From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EFF50CD343B for ; Wed, 6 May 2026 16:14:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=scqFfPItdGINGCWBU061MbMp1aJ9X/xDHgUNHVisgCE=; b=QE3ak5jEf58RnrnLKTuGzm66Dc 0iwe3N84XDd/UwEforlcEoG/hqhbsDTk7ERkRZswOt/h38t11lbG1NcNLh1oVlE1BneQrQk20DM/l TvkzTyQJ5D7yhJ0t3/srRjVDymPEUv5S35f6vNrNVj1OllE8erTlCAHWo0dVqbyR63VLXlnqZVH9q nLwoV7TgJxepa/zE1rq5jcNcnNuV5Vk6LmEWtbAhnrdR5/7z1GJx4ylvSYI8Ruehu5KozCwbaCwJe 7Mfzw/MtaKm725OndGdAqMxaIRXATEKD/nZrWNiiVc/LuJZntZ4Vdi0e4WQQXjJ2Tqst1gTbbbUtM PTUuhW2A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKetW-00000001T4V-3uO5; Wed, 06 May 2026 16:14:42 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKetS-00000001T2M-445o for linux-arm-kernel@lists.infradead.org; Wed, 06 May 2026 16:14:40 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id B112F44224; Wed, 6 May 2026 16:14:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CDFCC2BCB8; Wed, 6 May 2026 16:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778084078; bh=NWybhyhZOftJ9uYzJ6gBhCYWxRgsVrDsoYwiBx0JL+M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d5fY96X9nEDw11sMbwI3KaWS9j+3p2jEuuARhK9OvDaBwQN9wAzJfEOtWtSDYHx4d 5u1Bj/VqUmri3eMVa6zUn5h8lZZ7o1UAJQ7w1+F8SSiwkYhvC8orc6RISZX0hzCycL PWwrNOPQ3CstXUbeKGvYkn9Eg9wuOoLniZrCGOXZBWXzmgg5VpUNz9Z1440KnXV/0X 6xNWZTWAu9BWtF8/2gWoP8Ko9LcD7mjGd79E4jzFe0sb20whz6+UO6tsPVK3qJ0Gzt wxCgbnXkbrZ0t5cnxBOjIAhS7WlD3hoKdbKXcnv/TJ86GNE8SvGM5Yfnz0gH42nFmT b9Ps6XZ4W1bWw== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wKetQ-00000000MI9-1pD4; Wed, 06 May 2026 16:14:36 +0000 From: Marc Zyngier To: Will Deacon , Catalin Marinas Cc: James Morse , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, Mark Rutland , Oliver Upton , Vincent Donnefort , Lorenzo Pieralisi , Sudeep Holla Subject: Re: [PATCH v2] KVM: arm64: Work around C1-Pro erratum 4193714 for protected guests Date: Wed, 6 May 2026 17:14:33 +0100 Message-ID: <177808404886.2712489.16077885657000139159.b4-ty@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260505165205.2690919-1-catalin.marinas@arm.com> References: <20260505165205.2690919-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: will@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, mark.rutland@arm.com, oupton@kernel.org, vdonnefort@google.com, lpieralisi@kernel.org, sudeep.holla@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260506_091440_334496_76FAD012 X-CRM114-Status: GOOD ( 11.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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.