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 a6bf2ad7429c07239547e052a846991fa0a598a8..de4bba99160db2b74362a4b8be0ca89e0e63bdd2 100644 (file)
--- 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);