KVM: X86: Sanity check on gfn before removal

The index returned by kvm_async_pf_gfn_slot() will be removed when an
async pf gfn is going to be removed.  However kvm_async_pf_gfn_slot()
is not reliable in that it can return the last key it loops over even
if the gfn is not found in the async gfn array.  It should never
happen, but it's still better to sanity check against that to make
sure no unexpected gfn will be removed.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200416155910.267514-1-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Xu 2020-04-16 11:59:10 -04:00 committed by Paolo Bonzini
parent 5b494aea13
commit 0fd4604469
1 changed files with 4 additions and 0 deletions

View File

@ -10353,6 +10353,10 @@ static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
u32 i, j, k;
i = j = kvm_async_pf_gfn_slot(vcpu, gfn);
if (WARN_ON_ONCE(vcpu->arch.apf.gfns[i] != gfn))
return;
while (true) {
vcpu->arch.apf.gfns[i] = ~0;
do {