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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 81F93C6FA82 for ; Tue, 13 Sep 2022 07:32:29 +0000 (UTC) Received: from localhost ([::1]:41752 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oY0PE-0001Xf-5C for qemu-devel@archiver.kernel.org; Tue, 13 Sep 2022 03:32:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36162) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oY09p-0008VN-Jx for qemu-devel@nongnu.org; Tue, 13 Sep 2022 03:16:34 -0400 Received: from 9.mo548.mail-out.ovh.net ([46.105.48.137]:49643) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oY09l-0000bS-4p for qemu-devel@nongnu.org; Tue, 13 Sep 2022 03:16:31 -0400 Received: from mxplan5.mail.ovh.net (unknown [10.109.143.174]) by mo548.mail-out.ovh.net (Postfix) with ESMTPS id C247022F25; Tue, 13 Sep 2022 07:16:15 +0000 (UTC) Received: from kaod.org (37.59.142.99) by DAG4EX2.mxp5.local (172.16.2.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Tue, 13 Sep 2022 09:16:14 +0200 Authentication-Results: garm.ovh; auth=pass (GARM-99G003c8f4b3f8-0b54-40d6-8d70-af0d56f397f9, 100000D2639293FA209945C79AD02F9CE6615B5E) smtp.auth=clg@kaod.org X-OVh-ClientIp: 82.64.250.170 Message-ID: Date: Tue, 13 Sep 2022 09:16:07 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.1 Subject: Re: Any interest in a QEMU emulation BoF at KVM Forum? Content-Language: en-US To: =?UTF-8?Q?Alex_Benn=c3=a9e?= , "qemu-devel@nongnu.org" CC: Mark Burton , Bill Mills , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , "Edgar E. Iglesias" , Richard Henderson , Paolo Bonzini , Peter Maydell , Michael Rolnik , Taylor Simpson , Song Gao , Xiaojuan Yang , Palmer Dabbelt , Alistair Francis , Bin Meng , David Gibson , Markus Armbruster , Michael Roth , Luc Michel , Damien Hedde , Alessandro Di Federico References: <87a67kphih.fsf@linaro.org> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [37.59.142.99] X-ClientProxiedBy: DAG5EX2.mxp5.local (172.16.2.42) To DAG4EX2.mxp5.local (172.16.2.32) X-Ovh-Tracer-GUID: 698a88f4-6712-4c1b-ad67-59c6f25ac1a0 X-Ovh-Tracer-Id: 3332382249972632406 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvfedrfedufedguddvtdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefkffggfgfuvfevfhfhjggtgfhisehtkeertddtfeejnecuhfhrohhmpeevrogurhhitggpnfgvpgfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepveffhfehgeeiieehieeiudevgfelleejjedtgfdtgeffgfeujedujeejudfhkeeknecuffhomhgrihhnpehophgvnhguvghvrdhorhhgpdhgohhoghhlvgdrtghomhenucfkpheptddrtddrtddrtddpfeejrdehledrudegvddrleelnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpohhuthdphhgvlhhopehmgihplhgrnhehrdhmrghilhdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomheptghlgheskhgrohgurdhorhhgpdhnsggprhgtphhtthhopedupdhrtghpthhtoheprghlvgesrhgvvhdrnhhgpdfovfetjfhoshhtpehmohehgeek Received-SPF: pass client-ip=46.105.48.137; envelope-from=clg@kaod.org; helo=9.mo548.mail-out.ovh.net X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-2.153, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 9/13/22 09:12, Alex Bennée wrote: > The BoF session will be in Lifey A (the big hall) this afternoon. I thought being able to sit around tables while we discuss things would make things a bit easier. We can share note taking on the etherpad: > > https://etherpad.opendev.org/p/qemu-emulation-bof%40kvmforum2022 > > I'll run a HO at: https://meet.google.com/rac-axef-xvv Thanks for that. I will try to join. What time approximately ? C. > > On Wed, 31 Aug 2022 at 16:19, Alex Bennée > wrote: > > Hi, > > Given our slowly growing range of TCG emulations and the evident > interest in keeping up with modern processor architectures is it worth > having an emulation focused BoF at the up-coming KVM Forum? > > Some potential topics for discussion I could think of might include: > >  * Progress towards heterogeneous vCPU emulation > >  We've been making slow progress in removing assumptions from the >  various front-ends about their global nature and adding accel:TCG >  abstractions and support for the translator loop. We can already have >  CPUs from the same architecture family in a model. What else do we need >  to do so we can have those funky ARM+RiscV+Tricore heterogeneous >  models? Is it library or something else? > >  * External Device Models > >  I know this is a contentious topic given the potential for GPL >  end-runs. However there are also good arguments for enabling the >  testing of open source designs without having forcing the >  implementation of a separate C model to test software. For example if >  we hypothetically modelled a Pi Pico would it make sense to model the >  PIO in C if we could just compile the Verilog for it into a SystemC >  model? Would a plethora of closed device models be the inevitable >  consequence of such an approach? Would it matter if we just >  concentrated on supporting useful open source solutions? > >  * Dynamic Machine Models > >  While we try and avoid modelling bespoke virtual HW in QEMU >  (virt/goldfish not withstanding ;-) there is obviously a desire in the >  EDA space to allow such experimentation. Is this something we can >  provide so aspiring HW engineers can experiment with system >  architectures without having to form QEMU and learn QOM. There have >  been suggestions about consuming device trees or maybe translating to >  QMP calls and adding support for wiring devices together. Given the >  number of forks that exist is this something that could be better >  supported upstream without degenerating into messy hacks? > >  * A sense of time > >  Currently we have the fairly limited support for -icount in QEMU. At >  the same time we have no desire to start expanding frontends with >  the details cost models required for a more realistic sense of time to >  be presented. One suggestion is to expand the TCG plugin interface to >  allow for the plugin to control time allowing as much or little logic >  to be pushed there as we like and freeing up frontends from ever having >  to consider it. > > Are any of these topics of interest? Are there any other emulation > topics people would like to discuss? > > -- > Alex Bennée > > > > -- > Alex Bennée > KVM/QEMU Hacker for Linaro