[SOLVED] VM: cannot access '/dev/bus': No such file or directory

[Proxygen]

I have a VM created from jammy-server-cloudimg-amd64-disk-kvm.img (for `Ubuntu 22.04 LTS (GNU/Linux 5.15.0-1013-kvm x86_64)`) with the agent applied via `virt-customize -a /mnt/storage/backups-pve/template/iso/jammy-server-cloudimg-amd64-disk-kvm.img --install qemu-guest-agent`

pve is fully current.

i successfully attached a (non storage) USB device to the vm, as visible in the qm monitor via `info usb` (it shows connected to the VM in the monitor but the host's `lsusb` also shows it)

but the VM doesn't even have a `/dev/bus` dir, so `lsusb` and others come up empty. what do I need to do to get the VM to make /dev/bus? I'd think t-shooting anything else at this point would be futile.

inside the vm:

strace lsusb 2>&1 | grep ^open | grep usb
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libusb-1.0.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/dev/bus/usb", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory)

# cat /etc/pve/qemu-server/202.conf
agent: enabled=1
boot: c
bootdisk: scsi0
cipassword:
ciuser: ubuntu
cores: 2
cpu: host
ide2: zfs-storage-sdx5:vm-202-cloudinit,media=cdrom
ipconfig0: ip=10.10.10.x/24,gw=10.10.10.1
memory: 4096
meta: creation-qemu=6.2.0,ctime=1658344197
name: signer
net0: virtio=F6:D0:D9:85:A5:F7,bridge=vmbr1
numa: 0
onboot: 1
ostype: l26
protection: 1
scsi0: zfs-storage-sdx5:vm-202-disk-0,size=14540M
scsihw: virtio-scsi-pci
serial0: socket
serial1: socket
smbios1: uuid=cd118f86-34a2-4c3d-b0ac-2f3da5ce5454
sockets: 1
==> usb0: host=xxxx:xxxx <==
vga: serial0
vmgenid: 0d0422e0-f60d-4740-aa7f-f74b6c4383ea

`systemd-udevd` is running fine on both VM and guest. I have another VM (Ubuntu 18) that successfully connects to the same USB device. i've tried regenerating the cloudinit drive.

 

[t.lamprecht]

Does the following sysfs entry exist: ls /sys/bus/usb/* as that isn't created by user space tools like udev and if it's empty I'd figure that the VM kernel either has the relevant USB support not built-in or the respective kernel modules either ain't loaded (automatically) or do not exist.

IMO the issue is inside the VM, I don't think a config change on PVE side can resolve this.

 

[Proxygen]

in order to have USB support one needs to use the images like jammy-server-cloudimg-amd64.img (generic kernel), NOT jammy-server-cloudimg-amd64-disk-kvm.img (kvm kernel). note the ending of the filenames. can't have "disk-kvm" if you need USB (and prob other stuff)