[PATCH net-next v19 02/13] net: netdev netlink api to bind dma-buf to a net device - Linux-kselftest-mirror

13 Aug 2024

API takes the dma-buf fd as input, and binds it to the netdevice. The
user can specify the rx queues to bind the dma-buf to.
Suggested-by: Stanislav Fomichev sdf@google.com
Signed-off-by: Mina Almasry almasrymina@google.com
Reviewed-by: Donald Hunter donald.hunter@gmail.com
Reviewed-by: Jakub Kicinski kuba@kernel.org
---
v16:
- Use subset-of: queue queue-id instead of queue-dmabuf (Jakub).
- Rename attribute 'bind-dmabuf' to more generic 'dmabuf' (Jakub).
- Use 'dmabuf' everywhere instead of mix of 'dma-buf' and 'dmabuf'
  (Donald).
- Remove repetitive 'dmabuf' naming that appeared in some places
  (Jakub).
- Reordered where the new operations went so I don't break the enum UAPI
  (Jakub).
v7:
- Use flags: [ admin-perm ] instead of a CAP_NET_ADMIN check.
Changes in v1:
- Add rx-queue-type to distingish rx from tx (Jakub)
- Return dma-buf ID from netlink API (David, Stan)
Changes in RFC-v3:
- Support binding multiple rx rx-queues
---
 Documentation/netlink/specs/netdev.yaml | 47 +++++++++++++++++++++++++
 include/uapi/linux/netdev.h             | 11 ++++++
 net/core/netdev-genl-gen.c              | 19 ++++++++++
 net/core/netdev-genl-gen.h              |  2 ++
 net/core/netdev-genl.c                  |  6 ++++
 tools/include/uapi/linux/netdev.h       | 11 ++++++
 6 files changed, 96 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 959755be4d7f..4930e8142aa6 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -457,6 +457,39 @@ attribute-sets:
           Number of times driver re-started accepting send
           requests to this queue from the stack.
         type: uint
+  -
+    name: queue-id
+    subset-of: queue
+    attributes:
+      -
+        name: id
+      -
+        name: type
+  -
+    name: dmabuf
+    attributes:
+      -
+        name: ifindex
+        doc: netdev ifindex to bind the dmabuf to.
+        type: u32
+        checks:
+          min: 1
+      -
+        name: queues
+        doc: receive queues to bind the dmabuf to.
+        type: nest
+        nested-attributes: queue-id
+        multi-attr: true
+      -
+        name: fd
+        doc: dmabuf file descriptor to bind.
+        type: u32
+      -
+        name: id
+        doc: id of the dmabuf binding
+        type: u32
+        checks:
+          min: 1
operations:
   list:
@@ -619,6 +652,20 @@ operations:
             - rx-bytes
             - tx-packets
             - tx-bytes
+    -
+      name: bind-rx
+      doc: Bind dmabuf to netdev
+      attribute-set: dmabuf
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - ifindex
+            - fd
+            - queues
+        reply:
+          attributes:
+            - id
mcast-groups:
   list:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 43742ac5b00d..91bf3ecc5f1d 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -173,6 +173,16 @@ enum {
    NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)
 };
+enum {
+	NETDEV_A_DMABUF_IFINDEX = 1,
+	NETDEV_A_DMABUF_QUEUES,
+	NETDEV_A_DMABUF_FD,
+	NETDEV_A_DMABUF_ID,
+
+	__NETDEV_A_DMABUF_MAX,
+	NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1)
+};
+
 enum {
    NETDEV_CMD_DEV_GET = 1,
    NETDEV_CMD_DEV_ADD_NTF,
@@ -186,6 +196,7 @@ enum {
    NETDEV_CMD_QUEUE_GET,
    NETDEV_CMD_NAPI_GET,
    NETDEV_CMD_QSTATS_GET,
+	NETDEV_CMD_BIND_RX,
__NETDEV_CMD_MAX,
    NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index 8350a0afa9ec..6b7fe6035067 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -27,6 +27,11 @@ const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFIND
    [NETDEV_A_PAGE_POOL_IFINDEX] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_page_pool_ifindex_range),
 };
+const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1] = {
+	[NETDEV_A_QUEUE_ID] = { .type = NLA_U32, },
+	[NETDEV_A_QUEUE_TYPE] = NLA_POLICY_MAX(NLA_U32, 1),
+};
+
 /* NETDEV_CMD_DEV_GET - do */
 static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {
    [NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
@@ -74,6 +79,13 @@ static const struct nla_policy netdev_qstats_get_nl_policy[NETDEV_A_QSTATS_SCOPE
    [NETDEV_A_QSTATS_SCOPE] = NLA_POLICY_MASK(NLA_UINT, 0x1),
 };
+/* NETDEV_CMD_BIND_RX - do */
+static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1] = {
+	[NETDEV_A_DMABUF_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
+	[NETDEV_A_DMABUF_FD] = { .type = NLA_U32, },
+	[NETDEV_A_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_id_nl_policy),
+};
+
 /* Ops table for netdev */
 static const struct genl_split_ops netdev_nl_ops[] = {
    {
@@ -151,6 +163,13 @@ static const struct genl_split_ops netdev_nl_ops[] = {
    	.maxattr	= NETDEV_A_QSTATS_SCOPE,
    	.flags		= GENL_CMD_CAP_DUMP,
    },
+	{
+		.cmd		= NETDEV_CMD_BIND_RX,
+		.doit		= netdev_nl_bind_rx_doit,
+		.policy		= netdev_bind_rx_nl_policy,
+		.maxattr	= NETDEV_A_DMABUF_FD,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
 };
static const struct genl_multicast_group netdev_nl_mcgrps[] = {
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index 4db40fd5b4a9..67c34005750c 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -13,6 +13,7 @@
/* Common nested types */
 extern const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1];
+extern const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1];
int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);
 int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
@@ -30,6 +31,7 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info);
 int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
    			struct netlink_callback *cb);
+int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info);
enum {
    NETDEV_NLGRP_MGMT,
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 05f9515d2c05..2d726e65211d 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -721,6 +721,12 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
    return err;
 }
+/* Stub */
+int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return 0;
+}
+
 static int netdev_genl_netdevice_event(struct notifier_block *nb,
    			       unsigned long event, void *ptr)
 {
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 43742ac5b00d..91bf3ecc5f1d 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -173,6 +173,16 @@ enum {
    NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)
 };
+enum {
+	NETDEV_A_DMABUF_IFINDEX = 1,
+	NETDEV_A_DMABUF_QUEUES,
+	NETDEV_A_DMABUF_FD,
+	NETDEV_A_DMABUF_ID,
+
+	__NETDEV_A_DMABUF_MAX,
+	NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1)
+};
+
 enum {
    NETDEV_CMD_DEV_GET = 1,
    NETDEV_CMD_DEV_ADD_NTF,
@@ -186,6 +196,7 @@ enum {
    NETDEV_CMD_QUEUE_GET,
    NETDEV_CMD_NAPI_GET,
    NETDEV_CMD_QSTATS_GET,
+	NETDEV_CMD_BIND_RX,
__NETDEV_CMD_MAX,
    NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
-- 
2.46.0.76.ge559c4bf1a-goog



    