RE: PV resume failed after self migration failed

["James Harper" <james.harper@bendigoit.com.au>]

> >
> > Windows will invoke a scsi reset if a request takes too long to
complete
> > (5 seconds I think). It will also issue a reset when a crash dump
> > starts, just to make sure all previous requests are flushed etc.
> >
> Thanks for the help, sorry for the late response, I've been leaving a
while
> lase weekend.
> 
> If VBD is already suspended, all further IO try to issue will find vbd
states
> is not SR_STATE_RUNNING,
> thus calls ScsiPortNotification to notify RequestComplete, right?
> 
> If so, I have an assumption.
> at time t, VBD is suspend, an IO is try to issue, but before it calls
> ScsiPortNotificaiton, the whole
> VM paused(VCPU paused, last step of step),  10 or more seconds later,
if VM
> resumes,  will the driver
> found the IO mentioned before has already timed out and trigger
> XenVbd_HwScsiResetBus?
> 

The xenvbd driver doesn't do any timeout, windows does the timeout and
tells xenvbd to reset. I haven't tested the scenario you describe very
recently, and xenvbd is now two different drivers, one for scsiport (<=
2003) and one for storport (>= Vista), so there could be bugs in either.

James