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

Wei Liu
2021-04-21T13:21:51Z

On Wed, Apr 21, 2021 at 07:15:54AM -0400, Vineeth Pillai wrote:
>
>
> 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.

Okay.

>
> >
> > 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.

Okay. Let's match what is written in TLFS.

Wei.

>
> Thanks,
> Vineeth
>