Re: [PATCH RFC 00/15] Add VFIO mediated device support and IMS support for the idxd driver.

Dey, Megha
2020-05-01T22:31:17Z

Hi Jason,

On 4/23/2020 12:49 PM, Jason Gunthorpe wrote:
> On Thu, Apr 23, 2020 at 12:17:50PM -0700, Dan Williams wrote:
>
>> Per Megha's follow-up can you send the details about that other device
>> and help clear a path for a device-specific MSI addr/data table
>> format. Ever since HMM I've been sensitive, perhaps overly-sensitive,
>> to claims about future upstream users. The fact that you have an
>> additional use case is golden for pushing this into a common area and
>> validating the scope of the proposed API.
>
> I think I said it at plumbers, but yes, we are interested in this, and
> would like dynamic MSI-like interrupts available to the driver (what
> Intel calls IMS)
>

So basically you are looking for a way to dynamically allocate the
platform-msi interrupts, correct?

Since I don't have access to any of the platform-msi devices, it is hard
for me to test this code for other drivers expect idxd for now.
Once I submit the next round of patches, after addressing all the
comments, would it be possible for you to test this code for any of your
devices?

> It is something easy enough to illustrate with any RDMA device really,
> just open a MR against the addr and use RDMA_WRITE to trigger the
> data. It should trigger a Linux IRQ. Nothing else should be needed.
>
> Jason
>