[net-next v2 0/1] hyperv: Link queues to NAPIs

[net-next v2 0/1] hyperv: Link queues to NAPIs

[Joe Damato]

Greetings:

Welcome to v2.

This was previously an RFC [1], see changelog below.

I've only compile tested this series; I don't have the software for testing
this so I am hoping some one from Microsoft can review and test this
following the instructions below :)

This change allows users to query the mapping of queues to NAPIs using
the netdev-genl interface.

Once this patch has been applied, this can be tested using the cli included
in the kernel tree like this:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump queue-get --json='{"ifindex": 2}'

Substituting the ifindex above for the correct ifindex on your system
(which is, presumably, a hyper-V VM).

A sample of expected output would look like:

[{'id': 0, 'ifindex': 2, 'napi-id': 145, 'type': 'rx'},
 {'id': 0, 'ifindex': 2, 'napi-id': 145, 'type': 'tx'}]

Which shows a mapping of queue ID (0) to NAPI ID (145) for both RX and TX
queues. Having this mapping is extremely useful for user apps for a variety
of use cases, including epoll-based busy poll which relies on the NAPI ID.

It would be really great to add support for this API to hyper-V so that
applications (including CI and automated testing facilities) could make use
of this API in VMs.

Sorry, I don't know much at all about hyper-V, but please let me know if
there is anything I can do to help.

Thanks,
Joe

[1]: https://lore.kernel.org/netdev/20240924234851.42348-1-jdamato@fastly.com/

v2:
  - Added Haiyang Zhang's Reviewed-by
  - Added Shradha Gupta's Tested-by
  - Commit message updated to include test output from Shradha
  - Wrapped lines to 80 characters, as suggested by Simon Horman (no
    functional changes introduced)

Joe Damato (1):
  hv_netvsc: Link queues to NAPIs

 drivers/net/hyperv/netvsc.c       | 13 ++++++++++++-
 drivers/net/hyperv/rndis_filter.c |  9 +++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

-- 
2.34.1

[net-next v2 1/1] hv_netvsc: Link queues to NAPIs

[Joe Damato]

Use netif_queue_set_napi to link queues to NAPI instances so that they
can be queried with netlink.

Shradha Gupta tested the patch and reported that the results are
as expected:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                           --dump queue-get --json='{"ifindex": 2}'

 [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
  {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
  {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
  {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
  {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
  {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'rx'},
  {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'rx'},
  {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'rx'},
  {'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
  {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'tx'},
  {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
  {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'},
  {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'tx'},
  {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'tx'},
  {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'tx'},
  {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'tx'}]

Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Tested-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
---
 drivers/net/hyperv/netvsc.c       | 13 ++++++++++++-
 drivers/net/hyperv/rndis_filter.c |  9 +++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 2b6ec979a62f..9afb08dbc350 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -712,8 +712,13 @@ void netvsc_device_remove(struct hv_device *device)
 	for (i = 0; i < net_device->num_chn; i++) {
 		/* See also vmbus_reset_channel_cb(). */
 		/* only disable enabled NAPI channel */
-		if (i < ndev->real_num_rx_queues)
+		if (i < ndev->real_num_rx_queues) {
+			netif_queue_set_napi(ndev, i, NETDEV_QUEUE_TYPE_TX,
+					     NULL);
+			netif_queue_set_napi(ndev, i, NETDEV_QUEUE_TYPE_RX,
+					     NULL);
 			napi_disable(&net_device->chan_table[i].napi);
+		}
 
 		netif_napi_del(&net_device->chan_table[i].napi);
 	}
@@ -1787,6 +1792,10 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
 	netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
 
 	napi_enable(&net_device->chan_table[0].napi);
+	netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_RX,
+			     &net_device->chan_table[0].napi);
+	netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_TX,
+			     &net_device->chan_table[0].napi);
 
 	/* Connect with the NetVsp */
 	ret = netvsc_connect_vsp(device, net_device, device_info);
@@ -1805,6 +1814,8 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
 
 close:
 	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
+	netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_TX, NULL);
+	netif_queue_set_napi(ndev, 0, NETDEV_QUEUE_TYPE_RX, NULL);
 	napi_disable(&net_device->chan_table[0].napi);
 
 	/* Now, we can close the channel safely */
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index ecc2128ca9b7..c0ceeef4fcd8 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1269,10 +1269,15 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
 	ret = vmbus_open(new_sc, netvsc_ring_bytes,
 			 netvsc_ring_bytes, NULL, 0,
 			 netvsc_channel_cb, nvchan);
-	if (ret == 0)
+	if (ret == 0) {
 		napi_enable(&nvchan->napi);
-	else
+		netif_queue_set_napi(ndev, chn_index, NETDEV_QUEUE_TYPE_RX,
+				     &nvchan->napi);
+		netif_queue_set_napi(ndev, chn_index, NETDEV_QUEUE_TYPE_TX,
+				     &nvchan->napi);
+	} else {
 		netdev_notice(ndev, "sub channel open failed: %d\n", ret);
+	}
 
 	if (atomic_inc_return(&nvscdev->open_chn) == nvscdev->num_chn)
 		wake_up(&nvscdev->subchan_open);
-- 
2.34.1

Re: [net-next v2 0/1] hyperv: Link queues to NAPIs

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Mon, 30 Sep 2024 17:27:08 +0000 you wrote:
> Greetings:
> 
> Welcome to v2.
> 
> This was previously an RFC [1], see changelog below.
> 
> I've only compile tested this series; I don't have the software for testing
> this so I am hoping some one from Microsoft can review and test this
> following the instructions below :)
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/1] hv_netvsc: Link queues to NAPIs
    https://git.kernel.org/netdev/net-next/c/8b641b5e4c78

You are awesome, thank you!
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