Hi Michael, I'm getting a qemu crash from a load/unload of virtio_net.ko in guest kernel with the following,
> ./x86_64-softmmu/qemu-system-x86_64 -hda > /var/lib/libvirt/images/Fedora-test0.img \ -m 4096 -enable-kvm -smp 4 -netdev tap,id=hn0,queues=4,vhost=on \ -device virtio-net-pci,netdev=hn0,mq=on,vectors=9 in the host I do a simple # rmmod virtio_net # modprobe virtio_net And bisecting points at this merge which just from the commit message looks like it could be the culprit, > Merge: 4eb28ab 5300063 > Author: Stefan Hajnoczi <stefa...@redhat.com> > Date: Thu Nov 3 14:41:53 2016 +0000 > > Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging > > virtio, pc: fixes and features > > nvdimm hotplug support > virtio migration and ioeventfd rework <--- ioeventfd bits? > virtio crypto device > ipmi fixes > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> Running without the above and everything works no issues. I started to debug but admittedly got a bit lost in the notifier hooks maybe someone will have a better idea. Here is the error I get, > kvm_io_ioeventfd_add: error adding ioeventfd: File exists > Aborted (core dumped) I had a gdb backtrace at one point and can post that if its helpful. Thanks, John