Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8facbbff authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots 



On svm, kvm_read_pdptr() may require reading guest memory, which can sleep.

Push the spinlock into mmu_alloc_roots(), and only take it after we've read
the pdptr.

Tested-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent cafd6659

arch/x86/kvm/mmu.c

+7 −0
Original line number Diff line number Diff line
@@ -2065,11 +2065,13 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu) 
			direct = 1;

			root_gfn = 0;

		}

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

		sp = kvm_mmu_get_page(vcpu, root_gfn, 0,

				      PT64_ROOT_LEVEL, direct,

				      ACC_ALL, NULL);

		root = __pa(sp->spt);

		++sp->root_count;

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

		vcpu->arch.mmu.root_hpa = root;

		return 0;

	}
@@ -2093,11 +2095,14 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu) 
			direct = 1;

			root_gfn = i << 30;

		}

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

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

				      PT32_ROOT_LEVEL, direct,

				      ACC_ALL, NULL);

		root = __pa(sp->spt);

		++sp->root_count;

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



		vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;

	}

	vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
@@ -2466,7 +2471,9 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) 
		goto out;

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

	kvm_mmu_free_some_pages(vcpu);

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

	r = mmu_alloc_roots(vcpu);

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

	mmu_sync_roots(vcpu);

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

	if (r)