Latest current -CURRENT (rev 255904) panics with "device hyperv" on XenServer 6.2

[Sergey Nasonov]

>I just tried FreeBSD 10 ALPHA4 ISO. The ISO fails to boot on
>XenServer 6.2 resulting with the same HyperV panic
>
>Regards.
>@shankerbalan

Hi,
You can disable viridian support for that VM by command:
xe vm-param-set platform:viridian=false uuid=<vm_uuid>

after that check platform parameter for FBSD VM by command:
xe vm-param-get param-name=platform uuid=<vm_uuid>
viridian: false; timeoffset: 0; nx: true; acpi: 1; apic: true; pae: true

It helps me run FreeBSD 10 ALPHA 4 without problems. 

I have tested live migration with both statis and dynamic memory configuration. If 
I set static configuration, for example 512 MB RAM then VM migration ends fine. 
VM migration during acive dynamic memory configuration (512 MB - min 1024 MB 
- max) triggers huge amount of console messages:

KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe003d291900
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe003d2919b0
witness_warn() at witness_warn+0x4a8/frame 0xfffffe003d291a70
uma_zalloc_arg() at uma_zalloc_arg+0x3b/frame 0xfffffe003d291ae0
malloc() at malloc+0x101/frame 0xfffffe003d291b30
balloon_process() at balloon_process+0x44a/frame 0xfffffe003d291bb0
fork_exit() at fork_exit+0x84/frame 0xfffffe003d291bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe003d291bf0
--- trap 0, rip = 0, rsp = 0xfffffe003d291cb0, rbp = 0 ---
uma_zalloc_arg: zone "16" with the following non-sleepable locks held:
exclusive sleep mutex balloon_lock (balloon_lock) r = 0 (0xffffffff816e7158) locked 
@ /usr/src/sys/dev/xen/balloon/balloon.c:339
exclusive sleep mutex balloon_mutex (balloon_mutex) r = 0 (0xffffffff816e7138) 
locked @ /usr/src/sys/dev/xen/balloon/balloon.c:373
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe003d291900
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe003d2919b0
witness_warn() at witness_warn+0x4a8/frame 0xfffffe003d291a70
uma_zalloc_arg() at uma_zalloc_arg+0x3b/frame 0xfffffe003d291ae0
malloc() at malloc+0x101/frame 0xfffffe003d291b30
balloon_process() at balloon_process+0x44a/frame 0xfffffe003d291bb0
fork_exit() at fork_exit+0x84/frame 0xfffffe003d291bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe003d291bf0
--- trap 0, rip = 0, rsp = 0xfffffe003d291cb0, rbp = 0 ---
uma_zalloc_arg: zone "16" with the following non-sleepable locks held:
exclusive sleep mutex balloon_lock (balloon_lock) r = 0 (0xffffffff816e7158) locked 
@ /usr/src/sys/dev/xen/balloon/balloon.c:339
exclusive sleep mutex balloon_mutex (balloon_mutex) r = 0 (0xffffffff816e7138) 
locked @ /usr/src/sys/dev/xen/balloon/balloon.c:373
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe003d291900
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe003d2919b0
witness_warn() at witness_warn+0x4a8/frame 0xfffffe003d291a70
uma_zalloc_arg() at uma_zalloc_arg+0x3b/frame 0xfffffe003d291ae0
malloc() at malloc+0x101/frame 0xfffffe003d291b30
balloon_process() at balloon_process+0x44a/frame 0xfffffe003d291bb0
fork_exit() at fork_exit+0x84/frame 0xfffffe003d291bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe003d291bf0
--- trap 0, rip = 0, rsp = 0xfffffe003d291cb0, rbp = 0 ---
uma_zalloc_arg: zone "16" with the following non-sleepable locks held:
exclusive sleep mutex balloon_lock (balloon_lock) r = 0 (0xffffffff816e7158) locked 
@ /usr/src/sys/dev/xen/balloon/balloon.c:339
exclusive sleep mutex balloon_mutex (balloon_mutex) r = 0 (0xffffffff816e7138) 
locked @ /usr/src/sys/dev/xen/balloon/balloon.c:373
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe003d291900
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe003d2919b0
witness_warn() at witness_warn+0x4a8/frame 0xfffffe003d291a70
uma_zalloc_arg() at uma_zalloc_arg+0x3b/frame 0xfffffe003d291ae0
malloc() at malloc+0x101/frame 0xfffffe003d291b30
balloon_process() at balloon_process+0x44a/frame 0xfffffe003d291bb0
fork_exit() at fork_exit+0x84/frame 0xfffffe003d291bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe003d291bf0
--- trap 0, rip = 0, rsp = 0xfffffe003d291cb0, rbp = 0 ---
uma_zalloc_arg: zone "16" with the following non-sleepable locks held:
exclusive sleep mutex balloon_lock (balloon_lock) r = 0 (0xffffffff816e7158) locked 
@ /usr/src/sys/dev/xen/balloon/balloon.c:339
exclusive sleep mutex balloon_mutex (balloon_mutex) r = 0 (0xffffffff816e7138) 
locked @ /usr/src/sys/dev/xen/balloon/balloon.c:373
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe003d291900  

After migration VM running on another physical host and ssh session didnt 
interrupted. But I loss console access over XenCenter. 


-- 
Best Regards,
Nasonov Sergey