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 47D0EC54756 for ; Tue, 20 May 2025 07:36:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uHHW7-0002TO-W9; Tue, 20 May 2025 03:36:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uHHVr-0002FL-UR for qemu-devel@nongnu.org; Tue, 20 May 2025 03:35:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uHHVp-0003tS-VZ for qemu-devel@nongnu.org; Tue, 20 May 2025 03:35:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747726543; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WWkL3HJfU9ZtRmhYuV0nrux9JGr0IQVUGgkPTbgezEU=; b=jMRnlGAwIHzChn33llAYCS9mOzBrpQ5YnFbdcvB3OyTNvcFDuxb0DMmb/x7/zP0EoxOIzY 7RQP7Or/AaERJzOVy2RoLu2dG8myWfvDXzBx9j9h9Xcoouk2EyfcL4ksTACV3tlLh0ulSG NMl55WjE6JPhh8IXPrtUM4r5BygfUr0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-39-kqojuQ7DMhSLIbiTvhYqDw-1; Tue, 20 May 2025 03:35:40 -0400 X-MC-Unique: kqojuQ7DMhSLIbiTvhYqDw-1 X-Mimecast-MFC-AGG-ID: kqojuQ7DMhSLIbiTvhYqDw_1747726539 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 03F001956086; Tue, 20 May 2025 07:35:39 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.27]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 98FC418004A7; Tue, 20 May 2025 07:35:38 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1336521E6768; Tue, 20 May 2025 09:35:36 +0200 (CEST) From: Markus Armbruster To: Mario Fleischmann Cc: qemu-devel@nongnu.org, alex.bennee@linaro.org, philmd@linaro.org, christian.boenig@lauterbach.com Subject: Re: [PATCH v2 00/20] Add Multi-Core Debug (MCD) API support In-Reply-To: <20250430052741.21145-1-mario.fleischmann@lauterbach.com> (Mario Fleischmann's message of "Wed, 30 Apr 2025 07:27:21 +0200") References: <20250430052741.21145-1-mario.fleischmann@lauterbach.com> Date: Tue, 20 May 2025 09:35:36 +0200 Message-ID: <87iklvd99z.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.13, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org Mario Fleischmann writes: > This patch series introduces support for the Multi-Core Debug (MCD) API, a > commonly used debug interface by emulators. The MCD API, defined through a > header file, consists of 54 functions for implementing debug and trace. > However, since it is a header-file-only interface, MCD does not specify a > communication protocol. > > To keep the overhead of a communication protocol on top of MCD minimal, > we follow a remote procedure call approach by using QAPI as an interface > definition and transport infrastructure. This way, we can use qapi-gen to > take care of generating the infrastructure to dispatch MCD functions and > to (un)marshal their arguments and results. Furthermore, qapi-doc and qtest > provide good integration into QEMU's documentation and test frameworks. > > In v1 of this patch series, the MCD protocol was directly integrated in QMP > and the QMP monitor was responsible for dispatching MCD's server stub. This > introduced a dependency between QEMU's machine protocol and the MCD debug > protocol which is not to be expected. For this reason, v2 introduces a MCD > monitor which uses as much of the QMP monitor's framework as possible but > keeps the two protocols separate from each other. > Similarly, MCD's test suite uses as much of the qtest framework as is useful > for sending JSON commands to the QEMU under test but adds new code where > required to prevent dependencies to QMP. > > To enable MCD, configure QEMU with `--enable-mcd`. > > To start the MCD monitor, run QEMU with the `-mcd` option: > qemu-system- [options] -qmp tcp::1235,server=on,wait=off > > To run the MCD test suite independently, start `mcd-test`: > V=1 QTEST_QEMU_BINARY="./qemu-system- [options]" tests/qtest/mcd-test > > To connect from a MCD client, a client stub corresponding to this > patch series can be found at https://gitlab.com/lauterbach/mcdrefsrv I'm okay with the general approach. [...] > MAINTAINERS | 9 + > docs/interop/index.rst | 1 + > docs/interop/mcd.rst | 65 + > gdbstub/gdbstub.c | 15 +- > include/exec/gdbstub.h | 18 +- > include/exec/mcdstub.h | 18 + > mcd/mcd_api.h | 3963 +++++++++++++++++++++++++++++++++ > mcd/mcd_monitor.c | 90 + > mcd/mcd_qapi.c | 505 +++++ > mcd/mcd_qapi.h | 81 + > mcd/mcd_server.c | 2274 +++++++++++++++++++ > mcd/mcd_stub.c | 988 ++++++++ > mcd/meson.build | 60 + > meson.build | 5 + > meson_options.txt | 3 + > qapi/mcd.json | 2366 ++++++++++++++++++++ The schema is too big for me to review in detail. I understand it's designed to mirror mcd/mcd_api.h closely, so review would be limited to checking the way you mirror is sane. I doubt that would be a good use of my time, but if you'd like advice on any non-trivial parts, just ask. Some formatting nits caught my eye. docs/devel/qapi-code-gen.rst section "Documentation markup": For legibility, wrap text paragraphs so every line is at most 70 characters long. Separate sentences with two spaces. I recommend to read the entire section. [...]