USB Device Limit?

[kaota]

I have a 2 large USB hubs containing 20 or 100 devices of all the same make and model. I have created a filter to pass them through to a Linux VM. I can successfully pass 15 devices, but on 16 or more I get the following error:

VERR_PDM_NO_USB_PORTS

It always caps out at 15 devices. Is this a legitimate limit? How can I override it?

Not sure if it's relevant, but this is a Debian 6 Linux guest on Mac OSX 10.8.

Cheers

[Perryg]

Good question! I have been working on the VirtualBox code for years and I have never tried to extend beyond 5 or 6 devices because I never had the need. I suspect that there is a ceiling though as the error states. You might want to ask the DEVs for a concrete answer though. Better to ask on the DEV mailing list or via IRC if you want a fast answer.

https://www.virtualbox.org/wiki/Community

[frank]

The current limit is 8 devices for the OHCI controller and 8 devices for the EHCI controller. Increasing that limit to 15 for each of the two controllers should be possible. Just have a look at OHCI_NDP and EHCI_NDP in DevOHCI.cpp and DevEHCI.cpp.