I tried to see the block
information in a HVM by using xm top, but it shows all zero.
      
f12 --b---         44   
0.0     528352   
6.3     528384      
6.3     1   
1       
0        0   
5        0
      
0       
0         
0          0    0
VBD BlkBack 51714 [ca:
2]  OO:        0  
RD:        0  
WR:        0   RSECT:         
0   WSECT:          0
VBD BlkBack 51715 [ca:
3]  OO:        0  
RD:        0  
WR:        0  
RSECT:          0  
WSECT:          0
VBD BlkBack  768 [ 3:
0]  OO:        0  
RD:        0  
WR:        0  
RSECT:          0  
WSECT:          0
VBD BlkBack 5632 [16:
0]  OO:        0  
RD:        0  
WR:        0  
RSECT:          0  
WSECT:          0
VBD BlkBack 2049 [ 8:
1]  OO:        0  
RD:        0  
WR:        0  
RSECT:          0  
WSECT:          0
 
I tried to use block-list
to see the status of block devices, and it seems can’t communicate across
Xenbus to devices.
[root@localhost
tap-6-768]# xm block-list f12
Vdev  BE handle state
evt-ch ring-ref BE-path
768   
0    0     1     
-1     -1   
/local/domain/0/backend/vbd/17/768
5632  
0    0     1     
-1     -1   
/local/domain/0/backend/vbd/17/5632
2049  
0    0     1     
-1     -1   
/local/domain/0/backend/vbd/17/2049
51714 
0    0     1     
-1     -1    /local/domain/0/backend/vbd/17/51714
51715 
0    0     1     
-1     -1   
/local/domain/0/backend/vbd/17/51715
 
 
In para-virtualized VM, it
works fine
Vdev  BE handle state
evt-ch ring-ref BE-path
51712 
0    0     4     
9      8    
/local/domain/0/backend/vbd/18/51712
    lalala
--b---         
8    0.1    1048576  
12.5    1048576     
12.5     2   
1       
3        0   
1        0     6499    
1366     353233     
19802    0
VBD BlkBack 51712 [ca:
0]  OO:        0  
RD:     6499   WR:    
1366   RSECT:     353233   WSECT:     
19802
 
The following is the
config  file of HVM
<domain type='xen'
id='17'>
 
<name>f12</name>
  <uuid>c5b66a0b-4ea8-67bf-4832-50d7a3957233</uuid>
 
<memory>524288</memory>
 
<currentMemory>524288</currentMemory>
 
<vcpu>1</vcpu>
  <os>
   
<type>hvm</type>
   
<loader>/usr/lib/xen/boot/hvmloader</loader>
   
<boot dev='hd'/>
   
<boot dev='cdrom'/>
  </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='/tmp/vm1.img'/>
     
<target dev='hda' bus='ide'/>
   
</disk>
   
<disk type='file' device='cdrom'>
     
<driver name='file'/>
     
<source file='/tmp/ISO/f12.iso'/>
     
<target dev='hdc' bus='ide'/>
     
<readonly/>
   
</disk>
   
<disk type='file' device='disk'>
     
<driver name='file'/>
     
<source file='/tmp/testvm1.img'/>
     
<target dev='/dev/sda1' bus='ide'/>
   
</disk>
   
<disk type='file' device='disk'>
     
<driver name='file'/>
     
<source file='/tmp/testvm2.img'/>
     
<target dev='/dev/xvda2' bus='ide'/>
   
</disk>
   
<disk type='file' device='disk'>
     
<driver name='file'/>
     
<source file='/tmp/testvm3.img'/>
     
<target dev='/dev/xvda3' bus='ide'/>
   
</disk>
   
<interface type='bridge'>
     
<mac address='00:16:3e:07:33:44'/>
     
<source bridge='virbr0'/>
     
<script path='/etc/xen/scripts/vif-bridge'/>
     
<target dev='vif17.0'/>
   
</interface>
   
<input type='mouse' bus='ps2'/>
   
<graphics type='vnc' port='5900' autoport='yes'/>
  </devices>
</domain>