"Invoking IPv6 network device address event may sleep with the following non-sleepable locks held: . . . exclusive sleep mutex vtnet0-rx0 (vtnet0-rx0) r = 0 (0xffffa000c1b2d480) . . .

Context has FreeBSD running under Parallels Desktop 20 for Mac 20.4.1 (55996).

With an official pkgbase debug kernel being booted I get: 
( from/for: FreeBSD 15.0-PRERELEASE main-n279616-a66e5ce3d5c9 GENERIC arm64 )

Aug 15 03:50:50 aarch64-main-pbase kernel: lo0: link state changed to UP
Aug 15 03:50:50 aarch64-main-pbase kernel: vtnet0: link state changed to UP
Aug 15 03:50:50 aarch64-main-pbase kernel: Invoking IPv6 network device address event may sleep with the following non-sleepable locks held:
Aug 15 03:50:50 aarch64-main-pbase kernel: exclusive sleep mutex vtnet0-rx0 (vtnet0-rx0) r = 0 (0xffffa000c1b2d480) locked @ /home/pkgbuild/worktrees/main/sys/dev/virtio/network/if_vtnet.c:2213
Aug 15 03:50:50 aarch64-main-pbase kernel: stack backtrace:
Aug 15 03:50:50 aarch64-main-pbase kernel: #0 0xffff00000053b4a8 at witness_debugger+0x60
Aug 15 03:50:50 aarch64-main-pbase kernel: #1 0xffff00000053c6dc at witness_warn+0x408
Aug 15 03:50:50 aarch64-main-pbase kernel: #2 0xffff0000006b5294 at in6_update_ifa+0xa68
Aug 15 03:50:50 aarch64-main-pbase kernel: #3 0xffff0000006e2074 at in6_ifadd+0x1dc
Aug 15 03:50:50 aarch64-main-pbase kernel: #4 0xffff0000006de470 at nd6_ra_input+0xe34
Aug 15 03:50:50 aarch64-main-pbase kernel: #5 0xffff0000006af63c at icmp6_input+0x900
Aug 15 03:50:50 aarch64-main-pbase kernel: #6 0xffff0000006c8f38 at ip6_input+0xf64
Aug 15 03:50:50 aarch64-main-pbase kernel: #7 0xffff000000627bf8 at netisr_dispatch_src+0xd8
Aug 15 03:50:50 aarch64-main-pbase kernel: #8 0xffff000000609a44 at ether_demux+0x174
Aug 15 03:50:50 aarch64-main-pbase kernel: #9 0xffff00000060b0f8 at ether_nh_input+0x374
Aug 15 03:50:50 aarch64-main-pbase kernel: #10 0xffff000000627bf8 at netisr_dispatch_src+0xd8
Aug 15 03:50:50 aarch64-main-pbase kernel: #11 0xffff000000609eac at ether_input+0xdc
Aug 15 03:50:50 aarch64-main-pbase kernel: #12 0xffff00000032a314 at vtnet_rxq_eof+0x6f4
Aug 15 03:50:50 aarch64-main-pbase kernel: #13 0xffff000000329b5c at vtnet_rx_vq_process+0xb0
Aug 15 03:50:50 aarch64-main-pbase kernel: #14 0xffff000000320c94 at vtpci_intx_intr+0xe8
Aug 15 03:50:50 aarch64-main-pbase kernel: #15 0xffff000000476104 at ithread_loop+0x29c
Aug 15 03:50:50 aarch64-main-pbase kernel: #16 0xffff000000472220 at fork_exit+0x78
Aug 15 03:50:50 aarch64-main-pbase kernel: #17 0xffff0000008a31e8 at fork_trampoline+0x18
Aug 15 03:50:50 aarch64-main-pbase kernel: lock order reversal: (sleepable after non-sleepable)
Aug 15 03:50:50 aarch64-main-pbase kernel:  1st 0xffffa000c1b2d480 vtnet0-rx0 (vtnet0-rx0, sleep mutex) @ /home/pkgbuild/worktrees/main/sys/dev/virtio/network/if_vtnet.c:2213
Aug 15 03:50:50 aarch64-main-pbase kernel:  2nd 0xffff000001162618 in6_multi_sx (in6_multi_sx, sx) @ /home/pkgbuild/worktrees/main/sys/netinet6/in6_mcast.c:1217
Aug 15 03:50:50 aarch64-main-pbase kernel: lock order vtnet0-rx0 -> in6_multi_sx attempted at:
Aug 15 03:50:50 aarch64-main-pbase kernel: #0 0xffff00000053b048 at witness_checkorder+0xad0
Aug 15 03:50:50 aarch64-main-pbase kernel: #1 0xffff0000004cc858 at _sx_xlock+0x70
Aug 15 03:50:50 aarch64-main-pbase kernel: #2 0xffff0000006bdb28 at in6_joingroup+0x48
Aug 15 03:50:50 aarch64-main-pbase kernel: #3 0xffff0000006b54c8 at in6_update_ifa+0xc9c
Aug 15 03:50:50 aarch64-main-pbase kernel: #4 0xffff0000006e2074 at in6_ifadd+0x1dc
Aug 15 03:50:50 aarch64-main-pbase kernel: #5 0xffff0000006de470 at nd6_ra_input+0xe34
Aug 15 03:50:50 aarch64-main-pbase kernel: #6 0xffff0000006af63c at icmp6_input+0x900
Aug 15 03:50:50 aarch64-main-pbase kernel: #7 0xffff0000006c8f38 at ip6_input+0xf64
Aug 15 03:50:50 aarch64-main-pbase kernel: #8 0xffff000000627bf8 at netisr_dispatch_src+0xd8
Aug 15 03:50:50 aarch64-main-pbase kernel: #9 0xffff000000609a44 at ether_demux+0x174
Aug 15 03:50:50 aarch64-main-pbase kernel: #10 0xffff00000060b0f8 at ether_nh_input+0x374
Aug 15 03:50:50 aarch64-main-pbase kernel: #11 0xffff000000627bf8 at netisr_dispatch_src+0xd8
Aug 15 03:50:50 aarch64-main-pbase kernel: #12 0xffff000000609eac at ether_input+0xdc
Aug 15 03:50:50 aarch64-main-pbase kernel: #13 0xffff00000032a314 at vtnet_rxq_eof+0x6f4
Aug 15 03:50:50 aarch64-main-pbase kernel: #14 0xffff000000329b5c at vtnet_rx_vq_process+0xb0
Aug 15 03:50:50 aarch64-main-pbase kernel: #15 0xffff000000320c94 at vtpci_intx_intr+0xe8
Aug 15 03:50:50 aarch64-main-pbase kernel: #16 0xffff000000476104 at ithread_loop+0x29c
Aug 15 03:50:50 aarch64-main-pbase kernel: #17 0xffff000000472220 at fork_exit+0x78

Also, in the shutdown I can get the likes of:

Aug 14 21:01:00 aarch64-main-pbase kernel: lock order reversal:
Aug 14 21:01:00 aarch64-main-pbase kernel:  1st 0xffff0000405eb438 netlink lock (netlink lock, rm) @ /home/pkgbuild/worktrees/main/sys/netlink/netlink_domain.c:219
Aug 14 21:01:00 aarch64-main-pbase kernel:  2nd 0xffff000196afefa0 so_rcv (so_rcv, sleep mutex) @ /home/pkgbuild/worktrees/main/sys/netlink/netlink_io.c:229
Aug 14 21:01:00 aarch64-main-pbase kernel: lock order netlink lock -> so_rcv attempted at:
Aug 14 21:01:00 aarch64-main-pbase kernel: #0 0xffff00000053b048 at witness_checkorder+0xad0
Aug 14 21:01:00 aarch64-main-pbase kernel: #1 0xffff00000049a3cc at __mtx_lock_flags+0x9c
Aug 14 21:01:00 aarch64-main-pbase kernel: #2 0xffff000000704a8c at nl_send+0xb4
Aug 14 21:01:00 aarch64-main-pbase kernel: #3 0xffff000000700c14 at nl_send_group+0x1b4
Aug 14 21:01:00 aarch64-main-pbase kernel: #4 0xffff000000704ec0 at _nlmsg_flush+0x30
Aug 14 21:01:00 aarch64-main-pbase kernel: #5 0xffff00000079bf30 at clnt_nl_call+0x288
Aug 14 21:01:00 aarch64-main-pbase kernel: #6 0xffff0000007a1d18 at clnt_call_private+0xc0
Aug 14 21:01:00 aarch64-main-pbase kernel: #7 0xffff0000007a2970 at rpcb_unset+0x70
Aug 14 21:01:00 aarch64-main-pbase kernel: #8 0xffff0000007a4168 at svc_unreg+0x34
Aug 14 21:01:00 aarch64-main-pbase kernel: #9 0xffff0000007a3678 at svcpool_cleanup+0x174
Aug 14 21:01:00 aarch64-main-pbase kernel: #10 0xffff0000007a3764 at svcpool_close+0x18
Aug 14 21:01:00 aarch64-main-pbase kernel: #11 0xffff0000003bd6b4 at nfsrvd_nfsd+0x1dc
Aug 14 21:01:00 aarch64-main-pbase kernel: #12 0xffff0000003d86f8 at nfssvc_nfsd+0x3d8
Aug 14 21:01:00 aarch64-main-pbase kernel: #13 0xffff00000070ef20 at sys_nfssvc+0xcc
Aug 14 21:01:00 aarch64-main-pbase kernel: #14 0xffff0000008a3f88 at do_el0_sync+0x618
Aug 14 21:01:00 aarch64-main-pbase kernel: #15 0xffff0000008789ac at handle_el0_sync+0x4c
Aug 14 21:01:01 aarch64-main-pbase ntpd[2540]: ntpd exiting on signal 15 (Terminated)
Aug 14 21:01:02 aarch64-main-pbase syslogd: exiting on signal 15


Note: I do not normally boot the debug kernel.


===
Mark Millard
marklmi at yahoo.com