Re: linux 3.13 guest crash with -cpu host

Paolo Bonzini
2014-02-03T15:02:07Z

Il 03/02/2014 15:28, Peter Zijlstra ha scritto:
>>> > > Right, and the virt thingy has no PEBS, so there is no correct value that we
>>> > > could return from the MSR. That's why the CPUID bit is zero.
>> >
>> > There's more than PEBS in there, there's also the LBR format (which you
>> > obviously also don't have)
> On that.. LBR is purely model based, what do you guys do with those
> MSRs?

On Intel nothing, the MSRs always returns 0.

AMD did add LBR virtualization to its virtualization exception, so on
AMD you can use LBR from a guest.

Paolo