[Qemu-devel] Re: [PATCH v3 1/1] Shared memory uio_pci driver

[Cam Macdonell <cam@cs.ualberta.ca>]

On Thu, Mar 25, 2010 at 10:35 AM, Avi Kivity <avi@redhat.com> wrote:
> On 03/25/2010 06:24 PM, Cam Macdonell wrote:
>>
>>> There is now a generic PCI 2.3 driver that can handle all PCI devices.
>>>  It
>>> doesn't support MSI, but if we add MSI support then it can be used
>>> without
>>> the need for a specialized driver.
>>>
>>
>> Agreed, I'd be happy to use the generic driver if MSI is there.  What
>> would MSI support for UIO look like?  An array of "struct uio_irq" for
>> the different vectors?
>>
>
> I'm not familiar with the uio internals, but for the interface, an ioctl()
> on the fd to assign an eventfd to an MSI vector.  Similar to ioeventfd, but
> instead of mapping a doorbell to an eventfd, it maps a real MSI to an
> eventfd.

uio will never support ioctls.  Maybe irqcontrol could be extended?

>
> That would be very useful for device assignment: we can pick up a uio
> device, map its vectors, and give them to a guest.
>
>
> --
> error compiling committee.c: too many arguments to function
>
>