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(-)
--- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2757,8 +2757,8 @@ 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: