From: Joerg Roedel <joerg.roedel@amd.com>
Date: Mon, 18 Apr 2011 09:42:52 +0000 (+0200)
Subject: KVM: SVM: Fix nested sel_cr0 intercept path with decode-assists
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=977b2d03e42e9ea9355d4baddb464810579719bd;p=deliverable%2Flinux.git

KVM: SVM: Fix nested sel_cr0 intercept path with decode-assists

This patch fixes a bug in the nested-svm path when
decode-assists is available on the machine. After a
selective-cr0 intercept is detected the rip is advanced
unconditionally. This causes the l1-guest to continue
running with an l2-rip.
This bug was with the sel_cr0 unit-test on decode-assists
capable hardware.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a6bf2ad7429c..de4bba99160d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2799,6 +2799,9 @@ static int cr_interception(struct vcpu_svm *svm)
 		case 0:
 			if (!check_selective_cr0_intercepted(svm, val))
 				err = kvm_set_cr0(&svm->vcpu, val);
+			else
+				return 1;
+
 			break;
 		case 3:
 			err = kvm_set_cr3(&svm->vcpu, val);