Re: [RFC v2 00/10] HFI Virtual Network Interface Controller (VNIC)

On Thu, Dec 15, 2016 at 10:07:13AM -0700, Jason Gunthorpe wrote:

On Thu, Dec 15, 2016 at 11:28:06AM -0500, Doug Ledford wrote:

quoted

1) Since your intent is to make this work with multiple versions of the
hfi drivers, I disagree with Jason that just because there is only one
driver today that we should keep it simple.  Design it right from the
beginning of multi driver is your intent is, IMO, a better way to go.
You'll work out the bugs in the initial implementation and when it comes
time to add the second driver, things will go much more smoothly.

If that is your position then this should be a straight up IB ULP that
works with any IB hardware.

There is nothing HFI specific about it except for the
micro-optimization of pushing packets via SDMA instead of post_send,
and that same micro optimization probably applies to ipoib.

Responded on the other thread. As mentioned, there are differences between 
ipoib and hfi_vnic interface. For hfi_vnic, we need simple interface as defined 
in the include/rdma/opa_hfi.h that represents HW to put/get already 
encapsulated OPA packets.

In other words, lets see the first version as a straight ULP with no
special HFI hooks, then we can discuss how best to micro optimize it
for HFI SDMA.

As mentioned in other thread, that would be putting hfi_vnic_ctrl_ops in 
ib_device structure.

Niranjana

Jason

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