Re: [Xen-devel] [PATCH v2 07/14] x86/cpuid: Handle leaves 0x80000005-7 in guest_cpuid()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 24/01/17 11:59, Jan Beulich wrote:
>>>> On 23.01.17 at 15:39, <andrew.cooper3@xxxxxxxxxx> wrote:
>> Intel reserves all of this information other than the L2 cache information,
>> and the ITSC bit from the power management leaf.
>>
>> AMD passes all of the cache/TLB information through to the guest, while most
>> of of the power management information is explicitly clobbered by the
>> toolstack.
> Both of these look to not be fully in line with ...
>
>> --- a/xen/arch/x86/cpuid.c
>> +++ b/xen/arch/x86/cpuid.c
>> @@ -167,6 +167,9 @@ static void recalculate_misc(struct cpuid_policy *p)
>>  
>>      p->extd.e1d &= ~CPUID_COMMON_1D_FEATURES;
>>  
>> +    /* Most of Power/RAS hidden from guests. */
>> +    p->extd.raw[0x7].a = p->extd.raw[0x7].b = p->extd.raw[0x7].c = 0;
> ... you leaving .d completely untouched. Can you clarify this please?

e7d is covered by the featureset bitmap, because it contains the ITSC
feature.

It is therefore covered by the main body of recalculate_domain_policy().

~Andrew

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