Messages in this thread | | | Date | Thu, 4 Aug 2022 14:11:16 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH Part2 v6 07/49] x86/sev: Invalid pages from direct map when adding it to RMP table |
| |
On Mon, Aug 01, 2022 at 11:57:09PM +0000, Kalra, Ashish wrote: > You mean set_memory_present() ?
Right, that.
We have set_memory_np() but set_memory_present(). Talk about consistence... ;-\
> But again, calling set_direct_map_invalid_noflush() is easier to > understand from the calling function's point of view as it correlates > to the functionality of invalidating the page from kernel direct map ?
You mean, we prefer easy to understand to performance?
set_direct_map_invalid_noflush() means crap to me. I have to go look it up - set memory P or NP is much clearer.
The patch which added those things you consider easier to understand is:
commit d253ca0c3865a8d9a8c01143cf20425e0be4d0ce Author: Rick Edgecombe <rick.p.edgecombe@intel.com> Date: Thu Apr 25 17:11:34 2019 -0700
x86/mm/cpa: Add set_direct_map_*() functions Add two new functions set_direct_map_default_noflush() and set_direct_map_invalid_noflush() for setting the direct map alias for the page to its default valid permissions and to an invalid state that cannot be cached in a TLB, respectively. These functions do not flush the TLB.
I don't see how this fits with your use case...
Also, your helpers are called restore_direct_map and invalidate_direct_map. That's already explaining what this is supposed to do.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
| |