Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965456AbcCJH5y (ORCPT ); Thu, 10 Mar 2016 02:57:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40199 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752681AbcCJH5s (ORCPT ); Thu, 10 Mar 2016 02:57:48 -0500 Date: Thu, 10 Mar 2016 13:27:28 +0530 From: Amit Shah To: "Li, Liang Z" Cc: "quintela@redhat.com" , "qemu-devel@nongnu.org" , "linux-kernel@vger.kernel.org" , "mst@redhat.com" , "akpm@linux-foundation.org" , "pbonzini@redhat.com" , "rth@twiddle.net" , "ehabkost@redhat.com" , "linux-mm@kvack.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "dgilbert@redhat.com" Subject: Re: [RFC qemu 0/4] A PV solution for live migration optimization Message-ID: <20160310075728.GB4678@grmbl.mre> References: <1457001868-15949-1-git-send-email-liang.z.li@intel.com> <20160308111343.GM15443@grmbl.mre> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 10 Mar 2016 07:57:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1096 Lines: 37 On (Thu) 10 Mar 2016 [07:44:19], Li, Liang Z wrote: > > Hi Amit, > > Could provide more information on how to use virtio-serial to exchange data? Thread , Wiki or code are all OK. > I have not find some useful information yet. See this commit in the Linux sources: 108fc82596e3b66b819df9d28c1ebbc9ab5de14c that adds a way to send guest trace data over to the host. I think that's the most relevant to your use-case. However, you'll have to add an in-kernel user of virtio-serial (like the virtio-console code -- the code that deals with tty and hvc currently). There's no other non-tty user right now, and this is the right kind of use-case to add one for! For many other (userspace) use-cases, see the qemu-guest-agent in the qemu sources. The API is documented in the wiki: http://www.linux-kvm.org/page/Virtio-serial_API and the feature pages have some information that may help as well: https://fedoraproject.org/wiki/Features/VirtioSerial There are some links in here too: http://log.amitshah.net/2010/09/communication-between-guests-and-hosts/ Hope this helps. Amit