Re: perf uncore & lkvm woes

[Avi Kivity <avi@redhat.com>]

On 08/16/2012 11:40 AM, Avi Kivity wrote:
> On 08/16/2012 10:41 AM, Pekka Enberg wrote:
>> On 08/16/2012 03:19 PM, Peter Zijlstra wrote:
>>>> On Thu, 2012-08-16 at 10:01 +0300, Pekka Enberg wrote:
>>>>> Has anyone seen this? It's kvmtool/next with 3.6.0-rc1. Looks like we
>>>>> are doing uncore_init() on virtualized CPU which breaks boot.
>>>>
>>>> I think you're the first.. I don't normally use kvm if I can at all
>>>> avoid it.
>>>>
>>>> But I think its a 'simple' matter of kvm not emulating the entire
>>>> hardware. Afaik the uncore isn't enumerated and we simply assume MSR
>>>> presence based on cpu model.
>> 
>> On Thu, Aug 16, 2012 at 10:38 AM, Yan, Zheng
>> <zheng.z.yan@linux.intel.com> wrote:
>>> The Intel uncore doc does not specify how to check if uncore exist.
>>> How about disabling uncore on virtualized CPU?
>> 
>> (CC'ing Avi.)
>> 
> 
> Seems reasonable, if unfortunate.  It's pretty easy to check for.
> 
> If those are separate MSRs, we can also trap the #GP and exit gracefully.

Another option is to deal with them on the host side.  That has the
benefit of working with non-Linux guests too.

We can just ignore the MSR and print some warning.

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