hi:

when I use openstack devstack to test QOS, wired phenomenon appeared, 

I set qos ingress rule in tapB, but when I reboot tapA, the ingress rule of tapB automatically removed, but the egress rule is still exist.

Test enviroment:

Linux: ubuntu 14.04.1 LTS

kernel: 3.13.0-32-generic

libvirt: 1.2.2

openstack: havana

1. use nova to create vm A and vm B. for the configuration of the libvirt xml, see the last paragraph in the end.

2. use tc cmd to create qos rule for vm A and vm B

   tc qdisc add dev tap3d0d2c4a-0b ingress  //vmA

   tc qdisc add dev tap896d5066-69 ingress //vmB

configurations:

  vmA:-------------------------------------------

  <domain type='qemu' id='15'>

  <name>instance-00000001</name>

  <uuid>142a08db-6e25-4a03-be13-7073104b0745</uuid>

  <memory unit='KiB'>524288</memory>

  <currentMemory unit='KiB'>524288</currentMemory>

  <vcpu placement='static'>1</vcpu>

  <resource>

    <partition>/machine</partition>

  </resource>

  <sysinfo type='smbios'>

    <system>

      <entry name='manufacturer'>OpenStack Foundation</entry>

      <entry name='product'>OpenStack Nova</entry>

      <entry name='version'>2013.2.3</entry>

      <entry name='serial'>5fd079ed-5bc3-45ed-8de5-8bf9b8533d82</entry>

      <entry name='uuid'>142a08db-6e25-4a03-be13-7073104b0745</entry>

    </system>

  </sysinfo>

  <os>

    <type arch='x86_64' machine='pc-i440fx-trusty'>hvm</type>

    <boot dev='hd'/>

    <smbios mode='sysinfo'/>

  </os>

  <features>

    <acpi/>

    <apic/>

  </features>

  <clock offset='utc'/>

  <on_poweroff>destroy</on_poweroff>

  <on_reboot>restart</on_reboot>

  <on_crash>destroy</on_crash>

  <devices>

    <emulator>/usr/bin/qemu-system-x86_64</emulator>

    <disk type='file' device='disk'>

      <driver name='qemu' type='qcow2' cache='none'/>

      <source file='/opt/stack/data/nova/instances/142a08db-6e25-4a03-be13-7073104b0745/disk'/>

      <target dev='vda' bus='virtio'/>

      <alias name='virtio-disk0'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>

    </disk>

    <controller type='usb' index='0'>

      <alias name='usb0'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>

    </controller>

    <controller type='pci' index='0' model='pci-root'>

      <alias name='pci.0'/>

    </controller>

    <interface type='bridge'>

      <mac address='fa:16:3e:22:68:6a'/>

      <source bridge='br-int'/>

      <virtualport type='openvswitch'>

        <parameters interfaceid='3d0d2c4a-0b72-4f91-b393-413e0c5a335b'/>

      </virtualport>

      <target dev='tap3d0d2c4a-0b'/>

      <model type='virtio'/>

      <driver name='qemu'/>

      <alias name='net0'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

    </interface>

    <serial type='file'>

      <source path='/opt/stack/data/nova/instances/142a08db-6e25-4a03-be13-7073104b0745/console.log'/>

      <target port='0'/>

      <alias name='serial0'/>

    </serial>

    <serial type='pty'>

      <source path='/dev/pts/31'/>

      <target port='1'/>

      <alias name='serial1'/>

    </serial>

    <console type='file'>

      <source path='/opt/stack/data/nova/instances/142a08db-6e25-4a03-be13-7073104b0745/console.log'/>

      <target type='serial' port='0'/>

      <alias name='serial0'/>

    </console>

    <input type='tablet' bus='usb'>

      <alias name='input0'/>

    </input>

    <input type='mouse' bus='ps2'/>

    <input type='keyboard' bus='ps2'/>

    <graphics type='vnc' port='5900' autoport='yes' listen='127.0.0.1' keymap='en-us'>

      <listen type='address' address='127.0.0.1'/>

    </graphics>

    <video>

      <model type='cirrus' vram='9216' heads='1'/>

      <alias name='video0'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>

    </video>

    <memballoon model='virtio'>

      <alias name='balloon0'/>

      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>

    </memballoon>

  </devices>

  <seclabel type='dynamic' model='apparmor' relabel='yes'>

    <label>libvirt-142a08db-6e25-4a03-be13-7073104b0745</label>

    <imagelabel>libvirt-142a08db-6e25-4a03-be13-7073104b0745</imagelabel>

  </seclabel>

</domain>