Re: [PATCH v15 11/21] x86/VPMU: Interface for setting PMU mode and flags

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 11/25/2014 08:49 AM, Jan Beulich wrote:
>>>> On 17.11.14 at 00:07, <boris.ostrovsky@oracle.com> wrote:
>> @@ -244,19 +256,19 @@ void vpmu_initialise(struct vcpu *v)
>>       switch ( vendor )
>>       {
>>       case X86_VENDOR_AMD:
>> -        if ( svm_vpmu_initialise(v, opt_vpmu_enabled) != 0 )
>> -            opt_vpmu_enabled = 0;
>> +        if ( svm_vpmu_initialise(v) != 0 )
>> +            vpmu_mode = XENPMU_MODE_OFF;
>>           break;
>>   
>>       case X86_VENDOR_INTEL:
>> -        if ( vmx_vpmu_initialise(v, opt_vpmu_enabled) != 0 )
>> -            opt_vpmu_enabled = 0;
>> +        if ( vmx_vpmu_initialise(v) != 0 )
>> +            vpmu_mode = XENPMU_MODE_OFF;
>>           break;
> So this turns off the vPMU globally upon failure of initializing
> some random vCPU. Why is that? I see this was the case even
> before your entire series, but shouldn't this be fixed _before_
> enhancing the whole thing to support PV/PVH?

Yes, that's probably too strong. Do you want to fix this as an early 
patch (before PV(H)) support gets in? I'd rather do it in the patch that 
moves things into initcalls.

-boris