Merge: CNB95: bpf: expose information about netdev xdp-metadata kfunc support

zampierilucas · zampierilucas · commit 3681c87369a0 · 2024-05-08T20:17:31.000Z
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/4041 JIRA: https://issues.redhat.com/browse/RHEL-31945 Tested: compile only Depends: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/3939 Commits: ``` 2e06c57 ("xdp: use trusted arguments in XDP hints kfuncs") fc45c5b ("bpf: make it easier to add new metadata kfunc") a9c2a60 ("bpf: expose information about supported xdp metadata kfunc") 0c6c9b1 ("tools: ynl: extend netdev sample to dump xdp-rx-metadata-features") 0629f22 ("ynl: netdev: drop unnecessary enum-as-flags") 9fea94d ("tools: ynl: fix converting flags to names after recent cleanup") ``` Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com> Approved-by: Felix Maurer <fmaurer@redhat.com> Approved-by: Petr Oros <poros@redhat.com> Approved-by: Ivan Vecera <ivecera@redhat.com> Merged-by: Lucas Zampieri <lzampier@redhat.com>
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
@@ -42,6 +42,19 @@ definitions:
         doc:
           This feature informs if netdev implements non-linear XDP buffer
           support in ndo_xdp_xmit callback.
+  -
+    type: flags
+    name: xdp-rx-metadata
+    render-max: true
+    entries:
+      -
+        name: timestamp
+        doc:
+          Device is capable of exposing receive HW timestamp via bpf_xdp_metadata_rx_timestamp().
+      -
+        name: hash
+        doc:
+          Device is capable of exposing receive packet hash via bpf_xdp_metadata_rx_hash().
 
 attribute-sets:
   -
@@ -61,13 +74,18 @@ attribute-sets:
         doc: Bitmask of enabled xdp-features.
         type: u64
         enum: xdp-act
-        enum-as-flags: true
       -
         name: xdp-zc-max-segs
         doc: max fragment count supported by ZC driver
         type: u32
         checks:
           min: 1
+      -
+        name: xdp-rx-metadata-features
+        doc: Bitmask of supported XDP receive metadata features.
+             See Documentation/networking/xdp-rx-metadata.rst for more details.
+        type: u64
+        enum: xdp-rx-metadata
 
 operations:
   list:
@@ -84,6 +102,7 @@ operations:
             - ifindex
             - xdp-features
             - xdp-zc-max-segs
+            - xdp-rx-metadata-features
       dump:
         reply: *dev-all
     -
diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
@@ -105,6 +105,13 @@ bpf_tail_call
 Adding programs that access metadata kfuncs to the ``BPF_MAP_TYPE_PROG_ARRAY``
 is currently not supported.
 
+Supported Devices
+=================
+
+It is possible to query which kfunc the particular netdev implements via
+netlink. See ``xdp-rx-metadata-features`` attribute set in
+``Documentation/netlink/specs/netdev.yaml``.
+
 Example
 =======
 
diff --git a/include/net/xdp.h b/include/net/xdp.h
@@ -419,14 +419,25 @@ void xdp_attachment_setup(struct xdp_attachment_info *info,
 
 #define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE
 
+/* Define the relationship between xdp-rx-metadata kfunc and
+ * various other entities:
+ * - xdp_rx_metadata enum
+ * - netdev netlink enum (Documentation/netlink/specs/netdev.yaml)
+ * - kfunc name
+ * - xdp_metadata_ops field
+ */
 #define XDP_METADATA_KFUNC_xxx	\
 	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_TIMESTAMP, \
-			   bpf_xdp_metadata_rx_timestamp) \
+			   NETDEV_XDP_RX_METADATA_TIMESTAMP, \
+			   bpf_xdp_metadata_rx_timestamp, \
+			   xmo_rx_timestamp) \
 	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
-			   bpf_xdp_metadata_rx_hash) \
+			   NETDEV_XDP_RX_METADATA_HASH, \
+			   bpf_xdp_metadata_rx_hash, \
+			   xmo_rx_hash) \
 
-enum {
-#define XDP_METADATA_KFUNC(name, _) name,
+enum xdp_rx_metadata {
+#define XDP_METADATA_KFUNC(name, _, __, ___) name,
 XDP_METADATA_KFUNC_xxx
 #undef XDP_METADATA_KFUNC
 MAX_XDP_METADATA_KFUNC,
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
@@ -38,11 +38,27 @@ enum netdev_xdp_act {
 	NETDEV_XDP_ACT_MASK = 127,
 };
 
+/**
+ * enum netdev_xdp_rx_metadata
+ * @NETDEV_XDP_RX_METADATA_TIMESTAMP: Device is capable of exposing receive HW
+ *   timestamp via bpf_xdp_metadata_rx_timestamp().
+ * @NETDEV_XDP_RX_METADATA_HASH: Device is capable of exposing receive packet
+ *   hash via bpf_xdp_metadata_rx_hash().
+ */
+enum netdev_xdp_rx_metadata {
+	NETDEV_XDP_RX_METADATA_TIMESTAMP = 1,
+	NETDEV_XDP_RX_METADATA_HASH = 2,
+
+	/* private: */
+	NETDEV_XDP_RX_METADATA_MASK = 3,
+};
+
 enum {
 	NETDEV_A_DEV_IFINDEX = 1,
 	NETDEV_A_DEV_PAD,
 	NETDEV_A_DEV_XDP_FEATURES,
 	NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
+	NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
 
 	__NETDEV_A_DEV_MAX,
 	NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
@@ -846,10 +846,11 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
 	if (!ops)
 		goto out;
 
-	if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP))
-		p = ops->xmo_rx_timestamp;
-	else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH))
-		p = ops->xmo_rx_hash;
+#define XDP_METADATA_KFUNC(name, _, __, xmo) \
+	if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
+	XDP_METADATA_KFUNC_xxx
+#undef XDP_METADATA_KFUNC
+
 out:
 	up_read(&bpf_devs_lock);
 
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
@@ -5,22 +5,32 @@
 #include <linux/rtnetlink.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
+#include <net/xdp.h>
 
 #include "netdev-genl-gen.h"
 
 static int
 netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
 		   const struct genl_info *info)
 {
+	u64 xdp_rx_meta = 0;
 	void *hdr;
 
 	hdr = genlmsg_iput(rsp, info);
 	if (!hdr)
 		return -EMSGSIZE;
 
+#define XDP_METADATA_KFUNC(_, flag, __, xmo) \
+	if (netdev->xdp_metadata_ops && netdev->xdp_metadata_ops->xmo) \
+		xdp_rx_meta |= flag;
+XDP_METADATA_KFUNC_xxx
+#undef XDP_METADATA_KFUNC
+
 	if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
 	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES,
-			      netdev->xdp_features, NETDEV_A_DEV_PAD)) {
+			      netdev->xdp_features, NETDEV_A_DEV_PAD) ||
+	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
+			      xdp_rx_meta, NETDEV_A_DEV_PAD)) {
 		genlmsg_cancel(rsp, hdr);
 		return -EINVAL;
 	}
diff --git a/net/core/xdp.c b/net/core/xdp.c
@@ -755,7 +755,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
 __bpf_kfunc_end_defs();
 
 BTF_SET8_START(xdp_metadata_kfunc_ids)
-#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, 0)
+#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
 XDP_METADATA_KFUNC_xxx
 #undef XDP_METADATA_KFUNC
 BTF_SET8_END(xdp_metadata_kfunc_ids)
@@ -766,7 +766,7 @@ static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {
 };
 
 BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted)
-#define XDP_METADATA_KFUNC(name, str) BTF_ID(func, str)
+#define XDP_METADATA_KFUNC(name, _, str, __) BTF_ID(func, str)
 XDP_METADATA_KFUNC_xxx
 #undef XDP_METADATA_KFUNC
 
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
@@ -38,11 +38,27 @@ enum netdev_xdp_act {
 	NETDEV_XDP_ACT_MASK = 127,
 };
 
+/**
+ * enum netdev_xdp_rx_metadata
+ * @NETDEV_XDP_RX_METADATA_TIMESTAMP: Device is capable of exposing receive HW
+ *   timestamp via bpf_xdp_metadata_rx_timestamp().
+ * @NETDEV_XDP_RX_METADATA_HASH: Device is capable of exposing receive packet
+ *   hash via bpf_xdp_metadata_rx_hash().
+ */
+enum netdev_xdp_rx_metadata {
+	NETDEV_XDP_RX_METADATA_TIMESTAMP = 1,
+	NETDEV_XDP_RX_METADATA_HASH = 2,
+
+	/* private: */
+	NETDEV_XDP_RX_METADATA_MASK = 3,
+};
+
 enum {
 	NETDEV_A_DEV_IFINDEX = 1,
 	NETDEV_A_DEV_PAD,
 	NETDEV_A_DEV_XDP_FEATURES,
 	NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
+	NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
 
 	__NETDEV_A_DEV_MAX,
 	NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
diff --git a/tools/net/ynl/generated/netdev-user.c b/tools/net/ynl/generated/netdev-user.c
@@ -45,12 +45,26 @@ const char *netdev_xdp_act_str(enum netdev_xdp_act value)
 	return netdev_xdp_act_strmap[value];
 }
 
+static const char * const netdev_xdp_rx_metadata_strmap[] = {
+	[0] = "timestamp",
+	[1] = "hash",
+};
+
+const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value)
+{
+	value = ffs(value) - 1;
+	if (value < 0 || value >= (int)MNL_ARRAY_SIZE(netdev_xdp_rx_metadata_strmap))
+		return NULL;
+	return netdev_xdp_rx_metadata_strmap[value];
+}
+
 /* Policies */
 struct ynl_policy_attr netdev_dev_policy[NETDEV_A_DEV_MAX + 1] = {
 	[NETDEV_A_DEV_IFINDEX] = { .name = "ifindex", .type = YNL_PT_U32, },
 	[NETDEV_A_DEV_PAD] = { .name = "pad", .type = YNL_PT_IGNORE, },
 	[NETDEV_A_DEV_XDP_FEATURES] = { .name = "xdp-features", .type = YNL_PT_U64, },
 	[NETDEV_A_DEV_XDP_ZC_MAX_SEGS] = { .name = "xdp-zc-max-segs", .type = YNL_PT_U32, },
+	[NETDEV_A_DEV_XDP_RX_METADATA_FEATURES] = { .name = "xdp-rx-metadata-features", .type = YNL_PT_U64, },
 };
 
 struct ynl_policy_nest netdev_dev_nest = {
@@ -97,6 +111,11 @@ int netdev_dev_get_rsp_parse(const struct nlmsghdr *nlh, void *data)
 				return MNL_CB_ERROR;
 			dst->_present.xdp_zc_max_segs = 1;
 			dst->xdp_zc_max_segs = mnl_attr_get_u32(attr);
+		} else if (type == NETDEV_A_DEV_XDP_RX_METADATA_FEATURES) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.xdp_rx_metadata_features = 1;
+			dst->xdp_rx_metadata_features = mnl_attr_get_u64(attr);
 		}
 	}
 
diff --git a/tools/net/ynl/generated/netdev-user.h b/tools/net/ynl/generated/netdev-user.h
@@ -18,6 +18,7 @@ extern const struct ynl_family ynl_netdev_family;
 /* Enums */
 const char *netdev_op_str(int op);
 const char *netdev_xdp_act_str(enum netdev_xdp_act value);
+const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value);
 
 /* Common nested types */
 /* ============== NETDEV_CMD_DEV_GET ============== */
@@ -48,11 +49,13 @@ struct netdev_dev_get_rsp {
 		__u32 ifindex:1;
 		__u32 xdp_features:1;
 		__u32 xdp_zc_max_segs:1;
+		__u32 xdp_rx_metadata_features:1;
 	} _present;
 
 	__u32 ifindex;
 	__u64 xdp_features;
 	__u32 xdp_zc_max_segs;
+	__u64 xdp_rx_metadata_features;
 };
 
 void netdev_dev_get_rsp_free(struct netdev_dev_get_rsp *rsp);
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
@@ -474,7 +474,7 @@ def _add_attr(self, space, name, value):
 
     def _decode_enum(self, raw, attr_spec):
         enum = self.consts[attr_spec['enum']]
-        if 'enum-as-flags' in attr_spec and attr_spec['enum-as-flags']:
+        if enum.type == 'flags' or attr_spec.get('enum-as-flags', False):
             i = 0
             value = set()
             while raw:
diff --git a/tools/net/ynl/samples/Makefile b/tools/net/ynl/samples/Makefile
@@ -4,7 +4,7 @@ include ../Makefile.deps
 
 CC=gcc
 CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
-	-I../lib/ -I../generated/ -idirafter $(UAPI_PATH)
+	-I../../../include/uapi -I../lib/ -I../generated/ -idirafter $(UAPI_PATH)
 ifeq ("$(DEBUG)","1")
   CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
 endif
diff --git a/tools/net/ynl/samples/netdev.c b/tools/net/ynl/samples/netdev.c
@@ -32,12 +32,18 @@ static void netdev_print_device(struct netdev_dev_get_rsp *d, unsigned int op)
 	if (!d->_present.xdp_features)
 		return;
 
-	printf("%llx:", d->xdp_features);
+	printf("xdp-features (%llx):", d->xdp_features);
 	for (int i = 0; d->xdp_features > 1U << i; i++) {
 		if (d->xdp_features & (1U << i))
 			printf(" %s", netdev_xdp_act_str(1 << i));
 	}
 
+	printf(" xdp-rx-metadata-features (%llx):", d->xdp_rx_metadata_features);
+	for (int i = 0; d->xdp_rx_metadata_features > 1U << i; i++) {
+		if (d->xdp_rx_metadata_features & (1U << i))
+			printf(" %s", netdev_xdp_rx_metadata_str(1 << i));
+	}
+
 	printf(" xdp-zc-max-segs=%u", d->xdp_zc_max_segs);
 
 	name = netdev_op_str(op);
