While attempting to reproduce:

With make -j 400 running in another shell:

danielgb@p87:~$ virsh suspend  jenkins-ppc64
Domain jenkins-ppc64 suspended

wait over 2 minutes.

danielgb@p87:~$ virsh resume  jenkins-ppc64
Domain jenkins-ppc64 resumed


danielgb@p87:~$ virsh list
 Id    Name                           State
----------------------------------------------------
 1     jenkins                        running
 2     jenkins-ppc64                  running


[ 5761.783275] INFO: task cmake:42287 blocked for more than 120 seconds.
[ 5761.783370]       Tainted: G            E   4.4.0-93-generic #116
[ 5761.783382] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5761.783448] cmake           D 00003fffac68e13c     0 42287  42278 0x00040000
[ 5761.783453] Call Trace:
[ 5761.783459] [c000005fd6c4b750] [0000000000008000] 0x8000 (unreliable)
[ 5761.783467] [c000005fd6c4b920] [c000000000015cb8] __switch_to+0x1f8/0x350
[ 5761.783473] [c000005fd6c4b970] [c000000000b08a1c] __schedule+0x30c/0x990
[ 5761.783476] [c000005fd6c4ba40] [c000000000b090e8] schedule+0x48/0xc0
[ 5761.783480] [c000005fd6c4ba70] [c000000000b09630] schedule_preempt_disabled+0x20/0x30
[ 5761.783484] [c000005fd6c4ba90] [c000000000b0b7fc] __mutex_lock_slowpath+0xec/0x1f0
[ 5761.783487] [c000005fd6c4bb10] [c000000000b0b978] mutex_lock+0x78/0xa0
[ 5761.783493] [c000005fd6c4bb40] [c0000000002f890c] walk_component+0x2fc/0x420
[ 5761.783496] [c000005fd6c4bbb0] [c0000000002f8bec] link_path_walk+0x1bc/0x660
[ 5761.783499] [c000005fd6c4bc40] [c0000000002f962c] path_lookupat+0xdc/0x1d0
[ 5761.783503] [c000005fd6c4bc90] [c0000000002fb9d8] filename_lookup+0xa8/0x1b0
[ 5761.783507] [c000005fd6c4bdb0] [c0000000002e1f70] SyS_faccessat+0xe0/0x2e0
[ 5761.783511] [c000005fd6c4be30] [c000000000009204] system_call+0x38/0xb4
[ 5761.783515] INFO: task cc1plus:42687 blocked for more than 120 seconds.
[ 5761.783579]       Tainted: G            E   4.4.0-93-generic #116
[ 5761.783641] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5761.783715] cc1plus         D 00003fffa515dc2c     0 42687  42686 0x00040000
[ 5761.783719] Call Trace:
[ 5761.783722] [c000005fd6c47720] [7265677368657265] 0x7265677368657265 (unreliable)
[ 5761.783726] [c000005fd6c478f0] [c000000000015cb8] __switch_to+0x1f8/0x350
[ 5761.783729] [c000005fd6c47940] [c000000000b08a1c] __schedule+0x30c/0x990
[ 5761.783732] [c000005fd6c47a10] [c000000000b090e8] schedule+0x48/0xc0
[ 5761.783736] [c000005fd6c47a40] [c000000000b09630] schedule_preempt_disabled+0x20/0x30
[ 5761.783739] [c000005fd6c47a60] [c000000000b0b7fc] __mutex_lock_slowpath+0xec/0x1f0
[ 5761.783743] [c000005fd6c47ae0] [c000000000b0b978] mutex_lock+0x78/0xa0
[ 5761.783746] [c000005fd6c47b10] [c0000000002f890c] walk_component+0x2fc/0x420
[ 5761.783749] [c000005fd6c47b80] [c0000000002f8bec] link_path_walk+0x1bc/0x660
[ 5761.783753] [c000005fd6c47c10] [c0000000002faadc] path_openat+0xac/0x3c0
[ 5761.783756] [c000005fd6c47c90] [c0000000002fca1c] do_filp_open+0xfc/0x170
[ 5761.783759] [c000005fd6c47db0] [c0000000002e3210] do_sys_open+0x1c0/0x3b0
[ 5761.783762] [c000005fd6c47e30] [c000000000009204] system_call+0x38/0xb4
[ 5761.783767] INFO: task cc1plus:42706 blocked for more than 120 seconds.
[ 5761.783830]       Tainted: G            E   4.4.0-93-generic #116
[ 5761.783892] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5761.783966] cc1plus         D 00003fff7f07dc2c     0 42706  42702 0x00040000


danielgb@p87:~$ virsh console jenkins-ppc64
Connected to domain jenkins-ppc64
Escape character is ^]


$ ssh root@jenkins-ppc64
ssh: connect to host jenkins-ppc64 port 22: No route to host


danielgb@p87:~$ virsh reset jenkins-ppc64
Domain jenkins-ppc64 was reset


(didn't result in a guest reset). No network or virsh console connection could be made for several minutes. Ended up doing a virsh destroy jenkins-ppc64.