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Commit 26eeb53c authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
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KVM: MMU: Bail out immediately if there is no available mmu page 



Bailing out immediately if there is no available mmu page to alloc.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 42bcbebf

arch/x86/kvm/mmu.c

+27 −9
Original line number Original line Diff line number Diff line
@@ -3257,7 +3257,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, 




static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,

static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,

			 gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable);

			 gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable);

static void make_mmu_pages_available(struct kvm_vcpu *vcpu);

static int make_mmu_pages_available(struct kvm_vcpu *vcpu);





static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,

static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,

			 gfn_t gfn, bool prefault)

			 gfn_t gfn, bool prefault)
@@ -3297,7 +3297,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code, 
	spin_lock(&vcpu->kvm->mmu_lock);

	spin_lock(&vcpu->kvm->mmu_lock);

	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))

	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))

		goto out_unlock;

		goto out_unlock;

	make_mmu_pages_available(vcpu);

	if (make_mmu_pages_available(vcpu) < 0)

		goto out_unlock;

	if (likely(!force_pt_level))

	if (likely(!force_pt_level))

		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);

		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);

	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);

	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
@@ -3376,7 +3377,10 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 




	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {

	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {

		spin_lock(&vcpu->kvm->mmu_lock);

		spin_lock(&vcpu->kvm->mmu_lock);

		make_mmu_pages_available(vcpu);

		if(make_mmu_pages_available(vcpu) < 0) {

			spin_unlock(&vcpu->kvm->mmu_lock);

			return 1;

		}

		sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL, 1, ACC_ALL);

		sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL, 1, ACC_ALL);

		++sp->root_count;

		++sp->root_count;

		spin_unlock(&vcpu->kvm->mmu_lock);

		spin_unlock(&vcpu->kvm->mmu_lock);
@@ -3387,7 +3391,10 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 




			MMU_WARN_ON(VALID_PAGE(root));

			MMU_WARN_ON(VALID_PAGE(root));

			spin_lock(&vcpu->kvm->mmu_lock);

			spin_lock(&vcpu->kvm->mmu_lock);

			make_mmu_pages_available(vcpu);

			if (make_mmu_pages_available(vcpu) < 0) {

				spin_unlock(&vcpu->kvm->mmu_lock);

				return 1;

			}

			sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),

			sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),

					i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL);

					i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL);

			root = __pa(sp->spt);

			root = __pa(sp->spt);
@@ -3424,7 +3431,10 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 
		MMU_WARN_ON(VALID_PAGE(root));

		MMU_WARN_ON(VALID_PAGE(root));





		spin_lock(&vcpu->kvm->mmu_lock);

		spin_lock(&vcpu->kvm->mmu_lock);

		make_mmu_pages_available(vcpu);

		if (make_mmu_pages_available(vcpu) < 0) {

			spin_unlock(&vcpu->kvm->mmu_lock);

			return 1;

		}

		sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,

		sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,

				      0, ACC_ALL);

				      0, ACC_ALL);

		root = __pa(sp->spt);

		root = __pa(sp->spt);
@@ -3458,7 +3468,10 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 
				return 1;

				return 1;

		}

		}

		spin_lock(&vcpu->kvm->mmu_lock);

		spin_lock(&vcpu->kvm->mmu_lock);

		make_mmu_pages_available(vcpu);

		if (make_mmu_pages_available(vcpu) < 0) {

			spin_unlock(&vcpu->kvm->mmu_lock);

			return 1;

		}

		sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL,

		sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL,

				      0, ACC_ALL);

				      0, ACC_ALL);

		root = __pa(sp->spt);

		root = __pa(sp->spt);
@@ -3867,7 +3880,8 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, 
	spin_lock(&vcpu->kvm->mmu_lock);

	spin_lock(&vcpu->kvm->mmu_lock);

	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))

	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))

		goto out_unlock;

		goto out_unlock;

	make_mmu_pages_available(vcpu);

	if (make_mmu_pages_available(vcpu) < 0)

		goto out_unlock;

	if (likely(!force_pt_level))

	if (likely(!force_pt_level))

		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);

		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);

	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);

	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
@@ -4786,12 +4800,12 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) 
}

}

EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);

EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);





static void make_mmu_pages_available(struct kvm_vcpu *vcpu)

static int make_mmu_pages_available(struct kvm_vcpu *vcpu)

{

{

	LIST_HEAD(invalid_list);

	LIST_HEAD(invalid_list);





	if (likely(kvm_mmu_available_pages(vcpu->kvm) >= KVM_MIN_FREE_MMU_PAGES))

	if (likely(kvm_mmu_available_pages(vcpu->kvm) >= KVM_MIN_FREE_MMU_PAGES))

		return;

		return 0;





	while (kvm_mmu_available_pages(vcpu->kvm) < KVM_REFILL_PAGES) {

	while (kvm_mmu_available_pages(vcpu->kvm) < KVM_REFILL_PAGES) {

		if (!prepare_zap_oldest_mmu_page(vcpu->kvm, &invalid_list))

		if (!prepare_zap_oldest_mmu_page(vcpu->kvm, &invalid_list))
@@ -4800,6 +4814,10 @@ static void make_mmu_pages_available(struct kvm_vcpu *vcpu) 
		++vcpu->kvm->stat.mmu_recycled;

		++vcpu->kvm->stat.mmu_recycled;

	}

	}

	kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);

	kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);



	if (!kvm_mmu_available_pages(vcpu->kvm))

		return -ENOSPC;

	return 0;

}

}





int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,

int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,

arch/x86/kvm/paging_tmpl.h

+2 −1
Original line number Original line Diff line number Diff line
@@ -819,7 +819,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, 
		goto out_unlock;

		goto out_unlock;





	kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);

	kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);

	make_mmu_pages_available(vcpu);

	if (make_mmu_pages_available(vcpu) < 0)

		goto out_unlock;

	if (!force_pt_level)

	if (!force_pt_level)

		transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);

		transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);

	r = FNAME(fetch)(vcpu, addr, &walker, write_fault,

	r = FNAME(fetch)(vcpu, addr, &walker, write_fault,