[4.19,071/267] KVM: nSVM: fix condition for filtering async PF

Message ID 20200619141652.304477872@linuxfoundation.org
State Superseded
Headers show
Series
  • Untitled series #28331
Related show

Commit Message

Greg Kroah-Hartman June 19, 2020, 2:30 p.m.
From: Paolo Bonzini <pbonzini@redhat.com>

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 <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/svm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3229,8 +3229,8 @@  static int nested_svm_exit_special(struc
 			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: