Re: [PATCH corrected RFC] uio: add generic driver for PCI 2.3 devices

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 09, 2009 at 03:14:53PM -0500, Anthony Liguori wrote:
> Michael S. Tsirkin wrote:
>> On Thu, Jul 09, 2009 at 09:54:43AM -0500, Anthony Liguori wrote:
>>   
>>> I know it's not strictly needed for PCI pass through, but it would be 
>>>  useful to register the IO regions via UIO.  The userspace 
>>> implementation  would then use UIO strictly instead of poking the 
>>> sysfs pci info  directly.  I think that ends up being cleaner.
>>>     
>>
>> Hmm, this is good for specific drivers, but for a generic one like qemu,
>> still need sysfs to figure out the size at least,
>
> size of what?

memory region which you mmap.

>>  and
>> we need config accesses which uio does not support now.
>> And if you use libpci as qemu does now, this interface will likely
>> go unused. So .. there does not seem to be much point at the moment.
>>   
>
> Right, I would expect uio to replace libpci.
> 
>> My idea is, let's start with a minimal interface, longer term
>> let's see if we can add config access, mmap and other stuff like eventfd.
>> Makes sense?
>>   
>
> It can certainly grow more features down the road.

OK, I'll try to get it included as is, then grow it.

-- 
MST