From 5f3043d61f8335fabab95c5321e1ba55b2dfdfff Mon Sep 17 00:00:00 2001
From: Rajath Shashidhara <rajaths@cs.utexas.edu>
Date: Tue, 22 Jun 2021 18:31:49 +0000
Subject: [PATCH] init flow steering even when autoscaling disabled

Signed-off-by: Rajath Shashidhara <rajaths@cs.utexas.edu>
---
 tas/fast/fast_kernel.c |  2 +-
 tas/fast/network.c     | 33 +++++++++++++++++++--------------
 tas/fast/network.h     |  6 +++---
 tas/tas.c              |  2 +-
 4 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/tas/fast/fast_kernel.c b/tas/fast/fast_kernel.c
index d92f1270..af1afffd 100644
--- a/tas/fast/fast_kernel.c
+++ b/tas/fast/fast_kernel.c
@@ -123,7 +123,7 @@ void fast_kernel_packet(struct dataplane_context *ctx,
   len = network_buf_len(nbh);
   dma_write(krx->addr, len, network_buf_bufoff(nbh));
 
-  if (network_buf_flowgroup(nbh, &krx->msg.packet.flow_group)) {
+  if (network_buf_flowgroup(nbh, &krx->msg.packet.flow_group, ctx->id)) {
     fprintf(stderr, "fast_kernel_packet: network_buf_flowgroup failed\n");
     abort();
   }
diff --git a/tas/fast/network.c b/tas/fast/network.c
index 1f8c5f57..7037d571 100644
--- a/tas/fast/network.c
+++ b/tas/fast/network.c
@@ -160,7 +160,6 @@ int network_init(unsigned n_threads)
     goto error_exit;
   }
 
-
   /* workaround for mlx5. */
   if (config.fp_autoscale) {
     if (reta_mlx5_resize() != 0) {
@@ -270,11 +269,9 @@ int network_thread_init(struct dataplane_context *ctx)
     }
 
     /* setting up RETA failed */
-    if (config.fp_autoscale) {
-      if (reta_setup() != 0) {
-        fprintf(stderr, "RETA setup failed\n");
-        goto error_tx_queue;
-      }
+    if (reta_setup() != 0) {
+      fprintf(stderr, "RETA setup failed\n");
+      goto error_tx_queue;
     }
     start_done = 1;
   }
@@ -438,6 +435,20 @@ static int reta_setup()
 
   /* allocate RSS redirection table and core-bucket count table */
   rss_reta_size = eth_devinfo.reta_size;
+  if (rss_reta_size == 0) {
+    fprintf(stderr, "Warning: NIC does not expose reta size\n");
+    rss_reta_size = rte_align32pow2(fp_cores_cur); /* map groups to fp cores in this case */
+  }
+  if (rss_reta_size > FLEXNIC_PL_MAX_FLOWGROUPS) {
+    fprintf(stderr, "reta_setup: reta size (%u) greater than maximum supported"
+        " (%u)\n", rss_reta_size, FLEXNIC_PL_MAX_FLOWGROUPS);
+    abort();
+  }
+  if (!rte_is_power_of_2(rss_reta_size)) {
+    fprintf(stderr, "reta_setup: reta size (%u) is not a power of 2\n", rss_reta_size);
+    abort();
+  }
+
   rss_reta = rte_calloc("rss reta", ((rss_reta_size + RTE_RETA_GROUP_SIZE - 1) /
         RTE_RETA_GROUP_SIZE), sizeof(*rss_reta), 0);
   rss_core_buckets = rte_calloc("rss core buckets", fp_cores_max,
@@ -448,12 +459,6 @@ static int reta_setup()
     goto error_exit;
   }
 
-  if (rss_reta_size > FLEXNIC_PL_MAX_FLOWGROUPS) {
-    fprintf(stderr, "reta_setup: reta size (%u) greater than maximum supported"
-        " (%u)\n", rss_reta_size, FLEXNIC_PL_MAX_FLOWGROUPS);
-    abort();
-  }
-
   /* initialize reta */
   for (i = 0, c = 0; i < rss_reta_size; i++) {
     rss_core_buckets[c]++;
@@ -463,9 +468,9 @@ static int reta_setup()
     c = (c + 1) % fp_cores_cur;
   }
 
-  if (rte_eth_dev_rss_reta_update(net_port_id, rss_reta, rss_reta_size) != 0) {
+  if (rte_eth_dev_rss_reta_update(net_port_id, rss_reta, rss_reta_size) != 0 && config.fp_autoscale) {
     fprintf(stderr, "reta_setup: rte_eth_dev_rss_reta_update failed\n");
-    return -1;
+    goto error_exit;
   }
 
   return 0;
diff --git a/tas/fast/network.h b/tas/fast/network.h
index fe18e767..297a5d10 100644
--- a/tas/fast/network.h
+++ b/tas/fast/network.h
@@ -187,15 +187,15 @@ static inline uint16_t network_buf_tcpxsums(struct network_buf_handle *bh, uint8
 }
 
 static inline int network_buf_flowgroup(struct network_buf_handle *bh,
-    uint16_t *fg)
+    uint16_t *fg, uint16_t core)
 {
   struct rte_mbuf *mb = (struct rte_mbuf *) bh;
   if (!(mb->ol_flags & PKT_RX_RSS_HASH)) {
-    *fg = 0;
+    *fg = core;
     return 0;
   }
 
-  *fg = mb->hash.rss & (rss_reta_size - 1);
+  *fg = mb->hash.rss & (rss_reta_size - 1); // NOTE: assume rte_is_power_of_2(rss_reta_size)
   return 0;
 }
 
diff --git a/tas/tas.c b/tas/tas.c
index c0647096..34461179 100644
--- a/tas/tas.c
+++ b/tas/tas.c
@@ -80,7 +80,7 @@ int main(int argc, char *argv[])
     res = EXIT_FAILURE;
     goto error_exit;
   }
-  fp_cores_max = config.fp_cores_max;
+  fp_cores_max = fp_cores_cur = config.fp_cores_max;
 
   /* allocate shared memory before dpdk grabs all huge pages */
   if (shm_preinit() != 0) {