OK, hold onto yer butts!
Launching APs: 8 69 6 5 36 12 14 50 26 7 13 49 60 1 25 62 39 27 61 68 71 53 57 3 16 33 58 43 10 70 18 28 20 44 41 38 37 47 2 48 55 59 4 64 11 35 52 40 29 32 67 9 30 42 21 17 65 34 24 51 22 46 23 66 56 19 15 63 54 45 31
random: unblocking device.
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
WARNING: WITNESS option enabled, expect reduced performance.
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache
arc4random: no preloaded entropy cache

fatal kernel trap:

   exception       = 0xe40 (hypervisor emulation assistance)
   HEIR = 0x0
   srr0            = 0xc000000003ebefe0 (0x1bcefe0)
   srr1            = 0x9000000000001032
   current msr     = 0x9000000000001032
   lr              = 0xc000000003ebefe0 (0x1bcefe0)
   curthread       = 0xc00000002a8b0000
          pid = 0, comm = zio_null_issue

timeout stopping cpus
panic: Assertion td->td_lock == TDQ_LOCKPTR(tdq) failed at /usr/src/sys/kern/sched_ule.c:2134
cpuid = 20
time = 12
KDB: stack backtrace:
0xe0000000c92b4110: at .kdb_backtrace+0x68
0xe0000000c92b4230: at .vpanic+0x254
0xe0000000c92b42f0: at .panic+0x34
0xe0000000c92b4370: at .sched_switch+0xad8
saved LR(0x6e2f73636865645b) is invalid.KDB: enter: panic
[ thread pid 0 tid 100804 ]
Stopped at      .kdb_enter+0x70:        ori     r0, r0, 0x0
db> timeout stopping cpus
panic: hypervisor emulation assistance trap
cpuid = 71
time = 12
KDB: stack backtrace:
0xe0000000c914fd70: at .kdb_backtrace+0x68
0xe0000000c914fe90: at .vpanic+0x254
0xe0000000c914ff50: at .panic+0x34
0xe0000000c914ffd0: at .sysarch+0x5cc
0xe0000000c9150060: at .trap+0x1108
0xe0000000c9150180: at .powerpc_interrupt+0x138
0xe0000000c9150220: kernel trap 0xe40 by proc0+0x158: srr1=0x9000000000001032
            r1=0xe0000000c91504d0 cr=0x28000442 xer=0 ctr=0xc000000002fc512c r2=0xc000000003c6f000
0xe0000000c91504d0: at proc0+0x154
0xe0000000c9150550: at .choosethread+0x14
0xe0000000c91505d0: at .sched_throw+0x80
0xe0000000c9150660: at .thread_exit+0x2ec
0xe0000000c9150710: at .kthread_exit+0x164
0xe0000000c91507b0: at .taskqueue_thread_loop+0x21c
0xe0000000c9150850: at .fork_exit+0xbc
0xe0000000c91508f0: at .fork_trampoline+0x10
0xe0000000c9150920: at -0x4
Uptime: 12s
[  171.353487543,5] OPAL: Reboot request...