[Qemu-devel] virtio-net sporadic error with QNX 7.0 guest: virtio-net ctrl missing headers

[Claudio]

Hello Michael, Jason and all,

I am currently using latest mainline QEMU on x86_64 to run a QNX 7 guest.

QNX 7 is not free software anymore unfortunately, with the
the last open source versions in the 6.x range.

I am using the official virtio-net guest driver from QNX 7.

During initialization I sporadically get this error message:

$ qemu-system-x86_64 -machine pc,accel=kvm,kernel_irqchip=on -smp 2 -m 2048 
-display none -nodefconfig -nodefaults -chardev stdio,mux=on,id=char0 -serial 
chardev:char0 -monitor none -mon chardev=char0,mode=readline -netdev 
user,id=user0,hostfwd=udp::9004-:9004 -device virtio-net,netdev=user0 qnx.img

virtio-net ctrl missing headers

and following that my host->guest UDP port forwarding does not work, that is,
the qemu process shows up as listening on the interface, but no packets appear 
in the guest.

This error during initialization does not appear every time I launch QEMU.
It appears to be more or less random.

Whenever the error does not appear, the interface works as expected, and port 
forwarding works.

Latest commit is 

19b599f7664b ("Merge remote-tracking branch 
'remotes/armbru/tags/pull-error-2018-08-27-v2'")

Thanks a lot for any advice!

Ciao,

Claudio