Hi all, 
 
I downloaded the xen 3.3.0 and now 
testing the pci pass-through with the NIC.
Using late binding, the pci slot 
 0000:08:01.0 is assigned to pciback.
But pci related xm commands are not 
working.
 
For eg: 
linux-242:/home/xen-3.3.0 # xm 
pci-list-assignable-devices
Unexpected error: <type 
'exceptions.OSError'>
 
Please report to xen-devel@xxxxxxxxxxxxxxxxxxx
Traceback (most recent call 
last):
  File "/usr/sbin/xm", line 10, 
in <module>
    
main.main(sys.argv)
  File 
"//usr/lib64/python/xen/xm/main.py", line 2883, in 
main
    _, rc = 
_run_cmd(cmd, cmd_name, args)
  File 
"//usr/lib64/python/xen/xm/main.py", line 2907, in 
_run_cmd
    return True, 
cmd(args)
  File 
"//usr/lib64/python/xen/xm/main.py", line 2202, in 
xm_pci_list_assignable_devices
    devs_list = 
check_FLR_capability(dev_list)
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 288, in 
check_FLR_capability
    
coassigned_pci_list = 
dev.find_coassigned_devices(True)
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 461, in 
find_coassigned_devices
    dev = 
self.find_the_uppermost_pci_bridge()
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 424, in 
find_the_uppermost_pci_bridge
    dev_parent = 
PciDevice(dom, b, d, f)
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 382, in 
__init__
    
self.detect_dev_info()
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 604, in 
detect_dev_info
    class_dev = 
self.pci_conf_read16(PCI_CLASS_DEVICE)
  File 
"/usr/lib64/python2.5/xen/util/pci.py", line 567, in 
pci_conf_read16
    fd = 
os.open(self.cfg_space_path, os.O_RDONLY)
OSError: [Errno 2] No such file or 
directory: 
'/sys/bus/pci/devices/0000:06:00.0/config'
 
I checked the above python 
scripts.
The function find_parent() in file 
util/pci.py, tries to find the parent device from the file link 
../../../devices/pci0000:06/0000:06:01.0/0000:08:01.0
When it sees pci0000:06, it tries to 
read the config space of 0000:06:00.0 which doesn’t exist. This causes the above 
error.
 
Lspci tree 
is,
 
linux-242:/home/xen-3.3.0 # lspci 
-t
-+-[0000:06]-+-01.0-[0000:08]----01.0
 |           
+-01.1
 |           
+-02.0-[0000:07]--
 |           
\-02.1
 \-[0000:00]-+-00.0
             
+-01.0
             
+-01.1
           
  +-06.0
             
+-07.0
             
+-08.0
             
+-09.0-[0000:05]----07.0
             
+-0b.0-[0000:04]----00.0
             
+-0c.0-[0000:03]----00.0
             
+-0d.0-[0000:02]--
             
+-0e.0-[0000:01]--
             
+-18.0
         
    +-18.1
             
+-18.2
             
+-18.3
             
+-19.0
             
+-19.1
             
+-19.2
             
\-19.3
 
Thanks,
Masroor