[PATCH 04/10] arm64: mops: document boot requirements for MOPS

Catalin Marinas catalin.marinas at arm.com
Fri Mar 17 08:07:37 PDT 2023


On Thu, Feb 16, 2023 at 04:00:06PM +0000, Kristina Martsenko wrote:
> +  For CPUs with Memory Copy and Memory Set instructions (FEAT_MOPS):
> +
> +  - If the kernel is entered at EL1 and EL2 is present:
> +
> +    - HCRX_EL2.MSCEn (bit 11) must be initialised to 0b1.
> +
> +    - HCRX_EL2.MCE2 (bit 10) must be initialised to 0b0.

Regarding MCE2, does EL1 actually care if EL2 wants to handle all the
memcpy/memset exceptions? There may even be a valid case to do this at
EL2 if you run a guest that uses these instructions but has no clue on
how to deal with the specific exception like WrongOption.

-- 
Catalin



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