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
