The patch below does not apply to the 3.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a2b9e6c1a35afcc0973acb72e591c714e78885ff Mon Sep 17 00:00:00 2001 From: Nadav Amit <namit@xxxxxxxxxxxxxxxxx> Date: Wed, 17 Sep 2014 02:50:50 +0300 Subject: [PATCH] KVM: x86: Don't report guest userspace emulation error to userspace Commit fc3a9157d314 ("KVM: X86: Don't report L2 emulation failures to user-space") disabled the reporting of L2 (nested guest) emulation failures to userspace due to race-condition between a vmexit and the instruction emulator. The same rational applies also to userspace applications that are permitted by the guest OS to access MMIO area or perform PIO. This patch extends the current behavior - of injecting a #UD instead of reporting it to userspace - also for guest userspace code. Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2d7f65daa8d0..e46da50e2cec 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5000,7 +5000,7 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu) ++vcpu->stat.insn_emulation_fail; trace_kvm_emulate_insn_failed(vcpu); - if (!is_guest_mode(vcpu)) { + if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) { vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; vcpu->run->internal.ndata = 0; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html