Re: [PATCH] Remove MSR_P6_{EVNTSEL0,PERFCTR0} from printk warning list.

[Jes Sorensen <Jes.Sorensen@redhat.com>]

On 07/01/10 16:44, Avi Kivity wrote:
> On 07/01/2010 05:41 PM, Jes Sorensen wrote:   
>> Saw it, which is why I only suggest we remove EVNTSEL0 and PERFCTR0 but
>> not the others. If the guest is expecting normal operation it is likely
>> to use more than just the first.   
> 
> Why is that?

Depends on usage obviously.

>> People are reporting these triggering in dmesg for both Linux and
>> Windows guests btw.
>>
>> We could put them so the two in question only trigger with a debug flag
>> or something like that?
>>    
> 
> What values are the guests writing?  Are they really expecting this
> thing to work?
> 
> What would it take to emulate those counters?  They're supposed to be
> relatively simple, no?
> 

Sometimes just 0x00, other times more advanced values. I'll have to dig
into the manuals to figure out what it is:

kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079
kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffd7698c
kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079
kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079
kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffd7699c
kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079

I'll try and figure out what it is.

Cheers,
Jes