[libvirt-users] Virsh blkstat doesn't work on Xen HVM

[張文哲]

Hi

I tried to use virsh blkstat to get information of a block, but it
returns an error message as shown below
This function works fine in KVM, but fail in XEN.
I tried XEN 3.4.3 ,4.0.0 and 4.0.1 with libvirt 0.7.1 from fedora yum
server and 0.8.1 from libvirt .
All of them are fail to get the block status.
The following is the config file and error message of virsh domblkstat.
Any one knows how to make this function work?

[root at localhost ~]# virsh dumpxml vm1
<domain type='xen' id='1'>
  <name>vm1</name>
  <uuid>12af1ed4-2f2d-f02d-9a2a-5d4f377889d5</uuid>
  <memory>524288</memory>
  <currentMemory>524288</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type>hvm</type>
    <loader>/usr/lib/xen/boot/hvmloader</loader>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/lib64/xen/bin/qemu-dm</emulator>
    <disk type='file' device='disk'>
      <driver name='file'/>
      <source file='/var/lib/libvirt/images/vm1.img'/>
      <target dev='hda' bus='ide'/>
    </disk>
    <disk type='file' device='cdrom'>
      <target dev='hdc' bus='ide'/>
      <readonly/>
    </disk>
    <interface type='bridge'>
      <mac address='00:16:36:0f:fb:7a'/>
      <source bridge='eth0'/>
      <script path='/etc/xen/scripts/vif-bridge'/>
      <target dev='vif1.0'/>
    </interface>
    <serial type='pty'>
      <source path='/dev/pts/0'/>
      <target port='0'/>
    </serial>
    <console type='pty' tty='/dev/pts/0'>
      <source path='/dev/pts/0'/>
      <target port='0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='5900' autoport='yes' keymap='en-us'/>
    <sound model='es1370'/>
  </devices>
</domain>

[root at localhost ~]# virsh domblkstat vm1 hda
error: Failed to get block stats vm1 hda
error: internal error read_bd_stats: Failed to read any block statistics