On Tue, Dec 20, 2022 at 2:25 PM Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
>
> > On Tue, Dec 20, 2022 at 2:11 AM Lorenzo Bianconi
> > <lorenzo.bianconi@xxxxxxxxxx> wrote:
> > >
> > > On Dec 19, Stanislav Fomichev wrote:
> > > > On Mon, Dec 19, 2022 at 3:51 PM Marek Majtyka <alardam@xxxxxxxxx> wrote:
> > > > >
> > > > > At the time of writing, I wanted to be able to read additional information about the XDP capabilities of each network interface using ethtool. This change was intended for Linux users/admins, and not for XDP experts who mostly don't need it and prefer tasting XDP with netlink and bpf rather than reading network interface features with ethtool.
> > > >
> > > > Anything preventing ethtool from doing probing similar to 'bpftool
> > > > feature probe'?
> > > > The problem with these feature bits is that they might diverge and/or
> > > > not work at all for the backported patches (where the fix/feature has
> > > > been backported, but the part that exports the bit hasn't) :-(
> > > > OTOH, I'm not sure we can probe everything from your list, but we
> > > > might try and see what's missing..
> > >
> > > Hi Stanislav,
> > >
> > > I have not added the ethtool support to this series yet since userspace part is
> > > still missing but I think we can consider XDP as a sort of sw offload so it
> > > would be nice for the user/sysadmin (not xdp or bpf developer) to check the NIC
> > > XDP capabilities similar to what we can already do for other hw offload
> > > features.
> >
> > [..]
> >
> > > Moreover let's consider XDP_REDIRECT of a scatter-gather XDP frame into a
> > > devmap. I do not think there is a way to test if the 'target' device supports
> > > SG and so we are forced to disable this feature until all drivers support it.
> >
> > See below for more questions, but why "target device has prog
> > installed and the aux->xdp_has_frags == true" won't work for the
> > internal kernel consumers?
>
> There are some drivers (e.g. all intel ones) that currently do not support
> non-linear xdp buff in the driver napi callback (XDP_FRAG_RX) but implement
> non-linear xdp buff support in ndo_xdp_xmit callback (XDP_FRAG_TARGET).
> Moreover, I guess for a sysadmin it would be better to check NIC capabilities in
> the same way he/she is used to with other features (e.g. ethool -k ...).
>
> >
> > > Introducing XDP features we can enable it on per-driver basis.
> > > I think the same apply for other capabilities as well and just assuming a given
> > > feature is not supported if an e2e test is not working seems a bit inaccurate.
> >
> > Ok, I see that these bits are used in the later patches in xsk and
> > devmap. But I guess I'm still confused about why we add all these
> > flags, but only use mostly XDP_F_REDIRECT_TARGET; maybe start with
> > that one? And why does it have to be exposed to the userspace?
> > (userspace can still probe per-device features by trying to load
> > different progs?)
>
> There are some drivers (e.g. ixgbevf or cavium thunder) that do not support
> XDP_REDIRECT but just XDP_PASS, XDP_DROP and XDP_TX, so I think we should
> differentiate between XDP_BASIC (XDP_PASS | XDP_DROP | XDP_TX) and XDP_FULL
> (XDP_BASIC | XDP_REDIRECT).
>
> >
> > Also, it seems like XDP_F_REDIRECT_TARGET really means "the bpf
> > program has been installed on this device". Instead of a flag, why not
> > explicitly check whether the target device has a prog installed (and,
> > if needed, whether the installed program has frags support)?
>
> XDP_F_REDIRECT_TARGET is used to inform if netdev implements ndo_xdp_xmit
> callback (most of the XDP drivers do not require to load a bpf program to
> XDP_REDIRECT into them).
All of the above makes sense, thanks for the details. In this case,
agreed that it's probably not possible to probe these easily without
explicit flags :-(
Let me bikeshed the names a bit as well, feel free to ignore...
1. Maybe group XDP_{ABORTED,DROP,PASS,TX,REDIRECT} with some common
prefix? XDP_ACT_xxx (ACT for action)? Or XDP_RET_xxx?
2. Maybe: XDP_SOCK_ZEROCOPY -> XSK_ZEROCOPY ?
3. XDP_HW_OFFLOAD we don't seem to set anywhere? nfp/netdevsim changes
are missing or out of scope?
4. Agree with Jakub, not sure XDP_TX_LOCK doesn't seem relevant?
5. XDP_REDIRECT_TARGET -> XDP_RCV_REDIRECT (can 'receive' and handle
redirects? in this case XDP_ACT_REDIRECT means can 'generate'
redirects)
6. For frags, maybe:
XDP_FRAG_RX -> XDP_SG_RX
XDP_FRAG_TARGET -> XDP_SG_RCV_REDIRECT (so this is that same as
XDP_RCV_REDIRECT but can handle frags)
But also probably fine to keep FRAG instead of SG to match BPF_F_XDP_HAS_FRAGS?
> Regards,
> Lorenzo
>
> >
> > > Regards,
> > > Lorenzo
> > >
> > > >
> > > > > On Mon, Dec 19, 2022 at 9:03 PM <sdf@xxxxxxxxxx> wrote:
> > > > >>
> > > > >> On 12/19, Lorenzo Bianconi wrote:
> > > > >> > From: Marek Majtyka <alardam@xxxxxxxxx>
> > > > >>
> > > > >> > Implement support for checking what kind of XDP features 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
> > > > >> > - sock_zerocopy
> > > > >> > - hw_offload
> > > > >> > - redirect_target
> > > > >> > - tx_lock
> > > > >> > - frag_rx
> > > > >> > - frag_target
> > > > >>
> > > > >> > 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. Frag target requires
> > > > >> > redirect_target one is supported by the driver.
> > > > >>
> > > > >> Can you share more about _why_ is it needed? If we can already obtain
> > > > >> most of these signals via probing, why export the flags?
> > > > >>
> > > > >> > Initially, these new flags are disabled for all drivers by default.
> > > > >>
> > > > >> > Co-developed-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> > > > >> > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> > > > >> > Co-developed-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> > > > >> > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> > > > >> > Signed-off-by: Marek Majtyka <alardam@xxxxxxxxx>
> > > > >> > ---
> > > > >> > .../networking/netdev-xdp-features.rst | 60 +++++++++++++++++
> > > > >> > include/linux/netdevice.h | 2 +
> > > > >> > include/linux/xdp_features.h | 64 +++++++++++++++++++
> > > > >> > include/uapi/linux/if_link.h | 7 ++
> > > > >> > include/uapi/linux/xdp_features.h | 34 ++++++++++
> > > > >> > net/core/rtnetlink.c | 34 ++++++++++
> > > > >> > tools/include/uapi/linux/if_link.h | 7 ++
> > > > >> > tools/include/uapi/linux/xdp_features.h | 34 ++++++++++
> > > > >> > 8 files changed, 242 insertions(+)
> > > > >> > create mode 100644 Documentation/networking/netdev-xdp-features.rst
> > > > >> > create mode 100644 include/linux/xdp_features.h
> > > > >> > create mode 100644 include/uapi/linux/xdp_features.h
> > > > >> > create mode 100644 tools/include/uapi/linux/xdp_features.h
> > > > >>
> > > > >> > diff --git a/Documentation/networking/netdev-xdp-features.rst
> > > > >> > b/Documentation/networking/netdev-xdp-features.rst
> > > > >> > new file mode 100644
> > > > >> > index 000000000000..1dc803fe72dd
> > > > >> > --- /dev/null
> > > > >> > +++ b/Documentation/networking/netdev-xdp-features.rst
> > > > >> > @@ -0,0 +1,60 @@
> > > > >> > +.. SPDX-License-Identifier: GPL-2.0
> > > > >> > +
> > > > >> > +=====================
> > > > >> > +Netdev XDP features
> > > > >> > +=====================
> > > > >> > +
> > > > >> > + * XDP FEATURES FLAGS
> > > > >> > +
> > > > >> > +Following netdev xdp features flags can be retrieved over route netlink
> > > > >> > +interface (compact form) - the same way as netdev feature flags.
> > > > >> > +These features flags are read only and cannot be change at runtime.
> > > > >> > +
> > > > >> > +* XDP_ABORTED
> > > > >> > +
> > > > >> > +This feature informs if netdev supports xdp aborted action.
> > > > >> > +
> > > > >> > +* XDP_DROP
> > > > >> > +
> > > > >> > +This feature informs if netdev supports xdp drop action.
> > > > >> > +
> > > > >> > +* XDP_PASS
> > > > >> > +
> > > > >> > +This feature informs if netdev supports xdp pass action.
> > > > >> > +
> > > > >> > +* XDP_TX
> > > > >> > +
> > > > >> > +This feature informs if netdev supports xdp tx action.
> > > > >> > +
> > > > >> > +* XDP_REDIRECT
> > > > >> > +
> > > > >> > +This feature informs if netdev supports xdp redirect action.
> > > > >> > +It assumes the all beforehand mentioned flags are enabled.
> > > > >> > +
> > > > >> > +* XDP_SOCK_ZEROCOPY
> > > > >> > +
> > > > >> > +This feature informs if netdev driver supports xdp zero copy.
> > > > >> > +It assumes the all beforehand mentioned flags are enabled.
> > > > >> > +
> > > > >> > +* XDP_HW_OFFLOAD
> > > > >> > +
> > > > >> > +This feature informs if netdev driver supports xdp hw oflloading.
> > > > >> > +
> > > > >> > +* XDP_TX_LOCK
> > > > >> > +
> > > > >> > +This feature informs if netdev ndo_xdp_xmit function requires locking.
> > > > >> > +
> > > > >> > +* XDP_REDIRECT_TARGET
> > > > >> > +
> > > > >> > +This feature informs if netdev implements ndo_xdp_xmit callback.
> > > > >> > +
> > > > >> > +* XDP_FRAG_RX
> > > > >> > +
> > > > >> > +This feature informs if netdev implements non-linear xdp buff support in
> > > > >> > +the driver napi callback.
> > > > >> > +
> > > > >> > +* XDP_FRAG_TARGET
> > > > >> > +
> > > > >> > +This feature informs if netdev implements non-linear xdp buff support in
> > > > >> > +ndo_xdp_xmit callback. XDP_FRAG_TARGET requires XDP_REDIRECT_TARGET is
> > > > >> > properly
> > > > >> > +supported.
> > > > >> > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> > > > >> > index aad12a179e54..ae5a8564383b 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_features.h>
> > > > >> > #include <linux/neighbour.h>
> > > > >> > #include <uapi/linux/netdevice.h>
> > > > >> > #include <uapi/linux/if_bonding.h>
> > > > >> > @@ -2362,6 +2363,7 @@ struct net_device {
> > > > >> > struct rtnl_hw_stats64 *offload_xstats_l3;
> > > > >>
> > > > >> > struct devlink_port *devlink_port;
> > > > >> > + xdp_features_t xdp_features;
> > > > >> > };
> > > > >> > #define to_net_dev(d) container_of(d, struct net_device, dev)
> > > > >>
> > > > >> > diff --git a/include/linux/xdp_features.h b/include/linux/xdp_features.h
> > > > >> > new file mode 100644
> > > > >> > index 000000000000..4e72a86ef329
> > > > >> > --- /dev/null
> > > > >> > +++ b/include/linux/xdp_features.h
> > > > >> > @@ -0,0 +1,64 @@
> > > > >> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > > > >> > +/*
> > > > >> > + * Network device xdp features.
> > > > >> > + */
> > > > >> > +#ifndef _LINUX_XDP_FEATURES_H
> > > > >> > +#define _LINUX_XDP_FEATURES_H
> > > > >> > +
> > > > >> > +#include <linux/types.h>
> > > > >> > +#include <linux/bitops.h>
> > > > >> > +#include <asm/byteorder.h>
> > > > >> > +#include <uapi/linux/xdp_features.h>
> > > > >> > +
> > > > >> > +typedef u32 xdp_features_t;
> > > > >> > +
> > > > >> > +#define __XDP_F_BIT(bit) ((xdp_features_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_REDIRECT_TARGET __XDP_F(REDIRECT_TARGET)
> > > > >> > +#define XDP_F_SOCK_ZEROCOPY __XDP_F(SOCK_ZEROCOPY)
> > > > >> > +#define XDP_F_HW_OFFLOAD __XDP_F(HW_OFFLOAD)
> > > > >> > +#define XDP_F_TX_LOCK __XDP_F(TX_LOCK)
> > > > >> > +#define XDP_F_FRAG_RX __XDP_F(FRAG_RX)
> > > > >> > +#define XDP_F_FRAG_TARGET __XDP_F(FRAG_TARGET)
> > > > >> > +
> > > > >> > +#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_SOCK_ZEROCOPY)
> > > > >> > +
> > > > >> > +#define XDP_FEATURES_ABORTED_STR "xdp-aborted"
> > > > >> > +#define XDP_FEATURES_DROP_STR "xdp-drop"
> > > > >> > +#define XDP_FEATURES_PASS_STR "xdp-pass"
> > > > >> > +#define XDP_FEATURES_TX_STR "xdp-tx"
> > > > >> > +#define XDP_FEATURES_REDIRECT_STR "xdp-redirect"
> > > > >> > +#define XDP_FEATURES_REDIRECT_TARGET_STR "xdp-redirect-target"
> > > > >> > +#define XDP_FEATURES_SOCK_ZEROCOPY_STR "xdp-sock-zerocopy"
> > > > >> > +#define XDP_FEATURES_HW_OFFLOAD_STR "xdp-hw-offload"
> > > > >> > +#define XDP_FEATURES_TX_LOCK_STR "xdp-tx-lock"
> > > > >> > +#define XDP_FEATURES_FRAG_RX_STR "xdp-frag-rx"
> > > > >> > +#define XDP_FEATURES_FRAG_TARGET_STR "xdp-frag-target"
> > > > >> > +
> > > > >> > +#define DECLARE_XDP_FEATURES_TABLE(name, length) \
> > > > >> > + const char name[][length] = { \
> > > > >> > + [XDP_F_ABORTED_BIT] = XDP_FEATURES_ABORTED_STR, \
> > > > >> > + [XDP_F_DROP_BIT] = XDP_FEATURES_DROP_STR, \
> > > > >> > + [XDP_F_PASS_BIT] = XDP_FEATURES_PASS_STR, \
> > > > >> > + [XDP_F_TX_BIT] = XDP_FEATURES_TX_STR, \
> > > > >> > + [XDP_F_REDIRECT_BIT] = XDP_FEATURES_REDIRECT_STR, \
> > > > >> > + [XDP_F_REDIRECT_TARGET_BIT] = XDP_FEATURES_REDIRECT_TARGET_STR, \
> > > > >> > + [XDP_F_SOCK_ZEROCOPY_BIT] = XDP_FEATURES_SOCK_ZEROCOPY_STR, \
> > > > >> > + [XDP_F_HW_OFFLOAD_BIT] = XDP_FEATURES_HW_OFFLOAD_STR, \
> > > > >> > + [XDP_F_TX_LOCK_BIT] = XDP_FEATURES_TX_LOCK_STR, \
> > > > >> > + [XDP_F_FRAG_RX_BIT] = XDP_FEATURES_FRAG_RX_STR, \
> > > > >> > + [XDP_F_FRAG_TARGET_BIT] = XDP_FEATURES_FRAG_TARGET_STR, \
> > > > >> > + }
> > > > >> > +
> > > > >> > +#endif /* _LINUX_XDP_FEATURES_H */
> > > > >> > diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
> > > > >> > index 1021a7e47a86..971c658ceaea 100644
> > > > >> > --- a/include/uapi/linux/if_link.h
> > > > >> > +++ b/include/uapi/linux/if_link.h
> > > > >> > @@ -374,6 +374,8 @@ enum {
> > > > >>
> > > > >> > IFLA_DEVLINK_PORT,
> > > > >>
> > > > >> > + IFLA_XDP_FEATURES,
> > > > >> > +
> > > > >> > __IFLA_MAX
> > > > >> > };
> > > > >>
> > > > >> > @@ -1318,6 +1320,11 @@ enum {
> > > > >>
> > > > >> > #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1)
> > > > >>
> > > > >> > +enum {
> > > > >> > + IFLA_XDP_FEATURES_WORD_UNSPEC = 0,
> > > > >> > + IFLA_XDP_FEATURES_BITS_WORD,
> > > > >> > +};
> > > > >> > +
> > > > >> > enum {
> > > > >> > IFLA_EVENT_NONE,
> > > > >> > IFLA_EVENT_REBOOT, /* internal reset / reboot */
> > > > >> > diff --git a/include/uapi/linux/xdp_features.h
> > > > >> > b/include/uapi/linux/xdp_features.h
> > > > >> > new file mode 100644
> > > > >> > index 000000000000..48eb42069bcd
> > > > >> > --- /dev/null
> > > > >> > +++ b/include/uapi/linux/xdp_features.h
> > > > >> > @@ -0,0 +1,34 @@
> > > > >> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > > > >> > +/*
> > > > >> > + * Copyright (c) 2020 Intel
> > > > >> > + */
> > > > >> > +
> > > > >> > +#ifndef __UAPI_LINUX_XDP_FEATURES__
> > > > >> > +#define __UAPI_LINUX_XDP_FEATURES__
> > > > >> > +
> > > > >> > +enum {
> > > > >> > + XDP_F_ABORTED_BIT,
> > > > >> > + XDP_F_DROP_BIT,
> > > > >> > + XDP_F_PASS_BIT,
> > > > >> > + XDP_F_TX_BIT,
> > > > >> > + XDP_F_REDIRECT_BIT,
> > > > >> > + XDP_F_REDIRECT_TARGET_BIT,
> > > > >> > + XDP_F_SOCK_ZEROCOPY_BIT,
> > > > >> > + XDP_F_HW_OFFLOAD_BIT,
> > > > >> > + XDP_F_TX_LOCK_BIT,
> > > > >> > + XDP_F_FRAG_RX_BIT,
> > > > >> > + XDP_F_FRAG_TARGET_BIT,
> > > > >> > + /*
> > > > >> > + * Add your fresh new property above and remember to update
> > > > >> > + * documentation.
> > > > >> > + */
> > > > >> > + XDP_FEATURES_COUNT,
> > > > >> > +};
> > > > >> > +
> > > > >> > +#define XDP_FEATURES_WORDS ((XDP_FEATURES_COUNT + 32 - 1) / 32)
> > > > >> > +#define XDP_FEATURES_WORD(blocks, index) ((blocks)[(index) / 32U])
> > > > >> > +#define XDP_FEATURES_FIELD_FLAG(index) (1U << (index) % 32U)
> > > > >> > +#define XDP_FEATURES_BIT_IS_SET(blocks, index) \
> > > > >> > + (XDP_FEATURES_WORD(blocks, index) & XDP_FEATURES_FIELD_FLAG(index))
> > > > >> > +
> > > > >> > +#endif /* __UAPI_LINUX_XDP_FEATURES__ */
> > > > >> > diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> > > > >> > index 64289bc98887..1c299746b614 100644
> > > > >> > --- a/net/core/rtnetlink.c
> > > > >> > +++ b/net/core/rtnetlink.c
> > > > >> > @@ -1016,6 +1016,14 @@ static size_t rtnl_xdp_size(void)
> > > > >> > return xdp_size;
> > > > >> > }
> > > > >>
> > > > >> > +static size_t rtnl_xdp_features_size(void)
> > > > >> > +{
> > > > >> > + size_t xdp_size = nla_total_size(0) + /* nest IFLA_XDP_FEATURES */
> > > > >> > + XDP_FEATURES_WORDS * nla_total_size(4);
> > > > >> > +
> > > > >> > + return xdp_size;
> > > > >> > +}
> > > > >> > +
> > > > >> > static size_t rtnl_prop_list_size(const struct net_device *dev)
> > > > >> > {
> > > > >> > struct netdev_name_node *name_node;
> > > > >> > @@ -1103,6 +1111,7 @@ static noinline size_t if_nlmsg_size(const struct
> > > > >> > net_device *dev,
> > > > >> > + rtnl_prop_list_size(dev)
> > > > >> > + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */
> > > > >> > + rtnl_devlink_port_size(dev)
> > > > >> > + + rtnl_xdp_features_size() /* IFLA_XDP_FEATURES */
> > > > >> > + 0;
> > > > >> > }
> > > > >>
> > > > >> > @@ -1546,6 +1555,27 @@ static int rtnl_xdp_fill(struct sk_buff *skb,
> > > > >> > struct net_device *dev)
> > > > >> > return err;
> > > > >> > }
> > > > >>
> > > > >> > +static int rtnl_xdp_features_fill(struct sk_buff *skb, struct net_device
> > > > >> > *dev)
> > > > >> > +{
> > > > >> > + struct nlattr *attr;
> > > > >> > +
> > > > >> > + attr = nla_nest_start_noflag(skb, IFLA_XDP_FEATURES);
> > > > >> > + if (!attr)
> > > > >> > + return -EMSGSIZE;
> > > > >> > +
> > > > >> > + BUILD_BUG_ON(XDP_FEATURES_WORDS != 1);
> > > > >> > + if (nla_put_u32(skb, IFLA_XDP_FEATURES_BITS_WORD, dev->xdp_features))
> > > > >> > + goto err_cancel;
> > > > >> > +
> > > > >> > + nla_nest_end(skb, attr);
> > > > >> > +
> > > > >> > + return 0;
> > > > >> > +
> > > > >> > +err_cancel:
> > > > >> > + nla_nest_cancel(skb, attr);
> > > > >> > + return -EMSGSIZE;
> > > > >> > +}
> > > > >> > +
> > > > >> > static u32 rtnl_get_event(unsigned long event)
> > > > >> > {
> > > > >> > u32 rtnl_event_type = IFLA_EVENT_NONE;
> > > > >> > @@ -1904,6 +1934,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
> > > > >> > if (rtnl_fill_devlink_port(skb, dev))
> > > > >> > goto nla_put_failure;
> > > > >>
> > > > >> > + if (rtnl_xdp_features_fill(skb, dev))
> > > > >> > + goto nla_put_failure;
> > > > >> > +
> > > > >> > nlmsg_end(skb, nlh);
> > > > >> > return 0;
> > > > >>
> > > > >> > @@ -1968,6 +2001,7 @@ static const struct nla_policy
> > > > >> > ifla_policy[IFLA_MAX+1] = {
> > > > >> > [IFLA_TSO_MAX_SIZE] = { .type = NLA_REJECT },
> > > > >> > [IFLA_TSO_MAX_SEGS] = { .type = NLA_REJECT },
> > > > >> > [IFLA_ALLMULTI] = { .type = NLA_REJECT },
> > > > >> > + [IFLA_XDP_FEATURES] = { .type = NLA_NESTED },
> > > > >> > };
> > > > >>
> > > > >> > static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
> > > > >> > diff --git a/tools/include/uapi/linux/if_link.h
> > > > >> > b/tools/include/uapi/linux/if_link.h
> > > > >> > index 82fe18f26db5..994228e9909a 100644
> > > > >> > --- a/tools/include/uapi/linux/if_link.h
> > > > >> > +++ b/tools/include/uapi/linux/if_link.h
> > > > >> > @@ -354,6 +354,8 @@ enum {
> > > > >>
> > > > >> > IFLA_DEVLINK_PORT,
> > > > >>
> > > > >> > + IFLA_XDP_FEATURES,
> > > > >> > +
> > > > >> > __IFLA_MAX
> > > > >> > };
> > > > >>
> > > > >> > @@ -1222,6 +1224,11 @@ enum {
> > > > >>
> > > > >> > #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1)
> > > > >>
> > > > >> > +enum {
> > > > >> > + IFLA_XDP_FEATURES_WORD_UNSPEC = 0,
> > > > >> > + IFLA_XDP_FEATURES_BITS_WORD,
> > > > >> > +};
> > > > >> > +
> > > > >> > enum {
> > > > >> > IFLA_EVENT_NONE,
> > > > >> > IFLA_EVENT_REBOOT, /* internal reset / reboot */
> > > > >> > diff --git a/tools/include/uapi/linux/xdp_features.h
> > > > >> > b/tools/include/uapi/linux/xdp_features.h
> > > > >> > new file mode 100644
> > > > >> > index 000000000000..48eb42069bcd
> > > > >> > --- /dev/null
> > > > >> > +++ b/tools/include/uapi/linux/xdp_features.h
> > > > >> > @@ -0,0 +1,34 @@
> > > > >> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > > > >> > +/*
> > > > >> > + * Copyright (c) 2020 Intel
> > > > >> > + */
> > > > >> > +
> > > > >> > +#ifndef __UAPI_LINUX_XDP_FEATURES__
> > > > >> > +#define __UAPI_LINUX_XDP_FEATURES__
> > > > >> > +
> > > > >> > +enum {
> > > > >> > + XDP_F_ABORTED_BIT,
> > > > >> > + XDP_F_DROP_BIT,
> > > > >> > + XDP_F_PASS_BIT,
> > > > >> > + XDP_F_TX_BIT,
> > > > >> > + XDP_F_REDIRECT_BIT,
> > > > >> > + XDP_F_REDIRECT_TARGET_BIT,
> > > > >> > + XDP_F_SOCK_ZEROCOPY_BIT,
> > > > >> > + XDP_F_HW_OFFLOAD_BIT,
> > > > >> > + XDP_F_TX_LOCK_BIT,
> > > > >> > + XDP_F_FRAG_RX_BIT,
> > > > >> > + XDP_F_FRAG_TARGET_BIT,
> > > > >> > + /*
> > > > >> > + * Add your fresh new property above and remember to update
> > > > >> > + * documentation.
> > > > >> > + */
> > > > >> > + XDP_FEATURES_COUNT,
> > > > >> > +};
> > > > >> > +
> > > > >> > +#define XDP_FEATURES_WORDS ((XDP_FEATURES_COUNT + 32 - 1) / 32)
> > > > >> > +#define XDP_FEATURES_WORD(blocks, index) ((blocks)[(index) / 32U])
> > > > >> > +#define XDP_FEATURES_FIELD_FLAG(index) (1U << (index) % 32U)
> > > > >> > +#define XDP_FEATURES_BIT_IS_SET(blocks, index) \
> > > > >> > + (XDP_FEATURES_WORD(blocks, index) & XDP_FEATURES_FIELD_FLAG(index))
> > > > >> > +
> > > > >> > +#endif /* __UAPI_LINUX_XDP_FEATURES__ */
> > > > >> > --
> > > > >> > 2.38.1
> > > > >>
> > > >
