Re: [Qemu-devel] Re: [PATCH 2/5] husb: support for USB host device auto connect.

[Max Krasnyansky <maxk@kernel.org>]

Guido Günther wrote:
> On Thu, Aug 14, 2008 at 03:41:28PM -0500, Anthony Liguori wrote:
>> Max Krasnyansky wrote:
>>>>> Do you mind if we do something like that incrementally ?
>>>>>         
>>>> Yeah, I don't really want to have QEMU depend on dbus so in this case,
>>>> polling would be better.
>>>>     
>>> I'm thinking that maybe we could use 'inotify' on /proc/bus/usb.
>>> Would you be ok with 'inotify' ?
>>>   
>> Yeah, but I would be a little surprised if /proc/bus/usb supports inotify...
> What about /dev/bus/usb - it supports inotify fine on udev?

Yes it should since it's a regular filesystem.

Now inotify based solution probably won't be pretty because we'd have to
monitor each subdir. ie When new device get added top level /dev/bus/usb is
not modified, what does get modified is /dev/bus/usb/<bus_num>/ directory so
we'd have to monitor /dev/bus/usb and dynamically register/unregister monitors
for each /dev/bus/usb/<bus_num>/.
Maybe it won't be that bad. If I get a chance I'll give it a shot.

btw Interface to HAL might still be useful in general to monitor other device
classes that we may want to automatically assign to the VMs. So I'll play
around with that too (some day :)).

Max