From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37862) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPoYG-0000LE-UW for qemu-devel@nongnu.org; Fri, 05 Sep 2014 04:07:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPoY5-0000bl-O9 for qemu-devel@nongnu.org; Fri, 05 Sep 2014 04:07:24 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:41911) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPoY5-0000XH-0U for qemu-devel@nongnu.org; Fri, 05 Sep 2014 04:07:13 -0400 Message-ID: <54096EFC.9080703@huawei.com> Date: Fri, 5 Sep 2014 16:06:20 +0800 From: "Zhangjie (HZ)" MIME-Version: 1.0 References: <1408424189-10510-1-git-send-email-jasowang@redhat.com> <53F46909.2040101@huawei.com> <53F575AF.2010100@redhat.com> <53F59174.7010104@huawei.com> <53F59771.2050602@redhat.com> <53F5A2FD.2060405@huawei.com> <20140827125939.GA17757@redhat.com> <54005898.70309@huawei.com> <20140901081824.GA21249@redhat.com> In-Reply-To: <20140901081824.GA21249@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V3] vhost_net: start/stop guest notifiers properly List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Jason Wang , qemu-devel@nongnu.org, William Dauchy On 2014/9/1 16:18, Michael S. Tsirkin wrote: > On Fri, Aug 29, 2014 at 06:40:24PM +0800, Zhangjie (HZ) wrote: >> >> >> On 2014/8/27 20:59, Michael S. Tsirkin wrote: >>> On Thu, Aug 21, 2014 at 03:42:53PM +0800, Zhangjie (HZ) wrote: >>>> On 2014/8/21 14:53, Jason Wang wrote: >>>>> On 08/21/2014 02:28 PM, Zhangjie (HZ) wrote: >>>>>> >>>>>> After migration, vhost is not disabled, virtual nic became unreachable because vhost is not awakened. >>>>>> By the logical of EVENT_IDX, virtio-net will not kick vhost again if the used idx is not updated. >>>>>> So, if one interrupts is lost during migration, virtio_net will not kick vhost again. >>>>>> Then, no skb from virtio-net can be sent to tap. >>>>> >>>>> Yes and I mean to test vhost=off to see if it was the issue of vhost. >>>> That sounds reasonable, but the test case is to test vhost. >>>>>> >>>>>> Jason's patch reduced the probability of occurrence, from about 1/20 to 1/80. It is really effective. I think the patch should be acked. >>>>>> May be we can try to solve the problem from another perspective. Do you have some methods to sense the migration? >>>>>> We can make up a signal from virtio-net after the migration. >>>>> >>>>> You can make a patch like this to debug. If problem disappears, it means >>>>> interrupt was really lost anyway. >>>>>> >>>>>>> Anyway, I will try to reproduce it by myself. >>>>>>> >>>>>> The test environment is really terrible, I build a environment myself, but it problem did not occur. >>>>>> The environment I use now is from a colleague Responsible for test work. >>>>>> Two hosts, every host has about 20 vms, they send packages(ipv4 and ipv6) between each other. >>>>>> The VM to be migrated also sens packages itself, and there is a ping(-i 0.001) from another host to it. >>>>>> The physical nic is 1GE, connected through a internal nework. >>>>> >>>>> Just want to confirm. For the problem did not occur, you mean with my >>>>> patch on top? >>>>> . >>>>> >>>> I mean, with your patch, I have to test 80 times before it occurs, the probability is reduced. >>> >>> Could you please try to apply the patch >>> [PATCH V4] net: Forbid dealing with packets when VM is not running >>> on top and see if this helps? >>> >>> Thanks! >>> >>>> -- >>>> Best Wishes! >>>> Zhang Jie >>> . >>> >> Thanks! I will have a test. > > Great, once you have the result of the two patches applied > together, please let us know on the list. > > >> -- >> Best Wishes! >> Zhang Jie > . > I'm sorry for not giving test results in time, test resource is busy these days. Perhaps I can give the result next week. -- Best Wishes! Zhang Jie