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 627A2CF34A9 for ; Thu, 3 Oct 2024 13:06:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1swLWc-00048W-VN; Thu, 03 Oct 2024 09:05:47 -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 1swLWZ-00048J-A8 for qemu-devel@nongnu.org; Thu, 03 Oct 2024 09:05:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1swLWW-0008Pp-Pm for qemu-devel@nongnu.org; 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Thu, 3 Oct 2024 13:05:33 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.46]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AC80319560A2; Thu, 3 Oct 2024 13:05:31 +0000 (UTC) Date: Thu, 3 Oct 2024 14:05:28 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Simon Rowe Cc: QEMU Developers , "freddy77@gmail.com" Subject: Re: Corrupt VNC display for 1366x768 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.143, 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=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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: , 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 Thu, Oct 03, 2024 at 01:01:04PM +0000, Simon Rowe wrote: > Looking at the trace output it seems that the displaysurface has been rounded from the start > vnc_client_connect VNC client connect state=0x556dce1c1b20 ioc=0x556dce9e1e70 > displaysurface_create_from surface=0x556dce104b30, 1360x768, format 0x20020888 > vnc_server_dpy_recreate VNC server dpy recreate dpy=0x7faa59026010 size=1360x768 fmt=537004168 > vnc_client_throttle_threshold VNC client throttle threshold state=0x556dce1c1b20 ioc=0x556dce9e1e70 oldoffset=0 newoffset=1048576 width=0 height=0 bpp=0 audio=(nil) > displaysurface_free surface=0x556dcebf10d0 > vnc_auth_start VNC client auth start state=0x556dce1c1b20 method=1 > vnc_auth_pass VNC client auth passed state=0x556dce1c1b20 method=1 > vnc_client_throttle_threshold VNC client throttle threshold state=0x556dce1c1b20 ioc=0x556dce9e1e70 oldoffset=1048576 newoffset=4177920 width=1360 height=768 bpp=4 audio=(nil) > displaysurface_create_from surface=0x556dce140de0, 1360x768, format 0x20020888 > vnc_server_dpy_pageflip VNC server dpy pageflip dpy=0x7faa59026010 size=1360x768 fmt=537004168 > displaysurface_free surface=0x556dce104b30 > vnc_client_throttle_threshold VNC client throttle threshold state=0x556dce1c1b20 ioc=0x556dce9e1e70 oldoffset=4177920 newoffset=1048576 width=1360 height=768 bpp=1 audio=(nil) > vnc_job_add_rect VNC add rect state=0x556dce1c1b20 job=0x556dce0ea1e0 offset=0,0 size=1360x768 > vnc_job_clamp_rect VNC job clamp rect state=0x7faa42de53a0 job=0x556dce0ea1e0 offset=0,0 size=1360x768 > vnc_job_clamped_rect VNC job clamp rect state=0x7faa42de53a0 job=0x556dce0ea1e0 offset=0,0 size=1360x768 > vnc_job_nrects VNC job state=0x7faa42de53a0 job=0x556dce0ea1e0 nrects=1 > vnc_client_unthrottle_forced VNC client unthrottle forced offset state=0x556dce1c1b20 ioc=0x556dce9e1e70 > vnc_job_add_rect VNC add rect state=0x556dce1c1b20 job=0x556dce217810 offset=0,0 size=1360x13 > vnc_job_clamp_rect VNC job clamp rect state=0x7faa42de53a0 job=0x556dce217810 offset=0,0 size=1360x13 > vnc_job_clamped_rect VNC job clamp rect state=0x7faa42de53a0 job=0x556dce217810 offset=0,0 size=1360x13 > vnc_job_nrects VNC job state=0x7faa42de53a0 job=0x556dce217810 nrects=1 > vnc_client_unthrottle_forced VNC client unthrottle forced offset state=0x556dce1c1b20 ioc=0x556dce9e1e70 > > I'm currently struggling to follow where the width parameter is taken from. The QEMU VNC code has logic which rounds up display sizes to a multiple of 16: static int vnc_width(VncDisplay *vd) { return MIN(VNC_MAX_WIDTH, ROUND_UP(surface_width(vd->ds), VNC_DIRTY_PIXELS_PER_BIT)); } Separately, it also tracks the "true" width, but untangling which it uses where & the implications is hard to do. ie i'm not going to try to explain it further, as I don't know what's going on without spending some hours to trace through it all :-) 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 :|