Re: TSC frequency configuration & invtsc migration (was Re: [PATCH 4/4] kvm: Allow migration with invtsc)

Marcelo Tosatti
2017-01-05T10:50:48Z

On Thu, Jan 05, 2017 at 08:48:32AM -0200, Marcelo Tosatti wrote:
> > Note that even if we follow your suggestion and implement an
> > alternative version of patch 4/4 to cover your use case, I will
> > strongly recommend libvirt developers to support configuring TSC
> > frequency if they want to support invtsc + migration without
> > surprising/unpredictable restrictions on migratability.
>
> Well, alright. If you make the TSC frequency of the host
> available to mgmt software as you describe, and write the steps mgmt
> software should take, i'm good.
>
> Thanks for the help Eduardo.
>

I'll be happy to not have to add a weird script to

1. Query the host TSC frequency.
2. Pass that to -cpu xxx,tsc-frequency=ZZZ

To my migration scripts.

Probably easy to make that the default behaviour...