Re: [Xen-devel] [Patch V2 2/3] usb: Introduce Xen pvUSB frontend

[David Vrabel <david.vrabel@citrix.com>]

On 12/06/15 17:20, Greg KH wrote:
> On Fri, Jun 12, 2015 at 04:10:00PM +0200, Juergen Gross wrote:
>> Introduces the Xen pvUSB frontend. With pvUSB it is possible for a Xen
>> domU to communicate with a USB device assigned to that domU. The
>> communication is all done via the pvUSB backend in a driver domain
>> (usually Dom0) which is owner of the physical device.
>>
>> The code is taken from the pvUSB implementation in Xen done by Fujitsu
>> based on Linux kernel 2.6.18.
>>
>> Changes from the original version are:
>> - port to upstream kernel
>> - put all code in just one source file
>> - move module to appropriate location in kernel tree
>> - adapt to Linux style guide
>> - minor code modifications to increase readability
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>>  drivers/usb/Kconfig            |    2 +
>>  drivers/usb/Makefile           |    2 +
>>  drivers/usb/xen/Kconfig        |   10 +
>>  drivers/usb/xen/Makefile       |    5 +
>>  drivers/usb/xen/xen-usbfront.c | 1647 ++++++++++++++++++++++++++++++++++++++++
> 
> A subdirectory for a single file?  That seems like overkill, don't you
> think?  As this is a USB "host" driver, why not put it in that
> directory?
> 
> Also, last time these patches were posted, people asked why you can't
> use libusb/usbfs instead, what happened with that?  Or usbip?

Using libusb was for the backend driver.  This frontend driver is a host
controller (which is why it should be drivers/usb/host/xen-pv-hcd.c or
similar).

David