netbsd 10 i386 domU panic

[Greg Troxel <gdt%lexort.com@localhost>]

I have a xen box, with only 8 GB, which is not really enough RAM I know.
My OS builds are from December 25th.

The dom0 is netbsd-10 amd64, xen 4.15.   It gets 4 GB.

I have 4 domUs, 9/10 i386/amd64.  The i386 ones get 1 GB and the amd64 3
GB.  I run either 9 or 10, not both.

Aside from the zfs lockup it is reliable.

Recently I shut down 9 i386 and booted 10 i386, updated the OS, and
kicked off pkg_rolling-replace.  It has now crashed twice, and I have
console info from the second crash from 'xl console' to a file.

  [ 45847.7690156] panic: fpudna from userland, ip 0xbb6cec9a, trapframe 0xda5f1fa8
  [ 45847.7690156] cpu1: Begin traceback...
  [ 45847.7690156] vpanic(c0505978,da5f1f8c,da5f1f9c,c01322db,c0505978,c050599c,bb6cec9a,da5f1fa8,bb697000,bf7fe170) at netbsd:vpanic+0x18e
  [ 45847.7690156] panic(c0505978,c050599c,bb6cec9a,da5f1fa8,bb697000,bf7fe170,c0102f9e,da5f1fa8,bb4b00b3,300ab) at netbsd:panic+0x18
  [ 45847.7690156] fpudna(da5f1fa8,bb4b00b3,300ab,bf7f001f,bf7f001f,bb4af000,bb48300c,bf7fe170,bb697000,83a39ff) at netbsd:fpudna+0x3b
  [ 45847.7690156] cpu1: End traceback...
  [ 45847.7690156] dump to dev 142,8 not possible
  [ 45847.7690156] rebooting...

This appears to be https://gnats.netbsd.org/55437.

I have not yet tried netbsd-10 amd64.

I am also in the process of switching to xen 4.18.