Commit c786c16d authored Nov 05, 2017 by Liran Alon Committed by Greg Kroah-Hartman Feb 07, 2018

KVM: x86: emulator: Return to user-mode on L1 CPL=0 emulation failure




[ Upstream commit 1f4dcb3b213235e642088709a1c54964d23365e9 ]

On this case, handle_emulation_failure() fills kvm_run with
internal-error information which it expects to be delivered
to user-mode for further processing.
However, the code reports a wrong return-value which makes KVM to never
return to user-mode on this scenario.

Fixes: 6d77dbfc ("KVM: inject #UD if instruction emulation fails and exit to
userspace")

Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f7c2ce3d

arch/x86/kvm/x86.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -5109,7 +5109,7 @@ static int handle_emulation_failure(struct kvm_vcpu *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;
		r = EMULATE_USER_EXIT;
		}
		kvm_queue_exception(vcpu, UD_VECTOR);