Re: [PATCH v2] misc: Reserve minor for VFIO
From: H. Peter Anvin
Date: Wed Dec 18 2013 - 17:03:15 EST
On 12/18/2013 01:01 PM, Greg KH wrote:
> On Wed, Dec 18, 2013 at 01:56:32PM -0700, Alex Williamson wrote:
>> VFIO currently allocates it's own dynamic chardev range, reserving the
>> first minor for the control part of the interface (/dev/vfio/vfio) and
>> the remainder for VFIO groups (/dev/vfio/$GROUP). This works, but it
>> doesn't support auto loading. For instance when libvirt checks for
>> VFIO support it looks for /dev/vfio/vfio, which currently doesn't
>> exist unless the vfio module is loaded. By converting the control
>> device to a misc driver and reserving a static minor, we can enable
>> auto loading.
>>
>> Reserving the minor is a prerequist to that conversion. Minor 196
>> is unused by anything currently in the kernel.
>>
>> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
>> ---
>>
>> v2: Plea for ack edition
>>
>> As Alan suspected, there's been no response from device@xxxxxxxxxx,
>> so there's probably nobody monitoring it anymore. I've done due
>> diligence looking at all the callers of misc_register() in linux-next
>> and cannot find any conflicts with minor 196. If anyone wants to toss
>> me an ack or sign-off I'll be happy to bring this in through my vfio
>> tree, otherwise I'd appreciate if someone wants to take it directly.
>> Thanks!
>>
>> Documentation/devices.txt | 1 +
>> include/linux/miscdevice.h | 1 +
>> 2 files changed, 2 insertions(+)
>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
I think Alan Cox was the last person to man <device@xxxxxxxxxx>... Alan,
are you still doing that? (Otherwise patching the file in the Linux
kernel tree seems eminently sensible... there really isn't any need to
reserve numbers for out-of-tree drivers anymore. Just another perk of
being in-tree.)
-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/