From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40495) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adgnq-0004vX-IB for qemu-devel@nongnu.org; Wed, 09 Mar 2016 11:17:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1adgnm-000075-QE for qemu-devel@nongnu.org; Wed, 09 Mar 2016 11:17:38 -0500 Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]:34295) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adgnm-000070-JT for qemu-devel@nongnu.org; Wed, 09 Mar 2016 11:17:34 -0500 Received: by mail-wm0-x241.google.com with SMTP id p65so11073479wmp.1 for ; Wed, 09 Mar 2016 08:17:34 -0800 (PST) Sender: Paolo Bonzini References: <1455470231-5223-1-git-send-email-pbonzini@redhat.com> <1455470231-5223-6-git-send-email-pbonzini@redhat.com> <56E01544.6060305@de.ibm.com> <56E01D3F.1060204@redhat.com> <56E03333.5020601@de.ibm.com> From: Paolo Bonzini Message-ID: <56E04C9B.7070801@redhat.com> Date: Wed, 9 Mar 2016 17:17:31 +0100 MIME-Version: 1.0 In-Reply-To: <56E03333.5020601@de.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 5/8] virtio-blk: fix "disabled data plane" mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger Cc: qemu-devel@nongnu.org On 09/03/2016 15:29, Christian Borntraeger wrote: > FWIW, it seems that this patch triggers this error, the "tracked_request_begin" > that I reported yesterday and / or some early read issues from the bootloader > in a random fashion. > Using 2906cddfecff21af20eedab43288b485a679f9ac^ seems to work all the time, > moving around vblk->dataplane_started = true also triggers all 3 types > of bugs In all likelihood, the bug is that virtio_blk_handle_output is being called in two threads. It's not clear to me how that's possible, though. Paolo