UCT/IB: Propagate traffic class in address for symmetric QoS

src/uct/ib/base/ib_device.h

@@ -129,7 +129,10 @@ enum {
     /* Used for IB link layer. */
     UCT_IB_ADDRESS_FLAG_SUBNET64       = UCS_BIT(5),
     /* Used for IB link layer. */
-    UCT_IB_ADDRESS_FLAG_IF_ID          = UCS_BIT(6)
+    UCT_IB_ADDRESS_FLAG_IF_ID          = UCS_BIT(6),
+
+    /* Traffic class value, used for both ETH or IB link layer. */
+    UCT_IB_ADDRESS_FLAG_TRAFFIC_CLASS  = UCS_BIT(7)
 };
 
 

src/uct/ib/base/ib_iface.c

@@ -353,7 +353,11 @@ static inline uct_ib_roce_version_t
 uct_ib_address_flags_get_roce_version(uint8_t flags)
 {
     ucs_assert(flags & UCT_IB_ADDRESS_FLAG_LINK_LAYER_ETH);
-    return (uct_ib_roce_version_t)(flags >> ucs_ilog2(UCT_IB_ADDRESS_FLAG_ETH_LAST));
+    /* Mask out the traffic class flag (bit 7) which is above the RoCE version
+     * bits (5-6) to avoid corrupting the extracted version */
+    return (uct_ib_roce_version_t)((flags &
+                                    ~UCT_IB_ADDRESS_FLAG_TRAFFIC_CLASS) >>
+                                   ucs_ilog2(UCT_IB_ADDRESS_FLAG_ETH_LAST));
 }
 
 static inline sa_family_t
@@ -408,6 +412,10 @@ size_t uct_ib_address_size(const uct_ib_address_pack_params_t *params)
         size += sizeof(uint16_t);
     }
 
+    if (params->flags & UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS) {
+        size += sizeof(uint8_t);
+    }
+
     return size;
 }
 
@@ -486,6 +494,11 @@ void uct_ib_address_pack(const uct_ib_address_pack_params_t *params,
         ib_addr->flags |= UCT_IB_ADDRESS_FLAG_PKEY;
         *ucs_serialize_next(&ptr, uint16_t) = params->pkey;
     }
+
+    if (params->flags & UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS) {
+        ib_addr->flags |= UCT_IB_ADDRESS_FLAG_TRAFFIC_CLASS;
+        *ucs_serialize_next(&ptr, uint8_t) = params->traffic_class;
+    }
 }
 
 unsigned uct_ib_iface_address_pack_flags(uct_ib_iface_t *iface)
@@ -512,6 +525,10 @@ unsigned uct_ib_iface_address_pack_flags(uct_ib_iface_t *iface)
         pack_flags |= UCT_IB_ADDRESS_PACK_FLAG_PATH_MTU;
     }
 
+    if (iface->config.traffic_class != 0) {
+        pack_flags |= UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS;
+    }
+
     return pack_flags;
 }
 
@@ -529,14 +546,15 @@ void uct_ib_iface_address_pack(uct_ib_iface_t *iface, uct_ib_address_t *ib_addr)
 {
     uct_ib_address_pack_params_t params;
 
-    params.flags     = uct_ib_iface_address_pack_flags(iface);
-    params.gid       = iface->gid_info.gid;
-    params.lid       = uct_ib_iface_port_attr(iface)->lid;
-    params.roce_info = iface->gid_info.roce_info;
-    params.path_mtu  = iface->config.path_mtu;
+    params.flags         = uct_ib_iface_address_pack_flags(iface);
+    params.gid           = iface->gid_info.gid;
+    params.lid           = uct_ib_iface_port_attr(iface)->lid;
+    params.roce_info     = iface->gid_info.roce_info;
+    params.path_mtu      = iface->config.path_mtu;
     /* to suppress gcc 4.3.4 warning */
-    params.gid_index = UCT_IB_ADDRESS_INVALID_GID_INDEX;
-    params.pkey      = iface->pkey;
+    params.gid_index     = UCT_IB_ADDRESS_INVALID_GID_INDEX;
+    params.pkey          = iface->pkey;
+    params.traffic_class = iface->config.traffic_class;
     uct_ib_address_pack(&params, ib_addr);
 }
 
@@ -610,6 +628,11 @@ ucs_status_t uct_ib_address_unpack(const uct_ib_address_t *ib_addr,
     /* PKEY is always in params */
     params.flags |= UCT_IB_ADDRESS_PACK_FLAG_PKEY;
 
+    if (ib_addr->flags & UCT_IB_ADDRESS_FLAG_TRAFFIC_CLASS) {
+        params.traffic_class = *ucs_serialize_next(&ptr, const uint8_t);
+        params.flags        |= UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS;
+    }
+
     *params_p = params;
     return UCS_OK;
 }
@@ -1125,6 +1148,15 @@ uct_ib_iface_fill_ah_attr_from_addr(uct_ib_iface_t *iface,
     lid = (flid == 0) ? params.lid : flid;
     uct_ib_iface_fill_ah_attr_from_gid_lid(iface, lid, gid, params.gid_index,
                                            path_index, ah_attr);
+
+    /* If the remote address carries a traffic class and the local interface
+     * does not have one configured, apply the remote value so that both
+     * directions of the connection use the same traffic class. */
+    if ((params.flags & UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS) &&
+        (iface->config.traffic_class == 0)) {
+        ah_attr->grh.traffic_class = params.traffic_class;
+    }
+
     return UCS_OK;
 }
 

src/uct/ib/base/ib_iface.h

@@ -105,7 +105,8 @@ enum {
     UCT_IB_ADDRESS_PACK_FLAG_SUBNET_PREFIX = UCS_BIT(2),
     UCT_IB_ADDRESS_PACK_FLAG_PATH_MTU      = UCS_BIT(3),
     UCT_IB_ADDRESS_PACK_FLAG_GID_INDEX     = UCS_BIT(4),
-    UCT_IB_ADDRESS_PACK_FLAG_PKEY          = UCS_BIT(5)
+    UCT_IB_ADDRESS_PACK_FLAG_PKEY          = UCS_BIT(5),
+    UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS = UCS_BIT(6)
 };
 
 
@@ -147,6 +148,9 @@ typedef struct uct_ib_address_pack_params {
     /* PKEY value,
        must be valid if @ref UCT_IB_ADDRESS_PACK_FLAG_PKEY is set. */
     uint16_t                          pkey;
+    /* Traffic class value,
+       must be valid if @ref UCT_IB_ADDRESS_PACK_FLAG_TRAFFIC_CLASS is set. */
+    uint8_t                           traffic_class;
 } uct_ib_address_pack_params_t;
 
 

src/uct/ib/mlx5/rc/rc_mlx5_devx.c

@@ -434,7 +434,7 @@ ucs_status_t uct_rc_mlx5_iface_common_devx_connect_qp(
             UCT_IB_MLX5DV_SET(qpc, qpc, primary_address_path.udp_sport,
                               ah_attr->dlid);
             UCT_IB_MLX5DV_SET(qpc, qpc, primary_address_path.dscp,
-                              uct_ib_iface_roce_dscp(&iface->super.super));
+                              ah_attr->grh.traffic_class >> 2);
         }
 
         uct_ib_mlx5_devx_set_qpc_port_affinity(md, path_index, qpc,
@@ -457,7 +457,7 @@ ucs_status_t uct_rc_mlx5_iface_common_devx_connect_qp(
                    UCT_IB_MLX5DV_FLD_SZ_BYTES(qpc, primary_address_path.rgid_rip));
             /* TODO add flow_label support */
             UCT_IB_MLX5DV_SET(qpc, qpc, primary_address_path.tclass,
-                              iface->super.super.config.traffic_class);
+                              ah_attr->grh.traffic_class);
         }
     }
 

test/gtest/uct/ib/test_ib.cc

@@ -102,8 +102,9 @@ class test_uct_ib_addr : public test_uct_ib {
         pack_params.lid       = lid_in;
         pack_params.roce_info = iface->gid_info.roce_info;
         pack_params.path_mtu  = iface->config.path_mtu;
-        pack_params.gid_index = std::numeric_limits<uint8_t>::max();
-        pack_params.pkey      = iface->pkey;
+        pack_params.gid_index     = std::numeric_limits<uint8_t>::max();
+        pack_params.pkey          = iface->pkey;
+        pack_params.traffic_class = iface->config.traffic_class;
         address_size          = uct_ib_address_size(&pack_params);
         ib_addr               = (uct_ib_address_t*)malloc(address_size);
         uct_ib_address_pack(&pack_params, ib_addr);