Re: [Qemu-devel] How to lock-up your tap-based VM network

[Paul Brook]

> A major reason for this deadlock could likely be removed by shutting
> down the tap (if peered) or dropping packets in user space (in case of
> vlan) when a NIC is stopped or otherwise shut down. Currently most (if
> not all) NIC models seem to signal both "queue full" and "RX disabled"
> via !can_receive().

No. A disabled device should return true from can_recieve, then discard the 
packets in its receive callback. Failure to do so is a bug in the device. It 
looks like the virtio-net device may be buggy.

Paul.