Commit a2b9e6c1 authored Sep 17, 2014 by Nadav Amit Committed by Paolo Bonzini Sep 24, 2014

KVM: x86: Don't report guest userspace emulation error to userspace

Commit fc3a9157 ("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@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 1f755a82

arch/x86/kvm/x86.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

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