limit connectivity of a KVM vm
 

I'm using Proxmox as virtualization platform to run my VMs on top of KVM,
Some times I need to limit the connevtivity of a VM to 1024 kb or 10 mb or ...
I know that the TC command in linux can do things that I need but after my search I've found these tc rules that must limit the speed rate of a VM but these are not working and I can see that VMs are downloading or uploading with much higher rates.

Any one has any suggestion?

tc qdisc add dev tap101i0d0 root handle 1: cbq avpkt 1000 bandwidth 10mbit

tc class add dev tap101i0d0 parent 1: classid 1:2 cbq rate 1024kbit allot 1500 prio 5 bounded isolated

tc filter add dev tap101i0d0 parent 1: protocol ip prio 16 u32 match ip src 123.123.123.123 flowid 1:2