diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-17 12:21:06 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 09:13:13 -0400 |
| commit | e72436bc3a5206f95bb384e741154166ddb3202e (patch) | |
| tree | 3bbd58436dcb3900f1f0c276e497b8381d0b169b /virt | |
| parent | 997b7e98990cd44243651827e4efa366d9885907 (diff) | |
| download | lwn-e72436bc3a5206f95bb384e741154166ddb3202e.tar.gz lwn-e72436bc3a5206f95bb384e741154166ddb3202e.zip | |
KVM: SVM: avoid infinite loop on NPF from bad address
When a nested page fault is taken from an address that does not have
a memslot associated to it, kvm_mmu_do_page_fault returns RET_PF_EMULATE
(via mmu_set_spte) and kvm_mmu_page_fault then invokes svm_need_emulation_on_page_fault.
The default answer there is to return false, but in this case this just
causes the page fault to be retried ad libitum. Since this is not a
fast path, and the only other case where it is taken is an erratum,
just stick a kvm_vcpu_gfn_to_memslot check in there to detect the
common case where the erratum is not happening.
This fixes an infinite loop in the new set_memory_region_test.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e2f60e313c87..e7436d054305 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1602,6 +1602,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn { return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn); } +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot); bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { |