Re: [PATCH 1/1] virsh: inherit qos from network definition when attaching an interface

On 11/1/21 8:52 AM, jx8zjs wrote: I don't think this is right. The bug is about setting QoS on the bridge itself not TAP devices plugged into it. From the bug, this is the QoS setting: <bandwidth> <inbound average='1000' peak='5000' burst='5120'/> <outbound average='128' peak='256' burst='256'/> </bandwidth> And this is the resulting tc setting: # tc qdisc show dev virbr0 qdisc htb 1: root refcnt 2 r2q 10 default 0x2 direct_packets_stat 0 direct_qlen 1000 qdisc sfq 2: parent 1:2 limit 127p quantum 1514b depth 127 divisor 1024 perturb 10sec qdisc ingress ffff: parent ffff:fff1 ---------------- # tc class show dev virbr0 class htb 1:1 root rate 8Mbit ceil 40Mbit burst 1600b cburst 1600b class htb 1:2 parent 1:1 leaf 2: prio 0 rate 8Mbit ceil 40Mbit burst 5Mb cburst 1600b # tc filter show dev virbr0 filter parent 1: protocol all pref 1 fw chain 0 filter parent 1: protocol all pref 1 fw chain 0 handle 0x1 classid :1 # tc filter show dev virbr0 ingress filter parent ffff: protocol all pref 49152 u32 chain 0 filter parent ffff: protocol all pref 49152 u32 chain 0 fh 800: ht divisor 1 filter parent ffff: protocol all pref 49152 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid :1 not_in_hw match 00000000/00000000 at 0 police 0x1 rate 1024Kbit burst 256Kb mtu 64Kb action drop overhead 0b ref 1 bind 1 what this does is when there's an <interface/> from this network (without its own QoS) in a guest, it is rate limited by default. Moreover, if there are two interfaces, with no QoS set, then they share the same rate, which means in this case that they both share 1mbps bandwidth. It does NOT mean that each <interface/> has its own 1mbps bandwidth to spare. The only way to achieve this behaviour is to set QoS on the bridge itself and not individual interfaces. Michal