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 CCF7C3D8128; Fri, 17 Jul 2026 12:09:08 +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=1784290149; cv=none; b=NpHpR5jX/qGPe1go67gr9tr2DWr247+EPMN3EaCOlA0JPpvk0NNmFjaYuvsElYFcBg8YpZ0pim3zVwGu7jdIc+qlVbSmsVvPGzeCcFGyqtMcuryoGq0Jt0gRrCsQiwBOeUWyHs52HChUZrLvhs/t0KM4F4Uc9rV1VytMQEuy9G0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784290149; c=relaxed/simple; bh=iNEqYuOjm7uIPttT8oUjfw6gEZ4rjmmSb7FLemK1JME=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=CLs4ofHVkTxg8bynXiaQwzRKTtrfySTXEbX+IMRXcnC7WvgHZ3T90c0Il6FVjIUF5XmTyPPt9ZvGY+x9cuzoWm6oGnzEOOGauznr5dMmp7zKe+oE2XLcvUmMZ1ND7mmjZ40e5zp10yjN1NVIbbPMhK/UExIus1a/zZH4Dsb2ARE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mhRPrpJM; 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="mhRPrpJM" 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) Precedence: bulk X-Mailing-List: linux-doc@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: 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 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.