On Mon, Nov 21, 2016 at 02:39:30PM -0700, Jason Gunthorpe wrote:
On Mon, Nov 21, 2016 at 01:30:17PM -0800, Vishwanathapura, Niranjana wrote:
On Sat, Nov 19, 2016 at 12:04:45PM -0700, Jason Gunthorpe wrote:
>On Fri, Nov 18, 2016 at 02:42:10PM -0800, Vishwanathapura, Niranjana wrote:
>>+HFI-VNIC DRIVER
>>+M: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
>>+M: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
>>+L: linux-rdma@xxxxxxxxxxxxxxx
>>+S: Supported
>>+F: drivers/infiniband/sw/intel/vnic
>
>This is either a net driver or a ULP, no idea why it should go in this
>directory!?
>
>It sounds like an ethernet driver, so you should probably put it
>there...
>
The hfi_vnic is an Ethernet driver. It is similar to ULP like ipoib, but
instead it is Ethernet over Omni-path here.
The VNIC Ethernet (hfi_vnic) driver encapsulates Ethernet packets in an
Omni-path header.
The hfi_vnic Ethernet driver do not access the HW. It interfaces with HFI1
driver which sends/receives Omni-Path encapsulated Ethernet frames from HW.
Also, the VNIC control path driver (VEMA) is an IB MAD agent which should be
under drivers/infiniband/.. .
Putting the VNIC Ethernet driver and the VNIC control driver together under
a single module (hfi_vnic.ko) provided a simpler interface between them.
So, we have put the driver under drivers/infiniband/sw/intel for two reasons:
a) We have VNIC control driver (VEMA) which is an IB mad agent.
b) hfi_vnic Ethernet driver is dependent on HFI1 driver for sending/receving
Omni-path encapsulated Ethernet packets from HW.
Sounds like this driver belongs under net/ someplace to me.
NAK on drivers/infiniband/sw/ at least - that dir is only for HCA
drivers.
I did not see any example IB mad agent outside drivers/inifiniband folder.
I did see some netdev drivers outside the net/ folder (like ipoib and
drivers/infiniband/hw/nes/).
The hfi_vnic Ethernet driver is entirely a soft driver without any HW access.
Also, any interface changes between hfi_vnic and the HFI driver makes it
difficult to manage if they are under two subsystems/maintainers.
So drivers/infiniband is probably more approriate for this driver.
We have 'rdmavt' and 'soft-roce' drivers under drivers/infiniband/sw/ folder
which are soft drivers similar to hfi_vnic. So we decided to put 'hif_vnic'
under there.
Other places under drivers/infiniband where we can put this driver are,
drivers/infiniband/ulp/hfi_vnic
drivers/infiniband/hw/hfi_vnic
>>+/* hfi_vnic_bus_init - initialize the hfi vnic bus drvier */
>>+static int hfi_vnic_bus_init(void)
>>+{
>>+ int rc;
>>+
>>+ ida_init(&hfi_vnic_ctrl_ida);
>>+ idr_init(&hfi_vnic_idr);
>>+
>>+ rc = bus_register(&hfi_vnic_bus);
>
>Why on earth do we need this? Didn't I give you enough grief for the
>psm stuff and now you want to create an entire subystem hidden away!?
>
>Use some netlink scheme to control your vnic like the rest of the net
>stack..
>
The hfi_vnic_bus is only abstracting the HW independent functionality (like
Ethernet interface, encapsulation, IB MAD interface etc) with the HW
dependent functionality (sending/receiving packets on the wire).
Thus providing a cleaner interface between HW independent hfi_vnic Ethernet
and Control drivers and the HW dependent HFI1 driver.
That doesn't explain anything, sound like you don't need it so get rid
of it.
There is no other User interface here other than the standard Ethernet
interface through network stack.
Good, then this isn't needed, because it doesn't provide a user interface.
Can you explain what exactly you are asking to get rid of here and why?
#ls /sys/bus/hfi_vnic_bus/devices/
hfi_vnic_ctrl_00 /* control device for HFI instance 0 */
hfi_vnic_00.01.00 /* first VNIC port on HFI instance 0, port 1 */
Jason
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