Missing memory with PVH domu's?

[Brian Buhrow <buhrow%nfbcal.org@localhost>]

	hello.   I recently began using PVH domu's with my xen installations.  I took working PV
domu's, replaced the kernel with PVH capable kernels, changed the type in the domu config file
and set things going.  All seemed to work well, except I notice a discrepancy between the
amount of memory I configured in the config file and the amount of memory the domu sees.

For example:

Given the below config file, I think I should see 8GB of memory in the domu this controls.
When it was configured as a PV domu, I did.  
Now, I get 4GB:

Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
    2018, 2019, 2020, 2021 The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 9.99.77 (MIRKWOOD_PVH) #0: Mon May 20 16:09:04 PDT 2024
        buhrow%loth-9.nfbcal.org@localhost:/usr/src/sys/arch/amd64/compile/MIRKWOOD_PVH
total memory = 4096 MB
avail memory = 3944 MB
entropy: no seed from bootloader


This is with xen-4.16.0 with FreeBSD-13.1 running as the dom0.
Any thoughts?

<Cut here for config file>

msr_relaxed = 1
kernel = "/var/xen/nfbcal/loth_9/netbsd"
type = "pvh"
memory = 8192
vcpus = 2
name = "loth_9"
vif = [  'mac=XX:XX:XX:XX:42:cc,bridge=bridge0' ]
disk = [ 
'file:/var/xen/nfbcal/loth_9/disk0,0x1,rw'
 ]
boot = 'c'
extra = ""
on_poweroff = "restart"