Re: [Xen-devel] [PATCH v2 2/3] x86/vpmu: Disable VPMU if guest's CPUID indicates no PMU support

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 22.02.17 at 15:15, <boris.ostrovsky@xxxxxxxxxx> wrote:
> On 02/22/2017 04:55 AM, Jan Beulich wrote:
>>>>> On 17.02.17 at 18:40, <boris.ostrovsky@xxxxxxxxxx> wrote:
>>> --- a/xen/arch/x86/cpu/vpmu_intel.c
>>> +++ b/xen/arch/x86/cpu/vpmu_intel.c
>>> @@ -884,6 +884,10 @@ int vmx_vpmu_initialise(struct vcpu *v)
>>>      if ( vpmu_mode == XENPMU_MODE_OFF )
>>>          return 0;
>>>  
>>> +    if ( MASK_EXTR(v->domain->arch.cpuid->basic.raw[0xa].a, 
>>> +                   PMU_VERSION_MASK) == 0 )
>>> +        return -EINVAL;
>> How about other unsupported (too large) values?
> 
> Yes, we can check here for version >=5 as well.
> 
> (I don't think we should make this additional test in
> update_domain_cpuid_info())

... because of ... ? After all it's the purpose of this patch to not
expose the vPMU in such cases, which imo ought to be done
consistently in both places.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel