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 X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A478DC433E0 for ; Thu, 25 Jun 2020 13:25:54 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 70B832076E for ; Thu, 25 Jun 2020 13:25:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jU4p10iq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70B832076E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44798 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joRt3-00077h-NU for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 09:25:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59542) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joRr3-00038a-70 for qemu-devel@nongnu.org; Thu, 25 Jun 2020 09:23:49 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:60244 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1joRr0-000358-LN for qemu-devel@nongnu.org; Thu, 25 Jun 2020 09:23:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593091426; h=from:from:reply-to: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=90QuJzEBty3CyEW20U1eEkmG9pg1eL4as5ebPprZdFQ=; b=jU4p10iqbc7u00wue5RP5QuJGYRe9o5IuWGCNX/UqZ+hZu21ayuBOUcBRFm57nlX67wwdW vQDDHupFtESghF2iSYgNDMmzJsFnkGNxjJxXAQrUpQRCJklWhWoAtiWyhr1w/3AkPbKRPM seYInJboP++JHEUYF/MARy7j7jU3+Oc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-133-1JYstRnOPqKpGYB7dKYstA-1; Thu, 25 Jun 2020 09:23:39 -0400 X-MC-Unique: 1JYstRnOPqKpGYB7dKYstA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 76F481B2C980; Thu, 25 Jun 2020 13:23:38 +0000 (UTC) Received: from redhat.com (unknown [10.36.110.27]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E7F275C1BB; Thu, 25 Jun 2020 13:23:30 +0000 (UTC) Date: Thu, 25 Jun 2020 14:23:28 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Michael S. Tsirkin" Subject: Re: [PATCH v2 0/6] virtio-console: notify about the terminal size Message-ID: <20200625132328.GG1014704@redhat.com> References: <20200624112640.82673-1-noh4hss@gmail.com> <20200624114915.GH774096@redhat.com> <20200625091815-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: <20200625091815-mutt-send-email-mst@kernel.org> User-Agent: Mutt/1.14.0 (2020-05-02) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.120; envelope-from=berrange@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 01:47:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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=-1, 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_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: lvivier@redhat.com, amit@kernel.org, qemu-devel@nongnu.org, Szymon Lukasz , marcandre.lureau@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jun 25, 2020 at 09:18:51AM -0400, Michael S. Tsirkin wrote: > On Wed, Jun 24, 2020 at 12:49:15PM +0100, Daniel P. Berrangé wrote: > > On Wed, Jun 24, 2020 at 01:26:34PM +0200, Szymon Lukasz wrote: > > > Also there is a problem with the virtio spec and Linux Kernel > > > implementation, the order of fields in virtio_console_resize struct > > > differs between the kernel and the spec. I do not know if there is any > > > implementation of the virtio-console driver that handles resize messages > > > and uses a different order than Linux. > > > > Well this is a bit of a mess :-( > > > > The main virtio_console_config struct has cols, then rows. > > > > The Linux impl of resizing appears to have arrived in 2010, and created > > a new struct with rows, then cols. > > > > commit 8345adbf96fc1bde7d9846aadbe5af9b2ae90882 > > Author: Amit Shah > > Date: Thu May 6 02:05:09 2010 +0530 > > > > virtio: console: Accept console size along with resize control message > > > > The VIRTIO_CONSOLE_RESIZE control message sent to us by the host now > > contains the new {rows, cols} values for the console. This ensures each > > console port gets its own size, and we don't depend on the config-space > > rows and cols values at all now. > > > > Signed-off-by: Amit Shah > > CC: Christian Borntraeger > > CC: linuxppc-dev@ozlabs.org > > CC: Kusanagi Kouichi > > Signed-off-by: Rusty Russell > > > > > > The virtio spec documenting this came 4 years later in 2014 and documented > > the resize struct with cols, then rows, which differs from Linux impl, > > but matches ordering of the main virtio_console_config: > > > > commit 908cfaa782e950d6656d947599d7a6c9fb16cad1 > > Author: rusty > > Date: Wed Feb 12 03:15:57 2014 +0000 > > > > Feedback #6: Applied > > > > As per minutes: > > https://lists.oasis-open.org/archives/virtio/201402/msg00121.html > > > > Signed-off-by: Rusty Russell > > > > git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@237 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652 > > > > I can understand why it is desirable for the resize struct to match > > the order of the initial config struct. I'm guessing it just wasn't > > realized that the Linux impl was inverted for resize > > > > The FreeBSD impl of virtio-console doesn't do resize: > > > > https://github.com/freebsd/freebsd/blob/master/sys/dev/virtio/console/virtio_console.c#L874 > > > > Not sure what other impls are going to be around, but I feel like > > Linux is going to be the most commonly deployed by orders of magnitude. > > > > So I'd say QEMU should match Linux, and the spec should be fixed. > > > > > > Have you reported this bug to the virtio spec people directly yet ? > > > > I don't see an issue open at > > > > https://github.com/oasis-tcs/virtio-spec/issues/ > > > > so I think one should be filed there > > > > Regards, > > Daniel > > > One reports defects on the virtio-comments mailing list, issue tracker is just for > tracking spec changes. NB That contradicts what the CONTRIBUTING.md file in virtio-spec says, which welcomes use of the issue tracker: "Persons who are not TC members are invited to open issues and provide comments using this repository's GitHub Issues tracking facility or using the TC's comment list. " https://github.com/oasis-tcs/virtio-spec/blob/master/CONTRIBUTING.md Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|