[Xen-devel] xm save -c problem

["Liu.yi" <liu.yi24@xxxxxxxxxx>]

hi,all
    I have a winxpsp2 vm with gplpv driver installed. The problem is that
when I excute "xm save -c winxpsp2 save.bin", the command is excuted
successfully but the vm hang after issuing a disk operaton.
    After installing gplpv debug driver, from the qemu log I found vbd
resume failed, after a while windows issues disk reset command, then vm
hang.
    xm debug-keys shows as follows before "xm save -c":
(XEN)        1 [0/1]: s=3 n=0 d=0 p=72 x=1
(XEN)        2 [0/0]: s=3 n=0 d=0 p=71 x=0
(XEN)        3 [0/1]: s=2 n=0 d=0 x=0
(XEN)        4 [0/0]: s=6 n=0 x=0                   // pdo_event_channel
(XEN)        5 [0/0]: s=2 n=0 d=0 x=0             // suspend_evtchn
(XEN)        6 [0/0]: s=3 n=0 d=0 p=73 x=0     // vbd-768 event-channel
(XEN)        7 [0/0]: s=3 n=0 d=0 p=74 x=0     // vif-0 event-channel
    xm debug-keys shows as follows after "xm save -c":
(XEN)        1 [0/1]: s=3 n=0 d=0 p=72 x=1
(XEN)        2 [0/0]: s=3 n=0 d=0 p=71 x=0
(XEN)        3 [0/1]: s=2 n=0 d=0 x=0
(XEN)        4 [0/0]: s=6 n=0 x=0                   // pdo_event_channel
(XEN)        5 [0/0]: s=2 n=0 d=0 x=0             // suspend_evtchn
(XEN)        6 [0/0]: s=6 n=0 x=0                   // new pdo_event_channel
(XEN)        7 [0/0]: s=2 n=0 d=0 x=0             // new suspend_evtchn
(XEN)        8 [0/0]: s=3 n=0 d=0 p=? x=0       // new vbd-768 event-channel
                                                              // vif-0
resume don't start at all because resume hang at vbd

    blkback and blkif driver seem free their event-channel in
unbind_from_irqhandler when suspending, so when gplpv driver resumes it
starts allocing event-channel from 6. The strange things is that gplpv
driver allocs new pdo_event_channel and suspend_evtchn (6 and 7), the
previous ones retain active.
    I tried to unbind the old pdo_event_channel and suspend_evtchn, but
suspending vm hang. "xm save -c" wokrs if I reuse the old pdo_event_channel
and suspend_evtchn as follows:

  in evtchn.c:EvtChn_Init()
      KeInitializeEvent(&xpdd->pdo_suspend_event, SynchronizationEvent,
FALSE);
      if (xpdd->pdo_event_channel == 0) {
          KdPrint((__DRIVER_NAME "     create new pdo_event_channel\n"));
          xpdd->pdo_event_channel = EvtChn_AllocIpi(xpdd, 0);
      }
  in xenpci_fdo.c:XenPci_ConnectSuspendEvt()
      if (xpdd->suspend_evtchn == 0) {
          xpdd->suspend_evtchn = EvtChn_AllocUnbound(xpdd, 0);
          KdPrint((__DRIVER_NAME "     create new suspend event
channel\n"));
      } 

    The qemu log show vbd and vif resume successfully, vm runs fine.
    I'm not sure about these modifications to gplpv windows driver. I will
be grateful for any suggestions, thks.



--
View this message in context: 
http://xen.1045712.n5.nabble.com/xm-save-c-problem-tp5713082.html
Sent from the Xen - Dev mailing list archive at Nabble.com.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel