lkml.org 
[lkml]   [2018]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] KVM: X86: Allow userspace to define the microcode version
From
On April 24, 2018 1:09:00 AM EDT, Paolo Bonzini <pbonzini@redhat.com> wrote:
>On 24/04/2018 05:14, Konrad Rzeszutek Wilk wrote:
>> You would need to include the microcode version in the migration
>stream.
>>
>> But this brings another point - what if we want to manifest certain
>> new CPUID bits?
>
>You don't do that across migration. Generally if you want to do live
>migration and you set up the guest to know everything about the host
>(down to the microcode level), you should make sure your host are
>pretty
>much identical.

I understand how it ought to be but sadly the cloud vendors have a mix of hardware.


With the retpoline/IBRS support (like what RH kernel has) you could migrate from Skylake to Broadwell and switching over from IBRS to retpoline would be good.

Hence asking about this.

>
>Paolo

\
 
 \ /
  Last update: 2018-04-24 15:47    [W:0.049 / U:0.516 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site