From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Tue, 13 Aug 2019 13:53:29 +0000 (+0200)
Subject: x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results... 
X-Git-Tag: v5.15~5513^2~37
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=05402f64544f054edbe41f45f6ec52dbe0c1a324;p=platform%2Fkernel%2Flinux-starfive.git

x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results in #GP

svm->next_rip is only used by skip_emulated_instruction() and in case
kvm_set_msr() fails we rightfully don't do that. Move svm->next_rip
advancement to 'else' branch to avoid creating false impression that
it's always advanced (and make it look like rdmsr_interception()).

This is a preparatory change to removing hardcoded RIP advancement
from instruction intercepts, no functional change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c5120a9..1819033 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4444,13 +4444,13 @@ static int wrmsr_interception(struct vcpu_svm *svm)
 	msr.index = ecx;
 	msr.host_initiated = false;
 
-	svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
 	if (kvm_set_msr(&svm->vcpu, &msr)) {
 		trace_kvm_msr_write_ex(ecx, data);
 		kvm_inject_gp(&svm->vcpu, 0);
 		return 1;
 	} else {
 		trace_kvm_msr_write(ecx, data);
+		svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
 		return kvm_skip_emulated_instruction(&svm->vcpu);
 	}
 }