Date:   Fri, 17 Mar 2023 15:07:37 +0000
From:   Catalin Marinas <catalin.marinas@arm.com>
To:     Kristina Martsenko <kristina.martsenko@arm.com>
Cc:     linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Mark Brown <broonie@kernel.org>,
        Luis Machado <luis.machado@arm.com>,
        Vladimir Murzin <vladimir.murzin@arm.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 04/10] arm64: mops: document boot requirements for MOPS
Message-ID: <ZBSCObGmIXjyeMA6@arm.com>
References: <20230216160012.272345-1-kristina.martsenko@arm.com>
 <20230216160012.272345-5-kristina.martsenko@arm.com>
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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