Re: [dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance

[Vlad Zolotarov <vladz@cloudius-systems.com>]

On 10/01/15 00:36, Stephen Hemminger wrote:
> On Wed, 30 Sep 2015 23:09:33 +0300
> Vlad Zolotarov <vladz@cloudius-systems.com> wrote:
>
>>
>> On 09/30/15 22:39, Michael S. Tsirkin wrote:
>>> On Wed, Sep 30, 2015 at 10:06:52PM +0300, Vlad Zolotarov wrote:
>>>>>> How would iommu
>>>>>> virtualization change anything?
>>>>> Kernel can use an iommu to limit device access to memory of
>>>>> the controlling application.
>>>> Ok, this is obvious but what it has to do with enabling using MSI/MSI-X
>>>> interrupts support in uio_pci_generic? kernel may continue to limit the
>>>> above access with this support as well.
>>> It could maybe. So if you write a patch to allow MSI by at the same time
>>> creating an isolated IOMMU group and blocking DMA from device in
>>> question anywhere, that sounds reasonable.
>> No, I'm only planning to add MSI and MSI-X interrupts support for
>> uio_pci_generic device.
>> The rest mentioned above should naturally be a matter of a different
>> patch and writing it is orthogonal to the patch I'm working on as has
>> been extensively discussed in this thread.
>>
> I have a generic MSI and MSI-X driver (posted earlier on this list).
> About to post to upstream kernel.

Stephen, hi!

I found the mentioned series and first thing I noticed was that it's 
been sent in May so the first question is how far in your list of tasks 
submitting it upstream is? We need it more or less yesterday and I'm 
working on it right now. Therefore if u don't have time for it I'd like 
to help... ;) However I'd like u to clarify a few small things. Pls., 
see below...

I noticed that u've created a separate msi_msix driver and the second 
question is what do u plan for the upstream? I was thinking of extending 
the existing uio_pci_generic with the MSI-X functionality similar to 
your code and preserving the INT#X functionality as it is now:

  *   INT#X and MSI would provide the IRQ number to the UIO module while
    only MSI-X case would register with UIO_IRQ_CUSTOM.

I also noticed that u enable MSI-X on a first open() call. I assume 
there was a good reason (that I miss) for not doing it in probe(). Could 
u, pls., clarify?