Comment 35 for bug 1956166

Hi

I still have this problem on Ubuntu 22.04.1 when creating a 22.04 guest

# xl create /etc/xen/stp0.cfg
Parsing config from /etc/xen/stp0.cfg
xc: error: panic: xg_dom_bzimageloader.c:619: xc_try_zstd_decode: ZSTD decompress support unavailable
: Internal error
xc: error: panic: xg_dom_bzimageloader.c:772: xc_dom_probe_bzimage_kernel unable to ZSTD decompress kernel: Invalid kernel
xc: error: panic: xg_dom_core.c:690: xc_dom_find_loader: no loader found: Invalid kernel
libxl: error: libxl_dom.c:571:libxl__build_dom: xc_dom_parse_image failed
libxl: error: libxl_create.c:1611:domcreate_rebuild_done: Domain 1:cannot (re-)build domain: -3
libxl: error: libxl_domain.c:1183:libxl__destroy_domid: Domain 1:Non-existant domain
libxl: error: libxl_domain.c:1137:domain_destroy_callback: Domain 1:Unable to destroy guest
libxl: error: libxl_domain.c:1064:domain_destroy_cb: Domain 1:Destruction of domain failed

The host is running Xen 4.16 on 22.04.1:

root@host:~# dpkg -l | grep xen-hypervisor
ii xen-hypervisor-4.16-amd64 4.16.0-1~ubuntu2 amd64 Xen Hypervisor on AMD64
ii xen-hypervisor-common 4.16.0-1~ubuntu2 all Xen Hypervisor - common files
root@host:~# cat /etc/issue
Ubuntu 22.04.1 LTS \n \l

The guest has a 5.15 kernel:

# mount -o ro /dev/VolumeGroupXen/stp0-disk /mnt
# ls /mnt/boot/vmlinuz-5.15.0-48-generic
/mnt/boot/vmlinuz-5.15.0-48-generic

The stp0.cfg file boils down to:
bootloader = 'pygrub'
vcpus = '1'
memory = '1024'
type = 'pvh'
root = '/dev/xvda1 ro'
disk = [
                  'phy:/dev/VolumeGroupXen/stp0-disk,xvda1,w',
              ]
name = 'stp0'
dhcp = 'dhcp'
vif = [ 'mac=00:16:3E:EF:F3:BC,bridge=xenbr0' ]
on_poweroff = 'destroy'
on_reboot = 'restart'
on_crash = 'restart'