I have a few questions about AVIC. On 12/02/2016 14:59, Suravee Suthikulpanit wrote: > CURRENT UNSUPPORT USE-CASES > =========================== > - Nested VM > - VM Migration I'm interested in what you mean with "VM migration". I've noticed that, because x2APIC is disabled by default, it's possible that a VM on a non-AVIC host will fail when moved to an AVIC host. I would prefer if you kept x2APIC working through VMEXITs. Getting the full performance benefit would require disabling x2APIC of course (or waiting for improved support in the processor), but at least there would be no surprise. Is it just this, or is there anything else? (I'm quite surprised that x2APIC is not supported. MSRs are faster than memory accesses due to the cost of TLB misses, which can be hefty for VMs). I have a few other doubts about the architecture that hopefully you (or Wei Huang too) can clarify before I can review this patch meaningfully. I have replied to other patches with these questions. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
