From: Haozhong Zhang <haozhong.zhang@intel.com>
Date: Wed, 10 Jan 2018 21:44:42 +0800
Subject: KVM MMU: check pending exception before injecting APF
Patch-mainline: v4.15-rc8
Git-commit: 2a266f23550be997d783f27e704b9b40c4010292
References: bsc#1077761
For example, when two APF's for page ready happen after one exit and
the first one becomes pending, the second one will result in #DF.
Instead, just handle the second page fault synchronously.
Reported-by: Ross Zwisler <zwisler@gmail.com>
Message-ID: <CAOxpaSUBf8QoOZQ1p4KfUp0jq76OKfGY4Uxs-Gg8ngReD99xww@mail.gmail.com>
Reported-by: Alec Blayne <ab@tevsa.net>
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
arch/x86/kvm/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3781,7 +3781,8 @@
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
{
if (unlikely(!lapic_in_kernel(vcpu) ||
- kvm_event_needs_reinjection(vcpu)))
+ kvm_event_needs_reinjection(vcpu) ||
+ vcpu->arch.exception.pending))
return false;
if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))