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

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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: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity
2010-05-04 12:58:32 +03:00
parent cafd66595d
commit 8facbbff07
1 changed files with 7 additions and 0 deletions
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7
arch/x86/kvm/mmu.c
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@@ -2065,11 +2065,13 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
direct = 1; direct = 1;
root_gfn = 0; root_gfn = 0;
} }
spin_lock(&vcpu->kvm->mmu_lock);
sp = kvm_mmu_get_page(vcpu, root_gfn, 0, sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
PT64_ROOT_LEVEL, direct, PT64_ROOT_LEVEL, direct,
ACC_ALL, NULL); ACC_ALL, NULL);
root = __pa(sp->spt); root = __pa(sp->spt);
++sp->root_count; ++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.root_hpa = root; vcpu->arch.mmu.root_hpa = root;
return 0; return 0;
} }
@@ -2093,11 +2095,14 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
direct = 1; direct = 1;
root_gfn = i << 30; root_gfn = i << 30;
} }
spin_lock(&vcpu->kvm->mmu_lock);
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
PT32_ROOT_LEVEL, direct, PT32_ROOT_LEVEL, direct,
ACC_ALL, NULL); ACC_ALL, NULL);
root = __pa(sp->spt); root = __pa(sp->spt);
++sp->root_count; ++sp->root_count;
spin_unlock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
} }
vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); 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; goto out;
spin_lock(&vcpu->kvm->mmu_lock); spin_lock(&vcpu->kvm->mmu_lock);
kvm_mmu_free_some_pages(vcpu); kvm_mmu_free_some_pages(vcpu);
spin_unlock(&vcpu->kvm->mmu_lock);
r = mmu_alloc_roots(vcpu); r = mmu_alloc_roots(vcpu);
spin_lock(&vcpu->kvm->mmu_lock);
mmu_sync_roots(vcpu); mmu_sync_roots(vcpu);
spin_unlock(&vcpu->kvm->mmu_lock); spin_unlock(&vcpu->kvm->mmu_lock);
if (r) if (r)