Hello there, When I run migration test for my PV drivers, I find that EVTCHNOP_send hypercall crash windows with error code 0x7F (0x8...) http://msdn.microsoft.com/en-us/library/ff559244(v=VS.85).aspx <http://msdn.microsoft.com/en-us/library/ff559244%28v=VS.85%29.aspx> when system was migrated for more than 500 times. PV drivers can call it successfully for several times before crash when system is suspending or resuming. It always happens in some xenstore watch event callback routine. Such as read/write device state key or state key changing watcher callback routine. The hypercall didn''t return from hypervisor but windows crashes. I''ve checked the xenstore base address from share info and parameter of that hyper call, looks like are fine. So which situation of that hypercall will crash windows? Which part I should double check in my PV drivers? I am using WDK 7600.16385.1, Windows 7 X86, Xen 3.4.0. BTW, seems that Windows 7 X64 works fine in migration test. Thanks Wayne _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel