Freebsd-13.1 as domu cannot use multiple virtual disks

	Hello.  I'm running FreeBSD-13.1 as a domu on xen-4.16.0 and I find I cannot use multiple
virtual disks on  the same virtual guest.


The problem appears to be related to the way the geom layer sorts the disks.  Somehow it thinks
the first and second disks are related.  

Here is the configuration of the disks for the virtual machine:


disk = [
'file:/var/xen/nfbcal/fbsd_dev/disk0,0x1,rw',
'file:/var/xen/nfbcal/fbsd_dev/disk1,0x2,rw'
 ]


Here's what the virtual guest reports when it boots:


xbd0: 51200MB <Virtual Block Device> at device/vbd/1 on xenbusb_front0
xbd0: features: flush, write_barrier
xbd0: synchronize cache commands enabled.
xbd1: 100000MB <Virtual Block Device> at device/vbd/2 on xenbusb_front0
xbd1: features: flush, write_barrier
xbd1: synchronize cache commands enabled.
Trying to mount root from ufs:/dev/gpt/root []...
sysctl_warn_reuse: can't re-use a leaf (kern.geom.disk.xbd0.led)!
sysctl_warn_reuse: can't re-use a leaf (kern.geom.disk.xbd0.flags)!
g_dev_taste: make_dev_p() failed (gp->name=xbd0, error=17)


Any ideas what I'm doing wrong?  this must work, right?
-thanks
-Brian