Re: [PATCH 6/6] x86/kvm: add boot parameter for setting max number of vcpus per guest

[Vitaly Kuznetsov]

Juergen Gross <jgross@xxxxxxxx> writes:

> On 14.07.21 13:45, Vitaly Kuznetsov wrote:
>
>> Personally, I'd vote for introducing a 'ratio' parameter then so
>> generally users will only have to set 'kvm.max_vcpus'.
>
> Okay.
>
> Default '4' then? Or '2 ^ (topology_levels - 2)' (assuming a
> topology_level of 3 on Intel: thread/core/socket and 4 on EPYC:
> thread/core/package/socket).

I'd suggest we default to '4' for both Intel and AMD as we haven't given
up completely on cross-vendor VMs (running AMD VMs on Intel CPUs and
vice versa). It would be great to leave a comment where the number comes
from of course.

-- 
Vitaly