[Qemu-discuss] Multiple queues for macvtap interface

[Chandrasekhar Nagaraj]

Hi,

I have a Dell PowerEdge 730 server with Ubuntu 16.04 and KVM running on it. 
QEMU version used is 2.5.0.  I have a guest OS with linux running on it which 
does packet processing and forwarding. I have 4 10G interfaces connected to the 
Dell server and all of them are connected to the guest via macvtap. For 
improving the throughput of the guest I am using multiple queues on the vhost 
driver by defining “<driver name='vhost' queues='8'/>” in the guest xml file. 
By using interrupt affinity for the queue interrupts I am able to use multiple 
VCPUs on the guest.
However I am seeing that on the host the macvtap interface is created with only 
1 Rx/Tx queue as shown below.
address@hidden:~$ ls /sys/class/net/macvtap0/queues/
rx-0  tx-0
Also only 1 tap device is opened per macvtap interface.
For lower input rate of around 10Gbps, there are not many issues. However when 
the input rate starts increasing, I don’t see the guest getting the packets at 
a very high rate.
Can anyone tell me how to create multiple queues for macvtap interface in QEMU?

Thanks,
Chandrasekhar