Despite of traffic control on host netdevice, is it worth to impose a limit control on qemu emulated net device?

Hi,

As we know, in order to control the guest OS's TX rate limit, we can
apply rate limit on ingress Qdisc of host's tap device.
But I think skb will be dropped on host's tap ingress Qdisc, which
means that for those protocol lacking of congestion control such as
UDP, it will cost a lot of meaningless time to produce dropped packet
.

What about introducing rate limit on qemu's emulated net device?  I
think guest's UDP transaction will be  blocked at wait_for_wmem.

Thanks and regards,
pingfan