From 3c0bee0c0757161cde31240ed7ca625877147516 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Sat, 16 May 2020 09:19:06 -0400 Subject: [PATCH] KVM: nSVM: fix condition for filtering async PF commit a3535be731c2a343912578465021f50937f7b099 upstream. Async page faults have to be trapped in the host (L1 in this case), since the APF reason was passed from L0 to L1 and stored in the L1 APF data page. This was completely reversed: the page faults were passed to the guest, a L2 hypervisor. Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index cc7da664..580e4cb 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3237,8 +3237,8 @@ static int nested_svm_exit_special(struct vcpu_svm *svm) return NESTED_EXIT_HOST; break; case SVM_EXIT_EXCP_BASE + PF_VECTOR: - /* When we're shadowing, trap PFs, but not async PF */ - if (!npt_enabled && svm->vcpu.arch.apf.host_apf_reason == 0) + /* Trap async PF even if not shadowing */ + if (!npt_enabled || svm->vcpu.arch.apf.host_apf_reason) return NESTED_EXIT_HOST; break; default: -- 2.7.4