From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0D32A25776 for ; Wed, 5 Feb 2025 17:02:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738774947; cv=none; b=CoGYA4o5OPxFM8i8joiEgfDk/H61mIoSrDoYxcidxFtuZTW6zBjwYCXdmvNAvlD+DPJHpTgK1p6FvaA3lbvMxeqVHwJwSPSPHJez06MIS2EjLlKOsajwnacAyP1r8zJNdg1tsmdbEDMdNYFZBvjRLfdtzvem2MBTkUswWjxRr+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738774947; c=relaxed/simple; bh=5DayLdJidyaaF50WtqZ5UKKOQ7ZjMYF7PpSflEB5fkg=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=S54hOxXKGeCWTlmFaDQwF00zKdssS8/UsdLLKGb1Kb9vIpN3P6O/cuqrhBz9hYDUEzLSgh3AULaFNtKCScLBcmZPpgTtR9np2h8asvhxhM2zgxrBn5OhEzVObSq7dW29+uruvy+hmQXdSvCttUkAA+0+maGbzaFBRMZCLpkq83Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iczTJmTv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iczTJmTv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57B94C4CED1; Wed, 5 Feb 2025 17:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738774946; bh=5DayLdJidyaaF50WtqZ5UKKOQ7ZjMYF7PpSflEB5fkg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=iczTJmTvDBh/ih2YjFeeRgo+b4t4JmWyvk0NJnDzS8BbLHKsY/BKGBCKvwrSv5eLJ UKGpTOkICfhL0N5jUICGkKpX7cQZYPBB98jD78MseUqG9t+O+X6H/c2R4jvpNo9qzN 23V12OVEdG8jvESU4aj9l1WkGXeC7TKK3l4f+r80QjJB/2BTOj4hqmeUmHkomnqmDs MzH72Dnd4zpAe8wL3qMahqkEH7QO6jHGD1hqkcOchPJNk395SUHnBvbnrN0Gj/YXHe mKYQTq2hC+cbVzwaQlNfF6shghQgG1FxCPbaAV8doo+2N4SmwkGFJ2pxBHgDJakpKi aMNSLsBS63AZw== 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 4.95) (envelope-from ) id 1tfin9-000qho-JN; Wed, 05 Feb 2025 17:02:23 +0000 Date: Wed, 05 Feb 2025 17:02:22 +0000 Message-ID: <86tt98tjdt.wl-maz@kernel.org> From: Marc Zyngier To: Fuad Tabba Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oliver.upton@linux.dev, will@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, james.morse@arm.com, jingzhangos@google.com, anshuman.khandual@arm.com, shameerali.kolothum.thodi@huawei.com, gshan@redhat.com Subject: Re: [PATCH v1] arm64: head.S: Do not trap access to MPAMSM_EL1 In-Reply-To: <20250205164630.1706058-1-tabba@google.com> References: <20250205164630.1706058-1-tabba@google.com> 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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev 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: tabba@google.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oliver.upton@linux.dev, will@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, james.morse@arm.com, jingzhangos@google.com, anshuman.khandual@arm.com, shameerali.kolothum.thodi@huawei.com, gshan@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 05 Feb 2025 16:46:27 +0000, Fuad Tabba wrote: > > Bit 50 of MPAM2_EL2, EnMPAMSM, traps access to MPAMSM_EL1 when 0, > as per ARM ARM DDI DDI0487L.a, section D24.12.3. Therefore, > ensure it is set to 1 for the host to disable the traps. But what makes use of this register in the kernel? I can't find any trace of it in 6.14-rc1. Thanks, M. -- Without deviation from the norm, progress is not possible.