| Message ID | 20250129172431.65773-2-jdamato@fastly.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | netdevgenl: Add an xsk attribute to queues | expand |
On Wed, 29 Jan 2025 17:24:24 +0000 Joe Damato wrote: > Expose a new per-queue attribute, xsk, which indicates that a queue is > being used for AF_XDP. Update the documentation to more explicitly state > which queue types are linked. Let's do the same thing we did for io_uring queues? An empty nest: https://lore.kernel.org/all/20250116231704.2402455-6-dw@davidwei.uk/ At the protocol level nest is both smaller and more flexible. It's just 4B with zero length and a "this is a nest" flag. We can add attributes to it as we think of things to express.
On Wed, Jan 29, 2025 at 05:52:24PM -0800, Jakub Kicinski wrote: > On Wed, 29 Jan 2025 17:24:24 +0000 Joe Damato wrote: > > Expose a new per-queue attribute, xsk, which indicates that a queue is > > being used for AF_XDP. Update the documentation to more explicitly state > > which queue types are linked. > > Let's do the same thing we did for io_uring queues? An empty nest: > https://lore.kernel.org/all/20250116231704.2402455-6-dw@davidwei.uk/ > > At the protocol level nest is both smaller and more flexible. > It's just 4B with zero length and a "this is a nest" flag. > We can add attributes to it as we think of things to express. Thanks for the pointer; will do.
On Wed, Jan 29, 2025 at 05:52:24PM -0800, Jakub Kicinski wrote: > On Wed, 29 Jan 2025 17:24:24 +0000 Joe Damato wrote: > > Expose a new per-queue attribute, xsk, which indicates that a queue is > > being used for AF_XDP. Update the documentation to more explicitly state > > which queue types are linked. > > Let's do the same thing we did for io_uring queues? An empty nest: > https://lore.kernel.org/all/20250116231704.2402455-6-dw@davidwei.uk/ > > At the protocol level nest is both smaller and more flexible. > It's just 4B with zero length and a "this is a nest" flag. > We can add attributes to it as we think of things to express. I got a thing working locally, but just to make sure I'm following... you are saying that the attribute will exist (but have nothing in it) when the queue has a pool, and when !q->pool the attribute will not exist? For example: [{'id': 0, 'ifindex': 5, 'napi-id': 8266, 'type': 'rx', 'xsk': {}}, {'id': 1, 'ifindex': 5, 'napi-id': 8267, 'type': 'rx'}, ... Is that what you are thinking? Completely fine with me as I haven't read enough of the xsk code to really have a good sense of what attributes might be helpful to expose at this point.
On Thu, 30 Jan 2025 13:06:47 -0500 Joe Damato wrote: > On Wed, Jan 29, 2025 at 05:52:24PM -0800, Jakub Kicinski wrote: > > On Wed, 29 Jan 2025 17:24:24 +0000 Joe Damato wrote: > > > Expose a new per-queue attribute, xsk, which indicates that a queue is > > > being used for AF_XDP. Update the documentation to more explicitly state > > > which queue types are linked. > > > > Let's do the same thing we did for io_uring queues? An empty nest: > > https://lore.kernel.org/all/20250116231704.2402455-6-dw@davidwei.uk/ > > > > At the protocol level nest is both smaller and more flexible. > > It's just 4B with zero length and a "this is a nest" flag. > > We can add attributes to it as we think of things to express. > > I got a thing working locally, but just to make sure I'm > following... you are saying that the attribute will exist (but have > nothing in it) when the queue has a pool, and when !q->pool the > attribute will not exist? > > For example: > > [{'id': 0, 'ifindex': 5, 'napi-id': 8266, 'type': 'rx', 'xsk': {}}, > {'id': 1, 'ifindex': 5, 'napi-id': 8267, 'type': 'rx'}, > ... > > Is that what you are thinking? Yup! That's it. > Completely fine with me as I haven't read enough of the xsk code to > really have a good sense of what attributes might be helpful to > expose at this point.
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index cbb544bd6c84..7a72788cce03 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml @@ -286,6 +286,8 @@ 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 have the xsk attribute set. type: u32 enum: queue-type - @@ -296,7 +298,12 @@ attribute-sets: name: dmabuf doc: ID of the dmabuf attached to this queue, if any. type: u32 - + - + name: xsk + doc: Non-zero for queues which are used for XSK (AF_XDP), 0 otherwise. + type: u32 + checks: + max: 1 - name: qstats doc: | @@ -637,6 +644,7 @@ operations: - napi-id - ifindex - dmabuf + - xsk dump: request: attributes: diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h index e4be227d3ad6..4d2dcf4960ec 100644 --- a/include/uapi/linux/netdev.h +++ b/include/uapi/linux/netdev.h @@ -136,6 +136,7 @@ enum { NETDEV_A_QUEUE_TYPE, NETDEV_A_QUEUE_NAPI_ID, NETDEV_A_QUEUE_DMABUF, + 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 715f85c6b62e..964aebfcb079 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -394,12 +394,18 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev, nla_put_u32(rsp, NETDEV_A_QUEUE_DMABUF, binding->id)) goto nla_put_failure; + if (nla_put_u32(rsp, NETDEV_A_QUEUE_XSK, !!rxq->pool)) + goto nla_put_failure; + break; case NETDEV_QUEUE_TYPE_TX: txq = netdev_get_tx_queue(netdev, q_idx); if (txq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID, txq->napi->napi_id)) goto nla_put_failure; + + if (nla_put_u32(rsp, NETDEV_A_QUEUE_XSK, !!txq->pool)) + goto nla_put_failure; } genlmsg_end(rsp, hdr); diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h index e4be227d3ad6..4d2dcf4960ec 100644 --- a/tools/include/uapi/linux/netdev.h +++ b/tools/include/uapi/linux/netdev.h @@ -136,6 +136,7 @@ enum { NETDEV_A_QUEUE_TYPE, NETDEV_A_QUEUE_NAPI_ID, NETDEV_A_QUEUE_DMABUF, + NETDEV_A_QUEUE_XSK, __NETDEV_A_QUEUE_MAX, NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
Expose a new per-queue attribute, xsk, which indicates that a queue is being used for AF_XDP. Update the documentation to more explicitly state which queue types are linked. Signed-off-by: Joe Damato <jdamato@fastly.com> --- Documentation/netlink/specs/netdev.yaml | 10 +++++++++- include/uapi/linux/netdev.h | 1 + net/core/netdev-genl.c | 6 ++++++ tools/include/uapi/linux/netdev.h | 1 + 4 files changed, 17 insertions(+), 1 deletion(-)