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Commit fc3a9157 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
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KVM: X86: Don't report L2 emulation failures to user-space 



This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 2030753d

arch/x86/kvm/x86.c

+10 −4
Original line number Diff line number Diff line
@@ -4314,13 +4314,19 @@ EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt); 


static int handle_emulation_failure(struct kvm_vcpu *vcpu)

{

	int r = EMULATE_DONE;



	++vcpu->stat.insn_emulation_fail;

	trace_kvm_emulate_insn_failed(vcpu);

	if (!is_guest_mode(vcpu)) {

		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;

		vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;

		vcpu->run->internal.ndata = 0;

		r = EMULATE_FAIL;

	}

	kvm_queue_exception(vcpu, UD_VECTOR);

	return EMULATE_FAIL;



	return r;

}



static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)