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=-22.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, 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 80237C4361B for ; Tue, 8 Dec 2020 18:41:57 +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 0D801207AA for ; Tue, 8 Dec 2020 18:41:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D801207AA 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]:49198 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kmhvw-0006gi-47 for qemu-devel@archiver.kernel.org; Tue, 08 Dec 2020 13:41:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59350) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kmhUp-0003So-JD for qemu-devel@nongnu.org; Tue, 08 Dec 2020 13:13:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33047) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kmhUn-0007bX-AA for qemu-devel@nongnu.org; Tue, 08 Dec 2020 13:13:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607451232; 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=Z8ScYZxMUH9OKQcFJcbkchgt+Ov9QwhPN3v928qAEo4=; b=SlFsdJbsIE4qHtNnoEvving6d6kyAKz7NDT6CmdzSqeyVUdO6oQjndFMoDOqkHsvNGk+6h 5J81sZmR5BpgZiU/tkSz61vPXY+ee0xq4gFPdFUiwNOONYh5AFGsGCMEF0QGKzMrRU0I0b Y82yRupXrtJeu83uHE/AB2SMHkOgnb0= 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-263-nLE2l4XKOXCC-Nr7SAeA-g-1; Tue, 08 Dec 2020 13:13:47 -0500 X-MC-Unique: nLE2l4XKOXCC-Nr7SAeA-g-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 A430619251A4 for ; Tue, 8 Dec 2020 18:13:45 +0000 (UTC) Received: from redhat.com (ovpn-113-15.ams2.redhat.com [10.36.113.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A7E0C5C22A; Tue, 8 Dec 2020 18:13:31 +0000 (UTC) Date: Tue, 8 Dec 2020 18:13:28 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Gerd Hoffmann Subject: Re: [PATCH v2 8/9] vnc: add support for extended desktop resize Message-ID: <20201208181328.GW3136942@redhat.com> References: <20201208115737.18581-1-kraxel@redhat.com> <20201208115737.18581-9-kraxel@redhat.com> MIME-Version: 1.0 In-Reply-To: <20201208115737.18581-9-kraxel@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; 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_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Dec 08, 2020 at 12:57:36PM +0100, Gerd Hoffmann wrote: > The extended desktop resize encoding adds support for (a) clients > sending resize requests to the server, and (b) multihead support. > > This patch implements (a). All resize requests are rejected by qemu. > Qemu can't resize the framebuffer on its own, this is in the hands of > the guest, so all qemu can do is forward the request to the guest. > Should the guest actually resize the framebuffer we can notify the vnc > client later with a separate message. > > This requires support in the display device. Works with virtio-gpu. > > https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#extendeddesktopsize-pseudo-encoding The spec says "The server must send an ExtendedDesktopSize rectangle in response to a FramebufferUpdateRequest with incremental set to zero, assuming the client has requested the ExtendedDesktopSize pseudo-encoding using the SetEncodings message. This requirement is needed so that the client has a reliable way of fetching the initial screen configuration, and to determine if the server supports the SetDesktopSize message. A consequence of this is that a client must not respond to an ExtendedDesktopSize rectangle by sending a FramebufferUpdateRequest with incremental set to zero. Doing so would make the system go into an infinite loop." Historically gtk-vnc always sets incremental=0 after a resize message, so it should trigger an infinite loop. This doesn't happen with QEMU's impl, so I think QEMU isn't correctly following the sec here. IIUC, tt needs to force send an ExtendedDesktopSize message every time incremental=0, not merely when a resize happens. Having said that, I find this part of the spec rather crazy. I dont see why clients need more than the first ExtendedDesktopSize message in order to detect the feature, rather than after every single incremental=0 update request. None the less the spec says we should get an infinite loop and with my intentional attempt to cause this, QEMU doesn't play ball. > > Signed-off-by: Gerd Hoffmann > --- > ui/vnc.h | 2 ++ > ui/vnc.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- > 2 files changed, 65 insertions(+), 1 deletion(-) > > diff --git a/ui/vnc.h b/ui/vnc.h > index c8d3ad9ec496..77a310947bd6 100644 > --- a/ui/vnc.h > +++ b/ui/vnc.h > @@ -442,6 +442,7 @@ enum { > > enum VncFeatures { > VNC_FEATURE_RESIZE, > + VNC_FEATURE_RESIZE_EXT, > VNC_FEATURE_HEXTILE, > VNC_FEATURE_POINTER_TYPE_CHANGE, > VNC_FEATURE_WMVI, > @@ -456,6 +457,7 @@ enum VncFeatures { > }; > > #define VNC_FEATURE_RESIZE_MASK (1 << VNC_FEATURE_RESIZE) > +#define VNC_FEATURE_RESIZE_EXT_MASK (1 << VNC_FEATURE_RESIZE_EXT) > #define VNC_FEATURE_HEXTILE_MASK (1 << VNC_FEATURE_HEXTILE) > #define VNC_FEATURE_POINTER_TYPE_CHANGE_MASK (1 << VNC_FEATURE_POINTER_TYPE_CHANGE) > #define VNC_FEATURE_WMVI_MASK (1 << VNC_FEATURE_WMVI) > diff --git a/ui/vnc.c b/ui/vnc.c > index bdaf384f71a4..094ba6cd14cb 100644 > --- a/ui/vnc.c > +++ b/ui/vnc.c > @@ -663,10 +663,35 @@ void vnc_framebuffer_update(VncState *vs, int x, int y, int w, int h, > vnc_write_s32(vs, encoding); > } > > +static void vnc_desktop_resize_ext(VncState *vs, int reject_reason) > +{ > + vnc_lock_output(vs); > + vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE); > + vnc_write_u8(vs, 0); > + vnc_write_u16(vs, 1); /* number of rects */ > + vnc_framebuffer_update(vs, > + reject_reason ? 1 : 0, > + reject_reason, > + vs->client_width, vs->client_height, > + VNC_ENCODING_DESKTOP_RESIZE_EXT); > + vnc_write_u8(vs, 1); /* number of screens */ > + vnc_write_u8(vs, 0); /* padding */ > + vnc_write_u8(vs, 0); /* padding */ > + vnc_write_u8(vs, 0); /* padding */ > + vnc_write_u32(vs, 0); /* screen id */ > + vnc_write_u16(vs, 0); /* screen x-pos */ > + vnc_write_u16(vs, 0); /* screen y-pos */ > + vnc_write_u16(vs, vs->client_width); > + vnc_write_u16(vs, vs->client_height); > + vnc_write_u32(vs, 0); /* screen flags */ > + vnc_unlock_output(vs); > + vnc_flush(vs); > +} > > static void vnc_desktop_resize(VncState *vs, bool force) > { > - if (vs->ioc == NULL || !vnc_has_feature(vs, VNC_FEATURE_RESIZE)) { > + if (vs->ioc == NULL || (!vnc_has_feature(vs, VNC_FEATURE_RESIZE) && > + !vnc_has_feature(vs, VNC_FEATURE_RESIZE_EXT))) { > return; > } > if (vs->client_width == pixman_image_get_width(vs->vd->server) && > @@ -681,6 +706,12 @@ static void vnc_desktop_resize(VncState *vs, bool force) > pixman_image_get_height(vs->vd->server) >= 0); > vs->client_width = pixman_image_get_width(vs->vd->server); > vs->client_height = pixman_image_get_height(vs->vd->server); > + > + if (vnc_has_feature(vs, VNC_FEATURE_RESIZE_EXT)) { > + vnc_desktop_resize_ext(vs, 0); > + return; > + } > + > vnc_lock_output(vs); > vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE); > vnc_write_u8(vs, 0); > @@ -2110,6 +2141,9 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings) > case VNC_ENCODING_DESKTOPRESIZE: > vs->features |= VNC_FEATURE_RESIZE_MASK; > break; > + case VNC_ENCODING_DESKTOP_RESIZE_EXT: > + vs->features |= VNC_FEATURE_RESIZE_EXT_MASK; > + break; > case VNC_ENCODING_POINTER_TYPE_CHANGE: > vs->features |= VNC_FEATURE_POINTER_TYPE_CHANGE_MASK; > break; > @@ -2431,6 +2465,34 @@ static int protocol_client_msg(VncState *vs, uint8_t *data, size_t len) > break; > } > break; > + case VNC_MSG_CLIENT_SET_DESKTOP_SIZE: > + { > + size_t size; > + uint8_t screens; > + > + if (len < 8) { > + return 8; > + } > + > + screens = read_u8(data, 6); > + size = 8 + screens * 16; > + if (len < size) { > + return size; > + } > + > + if (dpy_ui_info_supported(vs->vd->dcl.con)) { > + QemuUIInfo info; > + memset(&info, 0, sizeof(info)); > + info.width = read_u16(data, 2); > + info.height = read_u16(data, 4); > + dpy_set_ui_info(vs->vd->dcl.con, &info); > + vnc_desktop_resize_ext(vs, 4 /* Request forwarded */); > + } else { > + vnc_desktop_resize_ext(vs, 3 /* Invalid screen layout */); > + } > + > + break; > + } > default: > VNC_DEBUG("Msg: %d\n", data[0]); > vnc_client_error(vs); > -- > 2.27.0 > > 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 :|