Hi James:
 
       In addtion, I think the if statement in XenVbd_HwScsiResetBus, we might need use 
suspend_resume_state_fdo, not suspend_resume_state_pdo. 
       Since suspend_resume_state_pdo is changed to SR_STATE_SUSPENDING, but there
are still io request not finished, when reset happen, those IO can be finished.
 
       What do u think? 
        Thanks.
 
 
static BOOLEAN
XenVbd_HwScsiResetBus(PVOID DeviceExtension, ULONG PathId)
{
  PXENVBD_DEVICE_DATA xvdd = DeviceExtension;
  srb_list_entry_t *srb_entry;
  PSCSI_REQUEST_BLOCK srb;
  int i;
  UNREFERENCED_PARAMETER(DeviceExtension);
  UNREFERENCED_PARAMETER(PathId);
  FUNCTION_ENTER();
  KdPrint((__DRIVER_NAME "     IRQL = %d\n", KeGetCurrentIrql()));
  if (xvdd->ring_detect_state == RING_DETECT_STATE_COMPLETE && xvdd->device_state->suspend_resume_state_pdo == SR_STATE_RUNNING) *********this line
  {
    while((srb_entry = (srb_list_entry_t *)RemoveHeadList(&xvdd->srb_list)) != (srb_list_entry_t *)&xvdd->srb_list)
    {
      srb = srb_entry->srb;
      srb->SrbStatus = SRB_STATUS_BUS_RESET;
      KdPrint((__DRIVER_NAME "     completing queued SRB %p with status SRB_STATUS_BUS_RESET\n", srb));
      ScsiPortNotification(RequestComplete, xvdd, srb);
    }
 
 
>> Subject: RE: PV resume failed after self migration failed
>> Date: Wed, 22 Jun 2011 14:06:18 +1000
>> From: james.harper@bendigoit.com.au
>> To: tinnycloud@hotmail.com; xen-devel@lists.xensource.com
>> 
>> > >
>> > > 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.
>> > >
>> > 
>> > The bug can be reproduced in 2003 32bit system. We are using scsi
>> driver.
>> > I put some log in XenVbd_HwScsiResetBus to see if there are not
>> completed
>> > srb(Like below)
>> > but I didn't see the log when XenVbd_HwScsiResetBus called. So No IO
>> is in
>> > queue.
>> 
>> Just to confirm, is this the issue that only happens when the migration
>> fails in xen and is cancelled?
>> 
>>Exactly.
>>I've noticed some difference in log.
> 
>In normal resuming, from the log, we can see event port assign like below:
>pdo_event_channel = 5 (Notifying event channel 5)
>suspend event channel = 6
>XEN_INIT_TYPE_EVENT_CHANNEL - event-channel = 7  (for VBD)
>XEN_INIT_TYPE_EVENT_CHANNEL - event-channel = 8  (VIF)
> 
>>when guest resuming locally from suspend(that is migration failed in xen, guest
>>has already suspended, so it need resuming)
> 
>>pdo_event_channel = 7 ( Notifying event channel 7)
>>suspend event channel = 8
>>XEN_INIT_TYPE_EVENT_CHANNEL - event-channel = 9 (vif)
> 
>>VBD port is not allocated, since pdo is waiting fdo change.
> 
>>It looks like port 5 and 6 is still occpuied, or pdo_event_channel bind twice?
> 
>it works when I unbind pdo_event_channel & suspend_evtchn. 
>===================================================================
>--- xenpci_fdo.c (revision 4304)
>+++ xenpci_fdo.c (working copy)
>@@ -656,6 +656,12 @@
>     }
>     WdfChildListEndIteration(child_list, &child_iterator);
> 
>+    EvtChn_Unbind(xpdd, xpdd->pdo_event_channel);
>+    EvtChn_Close(xpdd, xpdd->pdo_event_channel);
>+
>+    EvtChn_Unbind(xpdd, xpdd->suspend_evtchn);
>+    EvtChn_Close(xpdd, xpdd->suspend_evtchn);
>+    
>     XenBus_Suspend(xpdd);
>     EvtChn_Suspend(xpdd);
>     XenPci_HighSync(XenPci_Suspend0, XenPci_SuspendN, xpdd);
> 
> 
>BTW, is there a missing "break" in XenVbd_HwScsiInterrupt,  xenvbd_scsiport.c:928
>before default? Well, it is harmless.
> 
>924 case SR_STATE_RUNNING: 
>925 KdPrint((__DRIVER_NAME " New pdo state %d\n", suspend_resume_state_pdo)); 
>926 xvdd->device_state->suspend_resume_state_fdo = suspend_resume_state_pdo; 
>927 xvdd->vectors.EvtChn_Notify(xvdd->vectors.context, xvdd->device_state->pdo_event_channel); 
>928 ScsiPortNotification(NextRequest, DeviceExtension); 
>929 default: 
>930 KdPrint((__DRIVER_NAME " New pdo state %d\n", suspend_resume_state_pdo)); 
>931 xvdd->device_state->suspend_resume_state_fdo = suspend_resume_state_pdo; 
>932 xvdd->vectors.EvtChn_Notify(xvdd->vectors.context, xvdd->device_state->pdo_event_channel); 
>933 break; 
> 
>Thanks.
>>> James
>>> 
>