Created attachment 441018 [details]
upstream commit that fixes the problem
Description of problem:
When attempting to use a passthrough USB device (configured via libvirt or directly via qemu-kvm command line) the vm fails to use the device, the error message below is printed to logs (or stderr of qemu)
husb: ctrl buffer too small (2597 > 2048)
NOTE: this has been fixed in upstream qemu, see attachment.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Install a USB device which uses large control packets, e.g.
Bus 002 Device 004: ID 046d:0809 Logitech, Inc. Webcam Pro 9000
2. pass this to vm with "-usbdevice host:046d:0809" options
3. boot a rhel 5.5 guest
fails to open vm, messages in the vm show
usb 1-2: unable to read config index 0 descriptor/all
usb 1-2: can't read configurations, error -32
I have not actually tested the attached patch fixes my particular problem yet, but I will and report back.
above patch has been confirmed to fix the problem.
Would you please use fixed build(kvm-83-208.el5) to verify this bug?thanks in advance.
regarding the above comment#8 and the separate comment from cward:
I cannot test this anyway as the VM in question wasn't viable for other reasons than this bug, and it's gone. As noted above, I did test the upstream patch and it was fine.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.