Re: Bug: USB Bridge Will Not PassThru

["Pasi Kärkkäinen" <pasik@iki.fi>]

On Tue, Jun 17, 2014 at 11:00:31PM -0700, merc1984@f-m.fm wrote:
> 
> I have a device which is a programmable bridge by Cirrus Semiconductor. 
> It converts parallel TTL to USB2.  I've built udev rules to upload its
> firmware when detected (by VID/PID), and to set the permissions and a
> systemd alias of its new identity after the firmware is loaded.
> 
> With Xen 4.3 its Cirrus (unprogrammed) identity would not show up when
> passed thru to an HVM, but after it got its firmware its new identity
> (Anchor) would pass thru, and worked fine.  With Xen 4.4 its
> unprogrammed and programmed  identities no longer pass through.  The
> error in dmesg is not helpful.  I'll follow up with that tomorrow.  
> 
> I know that this is a special case, but there are alot of these
> programmable bridges out there for various functions.  And actually,
> with Xen 4.4 I am not able to pass through -any- of my USB devices
> anymore.  The mouse, keyboard, Canon scanner, sd card reader, all fail
> to show in the HVM domU.  PCI forwarding dom0's USB hub is not an option
> as there is only one hub for the whole machine that handles all 14
> ports.
> 

Are you using qemu-traditional or qemu-upstream for this HVM guest?

Note that qemu-traditional only supports USB 1.1 emulated passthru,
while qemu-upstream also supports USB2 and USB3.


-- Pasi