From: Liran Alon <liran.alon@oracle.com>
Date: Sun, 5 Nov 2017 14:56:33 +0000 (+0200)
Subject: KVM: x86: emulator: Return to user-mode on L1 CPL=0 emulation failure
X-Git-Tag: v4.14.17~120
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fbd81f09793b8ab0696782da0c081599b6620efc;p=platform%2Fkernel%2Flinux-rpi.git

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: 6d77dbfc88e3 ("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@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 575c895..b25326a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5416,7 +5416,7 @@ 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);