From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 797104749EA; Tue, 18 Aug 2026 12:51:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787057496; cv=none; b=BoO3HEZ1rhxwZDFrxhrbCN3EmGloL0/rByISL50pHzosr+kKBzCtxQqpoAjAkCttzMqgols4KZ0E/XafE8pq6d9utpDo6xojSWg0jshJ89Fcpz952++HRMJmV8GQy2fwJD1CORU3pqX+H62Dnn+lX3YEIG3XnmX7OeMe9bWSH7c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787057496; c=relaxed/simple; bh=CaQlhnRfhHiCPvm4MoRFQkp0GY3OUY4+aqKgtEjqryo=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=CXeES3N9yokNnh4L3igU2iYPSqqrtUuhHtHFHyUFlDcR5aa9QOafO/R8SX0ibfi5ZbtzxPqU7D87aG83Eyj0xi/JxgdVCl4hO+FaScCcrmzQw1BUzjy9S41TTizpuIFUXu2IsXvMzp7reYaSMwrrreivag0G/17heB5D420tXeg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bL7DhPbe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bL7DhPbe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D959E1F000E9; Tue, 18 Aug 2026 12:51:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787057493; bh=fVQkbnkcPID0tlGdkZD/qk8GG6F0/FGCGkoKwHJzbKc=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=bL7DhPbe5v9QlCLIGfnAMcHPus/g5gYQEQ8stEgthXcOMeZ780Qw4aT0a5dQTYeHF aW/5ndKvld9cH7ix6o2jQ+BQRnJhr59RSc9cA3lr9vWNqAJrraEks3fLCjdsCW7et5 8GI66GeHDJ/QG871ZlnvaFxPnNSnHtWEtThb5IDFLpJuw/xULuUAzLKDMC40eqrjhK eKHYDTPgfBeIKZs9Lfb3Xmcvd9Oz20Q7JSP3H9Po4pdIjnYAIjMWadLt50UMwXXhFD k8mWA1IPdSfBdf6c5C67urFhzSWDcnuJ2Mqf3csG6xwWEjy1pOTIP1LcfvphAdy2Kj AnoJOQkHw0Ung== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) 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 1wwJHv-0000000GdB6-2g0Z; Tue, 18 Aug 2026 12:51:31 +0000 Date: Tue, 18 Aug 2026 13:51:24 +0100 Message-ID: <86fr0b6183.wl-maz@kernel.org> From: Marc Zyngier To: Fuad Tabba Cc: Oliver Upton , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Quentin Perret , Stefan Teodorescu , tabba@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve() In-Reply-To: <20260818093117.2379344-1-fuad.tabba@linux.dev> References: <20260818093117.2379344-1-fuad.tabba@linux.dev> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: fuad.tabba@linux.dev, oupton@kernel.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, qperret@google.com, fane@google.com, tabba@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Tue, 18 Aug 2026 10:31:17 +0100, Fuad Tabba wrote: > > pkvm_vcpu_init_sve() clamps only the upper bound of the host-provided > sve_max_vl, so an invalid vector length reaches sve_state_size_from_vl() > and the WARN_ON() there, which is fatal at EL2. The existing > !sve_state_size test rejects such a length, but only after the macro has > run. > > Check sve_vl_valid() before deriving the state size. A valid length > cannot yield a zero size, so the !sve_state_size test goes with it. > > Fixes: 5db1bef93342 ("KVM: arm64: Track SVE state in the hypervisor vcpu structure") > Reported-by: Stefan Teodorescu > Signed-off-by: Fuad Tabba Reviewed-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.