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 28132CA0FED for ; Wed, 27 Aug 2025 16:45:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1urJFq-0002lc-O3; Wed, 27 Aug 2025 12:44:10 -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 1urJFp-0002ky-B9 for qemu-devel@nongnu.org; Wed, 27 Aug 2025 12:44:09 -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 1urJFm-0004z3-Ii for qemu-devel@nongnu.org; Wed, 27 Aug 2025 12:44:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756313043; 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:in-reply-to:in-reply-to: references:references; bh=CqkqATo7kFrdveon3LQ/N/1rCMQ4ulOJKcVe7RW4hvk=; b=IjFBZNX8/TuFVfh79yHbQtnaficxevImUGyc2Hil64TtV2yIV8/zo6uwF1V+QqNIpmZN/b ADbEfMouwjIfd9Q0fy7QzAyS75KxPO98D0/jeGX490Vh5KEo7i3rmsLiPIDJE7xjxvkSaO HD9k+f6/F13HmMalIx8XAdMDYeMAd1w= Received: from mx-prod-mc-01.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-241-38IlqNiDMOmkZfesqKxq2w-1; Wed, 27 Aug 2025 12:43:59 -0400 X-MC-Unique: 38IlqNiDMOmkZfesqKxq2w-1 X-Mimecast-MFC-AGG-ID: 38IlqNiDMOmkZfesqKxq2w_1756313038 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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 44974195608E; Wed, 27 Aug 2025 16:43:58 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.195]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F003730001A6; Wed, 27 Aug 2025 16:43:56 +0000 (UTC) Date: Wed, 27 Aug 2025 17:43:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Andrew Keesler Cc: marcandre.lureau@gmail.com, qemu-devel@nongnu.org Subject: Re: [PATCH 1/1] hw/display: Support per-head resolutions with virtio-gpu Message-ID: References: <20250722190824.3419413-1-ankeesler@google.com> <20250722190824.3419413-2-ankeesler@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Aug 27, 2025 at 11:48:34AM -0400, Andrew Keesler wrote: > Sending again (replying all this time). > > > IIUC from the current code, xres/yres are only set against the > > first head. The 2nd and later heads are left undefined by the > > virtio-gpu-base code at least - I'm unclear if something else > > in QEMU will fill in defaults later, or if they set to 0x0. > > That is correct - xres/yres are only set against the first head in the > current code. The wording in my commit message (and cover letter) was > misleading. I will fix that to say that "If no > virtio_gpu_base_conf.outputs are provided, > virtio_gpu_base_conf.xres/virtio_gpu_base_conf.yres will still be > respected _for the first head_ for backwards compatibility". > > The only way I could get QEMU to fill in xres/yres for a 2nd and later > head was to trigger virtio_gpu_ops.ui_info via a VNC client. > > > Is it relevant to set xres/yres on outputs, even when they are > > not (yet) enabled ? Perhaps we should have an explicit 'enabled: bool' > > property in the 'outputs' struct ? > > Maybe you might want to set xres/yres on an output, but not enable it > yet? I don't have any concrete examples of when you might want to do > that, maybe you have some examples? No, I don't have an example. > I feel like I could see a user setting xres/yres on an output, > forgetting to set enabled on that output, and then being confused why > their head is blank. Because of this, my vote would be to default to > enabling an output when it has configuration. I am easily swayed by > your guidance, though. Ok, lets just document that setting xres/yres will cause the output to be automatically enabled. We can always retrofit an 'enabled' property at a later date if someone arrives with a use case for setting res without enabling the output. With 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 :|