EFI / Bootloader To avoid having to setup the boot options, I enter the EFI Boot menu by pressing Escape during the AVA booting process, then select “Boot Maintenance Manager” → “Boot from file” and select “xen.efi” from the disk where the TRS image is flashed.
Creating the Xen guest How to change the QEMU invocation command flags for a guest Using the device_model_override option inside a guest .cfg file we can change the QEMU binary that runs for a guest. The following Python3 script can be used as a device_model_override binary and launch the QEMU build of your choice with the command flags you want.
Custom command flags for QEMU go to the hard-coded global variable guest_device_args list in the script’s source code.
QEMU Binary path is hard-coded in the QEMU_BINARY_PATH global variable.
Environment flags can be set by adding os.environ["ENV_VAR"] = "VALUE" lines.
stdout/stderr are redirected to the path in the hard-coded LOG_FILE global variable.
Save the following source code as qemu_device_model.py, set executable permissions with chmod +x qemu_device_model.py and override the xen device model parameter in the guest .cfg file:
device_model_version="qemu-xen"
device_model_override="/home/root/qemu_device_model.py" This will call the script with the same arguments it’d otherwise pass to the QEMU binary.
The source code:
qemu_device_model.py script
#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-3.0-or-later
# <manos.pitsidianakis@linaro.org>
import sys, signal, os
from subprocess import Popen
""" Usage
Save as `qemu_device_model.py`, set as executable
(`chmod +x qemu_device_model.py`) and add in xen guest .cfg:
device_model_version="qemu-xen"
device_model_override="/home/root/qemu_device_model.py"
"""
def handler_exit_signals(signum, frame):
raise SystemExit(0)
signal.signal(signal.SIGINT, handler_exit_signals)
signal.signal(signal.SIGTERM, handler_exit_signals)
#os.environ["LD_LIBRARY_PATH"] = "/usr/local/lib/aarch64-linux-gnu"
QEMU_BINARY_PATH = "/usr/bin/qemu-system-aarch64"
LOG_FILE = "/home/root/qemu_log.txt"
args = sys.argv[1:]
dom_id = None
name = None
# print("args are:",args)
i = 0
try:
while i < len(args):
if args[i].startswith("-xen-domid"):
dom_id = args[i + 1]
i += 2
continue
if args[i].startswith("-name"):
name = args[i + 1]
i += 2
continue
i += 1
except IndexError as exc:
print(exc, "for i =", i)
print("Invalid command line arguments: ", args)
sys.exit(1)
if name is None:
name = "trs-vm"
if dom_id is None:
print("No -xen-domid found in arguments:\nArguments were:", args)
sys.exit(1)
libxl_cmd_socket = "/var/run/xen/qmp-libxl-{}".format(dom_id)
libxenstat_cmd_socket = "/var/run/xen/qmp-libxenstat-{}".format(dom_id)
# Create new argv with flags that include the domid and guest name first, then
# add the device flags
xen_guest_specific_args = [
"-name",
name,
"-xen-domid",
dom_id,
"-chardev",
"socket,id=libxl-cmd,path={},server=on,wait=off".format(libxl_cmd_socket),
"-chardev",
"socket,id=libxenstat-cmd,path={},server=on,wait=off".format(libxenstat_cmd_socket),
"-mon",
"chardev=libxl-cmd,mode=control",
"-mon",
"chardev=libxenstat-cmd,mode=control",
"-nodefaults",
"-no-user-config",
"-xen-attach",
"-no-shutdown",
"-smp",
"4,maxcpus=4",
"-machine",
"xenpvh",
"-m",
"6144",
]
guest_device_args = [
"-vga",
"std",
"-vnc",
"none",
"-display",
"sdl,gl=on",
"-device",
"virtio-gpu-pci,disable-legacy=on,iommu_platform=on,xres=1080,yres=600",
"-global",
"virtio-mmio.force-legacy=false",
"-device",
"virtio-mouse-pci,disable-legacy=on,iommu_platform=on",
"-device",
"virtio-keyboard-pci,disable-legacy=on,iommu_platform=on",
"-device",
"virtio-snd-pci,audiodev=snd0,disable-legacy=on,iommu_platform=on",
"-audiodev",
"alsa,id=snd0,out.dev=default",
]
new_args = [QEMU_BINARY_PATH] + xen_guest_specific_args + guest_device_args
# print("new args are:",new_args)
with open(LOG_FILE, "a") as log, Popen(new_args, stdout=log, stderr=log) as proc:
try:
proc.wait()
except SystemExit:
proc.kill()
sys.exit(proc.returncode)
Create guest xl create /path/to/guest.cfg Inspect guest domain state:
Sometimes, QEMU doesn’t exit cleanly and the guest shows up as (null) . Issue pkill qemu and it should go away.
Attach to guest console xl console -t pv -n 0 GUEST_NAME where GUEST_NAME is the value of "name" in the guest configuration.
Example guest .cfg file guest.cfg
name = "trs-vm"
memory = 6144
vcpus = 4
# extra linux cmdline parameters
extra = " earlyprintk=xenboot console=hvc0 rw fb=false root=/dev/xvda1 modules_load=virtio_snd,virtio_gpu r
d.modules_load=virtio_snd,virtio_gpu"
# guest files on host storage
kernel = "/home/root/vmlinuz-6.5.13"
ramdisk = "/home/root/initrd.img-6.5.13"
# disks will show up as /dev/xvd{a,b}:
disk = ['format=qcow2, vdev=xvda, access=rw, backendtype=qdisk, target=/home/roo
t/debian-13-nocloud-arm64-daily-20240108-1620.qcow2', 'format=qcow2, vdev=xvdb, a
ccess=rw, backendtype=qdisk, target=/home/root/storage.qcow2']
# device parameters
device_model_version="qemu-xen"
device_model_override="/home/root/qemu_device_model.py"
virtio_qemu_domid = 0
xen_platform_pci = 1
gfx_passthru =1
vif = ['mac=00:16:3E:74:34:32,script=vif-bridge,bridge=xenbr0']
# Manpage xl.cfg(5) says:
#
# the type field must be set to "virtio,device" or "virtio,device<N>",
# where "N" is the virtio device id in hexadecimal format,
# without the "0x" prefix and all in lower case,
# like "virtio,device1a" for the file system device.
#
# https://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html
#
# the `bdf` field is the PCI ID the guest sees for the specific VIRTIO device.
virtio = [ "backend=0,type=virtio,device19,transport=pci,bdf=00:04.0,backend_typ
e=qemu,grant_usage=true", "backend=0,type=virtio,device10,transport=pci,bdf=00:0
5.0,backend_type=qemu,grant_usage=true", "backend=0,type=virtio,device,transport
=pci,bdf=00:03.0,backend_type=qemu,grant_usage=true" ]
# ## Type value ID Virtio Device
# 0 reserved (invalid)
# type=virtio,device1 1 network card
# type=virtio,device2 2 block device
# type=virtio,device3 3 console
# type=virtio,device4 4 entropy source
# type=virtio,device5 5 memory ballooning (traditional)
# type=virtio,device6 6 ioMemory
# type=virtio,device7 7 rpmsg
# type=virtio,device8 8 SCSI host
# type=virtio,device9 9 9P transport
# type=virtio,devicea 10 mac80211 wlan
# type=virtio,deviceb 11 rproc serial
# type=virtio,devicec 12 virtio CAIF
# type=virtio,deviced 13 memory balloon
# 14 (none)
# 15 (none)
# type=virtio,device10 16 GPU device
# type=virtio,device11 17 Timer/Clock device
# type=virtio,device12 18 Input device
# type=virtio,device13 19 Socket device
# type=virtio,device14 20 Crypto device
# type=virtio,device15 21 Signal Distribution Module
# type=virtio,device16 22 pstore device
# type=virtio,device17 23 IOMMU device
# type=virtio,device18 24 Memory device
# type=virtio,device19 25 Audio device
# type=virtio,device1a 26 file system device
# type=virtio,device1b 27 PMEM device
# type=virtio,device1c 28 RPMB device
# type=virtio,device1d 29 mac80211 hwsim wireless simulation device
# type=virtio,device1e 30 Video encoder device
# type=virtio,device1f 31 Video decoder device
# type=virtio,device20 32 SCMI device
# type=virtio,device21 33 NitroSecureModule
# type=virtio,device22 34 I2C adapter
# type=virtio,device23 35 Watchdog
# type=virtio,device24 36 CAN device
# type=virtio,device25 38 Parameter Server
# type=virtio,device26 39 Audio policy device
# type=virtio,device27 40 Bluetooth device
# type=virtio,device28 41 GPIO device
# type=virtio,device29 42 RDMA device