[ovs-dev] [PATCH V7 06/13] dpif-netdev: Add HW miss packet state recover logic.

Eli Britstein elibr at nvidia.com
Wed Jun 23 15:52:45 UTC 2021


Recover the packet if it was partially processed by the HW. Fallback to
lookup flow by mark association.

Signed-off-by: Eli Britstein <elibr at nvidia.com>
Reviewed-by: Gaetan Rivet <gaetanr at nvidia.com>
Acked-by: Sriharsha Basavapatna <sriharsha.basavapatna at broadcom.com>
Tested-by: Emma Finn <emma.finn at intel.com>
Tested-by: Marko Kovacevic <marko.kovacevic at intel.com>
Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
---
 lib/dpif-netdev.c | 45 +++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 8fa7eb6d4..d5b7d5b73 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -114,6 +114,7 @@ COVERAGE_DEFINE(datapath_drop_invalid_port);
 COVERAGE_DEFINE(datapath_drop_invalid_bond);
 COVERAGE_DEFINE(datapath_drop_invalid_tnl_port);
 COVERAGE_DEFINE(datapath_drop_rx_invalid_packet);
+COVERAGE_DEFINE(datapath_drop_hw_miss_recover);
 
 /* Protects against changes to 'dp_netdevs'. */
 static struct ovs_mutex dp_netdev_mutex = OVS_MUTEX_INITIALIZER;
@@ -7062,6 +7063,39 @@ smc_lookup_batch(struct dp_netdev_pmd_thread *pmd,
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_SMC_HIT, n_smc_hit);
 }
 
+static struct tx_port * pmd_send_port_cache_lookup(
+    const struct dp_netdev_pmd_thread *pmd, odp_port_t port_no);
+
+static inline int
+dp_netdev_hw_flow(const struct dp_netdev_pmd_thread *pmd,
+                  odp_port_t port_no,
+                  struct dp_packet *packet,
+                  struct dp_netdev_flow **flow)
+{
+    struct tx_port *p;
+    uint32_t mark;
+
+    /* Restore the packet if HW processing was terminated before completion. */
+    p = pmd_send_port_cache_lookup(pmd, port_no);
+    if (OVS_LIKELY(p)) {
+        int err = netdev_hw_miss_packet_recover(p->port->netdev, packet);
+
+        if (err && err != EOPNOTSUPP) {
+            COVERAGE_INC(datapath_drop_hw_miss_recover);
+            return -1;
+        }
+    }
+
+    /* If no mark, no flow to find. */
+    if (!dp_packet_has_flow_mark(packet, &mark)) {
+        *flow = NULL;
+        return 0;
+    }
+
+    *flow = mark_to_flow_find(pmd, mark);
+    return 0;
+}
+
 /* Try to process all ('cnt') the 'packets' using only the datapath flow cache
  * 'pmd->flow_cache'. If a flow is not found for a packet 'packets[i]', the
  * miniflow is copied into 'keys' and the packet pointer is moved at the
@@ -7106,7 +7140,6 @@ dfc_processing(struct dp_netdev_pmd_thread *pmd,
 
     DP_PACKET_BATCH_REFILL_FOR_EACH (i, cnt, packet, packets_) {
         struct dp_netdev_flow *flow;
-        uint32_t mark;
 
         if (OVS_UNLIKELY(dp_packet_size(packet) < ETH_HEADER_LEN)) {
             dp_packet_delete(packet);
@@ -7125,9 +7158,13 @@ dfc_processing(struct dp_netdev_pmd_thread *pmd,
             pkt_metadata_init(&packet->md, port_no);
         }
 
-        if ((*recirc_depth_get() == 0) &&
-            dp_packet_has_flow_mark(packet, &mark)) {
-            flow = mark_to_flow_find(pmd, mark);
+        if (netdev_is_flow_api_enabled() && *recirc_depth_get() == 0) {
+            if (OVS_UNLIKELY(dp_netdev_hw_flow(pmd, port_no, packet, &flow))) {
+                /* Packet restoration failed and it was dropped, do not
+                 * continue processing.
+                 */
+                continue;
+            }
             if (OVS_LIKELY(flow)) {
                 tcp_flags = parse_tcp_flags(packet);
                 if (OVS_LIKELY(batch_enable)) {
-- 
2.28.0.2311.g225365fb51



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