Re: [PATCH for-next] RDMA/efa: Add CQ with external memory support

["Margolin, Michael" <mrgolin@amazon.com>]

On 5/26/2025 7:17 PM, Margolin, Michael wrote:
>
> On 5/26/2025 7:08 PM, Jason Gunthorpe wrote:
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>> On Mon, May 26, 2025 at 06:45:59PM +0300, Margolin, Michael wrote:
>>
>>> Are you suggesting turning mlx5dv_devx_umem_reg into a common verb 
>>> including
>>> the kernel part or some kind of rdma-core level abstraction for passing
>>> dmabuf+offset+length / address+length to a create CQ/QP function?
>> I think Leon was, but I'm not sure that is so worthwhile.
>>
>> I was thinking more of having the ioctls for things like QP/CQ/MR
>> accept a more standard common set of attributes to describe the buffer
>> memory and then making it simpler for the driver to get a umem from
>> those common attributes.
>>
>> But EFA is alread sort of different because it normally uses a kernel
>> allocated buffer, right?
>>
>> Jason
>
> Yes, EFA is an example for a driver that doesn't need this on the 
> "standard" flow.
>
> Michael
>
How can we move forward with this patch? It's possible to add additional 
attributes to the common create CQ ioctl and use it for EFA direct verbs 
but it won't be easy to move existing drivers to use it.


Michael