[ovs-dev] [v3 01/12] dpif-netdev: Add command line and function pointer for miniflow extract

Kumar Amber kumar.amber at intel.com
Mon May 17 13:56:57 UTC 2021


This patch introduces the mfex function pointers which allows
the user to switch between different miniflow extract implementations
which are provided by the OVS based on optimized ISA CPU.

The user can query for the available minflow extract variants available
for that CPU by following commands:

$ovs-appctl dpif-netdev/miniflow-parser-get

Similarly an user can set the miniflow implementation by the following
command :

$ ovs-appctl dpif-netdev/miniflow-parser-set name

This allow for more performance and flexibility to the user to choose
the miniflow implementation according to the needs.

Signed-off-by: Kumar Amber <kumar.amber at intel.com>
Co-authored-by: Harry van Haaren <harry.van.haaren at intel.com>
Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>
---
 lib/automake.mk                   |   2 +
 lib/dpif-netdev-avx512.c          |  38 ++++++---
 lib/dpif-netdev-private-extract.c |  86 ++++++++++++++++++++
 lib/dpif-netdev-private-extract.h |  94 ++++++++++++++++++++++
 lib/dpif-netdev-private-thread.h  |   4 +
 lib/dpif-netdev.c                 | 126 +++++++++++++++++++++++++++++-
 6 files changed, 337 insertions(+), 13 deletions(-)
 create mode 100644 lib/dpif-netdev-private-extract.c
 create mode 100644 lib/dpif-netdev-private-extract.h

diff --git a/lib/automake.mk b/lib/automake.mk
index 6279662f8..6110cc922 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -117,6 +117,8 @@ lib_libopenvswitch_la_SOURCES = \
 	lib/dpif-netdev-private-dpcls.h \
 	lib/dpif-netdev-private-dpif.c \
 	lib/dpif-netdev-private-dpif.h \
+	lib/dpif-netdev-private-extract.c \
+	lib/dpif-netdev-private-extract.h \
 	lib/dpif-netdev-private-flow.h \
 	lib/dpif-netdev-private-hwol.h \
 	lib/dpif-netdev-private-thread.h \
diff --git a/lib/dpif-netdev-avx512.c b/lib/dpif-netdev-avx512.c
index 5c6f54799..3b82e3f6c 100644
--- a/lib/dpif-netdev-avx512.c
+++ b/lib/dpif-netdev-avx512.c
@@ -121,7 +121,16 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
     /* A 1 bit in this mask indicates a hit, so no DPCLS lookup on the pkt. */
     uint32_t hwol_emc_smc_hitmask = 0;
 
-    /* Perform first packet interation. */
+    /* Do a batch minfilow extract into keys. */
+    /* TODO: v2 will support cleaner integration into packet batch
+     * loops below. */
+    uint32_t mf_mask = 0;
+    if (pmd->miniflow_extract_opt) {
+        mf_mask = pmd->miniflow_extract_opt(packets, keys,
+                                            batch_size, in_port,
+                                            (void *) pmd);
+    }
+    /* Perform first packet interation */
     uint32_t lookup_pkts_bitmask = (1ULL << batch_size) - 1;
     uint32_t iter = lookup_pkts_bitmask;
     while (iter) {
@@ -133,6 +142,12 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
         pkt_metadata_init(&packet->md, in_port);
 
         struct dp_netdev_flow *f = NULL;
+        struct netdev_flow_key *key = &keys[i];
+
+        /* Check the minfiflow mask to see if the packet was correctly
+        * classifed by vector mfex else do a scalar miniflow extract
+        * for that packet. */
+        uint32_t mfex_hit = (mf_mask & (1 << i));
 
         /* Check for partial hardware offload mark. */
         uint32_t mark;
@@ -140,12 +155,12 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
             f = mark_to_flow_find(pmd, mark);
             if (f) {
                 rules[i] = &f->cr;
-
-                /* This is nasty - instead of using the HWOL provided flow,
-                 * parse the packet data anyway to find the location of the TCP
-                 * header to extract the TCP flags for the rule.
-                 */
-                pkt_meta[i].tcp_flags = parse_tcp_flags(packet);
+                /* If AVX512 MFEX already classified the packet, use it. */
+                if (mfex_hit) {
+                    pkt_meta[i].tcp_flags = miniflow_get_tcp_flags(&key->mf);
+                } else {
+                    pkt_meta[i].tcp_flags = parse_tcp_flags(packet);
+                }
 
                 pkt_meta[i].bytes = dp_packet_size(packet);
                 phwol_hits++;
@@ -154,11 +169,12 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
             }
         }
 
-        /* Do miniflow extract into keys. */
-        struct netdev_flow_key *key = &keys[i];
-        miniflow_extract(packet, &key->mf);
+        if (!mfex_hit) {
+            /* Do a scalar miniflow extract into keys */
+            miniflow_extract(packet, &key->mf);
+        }
 
-        /* Cache TCP and byte values for all packets. */
+        /* Cache TCP and byte values for all packets */
         pkt_meta[i].bytes = dp_packet_size(packet);
         pkt_meta[i].tcp_flags = miniflow_get_tcp_flags(&key->mf);
 
diff --git a/lib/dpif-netdev-private-extract.c b/lib/dpif-netdev-private-extract.c
new file mode 100644
index 000000000..fcc56ef26
--- /dev/null
+++ b/lib/dpif-netdev-private-extract.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2021 Intel.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "dp-packet.h"
+#include "dpif-netdev-private-dpcls.h"
+#include "dpif-netdev-private-extract.h"
+#include "dpif-netdev-private-thread.h"
+#include "flow.h"
+#include "openvswitch/vlog.h"
+#include "ovs-thread.h"
+#include "util.h"
+
+VLOG_DEFINE_THIS_MODULE(dpif_netdev_extract);
+
+/* Implementations of available extract options. */
+static struct dpif_miniflow_extract_impl mfex_impls[] = {
+    {
+        .probe = NULL,
+        .extract_func = NULL,
+        .name = "disable",
+    },
+};
+
+BUILD_ASSERT_DECL(MFEX_IMPLS_MAX_SIZE > ARRAY_SIZE(mfex_impls));
+
+int32_t
+dpif_miniflow_extract_opt_get(const char *name,
+                              struct dpif_miniflow_extract_impl **opt)
+{
+    ovs_assert(opt);
+    ovs_assert(name);
+
+    uint32_t i;
+    for (i = 0; i < ARRAY_SIZE(mfex_impls); i++) {
+        if (strcmp(name, mfex_impls[i].name) == 0) {
+            *opt = &mfex_impls[i];
+            return 0;
+        }
+    }
+    return -ENOTSUP;
+}
+
+void
+dpif_miniflow_extract_init(void)
+{
+    /* Call probe on each impl, and cache the result. */
+    uint32_t i;
+    for (i = 0; i < ARRAY_SIZE(mfex_impls); i++) {
+        int avail = 1;
+        if (mfex_impls[i].probe) {
+            /* Return zero is success, non-zero means error. */
+            avail = (mfex_impls[i].probe() == 0);
+        }
+        VLOG_INFO("Miniflow Extract implementation %s (available: %s)\n",
+                  mfex_impls[i].name, avail ? "True" : "False");
+        mfex_impls[i].available = avail;
+    }
+}
+
+int32_t
+dpif_miniflow_extract_info_get(struct dpif_miniflow_extract_impl **out_ptr)
+{
+    if (out_ptr == NULL) {
+        return -EINVAL;
+    }
+    *out_ptr = mfex_impls;
+    return ARRAY_SIZE(mfex_impls);
+}
diff --git a/lib/dpif-netdev-private-extract.h b/lib/dpif-netdev-private-extract.h
new file mode 100644
index 000000000..b7b0b2be4
--- /dev/null
+++ b/lib/dpif-netdev-private-extract.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2021 Intel.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DPIF_NETDEV_AVX512_EXTRACT
+#define DPIF_NETDEV_AVX512_EXTRACT 1
+
+#include <sys/types.h>
+
+#include "openvswitch/types.h"
+
+/* Max size of dpif_miniflow_extract_impl array. */
+#define MFEX_IMPLS_MAX_SIZE (16)
+
+/* Forward declarations. */
+struct dp_packet;
+struct miniflow;
+struct dp_netdev_pmd_thread;
+struct dp_packet_batch;
+struct netdev_flow_key;
+
+/* Function pointer prototype to be implemented in the optimized miniflow
+ * extract code.
+ * returns the hitmask of the processed packets on success.
+ * returns zero on failure.
+ */
+typedef uint32_t (*miniflow_extract_func)(struct dp_packet_batch *batch,
+                                          struct netdev_flow_key *keys,
+                                          uint32_t keys_size,
+                                          odp_port_t in_port,
+                                          void *pmd_handle);
+
+/* Probe function is used to detect if this CPU has the ISA required
+ * to run the optimized miniflow implementation.
+ * returns one on successful probe.
+ * returns zero on failure.
+ */
+typedef int32_t (*miniflow_extract_probe)(void);
+
+/* Structure representing the attributes of an optimized implementation. */
+struct dpif_miniflow_extract_impl {
+    /* When non-zero, this impl has passed the probe() checks. */
+    uint8_t available;
+
+    /* Probe function is used to detect if this CPU has the ISA required
+     * to run the optimized miniflow implementation.
+     */
+    miniflow_extract_probe probe;
+
+    /* Function to call to extract miniflows for a burst of packets. */
+    miniflow_extract_func extract_func;
+
+    /* Name of the optimized implementation. */
+    char *name;
+};
+
+/* Retrieve the opt structure for the requested implementation by name.
+ * Returns zero on success, and opt points to a valid struct, or
+ * returns a negative failure status.
+ * -ENOTSUP : invalid name requested
+ */
+int32_t
+dpif_miniflow_extract_opt_get(const char *name,
+                              struct dpif_miniflow_extract_impl **opt);
+
+/* Initializes the available miniflow extract implementations by probing for
+ * the CPU ISA requirements. As the runtime available CPU ISA does not change
+ * and the required ISA of the implementation also does not change, it is safe
+ * to cache the probe() results, and not call probe() at runtime.
+ */
+void
+dpif_miniflow_extract_init(void);
+
+/* Retrieve the array of miniflow implementations for iteration.
+ * On error, returns a negative number.
+ * On success, returns the size of the arrays pointed to by the out parameter.
+ */
+int32_t
+dpif_miniflow_extract_info_get(struct dpif_miniflow_extract_impl **out_ptr);
+
+
+#endif /* DPIF_NETDEV_AVX512_EXTRACT */
diff --git a/lib/dpif-netdev-private-thread.h b/lib/dpif-netdev-private-thread.h
index 19ce99f4e..6d6e37a87 100644
--- a/lib/dpif-netdev-private-thread.h
+++ b/lib/dpif-netdev-private-thread.h
@@ -29,6 +29,7 @@
 #include "openvswitch/thread.h"
 
 #include "dpif-netdev-private-dpif.h"
+#include "dpif-netdev-private-extract.h"
 
 #ifdef  __cplusplus
 extern "C" {
@@ -110,6 +111,9 @@ struct dp_netdev_pmd_thread {
     /* Pointer for per-DPIF implementation scratch space. */
     void *netdev_input_func_userdata;
 
+    /* Function pointer to call for miniflow_extract() functionality. */
+    miniflow_extract_func miniflow_extract_opt;
+
     struct seq *reload_seq;
     uint64_t last_reload_seq;
 
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index f46269ae3..c615e028d 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -46,6 +46,7 @@
 #include "dpif-netdev-lookup.h"
 #include "dpif-netdev-perf.h"
 #include "dpif-netdev-private-dfc.h"
+#include "dpif-netdev-private-extract.h"
 #include "dpif-provider.h"
 #include "dummy.h"
 #include "fat-rwlock.h"
@@ -1091,6 +1092,102 @@ dpif_netdev_impl_set(struct unixctl_conn *conn, int argc,
     ds_destroy(&reply);
 }
 
+static void
+dpif_miniflow_extract_impl_get(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
+{
+    struct dpif_miniflow_extract_impl *mfex_impls;
+    uint32_t count = dpif_miniflow_extract_info_get(&mfex_impls);
+    if (count == 0) {
+        unixctl_command_reply_error(conn, "error getting mfex names");
+        return;
+    }
+
+    /* Add all mfex functions to reply string. */
+    struct ds reply = DS_EMPTY_INITIALIZER;
+    ds_put_cstr(&reply, "Available Optimized Miniflow Extracts:\n");
+    for (uint32_t i = 0; i < count; i++) {
+        ds_put_format(&reply, "  %s (available: %s)\n",
+                      mfex_impls[i].name, mfex_impls[i].available ?
+                      "True" : "False");
+    }
+    unixctl_command_reply(conn, ds_cstr(&reply));
+    ds_destroy(&reply);
+}
+
+static void
+dpif_miniflow_extract_impl_set(struct unixctl_conn *conn, int argc,
+                     const char *argv[], void *aux OVS_UNUSED)
+{
+    /* This function requires just one parameter, the miniflow name.
+     * A second optional parameter can identify the datapath instance.
+     */
+    const char *mfex_name = argv[1];
+
+    static const char *error_description[2] = {
+        "Unknown miniflow implementation",
+        "implementation doesn't exist",
+    };
+    struct dpif_miniflow_extract_impl *opt;
+    miniflow_extract_func new_func;
+    int32_t err = dpif_miniflow_extract_opt_get(mfex_name, &opt);
+    if (err) {
+        struct ds reply = DS_EMPTY_INITIALIZER;
+        ds_put_format(&reply,
+                    "Miniflow implementation not available: %s %s.\n",
+                    error_description[ (err == -ENOTSUP) ], mfex_name);
+        const char *reply_str = ds_cstr(&reply);
+        unixctl_command_reply(conn, reply_str);
+        VLOG_INFO("%s", reply_str);
+        ds_destroy(&reply);
+        return;
+    }
+    new_func = opt->extract_func;
+    /* argv[2] is optional datapath instance. If no datapath name is provided.
+     * and only one datapath exists, the one existing datapath is reprobed.
+     */
+    ovs_mutex_lock(&dp_netdev_mutex);
+    struct dp_netdev *dp = NULL;
+
+    if (argc == 3) {
+        dp = shash_find_data(&dp_netdevs, argv[2]);
+    } else if (shash_count(&dp_netdevs) == 1) {
+        dp = shash_first(&dp_netdevs)->data;
+    }
+
+    if (!dp) {
+        ovs_mutex_unlock(&dp_netdev_mutex);
+        unixctl_command_reply_error(conn,
+                                    "please specify an existing datapath");
+        return;
+    }
+
+    /* Get PMD threads list. */
+    size_t n;
+    struct dp_netdev_pmd_thread **pmd_list;
+    sorted_poll_thread_list(dp, &pmd_list, &n);
+
+    for (size_t i = 0; i < n; i++) {
+        struct dp_netdev_pmd_thread *pmd = pmd_list[i];
+        if (pmd->core_id == NON_PMD_CORE_ID) {
+            continue;
+        }
+
+        /* Set PMD threads miniflow implementation to requested one. */
+        pmd->miniflow_extract_opt = *new_func;
+    };
+
+    ovs_mutex_unlock(&dp_netdev_mutex);
+
+    /* Reply with success to command. */
+    struct ds reply = DS_EMPTY_INITIALIZER;
+    ds_put_format(&reply, "Miniflow implementation set to %s.\n", mfex_name);
+    const char *reply_str = ds_cstr(&reply);
+    unixctl_command_reply(conn, reply_str);
+    VLOG_INFO("%s", reply_str);
+    ds_destroy(&reply);
+}
+
 static void
 dpif_netdev_pmd_rebalance(struct unixctl_conn *conn, int argc,
                           const char *argv[], void *aux OVS_UNUSED)
@@ -1317,9 +1414,16 @@ dpif_netdev_init(void)
                              "dpif_implementation_name [dp]",
                              1, 2, dpif_netdev_impl_set,
                              NULL);
+    unixctl_command_register("dpif-netdev/miniflow-parser-set",
+                             "miniflow implementation name [dp]",
+                             1, 2, dpif_miniflow_extract_impl_set,
+                             NULL);
     unixctl_command_register("dpif-netdev/dpif-get", "",
                              0, 0, dpif_netdev_impl_get,
                              NULL);
+    unixctl_command_register("dpif-netdev/miniflow-parser-get", "",
+                             0, 0, dpif_miniflow_extract_impl_get,
+                             NULL);
     return 0;
 }
 
@@ -1463,6 +1567,8 @@ create_dp_netdev(const char *name, const struct dpif_class *class,
 
     dp->conntrack = conntrack_init();
 
+    dpif_miniflow_extract_init();
+
     atomic_init(&dp->emc_insert_min, DEFAULT_EM_FLOW_INSERT_MIN);
     atomic_init(&dp->tx_flush_interval, DEFAULT_TX_FLUSH_INTERVAL);
 
@@ -6147,6 +6253,9 @@ dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd, struct dp_netdev *dp,
     /* Initialize DPIF function pointer to the default configured version. */
     pmd->netdev_input_func = dp_netdev_impl_get_default();
 
+    /*Init default miniflow_extract function */
+    pmd->miniflow_extract_opt = NULL;
+
     /* init the 'flow_cache' since there is no
      * actual thread created for NON_PMD_CORE_ID. */
     if (core_id == NON_PMD_CORE_ID) {
@@ -6701,10 +6810,12 @@ dfc_processing(struct dp_netdev_pmd_thread *pmd,
 {
     struct netdev_flow_key *key = &keys[0];
     size_t n_missed = 0, n_emc_hit = 0, n_phwol_hit = 0;
+    struct dp_packet_batch single_packet;
     struct dfc_cache *cache = &pmd->flow_cache;
     struct dp_packet *packet;
     const size_t cnt = dp_packet_batch_size(packets_);
     uint32_t cur_min = pmd->ctx.emc_insert_min;
+    int mf_ret;
     int i;
     uint16_t tcp_flags;
     bool smc_enable_db;
@@ -6757,8 +6868,19 @@ dfc_processing(struct dp_netdev_pmd_thread *pmd,
                 continue;
             }
         }
-
-        miniflow_extract(packet, &key->mf);
+        /* Set the count and packet for miniflow_opt with batch_size 1. */
+        if ((pmd->miniflow_extract_opt) && (!md_is_valid)) {
+            single_packet.count = 1;
+            single_packet.packets[0] = packet;
+            mf_ret = pmd->miniflow_extract_opt(&single_packet, key, 1,
+                                               port_no, (void *) pmd);
+            /* Fallback to original miniflow_extract if there is a miss. */
+            if (!mf_ret) {
+                miniflow_extract(packet, &key->mf);
+            }
+        } else {
+            miniflow_extract(packet, &key->mf);
+        }
         key->len = 0; /* Not computed yet. */
         key->hash =
                 (md_is_valid == false)
-- 
2.25.1



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