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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E6927C4338F for ; Fri, 23 Jul 2021 06:56:55 +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 73F6760ED7 for ; Fri, 23 Jul 2021 06:56:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 73F6760ED7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:47270 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m6p78-0000hB-B8 for qemu-devel@archiver.kernel.org; Fri, 23 Jul 2021 02:56:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48882) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m6p5s-0008Q3-UL for qemu-devel@nongnu.org; Fri, 23 Jul 2021 02:55:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:54874) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m6p5q-0006Un-Ri for qemu-devel@nongnu.org; Fri, 23 Jul 2021 02:55:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627023333; h=from:from: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=iaDzdIz16MvB7iJZBjj5VZGvfAaWj4QQT3ecnWS+dds=; b=LyN6VS5z49JC50/unwdfNfxXO9XCgixsNn02MhC97woxjd0lrJnYPUcRilj1hYhxAbfKj6 owbmpefR66uHsZvhXh9wPlXUofDuu1F0gSAvUwzZ/Kkgc4P28MViBqZ5W7muT/W8mV58mZ oIx0/j12r5IiRkmmU6R15iw6NOvX0+0= 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-390-jjlPJ4y-MoWgcuvRBf5hqw-1; Fri, 23 Jul 2021 02:55:31 -0400 X-MC-Unique: jjlPJ4y-MoWgcuvRBf5hqw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D681618C89CF for ; Fri, 23 Jul 2021 06:55:30 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-114-106.ams2.redhat.com [10.36.114.106]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9B2D260877; Fri, 23 Jul 2021 06:55:30 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id ACD931800926; Fri, 23 Jul 2021 08:55:27 +0200 (CEST) Date: Fri, 23 Jul 2021 08:55:27 +0200 From: Gerd Hoffmann To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PATCH 1/2] qxl: remove assert in qxl_pre_save. Message-ID: <20210723065527.glqc44gyga2lnqyc@sirius.home.kraxel.org> References: <20210721093347.338536-1-kraxel@redhat.com> <20210721093347.338536-2-kraxel@redhat.com> <20210723063233.ktjex5knfgz77pbq@sirius.home.kraxel.org> <13c8a40f-a879-a981-12f0-36a5289b39b1@redhat.com> MIME-Version: 1.0 In-Reply-To: <13c8a40f-a879-a981-12f0-36a5289b39b1@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.472, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=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: , Cc: armbru@redhat.com, "Dr. David Alan Gilbert" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Jul 23, 2021 at 08:47:09AM +0200, Philippe Mathieu-Daudé wrote: > On 7/23/21 8:32 AM, Gerd Hoffmann wrote: > > On Thu, Jul 22, 2021 at 03:44:54PM +0100, Dr. David Alan Gilbert wrote: > >> * Gerd Hoffmann (kraxel@redhat.com) wrote: > >>> Since commit 551dbd0846d2 ("migration: check pre_save return in > >>> vmstate_save_state") the pre_save hook can fail. So lets finally > >>> use that to drop the guest-triggerable assert in qxl_pre_save(). > >>> > >>> Signed-off-by: Gerd Hoffmann > >>> --- > >>> hw/display/qxl.c | 4 +++- > >>> 1 file changed, 3 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/hw/display/qxl.c b/hw/display/qxl.c > >>> index 84f99088e0a0..3867b94fe236 100644 > >>> --- a/hw/display/qxl.c > >>> +++ b/hw/display/qxl.c > >>> @@ -2283,7 +2283,9 @@ static int qxl_pre_save(void *opaque) > >>> } else { > >>> d->last_release_offset = (uint8_t *)d->last_release - ram_start; > >>> } > >>> - assert(d->last_release_offset < d->vga.vram_size); > >>> + if (d->last_release_offset < d->vga.vram_size) { > >>> + return 1; > >> > >> It would be great if there was an error_report or something there > >> so that we get some idea of what happened. > > > > Hmm. Strictly speaking qemu_log_mask(LOG_GUEST_ERROR, "..."); would be > > the correct approach here, but I guess that wouldn't help much for > > trouble-shooting as the message would only show up with "-d > > guest_errors". So better make that error_report("...") ? > > It depends who is interested in such errors. Migration fails and you want know why. Reason migration fails is the guest violates qxl specs (which doesn't cause actual problems unless you want migrate the guest). take care, Gerd