------- Original Message ------- Sender : Michael S. Tsirkin<m...@redhat.com> Date : Apr 05, 2016 13:46 (GMT+03:00) Title : Re: [PATCH 0/4] Fix QEMU crash on vhost-user socket disconnect.
> On Thu, Mar 31, 2016 at 09:02:01AM +0300, Ilya Maximets wrote: > > On 30.03.2016 20:01, Michael S. Tsirkin wrote: > > > On Wed, Mar 30, 2016 at 06:14:05PM +0300, Ilya Maximets wrote: > > >> Currently QEMU always crashes in following scenario (assume that > > >> vhost-user application is Open vSwitch with 'dpdkvhostuser' port): > > > > > > In fact, wouldn't the right thing to do be stopping the VM? > > > > I don't think that is reasonable to stop VM on failure of just one of > > network interfaces. > > We don't start QEMU until vhost user connects, either. > Making guest run properly with a backend is a much bigger > project, let's tackle this separately. > > Also, I think handling graceful disconnect is the correct first step. > Handling misbehaving clients is much harder as we have asserts on remote > obeying protocol rules all over the place. > > > There may be still working vhost-kernel interfaces. > > Even connection can still be established if vhost-user interface was in > > bonding with kernel interface. > > Could not parse this. > > > Anyway user should be able to save all his data before QEMU restart. > > So reconnect a new backend, and VM will keep going. We cant't do this because of 2 reasons: 1. Segmentation fault of QEMU on disconnect. (fixed by this patch-set) 2. There is no reconnect functionality in current QEMU version. So, what are you talking about? Best regards, Ilya Maximets.