From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54784) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1biHDG-0004bF-30 for qemu-devel@nongnu.org; Fri, 09 Sep 2016 04:31:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1biHDB-0002RI-Q5 for qemu-devel@nongnu.org; Fri, 09 Sep 2016 04:31:04 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41335 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1biHDB-0002Qd-KX for qemu-devel@nongnu.org; Fri, 09 Sep 2016 04:31:01 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u898TrHh014995 for ; Fri, 9 Sep 2016 04:31:00 -0400 Received: from e06smtp09.uk.ibm.com (e06smtp09.uk.ibm.com [195.75.94.105]) by mx0a-001b2d01.pphosted.com with ESMTP id 25bc2r5g6u-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 09 Sep 2016 04:30:59 -0400 Received: from localhost by e06smtp09.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 9 Sep 2016 09:30:58 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 9F5D71B08069 for ; Fri, 9 Sep 2016 09:32:41 +0100 (BST) Received: from d06av11.portsmouth.uk.ibm.com (d06av11.portsmouth.uk.ibm.com [9.149.37.252]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u898UtoN25231510 for ; Fri, 9 Sep 2016 08:30:55 GMT Received: from d06av11.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u898Us64020892 for ; Fri, 9 Sep 2016 02:30:55 -0600 Date: Fri, 9 Sep 2016 10:30:53 +0200 From: Cornelia Huck In-Reply-To: <20160908194939-mutt-send-email-mst@kernel.org> References: <147326875705.8546.11347276277137015855.stgit@bahia.lan> <147326876478.8546.16045138068342092499.stgit@bahia.lan> <20160908105926.0d968e64.cornelia.huck@de.ibm.com> <20160908111216.12a1b562@bahia> <20160908175237-mutt-send-email-mst@kernel.org> <20160908170447.2d864945.cornelia.huck@de.ibm.com> <20160908181732-mutt-send-email-mst@kernel.org> <20160908182652.2cf51ac0@bahia> <20160908194939-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20160909103053.7f2f7057.cornelia.huck@de.ibm.com> Subject: Re: [Qemu-devel] [PATCH 1/2] virtio-9p: print error message and exit instead of BUG_ON() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Greg Kurz , qemu-devel@nongnu.org, "Aneesh Kumar K.V" On Thu, 8 Sep 2016 19:55:16 +0300 "Michael S. Tsirkin" wrote: > On Thu, Sep 08, 2016 at 06:26:52PM +0200, Greg Kurz wrote: > > On Thu, 8 Sep 2016 18:19:27 +0300 > > "Michael S. Tsirkin" wrote: > > > > > On Thu, Sep 08, 2016 at 05:04:47PM +0200, Cornelia Huck wrote: > > > > On Thu, 8 Sep 2016 18:00:28 +0300 > > > > "Michael S. Tsirkin" wrote: > > > > > > > > > On Thu, Sep 08, 2016 at 11:12:16AM +0200, Greg Kurz wrote: > > If it continues > > execution, this means we're expecting the guest or the host to do something > > to fix the error condition. This requires QEMU to emit an event of some > > sort, but not necessarily to log an error message in a file. I guess this > > depends if QEMU is run by some tooling, or by a human. > > I'm not sure we need an event if tools are not expected to > do anything with it. If we limit # of times error > is printed, tools will need to reset this counter, > so we will need an event on overflow. If the device goes into a broken state, it should be discoverable from outside. I'm not sure we need an actual event signalling this if this happens due to the guest doing something wrong: That would be a task for tools monitoring _inside_ the guest. For tools monitoring the health of the machine (from the host perspective), the discovery interface would probably be enough?