[dpdk-dev] [PATCH v2 04/13] net/enic: allow flow mark ID 0

[Hyong Youb Kim <hyonkim@cisco.com>]

The driver currently accepts mark ID 0 but does not report it in
matching packet's mbuf. For example, the following testpmd command
succeeds. But, the mbuf of a matching IPv4 UDP packet does not have
PKT_RX_FDIR_ID set.

flow create 0 ingress pattern ... actions mark id 0 / queue index 0 / end

The problem has to do with mapping mark IDs (32-bit) to NIC filter
IDs. Filter ID is currently 16-bit, so values greater than 0xffff are
rejected. The firmware reserves filter ID 0 for filters that do not
mark (e.g. steer w/o mark). And, the driver reserves 0xffff for the
flag action. This leaves 1...0xfffe for app use.

It is possible to simply reject mark ID 0 as unsupported. But, 0 is
commonly used (e.g. OVS-DPDK and VPP). So, when adding a filter, set
filter ID = mark ID + 1 to support mark ID 0. The receive handler
subtracts 1 from filter ID to get back the original mark ID.

Fixes: dfbd6a9cb504 ("net/enic: extend flow director support for 1300 series")
Cc: stable@dpdk.org

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@cisco.com>
---
 doc/guides/nics/enic.rst            |  1 +
 drivers/net/enic/enic_flow.c        | 15 +++++++++++----
 drivers/net/enic/enic_rxtx_common.h |  3 ++-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/doc/guides/nics/enic.rst b/doc/guides/nics/enic.rst
index bc38f51aa..e456e6c2d 100644
--- a/doc/guides/nics/enic.rst
+++ b/doc/guides/nics/enic.rst
@@ -450,6 +450,7 @@ PKT_RX_VLAN_STRIPPED mbuf flags would not be set. This mode is enabled with the
     1000 for 1300 series VICs). Filters are checked for matching in the order they
     were added. Since there currently is no grouping or priority support,
     'catch-all' filters should be added last.
+  - The supported range of IDs for the 'MARK' action is 0 - 0xFFFD.
 
 - **Statistics**
 
diff --git a/drivers/net/enic/enic_flow.c b/drivers/net/enic/enic_flow.c
index 55d8d50a1..e12a6ec73 100644
--- a/drivers/net/enic/enic_flow.c
+++ b/drivers/net/enic/enic_flow.c
@@ -1081,12 +1081,18 @@ enic_copy_action_v2(const struct rte_flow_action actions[],
 			if (overlap & MARK)
 				return ENOTSUP;
 			overlap |= MARK;
-			/* ENIC_MAGIC_FILTER_ID is reserved and is the highest
-			 * in the range of allows mark ids.
+			/*
+			 * Map mark ID (32-bit) to filter ID (16-bit):
+			 * - Reject values > 16 bits
+			 * - Filter ID 0 is reserved for filters that steer
+			 *   but not mark. So add 1 to the mark ID to avoid
+			 *   using 0.
+			 * - Filter ID (ENIC_MAGIC_FILTER_ID = 0xffff) is
+			 *   reserved for the "flag" action below.
 			 */
-			if (mark->id >= ENIC_MAGIC_FILTER_ID)
+			if (mark->id >= ENIC_MAGIC_FILTER_ID - 1)
 				return EINVAL;
-			enic_action->filter_id = mark->id;
+			enic_action->filter_id = mark->id + 1;
 			enic_action->flags |= FILTER_ACTION_FILTER_ID_FLAG;
 			break;
 		}
@@ -1094,6 +1100,7 @@ enic_copy_action_v2(const struct rte_flow_action actions[],
 			if (overlap & MARK)
 				return ENOTSUP;
 			overlap |= MARK;
+			/* ENIC_MAGIC_FILTER_ID is reserved for flagging */
 			enic_action->filter_id = ENIC_MAGIC_FILTER_ID;
 			enic_action->flags |= FILTER_ACTION_FILTER_ID_FLAG;
 			break;
diff --git a/drivers/net/enic/enic_rxtx_common.h b/drivers/net/enic/enic_rxtx_common.h
index bfbb4909e..66f631dfe 100644
--- a/drivers/net/enic/enic_rxtx_common.h
+++ b/drivers/net/enic/enic_rxtx_common.h
@@ -226,7 +226,8 @@ enic_cq_rx_to_pkt_flags(struct cq_desc *cqd, struct rte_mbuf *mbuf)
 		if (filter_id) {
 			pkt_flags |= PKT_RX_FDIR;
 			if (filter_id != ENIC_MAGIC_FILTER_ID) {
-				mbuf->hash.fdir.hi = clsf_cqd->filter_id;
+				/* filter_id = mark id + 1, so subtract 1 */
+				mbuf->hash.fdir.hi = filter_id - 1;
 				pkt_flags |= PKT_RX_FDIR_ID;
 			}
 		}
-- 
2.16.2