Re: tainted Linux kernel in default SMP QEMU/KVM guests

[Avi Kivity <avi@redhat.com>]

On 03/19/2010 03:12 PM, Anthony Liguori wrote:
> On 03/19/2010 07:58 AM, Paolo Bonzini wrote:
>>
>>> 1) Change the default CPUID bits from 6/2/3 to 6/6/1, this passes the
>>> Linux kernel check. But I am not sure if that would introduce
>>> regressions, since some OSes apply quirks if they detect certain models
>>> (like we had with the sysenter issue in the past)
>>>
>>> 2) Only change the CPUID bits to 6/6/1 if we use SMP. Still has the
>>> above drawback, but would be limited to SMP guests only.
>>>
>>> 3) Set kvm64/kvm32 as the default CPU model if KVM is enabled. This
>>> would limit the report and taint to TCG, where SMP is rarely used.
>>> Additionally less people (if any) use it for production systems.
>>>
>>> 4) Make the Linux' kernel quirk dependent on the missing hypervisor 
>>> bit.
>>> I don't think this will be accepted easily upstream (and I don't 
>>> want to
>>> support Ingo's recent ideas ;-), also this would not fix older kernels.
>>>
>>> I can easily provide patches for all solutions, but I'd like to get
>>> advice from people on which one to pursue.
>>
>> Doing (3) seems the most sensible thing to do, and it does not 
>> prevent doing (1) later on for TCG only.
>
> Let's switch to -cpu host for kvm. 

Except for -M old.

This has the nice advantage of exposing new features as they are rolled out.

-- 
error compiling committee.c: too many arguments to function