net: netdev netlink api to bind dma-buf to a net device

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@fomichev.me>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-3-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 959755be4d7f9c15abef7e74813cf8837b8a38fc..4930e8142aa63294bcf1aa43d0320999173325de 100644 (file)
--- 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 43742ac5b00da0aa66660d86cb627561d8eaf298..91bf3ecc5f1d97989bc5450fa27eac3b9286c21e 100644 (file)
--- 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 8350a0afa9ec7bbf7ec88444cf48e8ff07165629..6b7fe6035067b16e30a5f97a7aa0062dce8af3d3 100644 (file)
--- 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 4db40fd5b4a9e9fe2cba786c6d0b1b6e8f21b39b..67c34005750c3f4de9f6311157e369b72caaa379 100644 (file)
--- 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 a17d7eaeb00192498a5e14e6d4565ca1f6355b9d..699c34b9b03cc645fb5d42cd0017e87aac77aa8f 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -723,6 +723,12 @@ 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 43742ac5b00da0aa66660d86cb627561d8eaf298..91bf3ecc5f1d97989bc5450fa27eac3b9286c21e 100644 (file)
--- 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)