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 22226C4332F for ; Wed, 30 Nov 2022 12:43:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p0MQo-0007xb-Hh; Wed, 30 Nov 2022 07:43:19 -0500 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 1p0MQj-0007xH-I0 for qemu-devel@nongnu.org; Wed, 30 Nov 2022 07:43:14 -0500 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 1p0MQh-0005qX-Oo for qemu-devel@nongnu.org; Wed, 30 Nov 2022 07:43:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669812188; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3xK6bvWhEsKX9sMW3J4SYj3txhoWI7+pwHeMKnLvOyY=; b=CgrE7u3MzByQ5Nwkwa9dAkYaEujPJrecKhOws3Zrasbd1aXaWTtXoXkFRD4R5qA5lvD3SW C0l87et/5OBVnylcn/4cwNYODKc/wgl3wStBnYP1d8GCGLIs2mu+aqZOueSHugfcwzibTv sx1oRuQfShV32/o8ZHdbKDjD4R0iMsI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-649-YfaIaOLYPayuMlzqqtNJKA-1; Wed, 30 Nov 2022 07:43:07 -0500 X-MC-Unique: YfaIaOLYPayuMlzqqtNJKA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BF6D0811E87 for ; Wed, 30 Nov 2022 12:43:06 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8DE01C15BA4; Wed, 30 Nov 2022 12:43:06 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 6C3B121E6921; Wed, 30 Nov 2022 13:43:03 +0100 (CET) From: Markus Armbruster To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, Daniel P. =?utf-8?Q?Berrang=C3=A9?= , Peter Krempa , Gerd Hoffmann Subject: Re: Who / what uses QMP command add_client? References: <878rjtretb.fsf@pond.sub.org> Date: Wed, 30 Nov 2022 13:43:03 +0100 In-Reply-To: (=?utf-8?Q?=22Marc-Andr=C3=A9?= Lureau"'s message of "Tue, 29 Nov 2022 19:26:43 +0400") Message-ID: <8735a0mx48.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H2=-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 Marc-Andr=C3=A9 Lureau writes: > Hi > > On Tue, Nov 29, 2022 at 6:55 PM Markus Armbruster wro= te: > >> QMP command add_client's schema: >> >> ## >> # @add_client: >> # >> # Allow client connections for VNC, Spice and socket based >> # character devices to be passed in to QEMU via SCM_RIGHTS. >> # >> # @protocol: protocol name. Valid names are "vnc", "spice", >> "@dbus-display" or >> # the name of a character device (eg. from -chardev id=3D= XXXX) >> # >> # @fdname: file descriptor name previously passed via 'getfd' command >> # >> # @skipauth: whether to skip authentication. Only applies >> # to "vnc" and "spice" protocols >> # >> # @tls: whether to perform TLS. Only applies to the "spice" >> # protocol >> # >> # Returns: nothing on success. >> # >> # Since: 0.14 >> # >> # Example: >> # >> # -> { "execute": "add_client", "arguments": { "protocol": "vnc", >> # "fdname": "myclient" = } } >> # <- { "return": {} } >> # >> ## >> { 'command': 'add_client', >> 'data': { 'protocol': 'str', 'fdname': 'str', '*skipauth': 'bool', >> '*tls': 'bool' } } >> >> Spot the design flaw! >> >> It's overloaded @protocol. Two issues. >> >> One, character device IDs "vnc", "spice", "@dbus-display" don't work >> here. If we ever add another protocol, we make another device ID not >> work. Perhaps this is why Marc-Andr=C3=A9 chose "@dbus-display", which >> otherwise looks like a typo :) >> > > That's right, I tried to avoid conflicting with chardev ID namespace. IDs > can't start with '@'. > > btw, I have a few patches pending to extend add_client for windows socket= s. > > I also have patches to check if fds are actually sockets, since that > command doesn't make much sense with other fds. > > >> Two, introspection can't tell us what protocols are supported. > > Hmm, not really a big deal I suppose. You would have both compile-time and > run-time config. There are other means to introspect the display protocol, > like query-vnc or query-spice. I thought I had something covering dbus as > well, but I can't find it, I'll look at it. Defeating introspection like this is careless design. I agree this one is no big deal in practice. > Let me know if you plan to touch that command, it will likely conflict wi= th > my work. I plan to submit it soon after the release, but I might do it > earlier. I looked at the command only because I'm trying to move crap out of monitor/. For PCI, that's "[PATCH 00/12] pci: Move and clean up monitor command code". add_client is a bit awkward. It's in qapi/misc.json and monitor/qmp-cmds.c. If it was only about VNC and Spice, I'd move it to qapi/ui.json and ui/. If it was only about socket character devices, to qapi/char.json and char/. But it's both. Unless we pick one of the two arbitrarily, it's stuck in monitor/.