an error after restore in pv driver

an error after restore in pv driver

[ANNIE LI]

Hi,

I am debugging the save/restore work in Windows PV Driver, and always 
hit a problem after restore. after VBD PV driver initialize the backend 
parameters, the domain0 can read back those parameters correctly, then 
begin the backend initialization, but i always hit the error in this step.
the error information is (error/backend/vbd/40/768/error 1 mapping 
ring-ref 335 port 5), please referring to the following xenstored-trace.log.
what may result in this problem? any help is appreciated.

Thanks
Annie

IN  0x9ba76d0 20081128 14:16:07 WRITE (device/vbd/768/state 1)
OUT 0x9ba6aa8 20081128 14:16:07 WATCH_EVENT 
(/local/domain/40/device/vbd/768/state E14C7210 )
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/state )
OUT 0x9ba6aa8 20081128 14:16:07 READ (1)
OUT 0x9ba76d0 20081128 14:16:07 WRITE (OK )
IN  0x9ba76d0 20081128 14:16:07 READ (control/shutdown )
OUT 0x9ba76d0 20081128 14:16:07 ERROR (ENOENT )
OUT 0x9ba49e0 20081128 14:16:07 TRANSACTION_END (OK )
IN  0x9ba76d0 20081128 14:16:07 WRITE (device/vbd/768/ring-ref 335)
OUT 0x9ba76d0 20081128 14:16:07 WRITE (OK )
IN  0x9ba76d0 20081128 14:16:07 WRITE (device/vbd/768/event-channel 5)
OUT 0x9ba76d0 20081128 14:16:07 WRITE (OK )
IN  0x9ba76d0 20081128 14:16:07 WRITE (device/vbd/768/state 3)
OUT 0x9ba6aa8 20081128 14:16:07 WATCH_EVENT 
(/local/domain/40/device/vbd/768/state E14C7210 )
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/state )
OUT 0x9ba6aa8 20081128 14:16:07 READ (3)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/ring-ref )
OUT 0x9ba6aa8 20081128 14:16:07 READ (335)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/event-channel )
OUT 0x9ba6aa8 20081128 14:16:07 READ (5)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/protocol )
OUT 0x9ba6aa8 20081128 14:16:07 ERROR (ENOENT )
OUT 0x9ba76d0 20081128 14:16:07 WRITE (OK )
IN  0x9ba6aa8 20081128 14:16:07 WRITE (error/backend/vbd/40/768/error 1 
mapping ring-ref 335 port 5)
OUT 0x9ba6aa8 20081128 14:16:07 WRITE (OK )
IN  0x9ba6aa8 20081128 14:16:07 READ (backend/vbd/40/768/state )
OUT 0x9ba6aa8 20081128 14:16:07 READ (2)
IN  0x9ba6aa8 20081128 14:16:07 WRITE (backend/vbd/40/768/state 5)
OUT 0x9ba6aa8 20081128 14:16:07 WATCH_EVENT (backend/vbd/40/768/state 
C0673A14 )
OUT 0x9ba6aa8 20081128 14:16:07 WRITE (OK )
IN  0x9ba6aa8 20081128 14:16:07 DIRECTORY (backend/vbd/40/768/state )
OUT 0x9ba6aa8 20081128 14:16:07 DIRECTORY ()
IN  0x9ba76d0 20081128 14:16:07 WRITE (device/vbd/768/state 4)
OUT 0x9ba6aa8 20081128 14:16:07 WATCH_EVENT 
(/local/domain/40/device/vbd/768/state E14C7210 )
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/state )
OUT 0x9ba6aa8 20081128 14:16:07 READ (4)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/ring-ref )
OUT 0x9ba6aa8 20081128 14:16:07 READ (335)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/event-channel )
OUT 0x9ba6aa8 20081128 14:16:07 READ (5)
IN  0x9ba6aa8 20081128 14:16:07 READ 
(/local/domain/40/device/vbd/768/protocol )
OUT 0x9ba6aa8 20081128 14:16:07 ERROR (ENOENT )
OUT 0x9ba76d0 20081128 14:16:07 WATCH_EVENT 
(/local/domain/0/backend/vbd/40/768/state 8255819C )
IN  0x9ba6aa8 20081128 14:16:07 WRITE (error/backend/vbd/40/768/error 1 
mapping ring-ref 335 port 5)
OUT 0x9ba6aa8 20081128 14:16:07 WRITE (OK )
OUT 0x9ba76d0 20081128 14:16:07 WRITE (OK )