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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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
(cherry picked from commit 8facbbff07)
This commit is contained in:
Avi Kivity 2010-05-04 12:58:32 +03:00 committed by Greg Kroah-Hartman
parent 66307ba164
commit 4a277f9cb8
1 changed files with 7 additions and 0 deletions
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7
arch/x86/kvm/mmu.c
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@ -2091,11 +2091,13 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
direct = 1;
if (mmu_check_root(vcpu, root_gfn))
return 1;
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;
}
@ -2117,11 +2119,14 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
root_gfn = 0;
if (mmu_check_root(vcpu, root_gfn))
return 1;
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);
@ -2485,7 +2490,9 @@ 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)