On 03/05/21 14:54, Maxim Levitsky wrote:
Since the nested migration is a result of a VMRUN, this makes it
possible to keep a warning that L1 vmcb should always have
VMRUN exit reason when switching back to it, which
otherwise triggers incorrectly.
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Does this fix "KVM: nSVM: If VMRUN is single-stepped, queue the #DB
intercept in nested_svm_vmexit()"? I don't like this, and also vmcb12
is not initialized here (nested_load_control_from_vmcb12 is using the
state passed in from userspace instead).
I think you should just remove the WARN instead.
Paolo
---
arch/x86/kvm/svm/nested.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 12a12ae940fa..146be4b5084b 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1338,6 +1338,12 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
svm->vmcb01.ptr->save.rip = save->rip;
svm->vmcb01.ptr->save.cpl = 0;
+ /*
+ * For consistency sake, restore the L1 exit reason
+ * (that happened prior to the migration) to SVM_EXIT_VMRUN.
+ */
+ svm->vmcb->control.exit_code = SVM_EXIT_VMRUN;
+
nested_load_control_from_vmcb12(svm, ctl);
svm_switch_vmcb(svm, &svm->nested.vmcb02);
