On 21/02/19 18:15, Sean Christopherson wrote: > This bug exists only in the 4.4.y backport; upstream, 4.9.y and 4.14.y > all had the correct code from the get-go. And there is already a KVM > unit test that *should* hit this, albeit somewhat indirectly. I'll > verify the tests that touch the TPR actually run with x2APIC enabled. eventinj from kvm-unit-tests should trigger it. There are other tests that touch the TPR, but they use cr8 so they don't show the bug. > Assuming the KVM unit test actually works, it's not a stretch for the > bug to esacpe, e.g. if the tests weren't run on 4.4.y at all, or were > only run on hardware with x2APIC. Yeah, you should be able to see this with kvm_intel.enable_apicv=0 on newer processors. But I've never run the tests for 4.4.y. Paolo
