From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52260) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gJj0t-00051N-4d for qemu-devel@nongnu.org; Mon, 05 Nov 2018 12:50:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gJj0m-0005Gy-Um for qemu-devel@nongnu.org; Mon, 05 Nov 2018 12:50:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52766) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gJj0k-0005Bm-SC for qemu-devel@nongnu.org; Mon, 05 Nov 2018 12:50:04 -0500 References: From: Eric Blake Message-ID: Date: Mon, 5 Nov 2018 11:49:55 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] How to emulate block I/O timeout on qemu side? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dongli Zhang , qemu-devel@nongnu.org, libguestfs On 11/2/18 3:11 AM, Dongli Zhang wrote: > Hi, > > Is there any way to emulate I/O timeout on qemu side (not fault injection in VM > kernel) without modifying qemu source code? You may be interested in Rich's work on nbdkit. If you don't mind the overhead of the host connecting through NBD, then you can use nbdkit's delay and fault-injection filters for inserting delays or even run-time-controllable failures to investigate how the guest reacts to those situations > > For instance, I would like to observe/study/debug the I/O timeout handling of > nvme, scsi, virtio-blk (not supported) of VM kernel. > > Is there a way to trigger this on purpose on qemu side? > > Thank you very much! > > Dongli Zhang > > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org