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From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Joey Gouly <joey.gouly@arm.com>,
	Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH v2 06/25] KVM: arm64: nv: Add sanitising to VNCR-backed
 HCRX_EL2
Message-ID: <Zb0_0fq4E1_L7lC6@linux.dev>
References: <20240130204533.693853-1-maz@kernel.org>
 <20240130204533.693853-7-maz@kernel.org>
 <ZbytUKPFYiP2cdd8@linux.dev>
 <86h6iq7w3x.wl-maz@kernel.org>
 <Zb0jRzTYyc0IxR00@linux.dev>
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On Fri, Feb 02, 2024 at 05:15:51PM +0000, Oliver Upton wrote:
> On Fri, Feb 02, 2024 at 02:56:50PM +0000, Marc Zyngier wrote:
> > No amount of warnings will do, because people don't give a damn.
> > 
> > I'm actually in favour of something far more radical: we snapshot the
> > raw value of all the used RES0/1, and put BUILD_BUG_ON()s that fire if
> > any value has changed. They will have to touch the KVM code to fix
> > that, and we catch them red-handed.
> 
> Oh I like that a lot more.

Unsure which registers you planned to give this treatment, but all of
the ID registers we know about should probably go in this bucket too.

-- 
Thanks,
Oliver