Re: [PATCH v2 1/3] KVM: x86: implement KVM_{GET|SET}_TSC_STATE

From: Thomas Gleixner
Date: Thu Dec 10 2020 - 19:05:59 EST


On Thu, Dec 10 2020 at 15:19, Andy Lutomirski wrote:
>> On Dec 10, 2020, at 2:28 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>> Can we please focus on real problems instead of making up new ones?
>>
>> Correctness of time is a real problem despite the believe of virt folks
>> that it can be ignored or duct taped to death.
>>
> I’m fine with this as long as it’s intentional. If we say “guest
> timekeeping across host suspend is correct because we notify the
> guest”, then we have a hole. But if we say “the host will try to
> notify the guest, and if the guest is out to lunch then the host
> reserves the right to suspend without waiting, and the guest should
> deal with this”, then okay.

Yes of course this would be intentional and documented behaviour, which
is an infinite improvement over the current situation.

Thanks,

tglx