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Passthrough USB 3G modem

Hi,

I would like to pass Pass-through some 3G modem to my qemu VM, but since an USB 3G modem use to expand to multiple sub-USB device after init, it’s a bit more complicate than a more standard device.

Since I would like to pass-through a couple of them to my VM, I’m not sure about the way to process.

I would like to pass-through, an USB HUB top my VM, but in this case the modem never appears inside the VM.

Maybe I should blacklist some kernel module to avoid initialization from the main host.

Adding a new PCI USB controller in not an option I’m running out of slot.

Any suggestion ?


first try:
addint a file in /etc/udev/rules.d
containing:

SUBSYSTEM=="usb", ATTRS{idVendor}=="12d1", ATTRS{idProduct}=="1436", ATTR{authorized}="0"

Then after reboot, after plugin in 2 KEY:

big:~ $ lsusb
...
Bus 001 Device 013: ID 12d1:1436 Huawei Technologies Co., Ltd. Broadband stick
Bus 001 Device 014: ID 12d1:1436 Huawei Technologies Co., Ltd. Broadband stick

And the main linux did not try to enable the keys.

a good start.

This is what you want, keep the host from poking at the device before it gets passed to the guest.

Check your IOMMU groups, maybe you’re lucky and have an onboard USB controller that’s isolated enough to VFIO and can pass it through to your guest.