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Date:   Thu, 25 May 2023 19:26:01 +0000
In-Reply-To: <20230509142235.3284028-7-kristina.martsenko@arm.com>
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Message-ID: <gsntcz2ob4c6.fsf@coltonlewis-kvm.c.googlers.com>
Subject: RE: [PATCH v2 06/11] KVM: arm64: hide MOPS from guests
From:   Colton Lewis <coltonlewis@google.com>
To:     Kristina Martsenko <kristina.martsenko@arm.com>
Cc:     linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        Catalin Marinas <catalin.marinas@arm.com>,
        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
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> As FEAT_MOPS is not supported in guests yet, hide it from the ID
> registers for guests.

> The MOPS instructions are UNDEFINED in guests as HCRX_EL2.MSCEn is not
> set in HCRX_GUEST_FLAGS, and will take an exception to EL1 if executed.

For my benefit, could you please explain why no support for guests yet?
Why not set HCRX_EL2.MSCEn in this series?