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authorAvi Kivity <avi@redhat.com>2010-05-04 12:58:32 +0300
committerAvi Kivity <avi@redhat.com>2010-05-19 11:36:35 +0300
commit8facbbff071ff2b19268d3732e31badc60471e21 (patch)
tree1779b2bb158c8e1bf99560fb3fd16647e3e371f7 /arch/x86/kvm
parentcafd66595d92591e4bd25c3904e004fc6f897e2d (diff)
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: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/mmu.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 51eb6d6abd86..de996380ec26 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -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)