Re: [PATCH v2 2/7] hyperv: SVM enlightened TLB flush support flag

Vineeth Pillai
2021-04-21T11:16:04Z

On 4/21/21 6:00 AM, Wei Liu wrote:
> On Thu, Apr 15, 2021 at 01:43:37PM +0000, Vineeth Pillai wrote:
>>
>> +/*
>> + * This is specific to AMD and specifies that enlightened TLB flush is
>> + * supported. If guest opts in to this feature, ASID invalidations only
>> + * flushes gva -> hpa mapping entries. To flush the TLB entries derived
>> + * from NPT, hypercalls should be used (HvFlushGuestPhysicalAddressSpace
>> + * or HvFlushGuestPhysicalAddressList).
>> + */
>> +#define HV_X64_NESTED_ENLIGHTENED_TLB BIT(22)
>> +
> c
> This is not yet documented in TLFS, right? I can't find this bit in the
> latest edition (6.0b).
This would be documented in the TLFS update which is soon to be
released.

>
> My first thought is the comment says this is AMD specific but the name
> is rather generic. That looks a bit odd to begin with.
I thought of of keeping the name generic to avoid renaming Intel
specific ones also. If I understand correctly, the TLFS would also
be having generic name for this and just translated the generic
name here in this header.

Thanks,
Vineeth