_hpa = INVALID_PAGE;

	context->prev_root = KVM_MMU_ROOT_INFO_INVALID;

	context->direct_map = false;

	context->base_role.word = root_page_role.word & mmu_base_role_mask.word;

	update_permission_bitmask(vcpu, context, true);
@@ -4819,8 +4805,13 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) 
	update_last_nonleaf_level(vcpu, g_context);

}



static void init_kvm_mmu(struct kvm_vcpu *vcpu)

void kvm_init_mmu(struct kvm_vcpu *vcpu, bool reset_roots)

{

	if (reset_roots) {

		vcpu->arch.mmu.root_hpa = INVALID_PAGE;

		vcpu->arch.mmu.prev_root = KVM_MMU_ROOT_INFO_INVALID;

	}



	if (mmu_is_nested(vcpu))

		init_kvm_nested_mmu(vcpu);

	else if (tdp_enabled)
@@ -4828,6 +4819,7 @@ static void init_kvm_mmu(struct kvm_vcpu *vcpu) 
	else

		init_kvm_softmmu(vcpu);

}

EXPORT_SYMBOL_GPL(kvm_init_mmu);



static union kvm_mmu_page_role

kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu)
@@ -4841,7 +4833,7 @@ kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu) 
void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)

{

	kvm_mmu_unload(vcpu);

	init_kvm_mmu(vcpu);

	kvm_init_mmu(vcpu, true);

}

EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
@@ -5245,7 +5237,7 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu) 
{

	MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa));



	init_kvm_mmu(vcpu);

	kvm_init_mmu(vcpu, true);

}



static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,

arch/x86/kvm/mmu.h

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value); 
void

reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);



void kvm_init_mmu(struct kvm_vcpu *vcpu, bool reset_roots);

void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu);

void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,

			     bool accessed_dirty);