This is the question: What the device is needed in quest VM ? I symlinked /dev/virtio-ports/org.linuxcontainers.incus to every /dev/vport5pX, but result the same.
Here is this VM qemu.conf for reference:
# Machine
[machine]
graphics = "off"
type = "virt"
gic-version = "max"
accel = "kvm"
usb = "off"
[boot-opts]
strict = "on"
# Memory
[memory]
size = "1024M"
# CPU
[smp-opts]
cpus = "1"
maxcpus = "4"
# Firmware (read only)
[drive]
file = "/opt/incus/share/qemu/OVMF_CODE.4MB.fd"
if = "pflash"
format = "raw"
unit = "0"
readonly = "on"
# Firmware settings (writable)
[drive]
file = "/dev/fd/4"
if = "pflash"
format = "raw"
unit = "1"
# Qemu control
[chardev "monitor"]
backend = "socket"
path = "/run/incus/test_owrt-test-vm/qemu.monitor"
server = "on"
wait = "off"
[mon]
chardev = "monitor"
mode = "control"
# Console
[chardev "console"]
backend = "ringbuf"
size = "1048576"
[device "qemu_pcie0"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.0"
chassis = "0"
multifunction = "on"
# Balloon driver
[device "qemu_balloon"]
driver = "virtio-balloon-pci"
bus = "qemu_pcie0"
addr = "00.0"
multifunction = "on"
# Random number generator
[object "qemu_rng"]
qom-type = "rng-random"
filename = "/dev/urandom"
[device "dev-qemu_rng"]
driver = "virtio-rng-pci"
bus = "qemu_pcie0"
addr = "00.1"
rng = "qemu_rng"
# Input
[device "qemu_keyboard"]
driver = "virtio-keyboard-pci"
bus = "qemu_pcie0"
addr = "00.2"
# Input
[device "qemu_tablet"]
driver = "virtio-tablet-pci"
bus = "qemu_pcie0"
addr = "00.3"
# Vsock
[device "qemu_vsock"]
driver = "vhost-vsock-pci"
bus = "qemu_pcie0"
addr = "00.4"
guest-cid = "2818095053"
vhostfd = "3"
# Virtual serial bus
[device "dev-qemu_serial"]
driver = "virtio-serial-pci"
bus = "qemu_pcie0"
addr = "00.5"
# Serial identifier
[chardev "qemu_serial-chardev"]
backend = "ringbuf"
size = "16B"
[device "qemu_serial"]
driver = "virtserialport"
name = "org.linuxcontainers.incus"
chardev = "qemu_serial-chardev"
bus = "dev-qemu_serial.0"
[device "qemu_serial_legacy"]
driver = "virtserialport"
name = "org.linuxcontainers.lxd"
bus = "dev-qemu_serial.0"
# Spice agent
[chardev "qemu_spice-chardev"]
backend = "spicevmc"
name = "vdagent"
[device "qemu_spice"]
driver = "virtserialport"
name = "com.redhat.spice.0"
chardev = "qemu_spice-chardev"
bus = "dev-qemu_serial.0"
# Spice folder
[chardev "qemu_spicedir-chardev"]
backend = "spiceport"
name = "org.spice-space.webdav.0"
[device "qemu_spicedir"]
driver = "virtserialport"
name = "org.spice-space.webdav.0"
chardev = "qemu_spicedir-chardev"
bus = "dev-qemu_serial.0"
# USB controller
[device "qemu_usb"]
driver = "qemu-xhci"
bus = "qemu_pcie0"
addr = "00.6"
p2 = "8"
p3 = "8"
[chardev "qemu_spice-usb-chardev1"]
backend = "spicevmc"
name = "usbredir"
[device "qemu_spice-usb1"]
driver = "usb-redir"
chardev = "qemu_spice-usb-chardev1"
[chardev "qemu_spice-usb-chardev2"]
backend = "spicevmc"
name = "usbredir"
[device "qemu_spice-usb2"]
driver = "usb-redir"
chardev = "qemu_spice-usb-chardev2"
[chardev "qemu_spice-usb-chardev3"]
backend = "spicevmc"
name = "usbredir"
[device "qemu_spice-usb3"]
driver = "usb-redir"
chardev = "qemu_spice-usb-chardev3"
[device "qemu_pcie1"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.1"
chassis = "1"
# SCSI controller
[device "qemu_scsi"]
driver = "virtio-scsi-pci"
bus = "qemu_pcie1"
addr = "00.0"
[device "qemu_pcie2"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.2"
chassis = "2"
# Shared config drive (9p)
[fsdev "qemu_config"]
fsdriver = "local"
security_model = "none"
readonly = "on"
path = "/var/lib/incus/devices/test_owrt-test-vm/config.mount"
[device "dev-qemu_config-drive-9p"]
driver = "virtio-9p-pci"
bus = "qemu_pcie2"
addr = "00.0"
multifunction = "on"
mount_tag = "config"
fsdev = "qemu_config"
# Shared agent drive (9p)
[fsdev "qemu_agent"]
fsdriver = "local"
security_model = "none"
readonly = "on"
path = "/opt/incus/agent/"
[device "dev-qemu_agent-drive-9p"]
driver = "virtio-9p-pci"
bus = "qemu_pcie2"
addr = "00.1"
mount_tag = "agent"
fsdev = "qemu_agent"
[device "qemu_pcie3"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.3"
chassis = "3"
# GPU
[device "qemu_gpu"]
driver = "virtio-gpu-pci"
bus = "qemu_pcie3"
addr = "00.0"
[device "qemu_pcie4"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.4"
chassis = "4"
[device "qemu_pcie5"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.5"
chassis = "5"
[device "qemu_pcie6"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.6"
chassis = "6"
[device "qemu_pcie7"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "1.7"
chassis = "7"
[device "qemu_pcie8"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.0"
chassis = "8"
multifunction = "on"
[device "qemu_pcie9"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.1"
chassis = "9"
[device "qemu_pcie10"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.2"
chassis = "10"
[device "qemu_pcie11"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.3"
chassis = "11"
[device "qemu_pcie12"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.4"
chassis = "12"
[device "qemu_pcie13"]
driver = "pcie-root-port"
bus = "pcie.0"
addr = "2.5"
chassis = "13"