On 6/2/2023 11:17 PM, Jakub Kicinski wrote:

On Thu, 01 Jun 2023 10:42:41 -0700 Amritha Nambiar wrote:

quoted

Add support in ynl/netdev.yaml for napi related information. The
netdev structure tracks all the napi instances and napi fields.
The napi instances and associated queue[s] can be retrieved this way.

Refactored netdev-genl to support exposing napi<->queue[s] mapping
that is retained in a netdev.

Signed-off-by: Amritha Nambiar <redacted>
---
  Documentation/netlink/specs/netdev.yaml |   39 +++++
  include/uapi/linux/netdev.h             |    4 +
  net/core/netdev-genl.c                  |  239 ++++++++++++++++++++++++++-----
  tools/include/uapi/linux/netdev.h       |    4 +
  4 files changed, 247 insertions(+), 39 deletions(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index b99e7ffef7a1..8d0edb529563 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml

@@ -62,6 +62,44 @@ attribute-sets:
          type: u64
          enum: xdp-act
          enum-as-flags: true
+      -
+        name: napi-info
+        doc: napi information such as napi-id, napi queues etc.
+        type: nest
+        multi-attr: true

Let's make a new attr space for the napi info command.
We don't reuse much of the attributes, and as the commands
grow stuffing all attrs into one space makes finding stuff
harder.

Agree. I should not have overloaded the 'dev' command to begin with.

quoted

+        nested-attributes: dev-napi-info

And what's inside this nest should also be a separate attr space.

So, I think we could have two new commands for napi data. Would this be 
acceptable, a 'napi-queue-get' command for napi-queue specific 
information (set of TX and RX queues, IRQ number etc.), and another 
'napi-info-get' for other information,  such as PID for the napi thread, 
CPU etc.

Example:
  $ ./cli.py --spec netdev.yaml  --do napi-queue-get --json='{"ifindex": 
12}'

[{'napi-info': [{'napi-id': 600, 'rx-queues': [7], 'tx-queues': [7], 
'irq': 298},
                 {'napi-id': 599, 'rx-queues': [6], 'tx-queues': [6], 
'irq': 297},
                 {'napi-id': 598, 'rx-queues': [5], 'tx-queues': [5], 
'irq': 296},
                 {'napi-id': 597, 'rx-queues': [4], 'tx-queues': [4], 
'irq': 295},
                 {'napi-id': 596, 'rx-queues': [3], 'tx-queues': [3], 
'irq': 294},
                 {'napi-id': 595, 'rx-queues': [2], 'tx-queues': [2], 
'irq': 293},
                 {'napi-id': 594, 'rx-queues': [1], 'tx-queues': [1], 
'irq': 292},
                 {'napi-id': 593, 'rx-queues': [0], 'tx-queues': [0], 
'irq': 291}]}]
				

$ ./cli.py --spec netdev.yaml  --do napi-info-get --json='{"ifindex": 12}'

[{'napi-info': [{'napi-id': 600, 'pid': 68114},
                 {'napi-id': 599, 'pid': 68113},
                 {'napi-id': 598, 'pid': 68112},
                 {'napi-id': 597, 'pid': 68111},
                 {'napi-id': 596, 'pid': 68110},
                 {'napi-id': 595, 'pid': 68109},
                 {'napi-id': 594, 'pid': 68108},
                 {'napi-id': 593, 'pid': 68107}]}]

quoted

+      -
+        name: napi-id
+        doc: napi id
+        type: u32
+      -
+        name: rx-queues
+        doc: list of rx queues associated with a napi
+        type: u16

Make it u32, at the uAPI level we're tried to the width of fields, and
u16 ends up being the same size as u32 "on the wire" due to padding.

Makes sense. Will fix.

quoted

+        multi-attr: true
+      -
+        name: tx-queues
+        doc: list of tx queues associated with a napi
+        type: u16
+        multi-attr: true

quoted

+  -
+    name: dev-napi-info
+    subset-of: dev

Yeah, this shouldn't be a subset just a full-on separate attr space.
The handshake family may be a good example to look at, it's the biggest
so far written with the new rules in mind.

Okay.

quoted

+    attributes:
+      -
+        name: napi-id
+        doc: napi id
+        type: u32
+      -
+        name: rx-queues
+        doc: list rx of queues associated with a napi
+        type: u16
+        multi-attr: true
+      -
+        name: tx-queues
+        doc: list tx of queues associated with a napi
+        type: u16
+        multi-attr: true
  
  operations:
    list:

@@ -77,6 +115,7 @@ operations:
            attributes:
              - ifindex
              - xdp-features
+            - napi-info

Aaah, separate command, please. Let's not stuff all the information
into a single command like we did for rtnl.

Okay.

quoted

        dump:
          reply: *dev-all
      -