[PATCH v2 bpf 1/5] net: ethtool: add xdp properties flag set

[alardam@gmail.com]

From: Marek Majtyka <marekx.majtyka@intel.com>

Implement support for checking what kind of xdp functionality a netdev
supports. Previously, there was no way to do this other than to try
to create an AF_XDP socket on the interface or load an XDP program and see
if it worked. This commit changes this by adding a new variable which
describes all xdp supported functions on pretty detailed level:
 - aborted
 - drop
 - pass
 - tx
 - redirect
 - zero copy
 - hardware offload.

Zerocopy mode requires that redirect xdp operation is implemented
in a driver and the driver supports also zero copy mode.
Full mode requires that all xdp operation are implemented in the driver.
Basic mode is just full mode without redirect operation.

Initially, these new flags are disabled for all drivers by default.

Signed-off-by: Marek Majtyka <marekx.majtyka@intel.com>
---
 .../networking/netdev-xdp-properties.rst      | 42 ++++++++
 include/linux/netdevice.h                     |  2 +
 include/linux/xdp_properties.h                | 53 +++++++++++
 include/net/xdp.h                             | 95 +++++++++++++++++++
 include/net/xdp_sock_drv.h                    | 10 ++
 include/uapi/linux/ethtool.h                  |  1 +
 include/uapi/linux/xdp_properties.h           | 32 +++++++
 net/ethtool/common.c                          | 11 +++
 net/ethtool/common.h                          |  4 +
 net/ethtool/strset.c                          |  5 +
 10 files changed, 255 insertions(+)
 create mode 100644 Documentation/networking/netdev-xdp-properties.rst
 create mode 100644 include/linux/xdp_properties.h
 create mode 100644 include/uapi/linux/xdp_properties.h

diff --git a/Documentation/networking/netdev-xdp-properties.rst b/Documentation/networking/netdev-xdp-properties.rst
new file mode 100644
index 000000000000..4a434a1c512b
--- /dev/null
+++ b/Documentation/networking/netdev-xdp-properties.rst
@@ -0,0 +1,42 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+Netdev XDP properties
+=====================
+
+ * XDP PROPERTIES FLAGS
+
+Following netdev xdp properties flags can be retrieve over netlink ethtool
+interface the same way as netdev feature flags. These properties flags are
+read only and cannot be change in the runtime.
+
+
+*  XDP_ABORTED
+
+This property informs if netdev supports xdp aborted action.
+
+*  XDP_DROP
+
+This property informs if netdev supports xdp drop action.
+
+*  XDP_PASS
+
+This property informs if netdev supports xdp pass action.
+
+*  XDP_TX
+
+This property informs if netdev supports xdp tx action.
+
+*  XDP_REDIRECT
+
+This property informs if netdev supports xdp redirect action.
+It assumes the all beforehand mentioned flags are enabled.
+
+*  XDP_ZEROCOPY
+
+This property informs if netdev driver supports xdp zero copy.
+It assumes the all beforehand mentioned flags are enabled.
+
+*  XDP_HW_OFFLOAD
+
+This property informs if netdev driver supports xdp hw oflloading.
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 52d1cc2bd8a7..2544c7f0e1b7 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -43,6 +43,7 @@
 #include <net/xdp.h>
 
 #include <linux/netdev_features.h>
+#include <linux/xdp_properties.h>
 #include <linux/neighbour.h>
 #include <uapi/linux/netdevice.h>
 #include <uapi/linux/if_bonding.h>
@@ -2171,6 +2172,7 @@ struct net_device {
 
 	/* protected by rtnl_lock */
 	struct bpf_xdp_entity	xdp_state[__MAX_XDP_MODE];
+	xdp_properties_t	xdp_properties;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 
diff --git a/include/linux/xdp_properties.h b/include/linux/xdp_properties.h
new file mode 100644
index 000000000000..c72c9bcc50de
--- /dev/null
+++ b/include/linux/xdp_properties.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Network device xdp properties.
+ */
+#ifndef _LINUX_XDP_PROPERTIES_H
+#define _LINUX_XDP_PROPERTIES_H
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <asm/byteorder.h>
+
+typedef u64 xdp_properties_t;
+
+enum {
+	XDP_F_ABORTED_BIT,
+	XDP_F_DROP_BIT,
+	XDP_F_PASS_BIT,
+	XDP_F_TX_BIT,
+	XDP_F_REDIRECT_BIT,
+	XDP_F_ZEROCOPY_BIT,
+	XDP_F_HW_OFFLOAD_BIT,
+
+	/*
+	 * Add your fresh new property above and remember to update
+	 * xdp_properties_strings [] in net/core/ethtool.c and maybe
+	 * some xdp_properties mask #defines below. Please also describe it
+	 * in Documentation/networking/xdp_properties.rst.
+	 */
+
+	/**/XDP_PROPERTIES_COUNT
+};
+
+#define __XDP_F_BIT(bit)	((xdp_properties_t)1 << (bit))
+#define __XDP_F(name)		__XDP_F_BIT(XDP_F_##name##_BIT)
+
+#define XDP_F_ABORTED		__XDP_F(ABORTED)
+#define XDP_F_DROP		__XDP_F(DROP)
+#define XDP_F_PASS		__XDP_F(PASS)
+#define XDP_F_TX		__XDP_F(TX)
+#define XDP_F_REDIRECT		__XDP_F(REDIRECT)
+#define XDP_F_ZEROCOPY		__XDP_F(ZEROCOPY)
+#define XDP_F_HW_OFFLOAD	__XDP_F(HW_OFFLOAD)
+
+#define XDP_F_BASIC		(XDP_F_ABORTED |	\
+				 XDP_F_DROP |		\
+				 XDP_F_PASS |		\
+				 XDP_F_TX)
+
+#define XDP_F_FULL		(XDP_F_BASIC | XDP_F_REDIRECT)
+
+#define XDP_F_FULL_ZC		(XDP_F_FULL | XDP_F_ZEROCOPY)
+
+#endif /* _LINUX_XDP_PROPERTIES_H */
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 700ad5db7f5d..a9fabc1282cf 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -7,6 +7,7 @@
 #define __LINUX_NET_XDP_H__
 
 #include <linux/skbuff.h> /* skb_shared_info */
+#include <linux/xdp_properties.h>
 
 /**
  * DOC: XDP RX-queue information
@@ -255,6 +256,100 @@ struct xdp_attachment_info {
 	u32 flags;
 };
 
+#if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
+
+static __always_inline void
+xdp_set_aborted_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_ABORTED;
+}
+
+static __always_inline void
+xdp_set_pass_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_PASS;
+}
+
+static __always_inline void
+xdp_set_drop_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_DROP;
+}
+
+static __always_inline void
+xdp_set_tx_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_TX;
+}
+
+static __always_inline void
+xdp_set_redirect_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_REDIRECT;
+}
+
+static __always_inline void
+xdp_set_hw_offload_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_HW_OFFLOAD;
+}
+
+static __always_inline void
+xdp_set_basic_properties(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_BASIC;
+}
+
+static __always_inline void
+xdp_set_full_properties(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_FULL;
+}
+
+#else
+
+static __always_inline void
+xdp_set_aborted_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_pass_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_drop_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_tx_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_redirect_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_hw_offload_property(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_basic_properties(xdp_properties_t *properties)
+{
+}
+
+static __always_inline void
+xdp_set_full_properties(xdp_properties_t *properties)
+{
+}
+
+#endif
+
 struct netdev_bpf;
 bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
 			     struct netdev_bpf *bpf);
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 4e295541e396..48a3b6d165c7 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h
@@ -8,6 +8,7 @@
 
 #include <net/xdp_sock.h>
 #include <net/xsk_buff_pool.h>
+#include <linux/xdp_properties.h>
 
 #ifdef CONFIG_XDP_SOCKETS
 
@@ -117,6 +118,11 @@ static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
 	xp_dma_sync_for_device(pool, dma, size);
 }
 
+static inline void xsk_set_zc_property(xdp_properties_t *properties)
+{
+	*properties |= XDP_F_ZEROCOPY;
+}
+
 #else
 
 static inline void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
@@ -242,6 +248,10 @@ static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
 {
 }
 
+static inline void xsk_set_zc_property(xdp_properties_t *properties)
+{
+}
+
 #endif /* CONFIG_XDP_SOCKETS */
 
 #endif /* _LINUX_XDP_SOCK_DRV_H */
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 9ca87bc73c44..dfcb0e2c98b2 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -688,6 +688,7 @@ enum ethtool_stringset {
 	ETH_SS_TS_TX_TYPES,
 	ETH_SS_TS_RX_FILTERS,
 	ETH_SS_UDP_TUNNEL_TYPES,
+	ETH_SS_XDP_PROPERTIES,
 
 	/* add new constants above here */
 	ETH_SS_COUNT
diff --git a/include/uapi/linux/xdp_properties.h b/include/uapi/linux/xdp_properties.h
new file mode 100644
index 000000000000..e85be03eb707
--- /dev/null
+++ b/include/uapi/linux/xdp_properties.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+/*
+ * Copyright (c) 2020 Intel
+ */
+
+#ifndef __UAPI_LINUX_XDP_PROPERTIES__
+#define __UAPI_LINUX_XDP_PROPERTIES__
+
+/* ETH_GSTRING_LEN define is needed. */
+#include <linux/ethtool.h>
+
+#define XDP_PROPERTIES_ABORTED_STR	"xdp-aborted"
+#define XDP_PROPERTIES_DROP_STR		"xdp-drop"
+#define XDP_PROPERTIES_PASS_STR		"xdp-pass"
+#define XDP_PROPERTIES_TX_STR		"xdp-tx"
+#define XDP_PROPERTIES_REDIRECT_STR	"xdp-redirect"
+#define XDP_PROPERTIES_ZEROCOPY_STR	"xdp-zerocopy"
+#define XDP_PROPERTIES_HW_OFFLOAD_STR	"xdp-hw-offload"
+
+#define	DECLARE_XDP_PROPERTIES_TABLE(name)		\
+	const char name[][ETH_GSTRING_LEN] = {		\
+		XDP_PROPERTIES_ABORTED_STR,		\
+		XDP_PROPERTIES_DROP_STR,		\
+		XDP_PROPERTIES_PASS_STR,		\
+		XDP_PROPERTIES_TX_STR,			\
+		XDP_PROPERTIES_REDIRECT_STR,		\
+		XDP_PROPERTIES_ZEROCOPY_STR,		\
+		XDP_PROPERTIES_HW_OFFLOAD_STR,		\
+	}
+
+#endif  /* __UAPI_LINUX_XDP_PROPERTIES__ */
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 24036e3055a1..8f15f96b8922 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -4,6 +4,7 @@
 #include <linux/net_tstamp.h>
 #include <linux/phy.h>
 #include <linux/rtnetlink.h>
+#include <uapi/linux/xdp_properties.h>
 
 #include "common.h"
 
@@ -283,6 +284,16 @@ const char udp_tunnel_type_names[][ETH_GSTRING_LEN] = {
 static_assert(ARRAY_SIZE(udp_tunnel_type_names) ==
 	      __ETHTOOL_UDP_TUNNEL_TYPE_CNT);
 
+const char xdp_properties_strings[XDP_PROPERTIES_COUNT][ETH_GSTRING_LEN] = {
+	[XDP_F_ABORTED_BIT] =		XDP_PROPERTIES_ABORTED_STR,
+	[XDP_F_DROP_BIT] =		XDP_PROPERTIES_DROP_STR,
+	[XDP_F_PASS_BIT] =		XDP_PROPERTIES_PASS_STR,
+	[XDP_F_TX_BIT] =		XDP_PROPERTIES_TX_STR,
+	[XDP_F_REDIRECT_BIT] =		XDP_PROPERTIES_REDIRECT_STR,
+	[XDP_F_ZEROCOPY_BIT] =		XDP_PROPERTIES_ZEROCOPY_STR,
+	[XDP_F_HW_OFFLOAD_BIT] =	XDP_PROPERTIES_HW_OFFLOAD_STR,
+};
+
 /* return false if legacy contained non-0 deprecated fields
  * maxtxpkt/maxrxpkt. rest of ksettings always updated
  */
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 3d9251c95a8b..85a35f8781eb 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -5,8 +5,10 @@
 
 #include <linux/netdevice.h>
 #include <linux/ethtool.h>
+#include <linux/xdp_properties.h>
 
 #define ETHTOOL_DEV_FEATURE_WORDS	DIV_ROUND_UP(NETDEV_FEATURE_COUNT, 32)
+#define ETHTOOL_XDP_PROPERTIES_WORDS	DIV_ROUND_UP(XDP_PROPERTIES_COUNT, 32)
 
 /* compose link mode index from speed, type and duplex */
 #define ETHTOOL_LINK_MODE(speed, type, duplex) \
@@ -22,6 +24,8 @@ extern const char
 tunable_strings[__ETHTOOL_TUNABLE_COUNT][ETH_GSTRING_LEN];
 extern const char
 phy_tunable_strings[__ETHTOOL_PHY_TUNABLE_COUNT][ETH_GSTRING_LEN];
+extern const char
+xdp_properties_strings[XDP_PROPERTIES_COUNT][ETH_GSTRING_LEN];
 extern const char link_mode_names[][ETH_GSTRING_LEN];
 extern const char netif_msg_class_names[][ETH_GSTRING_LEN];
 extern const char wol_mode_names[][ETH_GSTRING_LEN];
diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
index 0baad0ce1832..684e751b31a9 100644
--- a/net/ethtool/strset.c
+++ b/net/ethtool/strset.c
@@ -80,6 +80,11 @@ static const struct strset_info info_template[] = {
 		.count		= __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
 		.strings	= udp_tunnel_type_names,
 	},
+	[ETH_SS_XDP_PROPERTIES] = {
+		.per_dev	= false,
+		.count		= ARRAY_SIZE(xdp_properties_strings),
+		.strings	= xdp_properties_strings,
+	},
 };
 
 struct strset_req_info {
-- 
2.27.0