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From: Marc Zyngier <maz@kernel.org>
To: Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>,
	linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
	Mark Rutland <mark.rutland@arm.com>,
	Oliver Upton <oupton@kernel.org>,
	Vincent Donnefort <vdonnefort@google.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Sudeep Holla <sudeep.holla@kernel.org>
Subject: Re: [PATCH v2] KVM: arm64: Work around C1-Pro erratum 4193714 for protected guests
Date: Wed,  6 May 2026 17:14:33 +0100	[thread overview]
Message-ID: <177808404886.2712489.16077885657000139159.b4-ty@kernel.org> (raw)
In-Reply-To: <20260505165205.2690919-1-catalin.marinas@arm.com>

On Tue, 05 May 2026 17:52:03 +0100, Catalin Marinas wrote:
> C1-Pro cores with SME have an erratum where TLBI+DSB does not complete
> all outstanding SME accesses. Instead a DSB needs to be executed on the
> affected CPUs. The implication is that pages cannot be unmapped from the
> host Stage 2 and then provided to a protected guest or to the
> hypervisor. Host SME accesses may still complete after this point.
> 
> This erratum breaks pKVM's guarantees, and the workaround is hard to
> implement as EL2 and EL1 share a security state meaning EL1 can mask
> IPIs sent by EL2, leading to interrupt blackouts.
> 
> [...]

Applied to fixes, thanks!

[1/1] KVM: arm64: Work around C1-Pro erratum 4193714 for protected guests
      commit: 1f7305d87aa23db2579df222eba504a333c2c978

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.




      parent reply	other threads:[~2026-05-06 16:14 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-05 16:52 [PATCH v2] KVM: arm64: Work around C1-Pro erratum 4193714 for protected guests Catalin Marinas
2026-05-06 13:37 ` Vincent Donnefort
2026-05-06 14:21   ` Marc Zyngier
2026-05-06 15:48   ` Catalin Marinas
2026-05-06 16:06     ` Marc Zyngier
2026-05-06 16:14 ` Marc Zyngier [this message]

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