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 B282BCA101F for ; Mon, 15 Sep 2025 06:40:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uy2sK-0006Xe-Hq; Mon, 15 Sep 2025 02:39:44 -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 1uy2sG-0006Wn-Bb for qemu-devel@nongnu.org; Mon, 15 Sep 2025 02:39:40 -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 1uy2sC-0004KK-GT for qemu-devel@nongnu.org; Mon, 15 Sep 2025 02:39:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757918367; 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:resent-to: resent-from:resent-message-id:in-reply-to:in-reply-to: references:references; bh=HSWqyYfOzKDU8p059dQRKF41gx+JZDiIS5lsnZInSIQ=; b=YBI0A65MJYyty4anuJZDKJyHNcrX7v59SCpPuPWAZORqLiw+2wUc7oMs1ELBKcK+xGFK9j 65vOI2Ca75bR4X3reNMIkdkc4UZLJqK/FtC17GH1x5LXNutgTLnIMkvkEkLgrHtO++iYtT EPRQ4gf9ICuscIpdfVe58+sjX44psNM= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-131-amjVgC3FP1aeQw5o6_RG_Q-1; Mon, 15 Sep 2025 02:39:23 -0400 X-MC-Unique: amjVgC3FP1aeQw5o6_RG_Q-1 X-Mimecast-MFC-AGG-ID: amjVgC3FP1aeQw5o6_RG_Q_1757918362 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 98C471800297; Mon, 15 Sep 2025 06:39:21 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.9]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4F3CA300021A; Mon, 15 Sep 2025 06:39:20 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id D77A621E6A27; Mon, 15 Sep 2025 08:39:17 +0200 (CEST) Resent-To: filip.hejsek@gmail.com, marcel.apfelbaum@gmail.com, noh4hss@gmail.com, eduardo@habkost.net, wangyanan55@huawei.com, zhao1.liu@intel.com, amit@kernel.org, philmd@linaro.org, devel@lists.libvirt.org, qemu-devel@nongnu.org Resent-From: Markus Armbruster Resent-Date: Mon, 15 Sep 2025 08:39:17 +0200 Resent-Message-ID: <87wm60z0bu.fsf@pond.sub.org> From: Markus Armbruster To: Filip Hejsek Cc: qemu-devel@nongnu.org, =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Paolo Bonzini , "Michael S. Tsirkin" , Laurent Vivier , Amit Shah , Eric Blake , Eduardo Habkost , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Yanan Wang , Zhao Liu , Szymon Lukasz , Daniel =?utf-8?Q?P=2EBerrang=C3=A9?= , devel@lists.libvirt.org Subject: Re: [PATCH v4 07/10] qmp: add chardev-resize command In-Reply-To: <64d6252959750b8da6f3bc4ac7c738b10463bf6d.camel@gmail.com> (Filip Hejsek's message of "Fri, 12 Sep 2025 20:10:32 +0200") References: <20250912-console-resize-v4-0-7925e444afc4@gmail.com> <20250912-console-resize-v4-7-7925e444afc4@gmail.com> <871pob7ot7.fsf@pond.sub.org> <64d6252959750b8da6f3bc4ac7c738b10463bf6d.camel@gmail.com> Date: Mon, 15 Sep 2025 08:35:51 +0200 Message-ID: <87cy7s1auw.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 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: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 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_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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 Filip Hejsek writes: > On Fri, 2025-09-12 at 16:01 +0200, Markus Armbruster wrote: >> Cc: libvirt >>=20 >> Filip Hejsek writes: >>=20 >> > From: Szymon Lukasz >> >=20 >> > The managment software can use this command to notify QEMU about the >> > size of the terminal connected to a chardev, QEMU can then forward this >> > information to the guest if the chardev is connected to a virtio conso= le >> > device. >> >=20 >> > Signed-off-by: Szymon Lukasz >> > Suggested-by: Daniel P. Berrang=C3=A9 >> > Signed-off-by: Filip Hejsek >> > --- >> > chardev/char.c | 14 ++++++++++++++ >> > qapi/char.json | 22 ++++++++++++++++++++++ >> > 2 files changed, 36 insertions(+) >> >=20 >> > diff --git a/chardev/char.c b/chardev/char.c >> > index b45d79cb9b57643827eb7479257fdda2cf6b0434..6e3ade98614c949be8041e= c5905a490ff536dee9 100644 >> > --- a/chardev/char.c >> > +++ b/chardev/char.c >> > @@ -1269,6 +1269,20 @@ bool qmp_add_client_char(int fd, bool has_skipa= uth, bool skipauth, >> > return true; >> > } >> >=20=20 >> > +void qmp_chardev_resize(const char *id, uint16_t cols, uint16_t rows, >> > + Error **errp) >> > +{ >> > + Chardev *chr; >> > + >> > + chr =3D qemu_chr_find(id); >> > + if (chr =3D=3D NULL) { >> > + error_setg(errp, "Chardev '%s' not found", id); >> > + return; >> > + } >> > + >> > + qemu_chr_resize(chr, cols, rows); >> > +} >> > + >> > /* >> > * Add a timeout callback for the chardev (in milliseconds), return >> > * the GSource object created. Please use this to add timeout hook for >> > diff --git a/qapi/char.json b/qapi/char.json >> > index f0a53f742c8bee24c377551803a864fd36ac78cf..0a26c5eee6b71bc5de127a= 91b253cc69a9fe8ce6 100644 >> > --- a/qapi/char.json >> > +++ b/qapi/char.json >> > @@ -874,6 +874,28 @@ >> > { 'command': 'chardev-send-break', >> > 'data': { 'id': 'str' } } >> >=20=20 >> > +## >> > +# @chardev-resize: >>=20 >> This name doesn't tell me what is being resized. PATCH 04 uses >> "winsize", which is better. The (losely) related SIGWINCH suggests >> "window change" or "window size change". Below, you use "terminal >> size". > > How about chardev-console-resize? That would match the name of the > virtio event (VIRTIO_CONSOLE_RESIZE). Not bad. It could become slightly bad if we make devices other than "consoles" make us of it. Would that be possible? >> > +# >> > +# Notifies a chardev about the current size of the terminal connected >> > +# to this chardev. >>=20 >> Yes, but what is it good for? Your commit message tells: "managment >> software can use this command to notify QEMU about the size of the >> terminal connected to a chardev, QEMU can then forward this information >> to the guest if the chardev is connected to a virtio console device." > > How about: > > Notifies a chardev about the current size of the terminal connected > to this chardev. The information will be forwarded to the guest if > the chardev is connected to a virtio console device. Works for me. >> > +# >> > +# @id: the chardev's ID, must exist >> > +# @cols: the number of columns >> > +# @rows: the number of rows >>=20 >> Blank lines between the argument descriptions, bease. >>=20 >> What's the initial size? > > 0x0 A clearly invalid size. I guess it effectively means "unknown size". Should we document that? >> Do we need a way to query the size? > > I don't think it is necessary. What would be the usecase for that? I don't know, but it's my standard question when I see an interface to set something without an interface to get it. Its purpose is to make us think, not to make us at the get blindly. >> > +# >> > +# Since: 10.2 >> > +# >> > +# .. qmp-example:: >> > +# >> > +# -> { "execute": "chardev-resize", "arguments": { "id": "foo", "= cols": 80, "rows": 24 } } >> > +# <- { "return": {} } >> > +## >> > +{ 'command': 'chardev-resize', >> > + 'data': { 'id': 'str', >> > + 'cols': 'uint16', >> > + 'rows': 'uint16' } } >> > + >> > ## >> > # @VSERPORT_CHANGE: >> > #