On Thu, Mar 09, 2023 at 03:36:45PM +0100, Jörg Rödel wrote:
> Yes, that is right. The key is mainly for the NMI entry path which can
> be performance relevant in some situations. For SEV-ES some special
> handling is needed there to re-enable NMIs and adjust the #VC stack in
> case it was raised on the VC-handlers entry path.
So the performance argument is meh. That key will be replaced by
if (cc_vendor == CC_VENDOR_AMD &&
cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)
which is something like 4 insns or so. Tops.
Haven't looked yet but it should be cheap.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
