On Mon, 2018-04-09 at 12:24 -0700, Jim Mattson wrote: > On Mon, Apr 9, 2018 at 1:37 AM, KarimAllah Ahmed <karahmed@xxxxxxxxx> wrote: > > > > > + /* > > + * Force a nested exit that guarantees that any state capture > > + * afterwards by any IOCTLs (MSRs, etc) will not capture a mix of L1 > > + * and L2 state. > > + * > > + * One example where that would lead to an issue is the TSC DEADLINE > > + * MSR vs the guest TSC. If the L2 guest is running, the guest TSC will > > + * be the L2 TSC while the TSC deadline MSR will contain the L1 TSC > > + * deadline MSR. That would lead to a very large (and wrong) "expire" > > + * diff when LAPIC is initialized during instance restore (i.e. the > > + * instance will appear to have hanged!). > > + */ > > This sounds like a bug in the virtualization of IA32_TSC_DEADLINE. > Without involving save/restore, what happens if L2 sets > IA32_TSC_DEADLINE (and L1 permits it via the MSR permission bitmap)? > The IA32_TSC_DEADLINE MSR is always specified with respect to L1's > time domain. That makes sense! Let me look into that! Thanks! > Amazon Development Center Germany GmbH Berlin - Dresden - Aachen main office: Krausenstr. 38, 10117 Berlin Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger Ust-ID: DE289237879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
