[PATCH net-next v5 2/3] netdev-genl: Add an XSK attribute to queues

Joe Damato
2025-02-08T04:14:38Z

Expose a new per-queue nest attribute, xsk, which will be present for
queues that are being used for AF_XDP. If the queue is not being used for
AF_XDP, the nest will not be present.

In the future, this attribute can be extended to include more data about
XSK as it is needed.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
v5:
- Removed unused variable, ret, from netdev_nl_queue_fill_one.

v4:
- Updated netdev_nl_queue_fill_one to use the empty nest helper added
in patch 1.

v2:
- Patch adjusted to include an attribute, xsk, which is an empty nest
and exposed for queues which have a pool.

Documentation/netlink/specs/netdev.yaml | 13 ++++++++++++-
include/uapi/linux/netdev.h | 6 ++++++
net/core/netdev-genl.c | 11 +++++++++++
tools/include/uapi/linux/netdev.h | 6 ++++++
4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 288923e965ae..85402a2e289c 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -276,6 +276,9 @@ attribute-sets:
doc: The timeout, in nanoseconds, of how long to suspend irq
processing, if event polling finds events
type: uint
+ -
+ name: xsk-info
+ attributes: []
-
name: queue
attributes:
@@ -294,6 +297,9 @@ attribute-sets:
-
name: type
doc: Queue type as rx, tx. Each queue type defines a separate ID space.
+ XDP TX queues allocated in the kernel are not linked to NAPIs and
+ thus not listed. AF_XDP queues will have more information set in
+ the xsk attribute.
type: u32
enum: queue-type
-
@@ -309,7 +315,11 @@ attribute-sets:
doc: io_uring memory provider information.
type: nest
nested-attributes: io-uring-provider-info
-
+ -
+ name: xsk
+ doc: XSK information for this queue, if any.
+ type: nest
+ nested-attributes: xsk-info
-
name: qstats
doc: |
@@ -652,6 +662,7 @@ operations:
- ifindex
- dmabuf
- io-uring
+ - xsk
dump:
request:
attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 6c6ee183802d..4e82f3871473 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -136,6 +136,11 @@ enum {
NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
};

+enum {
+ __NETDEV_A_XSK_INFO_MAX,
+ NETDEV_A_XSK_INFO_MAX = (__NETDEV_A_XSK_INFO_MAX - 1)
+};
+
enum {
NETDEV_A_QUEUE_ID = 1,
NETDEV_A_QUEUE_IFINDEX,
@@ -143,6 +148,7 @@ enum {
NETDEV_A_QUEUE_NAPI_ID,
NETDEV_A_QUEUE_DMABUF,
NETDEV_A_QUEUE_IO_URING,
+ NETDEV_A_QUEUE_XSK,

__NETDEV_A_QUEUE_MAX,
NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 0dcd4faefd8d..b5a93a449af9 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -400,11 +400,22 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
if (params->mp_ops &&
params->mp_ops->nl_fill(params->mp_priv, rsp, rxq))
goto nla_put_failure;
+
+ if (rxq->pool)
+ if (nla_put_empty_nest(rsp, NETDEV_A_QUEUE_XSK))
+ goto nla_put_failure;
+
break;
case NETDEV_QUEUE_TYPE_TX:
txq = netdev_get_tx_queue(netdev, q_idx);
if (nla_put_napi_id(rsp, txq->napi))
goto nla_put_failure;
+
+ if (txq->pool)
+ if (nla_put_empty_nest(rsp, NETDEV_A_QUEUE_XSK))
+ goto nla_put_failure;
+
+ break;
}

genlmsg_end(rsp, hdr);
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 6c6ee183802d..4e82f3871473 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -136,6 +136,11 @@ enum {
NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
};

+enum {
+ __NETDEV_A_XSK_INFO_MAX,
+ NETDEV_A_XSK_INFO_MAX = (__NETDEV_A_XSK_INFO_MAX - 1)
+};
+
enum {
NETDEV_A_QUEUE_ID = 1,
NETDEV_A_QUEUE_IFINDEX,
@@ -143,6 +148,7 @@ enum {
NETDEV_A_QUEUE_NAPI_ID,
NETDEV_A_QUEUE_DMABUF,
NETDEV_A_QUEUE_IO_URING,
+ NETDEV_A_QUEUE_XSK,

__NETDEV_A_QUEUE_MAX,
NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
--
2.43.0