From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: Is fallback vhost_net to =?utf-8?Q?qem?= =?utf-8?Q?u_for_live_migrate_available=EF=BC=9F?= Date: Mon, 2 Sep 2013 11:11:47 +0300 Message-ID: <20130902081147.GA21387@redhat.com> References: <521C1DCF.5090202@huawei.com> <522174D7.6080903@huawei.com> <20130902075722.GZ15729@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Qin Chuanyu , Anthony Liguori , jasowang@redhat.com, KVM list , netdev@vger.kernel.org, qianhuibin@huawei.com, "xen-devel@lists.xen.org" , wangfuhai@huawei.com, likunyun@huawei.com, liuyongan@huawei.com, liuyingdong@huawei.com To: Wei Liu Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50831 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752789Ab3IBILH (ORCPT ); Mon, 2 Sep 2013 04:11:07 -0400 Content-Disposition: inline In-Reply-To: <20130902075722.GZ15729@zion.uk.xensource.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Sep 02, 2013 at 08:57:22AM +0100, Wei Liu wrote: > On Sat, Aug 31, 2013 at 12:45:11PM +0800, Qin Chuanyu wrote: > > On 2013/8/30 0:08, Anthony Liguori wrote: > > >Hi Qin, > >=20 > > >>By change the memory copy and notify mechanism =EF=BC=8Ccurrently= virtio-net with > > >>vhost_net could run on Xen with good performance=E3=80=82 > > > > > >I think the key in doing this would be to implement a property > > >ioeventfd and irqfd interface in the driver domain kernel. Just > > >hacking vhost_net with Xen specific knowledge would be pretty nast= y > > >IMHO. > > > > > Yes, I add a kernel module which persist virtio-net pio_addr and > > msix address as what kvm module did. Guest wake up vhost thread by > > adding a hook func in evtchn_interrupt. > >=20 > > >Did you modify the front end driver to do grant table mapping or i= s > > >this all being done by mapping the domain's memory? > > > > > There is nothing changed in front end driver. Currently I use > > alloc_vm_area to get address space=EF=BC=8C and map the domain's me= mory as > > what what qemu did. > >=20 >=20 > You mean you're using xc_map_foreign_range and friends in the backend= to > map guest memory? That's not very desirable as it violates Xen's > security model. It would not be too hard to pass grant references > instead of guest physical memory address IMHO. >=20 > Wei. It's a start and it should make it fast and work with existing infrastructure in the host, though. --=20 MST