[PATCH net-next v18 14/14] netdev: add dmabuf introspection

[Mina Almasry <almasrymina@google.com>]

Add dmabuf information to page_pool stats:

$ ./cli.py --spec ../netlink/specs/netdev.yaml --dump page-pool-get
...
 {'dmabuf': 10,
  'id': 456,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 455,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 454,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 453,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 452,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 451,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 450,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},
 {'dmabuf': 10,
  'id': 449,
  'ifindex': 3,
  'inflight': 1023,
  'inflight-mem': 4190208},

And queue stats:

$ ./cli.py --spec ../netlink/specs/netdev.yaml --dump queue-get
...
{'dmabuf': 10, 'id': 8, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 9, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 10, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 11, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 12, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 13, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 14, 'ifindex': 3, 'type': 'rx'},
{'dmabuf': 10, 'id': 15, 'ifindex': 3, 'type': 'rx'},

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>

---
 Documentation/netlink/specs/netdev.yaml | 10 ++++++++++
 include/uapi/linux/netdev.h             |  2 ++
 net/core/netdev-genl.c                  | 10 ++++++++++
 net/core/page_pool_user.c               |  4 ++++
 tools/include/uapi/linux/netdev.h       |  2 ++
 5 files changed, 28 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 0c747530c275e..08412c279297b 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -167,6 +167,10 @@ attribute-sets:
           "re-attached", they are just waiting to disappear.
           Attribute is absent if Page Pool has not been detached, and
           can still be used to allocate new memory.
+      -
+        name: dmabuf
+        doc: ID of the dmabuf this page-pool is attached to.
+        type: u32
   -
     name: page-pool-info
     subset-of: page-pool
@@ -268,6 +272,10 @@ attribute-sets:
         name: napi-id
         doc: ID of the NAPI instance which services this queue.
         type: u32
+      -
+        name: dmabuf
+        doc: ID of the dmabuf attached to this queue, if any.
+        type: u32
 
   -
     name: qstats
@@ -543,6 +551,7 @@ operations:
             - inflight
             - inflight-mem
             - detach-time
+            - dmabuf
       dump:
         reply: *pp-reply
       config-cond: page-pool
@@ -607,6 +616,7 @@ operations:
             - type
             - napi-id
             - ifindex
+            - dmabuf
       dump:
         request:
           attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 91bf3ecc5f1d9..7c308f04e7a06 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -93,6 +93,7 @@ enum {
 	NETDEV_A_PAGE_POOL_INFLIGHT,
 	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
 	NETDEV_A_PAGE_POOL_DETACH_TIME,
+	NETDEV_A_PAGE_POOL_DMABUF,
 
 	__NETDEV_A_PAGE_POOL_MAX,
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
@@ -131,6 +132,7 @@ enum {
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
+	NETDEV_A_QUEUE_DMABUF,
 
 	__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 bd54cf50b658a..e944fd56c6b8e 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -293,6 +293,7 @@ static int
 netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 			 u32 q_idx, u32 q_type, const struct genl_info *info)
 {
+	struct net_devmem_dmabuf_binding *binding;
 	struct netdev_rx_queue *rxq;
 	struct netdev_queue *txq;
 	void *hdr;
@@ -312,6 +313,15 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 		if (rxq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
 					     rxq->napi->napi_id))
 			goto nla_put_failure;
+
+		binding = (struct net_devmem_dmabuf_binding *)
+				  rxq->mp_params.mp_priv;
+		if (binding) {
+			if (nla_put_u32(rsp, NETDEV_A_QUEUE_DMABUF,
+					binding->id))
+				goto nla_put_failure;
+		}
+
 		break;
 	case NETDEV_QUEUE_TYPE_TX:
 		txq = netdev_get_tx_queue(netdev, q_idx);
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 3a3277ba167b1..ca13363aea343 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -212,6 +212,7 @@ static int
 page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 		  const struct genl_info *info)
 {
+	struct net_devmem_dmabuf_binding *binding = pool->mp_priv;
 	size_t inflight, refsz;
 	void *hdr;
 
@@ -241,6 +242,9 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 			 pool->user.detach_time))
 		goto err_cancel;
 
+	if (binding && nla_put_u32(rsp, NETDEV_A_PAGE_POOL_DMABUF, binding->id))
+		goto err_cancel;
+
 	genlmsg_end(rsp, hdr);
 
 	return 0;
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 91bf3ecc5f1d9..7c308f04e7a06 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -93,6 +93,7 @@ enum {
 	NETDEV_A_PAGE_POOL_INFLIGHT,
 	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
 	NETDEV_A_PAGE_POOL_DETACH_TIME,
+	NETDEV_A_PAGE_POOL_DMABUF,
 
 	__NETDEV_A_PAGE_POOL_MAX,
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
@@ -131,6 +132,7 @@ enum {
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
+	NETDEV_A_QUEUE_DMABUF,
 
 	__NETDEV_A_QUEUE_MAX,
 	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
-- 
2.46.0.rc2.264.g509ed76dc8-goog