From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33102) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gPZds-0004h5-OA for qemu-devel@nongnu.org; Wed, 21 Nov 2018 16:02:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gPZdm-0007YS-ME for qemu-devel@nongnu.org; Wed, 21 Nov 2018 16:02:36 -0500 Received: from newman.cs.utexas.edu ([128.83.139.110]:48657) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gPZdk-0007Ql-Nd for qemu-devel@nongnu.org; Wed, 21 Nov 2018 16:02:29 -0500 Received: from mail-lf1-f42.google.com (mail-lf1-f42.google.com [209.85.167.42]) (authenticated bits=0) by newman.cs.utexas.edu (8.14.4/8.14.4/Debian-4.1ubuntu1) with ESMTP id wALKoGPe048351 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 21 Nov 2018 14:50:17 -0600 Received: by mail-lf1-f42.google.com with SMTP id n18so4993225lfh.6 for ; Wed, 21 Nov 2018 12:50:17 -0800 (PST) MIME-Version: 1.0 From: Hangchen YU Date: Wed, 21 Nov 2018 14:50:02 -0600 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: [Qemu-devel] MMIO access hangs the whole virtual machine List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Hi- I created an IO by memory_region_init_io with a MemoryRegionOps in a block device. The IO r/w handler takes a while to finish, and during that time the whole VM hangs. There was a similar discussion about the synchronous qemu_aio_cancel four years ago ( https://lists.gnu.org/archive/html/qemu-devel/2014-08/msg01545.html). Has that issue been resolved or is there any alternative way to make the MMIO access asynchronous? Thanks, Hangchen