On Tue, Dec 27, 2022 at 03:49:39PM -0600, Kalra, Ashish wrote:
> Milan onward,
And before ML there's no SNP, right?
> there is H/W support for coherency between mappings of the
> same physical page with different encryption keys, so AFAIK, there should be
> no need to flush during page state transitions, where we invoke these direct
> map interface functions for re-mapping/invalidating pages.
Yah, that rings a bell.
In any case, the fact that flushing is not needed should be stated
somewhere in text so that it is clear why.
> I don't know if there is any other reason to flush after modifying
> the direct map ?
There's
/*
* No need to flush, when we did not set any of the caching
* attributes:
*/
cache = !!pgprot2cachemode(mask_set);
Does the above HW cover this case too?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
