Hi,
This patchset spins over the existing kernel representation for network
driver offloads based on the existing cls_flower dissector use for the
rule matching side and the TC action infrastructure to represent the
action side.
The proposed object that represent rules looks like this:
struct flow_rule {
struct flow_match match;
struct flow_action action;
};
The flow_match structure wraps Jiri Pirko's existing representation
available in cls_flower based on dissectors to represent the matching
side:
struct flow_match {
struct flow_dissector *dissector;
void *mask;
void *key;
};
The mask and key layouts are opaque, given the dissector object provides
the used_keys flags - to check for rule selectors that are being used -
and the offset to the corresponding key and mask in the opaque
container structures.
Then, the actions to be performs on the matching packets is represented
through the flow_action object:
struct flow_action {
int num_keys;
struct flow_action_key *keys;
};
This object comes with a num_keys field that specifies the number of
actions - this supports an arbitrary number of actions, the driver
will impose its own restrictions on this - and the array that stores
flow_action_key structures (keys). Each flow action key looks like this:
struct flow_action_key {
enum flow_action_key_id id;
union {
u32 chain_index; /*
FLOW_ACTION_KEY_GOTO */
struct net_device *dev; /*
FLOW_ACTION_KEY_REDIRECT */
struct { /*
FLOW_ACTION_KEY_VLAN */
u16 vid;
__be16 proto;
u8 prio;
} vlan;
struct { /*
FLOW_ACTION_KEY_PACKET_EDIT */
enum flow_act_mangle_base htype;
u32 offset;
u32 mask;
u32 val;
} mangle;
const struct ip_tunnel_info *tunnel; /*
FLOW_ACTION_KEY_TUNNEL_ENCAP */
u32 csum_flags; /*
FLOW_ACTION_KEY_CSUM */
u32 mark; /*
FLOW_ACTION_KEY_MARK */
u32 queue_index; /*
FLOW_ACTION_KEY_QUEUE */
};
};
Possible actions in this patchset are:
enum flow_action_key_id {
FLOW_ACTION_KEY_ACCEPT = 0,
FLOW_ACTION_KEY_DROP,
FLOW_ACTION_KEY_TRAP,
FLOW_ACTION_KEY_GOTO,
FLOW_ACTION_KEY_REDIRECT,
FLOW_ACTION_KEY_MIRRED,
FLOW_ACTION_KEY_VLAN_PUSH,
FLOW_ACTION_KEY_VLAN_POP,
FLOW_ACTION_KEY_VLAN_MANGLE,
FLOW_ACTION_KEY_TUNNEL_ENCAP,
FLOW_ACTION_KEY_TUNNEL_DECAP,
FLOW_ACTION_KEY_MANGLE,
FLOW_ACTION_KEY_ADD,
FLOW_ACTION_KEY_CSUM,
FLOW_ACTION_KEY_MARK,
FLOW_ACTION_KEY_WAKE,
FLOW_ACTION_KEY_QUEUE,
};
which are based on what existing drivers can do from the existing TC
actions.
Common code pattern from the drivers to populate the hardware
intermediate representation looks like this:
if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
struct flow_match_ipv4_addrs match;
flow_rule_match_ipv4_addrs(rule, &match);
flow->l3_key.ipv4.daddr.s_addr = match.key->dst;
flow->l3_mask.ipv4.daddr.s_addr = match.mask->dst;
flow->l3_key.ipv4.saddr.s_addr = match.key->src;
flow->l3_mask.ipv4.saddr.s_addr = match.mask->src;
}
Then, flow action code parser should look like:
flow_action_for_each(i, act, flow_action) {
switch (act->id) {
case FLOW_ACTION_KEY_DROP:
actions->flags |= DRIVER_XYZ_ACTION_FLAG_DROP;
break;
case ...:
break;
default:
return -EOPNOTSUPP;
}
}
A quick description of the patches:
Patch #1 introduces the flow_match structure and two new interfaces to
check for rule selectors that are used and to fetch the key
and the mask with one single function call. This patch also
introduces the flow_rule structure to avoid a follow up patch
that would very much update the same LoCs.
Patch #2 Preparation patch for mlx5e driver, for the packet edit parser.
Patch #3 Introduce flow_action infrastructure, as described above.
Patch #4 Add function to translate TC action to flow_action from
cls_flower.
Patch #5 Add infrastructure to fetch statistics into container structure
and synchronize them to TC actions from cls_flower. Another
preparation patch before patch #7.
Patch #6 Use flow_action infrastructure from drivers.
Patch #7 Do not expose TC actions to drivers anymore, now that drivers
have been converted to use the flow_action infrastructure after
patch #5.
Patch #8 Support to wake-up-on-lan and queue actions for the flow_action
infrastructure, which are another two common actions supported
by network interfaces, from the ethtool_rx_flow interface.
Patch #9 Add a function to translate from ethtool_rx_flow_spec structure
to the flow_action structure. This is a simple one, basic
enough for the first client, the bcm_sf2 driver. It can
be easily extended to support more selectors in case driver
needs it.
Patch #10 Update bcm_sf2 to use this new translator function and
update codebase to configure hardware IR using the
flow_action representation. This will allow later development
of cls_flower using the same backend code from the driver.
This patchset is adding a new layer between drivers and the existing
software frontends, so it's a bit more code, but it is core
infrastructure common to everyone and this comes with benefits for
driver developers:
1) No need to make ad-hoc driver code for each supported front-end,
one single codebase to populate the native hardware intermediate
representation for each existing specific purpose packet classifiers
such as TC, OVS, ethtool-rx-flow and net...
2) Independent API for drivers offloads, the use of the existing TC
action infrastructure makes it slightly hard to visibilize what drivers
are currently supporting in terms of features. Moreover, no more
exposure of TC software representation to drivers, so future
software changes to TC won't need to be propagated to drivers, which
might accidentally break existing hardware offload codebase in case
the software frontend gets extended with some new features.
There is still room for more future work, such as introduce more common
infrastructure: Most drivers use a hashtable to represent the hardware
table indexed by the cookie, it should be possible to share this.
I made basic testing for this initial RFC, so more extensive to ensure
things don't break might be needed still. That would happen in a later
stage if feedback is positive.
Comments welcome as usual, thanks.
Pablo Neira Ayuso (10):
flow_dissector: add flow_rule and flow_match structures and use them
net/mlx5e: allow two independent packet edit actions
flow_dissector: add flow action infrastructure
cls_flower: add translator to flow_action representation
cls_flower: add statistics retrieval infrastructure and use it
drivers: net: use flow action infrastructure
cls_flower: don't expose TC actions to drivers anymore
flow_dissector: add wake-up-on-lan and queue to flow_action
flow_dissector: add basic ethtool_rx_flow_spec to flow_rule structure
translator
dsa: bcm_sf2: use flow_rule infrastructure
drivers/net/dsa/bcm_sf2_cfp.c | 311 ++++-----
drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c | 256 +++-----
.../net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c | 451 ++++++-------
drivers/net/ethernet/intel/i40e/i40e_main.c | 178 ++---
drivers/net/ethernet/intel/i40evf/i40evf_main.c | 194 +++---
drivers/net/ethernet/intel/igb/igb_main.c | 64 +-
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 725 ++++++++++-----------
drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c | 2 +-
.../net/ethernet/mellanox/mlxsw/spectrum_flower.c | 260 ++++----
drivers/net/ethernet/netronome/nfp/flower/action.c | 194 +++---
drivers/net/ethernet/netronome/nfp/flower/match.c | 416 ++++++------
.../net/ethernet/netronome/nfp/flower/offload.c | 150 ++---
drivers/net/ethernet/qlogic/qede/qede_filter.c | 93 ++-
include/net/flow_dissector.h | 185 ++++++
include/net/pkt_cls.h | 20 +-
net/core/flow_dissector.c | 341 ++++++++++
net/sched/cls_flower.c | 151 ++++-
17 files changed, 2199 insertions(+), 1792 deletions(-)
--
2.11.0
