Installing linux domU on NetBSD-10.1 dom0 - questions

[Jeff Rizzo <riz%tastylime.net@localhost>]

I'm running into a few different issues while trying to do a "normal" 
install of

Ubuntu 24.04 (server, if it matters) in an HVM domU.


First, I seem to be unable to use a zvol to back the virtual disk.  If I 
use the block

device (/dev/zvol/dsk/tank/volumes/ubnt), then `xl create` barfs.  If I 
use the raw device,

(/dev/zvol/rdsk/tank/volumes/ubnt), then booting from the CD image takes 
a very long time

and then Linux doesn't find the disk.  OK, well, that's interesting.


Next, I used an LVM-backed virtual disk - this fares better, in that I 
can actually

run the installer and do a full install...which then doesn't boot ("not 
a bootable disk"),

which I suspect is that the installer is doing a UEFI install while the 
dom0 appears to

only have "seabios" support in the install I have.  (Xen 4.20 from 
pkgsrc). It's not

clear to me whether "modern" ubuntu can even boot from bios, and it's 
definitely not

the default.  I did some cursory exploration around the installer to see 
if I could

figure out how to install for bios boot, but I've done so many test 
installs that I'm

giving up for the moment.


So... should I expect to be able to use a zvol as backing storage? (It 
seems to work for

NetBSD, but I'm not running HVM there and I understand the gory details 
there a lot better)

And can I do an EFI boot of an HVM domU from a NetBSD dom0?  How do I 
make this happen?


In case it's helpful, here is the config file I'm using (hopefully the 
commented-out

bits make sense - I change boot from d to c after install)


memory = 2048
vcpus = 4
name = "ubnt"
type="hvm"

vnclisten='0.0.0.0'
vncdisplay=5
serial = 'pty'

vif = ['mac=02:02:02:97:97:97, bridge=bridge0' ]

# working for install but doesn't boot
disk = [ # 'format=raw, vdev=hda, access=rw, 
target=/dev/zvol/rdsk/tank/volumes/ubnt',
        'format=raw, vdev=hda, access=rw, target=/dev/mapper/vg0-ubnt',
       #'format=raw, vdev=hdc, access=ro, devtype=cdrom, 
target=/home/riz/ubuntu-24.04.3-live-server-amd64.iso'
        ]
boot = 'c'