From patchwork Wed Oct 18 13:37:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Edmund Raile X-Patchwork-Id: 13427085 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 D5485CDB47E for ; Wed, 18 Oct 2023 13:37:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qt6kA-0006pO-BM; Wed, 18 Oct 2023 09:37:50 -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 1qt6k8-0006ns-6s for qemu-devel@nongnu.org; Wed, 18 Oct 2023 09:37:48 -0400 Received: from mail-40132.protonmail.ch ([185.70.40.132]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qt6k5-00061s-67 for qemu-devel@nongnu.org; Wed, 18 Oct 2023 09:37:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1697636259; x=1697895459; bh=P9+KVbM/aPr1J3w6LfPCm+DJ38pFyvtb8SovGTBcRvo=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=XkS/Ku/BdCTTRssuPSDp4uz412g3n51j6jCgUhKK92+kl6HVqSD9hjlZ3Pl6szoI6 u+DYHS9nLh6d9bBVj0MV1TB8TPxWtoD/a1TKq5QsSMV+jY8SlaGcnzonDNO7G90eOa c8hMzcNPuwsv9dNP9tiPSU+E5ZZ/JNRPGCXZQvRp8J+AGDu8reG8VIFuSGCSVnlCDs GltjydRABV1RPd35KpyYC/JiTmRWhpqrWZ2TE4yWR+6CqJWaJgXauaKXDK4tjAtYOK EMB7DS3t7mcViAAC8A8JoLFfMMQ1Rkrkt1vysKnIldfxLJazZNe2bokJGqMRN/T6uS r1hUynQrb1dqw== Date: Wed, 18 Oct 2023 13:37:25 +0000 To: qemu-devel@nongnu.org From: Edmund Raile Cc: marcandre.lureau@redhat.com, kraxel@redhat.com, Edmund Raile Subject: [PATCH v3] ui/gtk-clipboard: async owner_change clipboard_request Message-ID: <20231018133621.721259-1-edmund.raile@proton.me> Feedback-ID: 45198251:user:proton MIME-Version: 1.0 Received-SPF: pass client-ip=185.70.40.132; envelope-from=edmund.raile@proton.me; helo=mail-40132.protonmail.ch 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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 Previous implementation of both functions was blocking and caused guest freezes / crashes on host clipboard owner change. * use callbacks instead of waiting for GTK to deliver clipboard content type evaluation and contents * evaluate a serial in the info struct to discard old events Fixes: d11ebe2ca257 ("ui/gtk: add clipboard support") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1150 Signed-off-by: Edmund Raile --- Gitlab user kolAflash is to credit for determining that the main issue of the QEMU-UI-GTK clipboard is the call to the blocking function gtk_clipboard_wait_is_text_available in gd_owner_change, causing guests to freeze / crash when GTK takes too long. Marc-André Lureau suggested: * gd_clipboard_request might express the same issue due to using gtk_clipboard_wait_for_text * the callbacks could use the QemuClipboardInfo struct's serial field to discard old events This patch implements asynchronous gd_clipboard_request and gd_owner_change with serial checking. What I haven't implemented is gd_clipboard_notify's QEMU_CLIPBOARD_RESET_SERIAL handling, I don't know how to. Please help me test this patch. The issue mentions the conditions, so far it has been stable. Note that you will need to build QEMU with `enable-gtk-clipboard`. command line options for qemu-vdagent: -device virtio-serial,packed=on,ioeventfd=on \ -device virtserialport,name=com.redhat.spice.0,chardev=vdagent0 \ -chardev qemu-vdagent,id=vdagent0,name=vdagent,clipboard=on,mouse=off \ The guests spice-vdagent user service may have to be started manually. If testing is sufficient and shows no way to break this, we could undo or modify 29e0bfffab87d89c65c0890607e203b1579590a3 to have the GTK UI's clipboard built-in by default again. Previous threads: * https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg06027.html * https://lists.gnu.org/archive/html/qemu-devel/2023-10/msg04397.html I am not responding to either of the previous threads so as to not break anything in the mailing list by correcting my mistake in the subject. ui/gtk-clipboard.c | 84 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 70 insertions(+), 14 deletions(-) diff --git a/ui/gtk-clipboard.c b/ui/gtk-clipboard.c index 8d8a636fd1..07fe8b0ce1 100644 --- a/ui/gtk-clipboard.c +++ b/ui/gtk-clipboard.c @@ -133,26 +133,85 @@ static void gd_clipboard_notify(Notifier *notifier, void *data) } } +/* + * asynchronous clipboard text transfer callback + * called when host (gtk) is ready to deliver to guest + */ +static void gd_clipboard_request_text_callback + (GtkClipboard *clipboard, const gchar *text, gpointer data) +{ + QemuClipboardInfo *info = (QemuClipboardInfo *)data; + + if (!text || !qemu_clipboard_check_serial(info, true)) { + return; + } + + qemu_clipboard_set_data(info->owner, info, QEMU_CLIPBOARD_TYPE_TEXT, + strlen(text), text, true); + return; +} + +/* + * asynchronous clipboard data transfer initiator + * guest requests, host delivers when ready + */ static void gd_clipboard_request(QemuClipboardInfo *info, QemuClipboardType type) { GtkDisplayState *gd = container_of(info->owner, GtkDisplayState, cbpeer); - char *text; switch (type) { case QEMU_CLIPBOARD_TYPE_TEXT: - text = gtk_clipboard_wait_for_text(gd->gtkcb[info->selection]); - if (text) { - qemu_clipboard_set_data(&gd->cbpeer, info, type, - strlen(text), text, true); - g_free(text); - } + gtk_clipboard_request_text + (gd->gtkcb[info->selection], + gd_clipboard_request_text_callback, info); break; default: break; } } +/* + * asynchronous clipboard text availability notification callback + * called when host (gtk) is ready to notify guest + */ +static void gd_owner_change_text_callback + (GtkClipboard *clipboard, const gchar *text, gpointer data) +{ + QemuClipboardInfo *info = (QemuClipboardInfo *)data; + + static uint32_t notification_serial_last; + + /* + * performing the subtraction of uints as ints + * is a neat trick to guard against rollover issues + */ + if (!text || + (((int32_t)(info->serial - notification_serial_last)) <= 0)) + { + goto end; + } + + notification_serial_last = info->serial; + + info->types[QEMU_CLIPBOARD_TYPE_TEXT].available = true; + qemu_clipboard_update(info); + + goto end; + +end: + /* + * this notification info struct is temporary + * and can safely be freed after use + */ + qemu_clipboard_info_unref(info); + return; +} + +/* + * asynchronous clipboard data availability notification initiator + * host notifies guest when ready + */ static void gd_owner_change(GtkClipboard *clipboard, GdkEvent *event, gpointer data) @@ -160,22 +219,19 @@ static void gd_owner_change(GtkClipboard *clipboard, GtkDisplayState *gd = data; QemuClipboardSelection s = gd_find_selection(gd, clipboard); QemuClipboardInfo *info; + static uint32_t notification_serial; if (gd->cbowner[s]) { /* ignore notifications about our own grabs */ return; } - switch (event->owner_change.reason) { case GDK_OWNER_CHANGE_NEW_OWNER: info = qemu_clipboard_info_new(&gd->cbpeer, s); - if (gtk_clipboard_wait_is_text_available(clipboard)) { - info->types[QEMU_CLIPBOARD_TYPE_TEXT].available = true; - } - - qemu_clipboard_update(info); - qemu_clipboard_info_unref(info); + info->serial = ++notification_serial; + gtk_clipboard_request_text + (clipboard, gd_owner_change_text_callback, info); break; default: qemu_clipboard_peer_release(&gd->cbpeer, s);