[Qemu-discuss] multiqueue tap queue selection

[Hui Jing]

Hi all,

Not sure if it is a right place to ask. Anyway, I am dealing with
multiqueue support using Linux bridge and multiqueue tap.

As far as I know, the tap device queue selection is based on hash of packet
headers. In case the hash is not available, the queue-mapping will be
tried, otherwise, it will just select the first available queue.

>From my experiment, transport layer packets can be hashed successfully and
flow goes to a proper queue based on the hash value. Also, pure l2 packets
falls into the first queue since no hash and queue-mapping available. Pure
l3 packets (has ip headers), somehow I think got hashed, however, the
packets are distributed to all queues apart from 1st available queue, and
it looks like a round robin fashion.

My question is how tap device deal with the hash of l3 packets?  Thanks