propolis-server and my VM stops responding

I have a VM that, about a minute after boot, becomes non responsive over the network and on the console.

Some info from the running process:

2J80WF9K # mdb -b d3b0a12b-acf3-4564-a43f-86fc75485f7c
mdb: target stopped at:
0xfffffffffb888350:     jne    +0x2491a <0xfffffffffb8acc70>
[0]> $C
fffffe00413b3e20 0xfffffffffb888350()
fffffe00413b3e90 0xfffffffffb838e45()
fffffe00413b3f00 0xfffffffffb839157()
fffffe00413b3fa0 0xfffffffffb839b73()
fffffe00413b4020 0xfffffffffb8319e5()
fffffe00413b40a0 0xfffffffffb831bd5()
fffffe00413b4140 0xfffffffffb8b42d5()
fffffe00413b41b0 0xfffffffffb8b43fc()
fffffe00413b41e0 0xfffffffffb8b44e0()
fffffe00413b4300 0xfffffffffbb049e9()
fffffe00413b4370 0xfffffffffbb05039()
fffffe00413b43d0 0xfffffffffbb04007()
fffffe00413b4440 0xfffffffffbb050ab()
fffffe00413b44d0 0xfffffffffba17b08()
fffffe00413b4520 0xfffffffffba1812b()
fffffe00413b4570 0xfffffffffba195bb()
fffffe00413b45c0 0xfffffffffba19826()
fffffe00413b4600 0xfffffffffba19920()
fffffe00413b4630 0xfffffffffb83564a()
fffffe00413b46c0 0xfffffffffb832729()
fffffe00413b4760 0xfffffffffb838b98()
fffffe00413b47d0 0xfffffffffb838e45()
fffffe00413b4840 0xfffffffffb839157()
fffffe00413b48e0 0xfffffffffb839b73()
fffffe00413b4960 0xfffffffffb8319e5()
fffffe00413b49e0 0xfffffffffb831bd5()
fffffe00413b4a20 0xfffffffffb831c45()
fffffe00413b4b30 0xfffffffffba7c9fa()
fffffe00413b4cd0 0xfffffffffba80ad1()
fffffe00413b4da0 0xfffffffffbb0cc82()
fffffe00413b4e20 0xfffffffffb86d64d()
fffffe00413b4f00 0xfffffffffb86b4ca()
fffffe00413b4f10 0xfffffffffb8001d9()
[0]> ::status
debugging live VM 'd3b0a12b-acf3-4564-a43f-86fc75485f7c'
VM memory size: 32770 MB
vCPUs: 32
current CPU: 0 (long mode, AMD64)
default segment: DS
[0]> ::regs
%rax = 0x0000000000000000                 %r9  = 0xfffffe2d25fdebc0 
%rbx = 0x00000000000009fd                 %r10 = 0x0000000000000000 
%rcx = 0x0000000000000001                 %r11 = 0x0000000000000000 
%rdx = 0xfffffe2d25f593e0                 %r12 = 0xfffffffffbc2b5a8 
%rsi = 0x0000000000000000                 %r13 = 0xfffffe2d0e9c7028 
%rdi = 0xfffffffffbc2b5a8                 %r14 = 0xfffffe2d0e9c7028 
%r8  = 0x0001dc9e577ddd1f                 %r15 = 0x0000000000000000 

%rip = 0xfffffffffb888350 
%rbp = 0xfffffe00413b3e20
%rsp = 0xfffffe00413b3d88
%rflags = 0x00000246
  id=0 vip=0 vif=0 ac=0 vm=0 rf=0 nt=0 iopl=0x0
  status=<of,df,IF,tf,sf,ZF,af,PF,cf>

%cs = 0x0030    %ds = 0x004b    %es = 0x004b    %fs = 0x0000
%gs = 0x0000    %gsbase = 0xfffffffffbc3f000    %kgsbase = 0x0
%trapno = 0x0   %err = 0x0      %cr2 = 0x848000 %cr3 = 0x83fca4000
[0]> 

Start by reproducing the VM becoming unresponsive about a minute after boot, then examine the supplied mdb backtrace, register dump, and ::status output. The issue names no source files or tests; done means identifying the failure cause and documenting a verified fix or diagnostic result.