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 16E5EC4451C for ; Fri, 17 Jul 2026 12:09:16 +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-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4rm4TVNxeMX719ukVGcBp97E106HiBaS44S5d6OARlw=; b=vwjKJKj/dPQigzH33juzWw+/GO B6XnnL9mfcSrFaBMKKyYRVj5pPrT9En5GnhGlzJqk8adUAyxQ8OOuVhuVWCadPd0KxvaCuRBM4SIm 5JNDn1DZlwCmMsj+gGX+E9P2OxKF/zMp4HZCO/t2CRW5WqjXQ6zjzWT7AtYJ2V0QQ5NxI79tQHFNy f1FCwNz3a8nKdY2CwP/Ut1hkRFTBSD4tKSfDxBx1a0PdkFo2mPW+y/BdsdJatyeIy+RgytFVfuzlH XrJydXDC6tx0p0GGVuNNZia/HzMuZ771TCDav9CreBCAytKk4HX4GhtM6oX2f+e1yIfhOTxPuL3/b Eqo+zyxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkhNO-00000002F3Y-09uN; Fri, 17 Jul 2026 12:09:10 +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 1wkhNN-00000002F3J-1Tvp for linux-arm-kernel@lists.infradead.org; Fri, 17 Jul 2026 12:09:09 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CF76D41FB3; Fri, 17 Jul 2026 12:09:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE9D71F000E9; Fri, 17 Jul 2026 12:09:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784290148; bh=4rm4TVNxeMX719ukVGcBp97E106HiBaS44S5d6OARlw=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=mhRPrpJMmd8MkXxWkYZ7k1BdtqFNLcNPQp69RvvRo881MOXC8CzN2rv7LpigjWzzY YvUv5KKqeO1j29IBde6wJeRh0cYohfv00EAkkfURCrVVQJAdmOckFdxVD6cR7aC9Ya PdanYlh7AAJmOmT7MtTKsyczNU0Se4FSGkwyZfUo2sHp+u3EmFpLm5fbiUpj1TP8EK hZ3RNkpAOkBaRUgL2uT2tmVmpwPVL/T2aAFF2sK3ueRS9o/BBF5dl/GYo7r2yUiJGv WAhl/i/LWMJMS2+cu/7WTVLmdu/cp8If/P5tZfGQ0kE3cCOR8RkTYg0+5UOh0k+xCc PLTwvxx/0Uu0w== Received: from sofa.misterjones.org ([185.219.108.64] helo=lobster-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 1wkhNJ-0000000644A-3sQ5; Fri, 17 Jul 2026 12:09:06 +0000 Date: Fri, 17 Jul 2026 13:09:04 +0100 Message-ID: <87ech1rf6n.wl-maz@kernel.org> From: Marc Zyngier To: Ryan Roberts , Will Deacon Cc: Greg Kroah-Hartman , Arnd Bergmann , Catalin Marinas , Mark Rutland , Jean-Philippe Brucker , Oded Gabbay , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, oupton@kernel.org, hch@infradead.org, jgg@nvidia.com Subject: Re: [RFC PATCH v1 0/8] Arm Core Local Accelerator Driver In-Reply-To: References: <20260717104759.123203-1-ryan.roberts@arm.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/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) 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: ryan.roberts@arm.com, will@kernel.org, gregkh@linuxfoundation.org, arnd@arndb.de, catalin.marinas@arm.com, mark.rutland@arm.com, jpb@kernel.org, ogabbay@kernel.org, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, oupton@kernel.org, hch@infradead.org, jgg@nvidia.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false 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 Thanks Will for roping me in. On Fri, 17 Jul 2026 12:33:17 +0100, Will Deacon wrote: > > > I'm deliberately constraining the scope to bare-metal support for now. > > Virtualization is something we are considering (and have prototyped), but plan > > to post a separate RFC for that as follow-up, once we have agreement on > > direction for the bare-metal driver. > > I'd actually like to see what the virtualisation part looks like first > because doing it as a bolt-on later feels like the wrong approach. The > structure you have at the moment is remarkably clean, given the > architectural/CPU interactions (this thing even apparently builds as a > module, nice!), but I'm unsure how far you can push the separation once > you need to start hacking at KVM. Maybe the MMU notifiers are enough, > but I can't tell. +1. Virtualisation cannot be a "bolt on the side" exercise. It is an integral part of the arm64 tree, particularly for memory management and scheduling, all of which have a direct impact on KVM. I don't think we can really evaluate anything here without looking at the full picture. Thanks, M. -- Jazz isn't dead. It just smells funny.