[ovs-dev] [v13 06/12] dpif-netdev: Add command to get dpif implementations.

[Cian Ferriter]

From: Harry van Haaren <harry.van.haaren at intel.com>

This commit adds a new command to retrieve the list of available
DPIF implementations. This can be used by to check what implementations
of the DPIF are available in any given OVS binary.

Usage:
 $ ovs-appctl dpif-netdev/dpif-get

Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>

---

v13:
- Add NEWS item about DPIF get and set commands here rather than in a
  later commit.
- Add documentation items about DPIF set commands here rather than in a
  later commit.
---
 Documentation/topics/dpdk/bridge.rst |  8 ++++++++
 NEWS                                 |  1 +
 lib/dpif-netdev-private-dpif.c       |  8 ++++++++
 lib/dpif-netdev-private-dpif.h       |  6 ++++++
 lib/dpif-netdev-unixctl.man          |  3 +++
 lib/dpif-netdev.c                    | 24 ++++++++++++++++++++++++
 6 files changed, 50 insertions(+)

diff --git a/Documentation/topics/dpdk/bridge.rst b/Documentation/topics/dpdk/bridge.rst
index fafa8c821..f59e26cbe 100644
--- a/Documentation/topics/dpdk/bridge.rst
+++ b/Documentation/topics/dpdk/bridge.rst
@@ -226,6 +226,14 @@ stats associated with the datapath.
 Just like with the SIMD DPCLS feature above, SIMD can be applied to the DPIF to
 improve performance.
 
+OVS provides multiple implementations of the DPIF. The available
+implementations can be listed with the following command ::
+
+    $ ovs-appctl dpif-netdev/dpif-get
+    Available DPIF implementations:
+      dpif_scalar
+      dpif_avx512
+
 By default, dpif_scalar is used. The DPIF implementation can be selected by
 name ::
 
diff --git a/NEWS b/NEWS
index 6a4a7b76d..c47ab349e 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Post-v2.15.0
      * Refactor lib/dpif-netdev.c to multiple header files.
      * Add avx512 implementation of dpif which can process non recirculated
        packets. It supports partial HWOL, EMC, SMC and DPCLS lookups.
+     * Add commands to get and set the dpif implementations.
    - ovs-ctl:
      * New option '--no-record-hostname' to disable hostname configuration
        in ovsdb on startup.
diff --git a/lib/dpif-netdev-private-dpif.c b/lib/dpif-netdev-private-dpif.c
index d829a7ee5..3649e775d 100644
--- a/lib/dpif-netdev-private-dpif.c
+++ b/lib/dpif-netdev-private-dpif.c
@@ -73,6 +73,14 @@ dp_netdev_impl_set_default(dp_netdev_input_func func)
     default_dpif_func = func;
 }
 
+uint32_t
+dp_netdev_impl_get(const struct dpif_netdev_impl_info_t **out_impls)
+{
+    ovs_assert(out_impls);
+    *out_impls = dpif_impls;
+    return ARRAY_SIZE(dpif_impls);
+}
+
 /* This function checks all available DPIF implementations, and selects the
  * returns the function pointer to the one requested by "name".
  */
diff --git a/lib/dpif-netdev-private-dpif.h b/lib/dpif-netdev-private-dpif.h
index a6db3c7f2..717e9e2f9 100644
--- a/lib/dpif-netdev-private-dpif.h
+++ b/lib/dpif-netdev-private-dpif.h
@@ -48,6 +48,12 @@ struct dpif_netdev_impl_info_t {
     const char *name;
 };
 
+/* This function returns all available implementations to the caller. The
+ * quantity of implementations is returned by the int return value.
+ */
+uint32_t
+dp_netdev_impl_get(const struct dpif_netdev_impl_info_t **out_impls);
+
 /* This function checks all available DPIF implementations, and selects the
  * returns the function pointer to the one requested by "name".
  */
diff --git a/lib/dpif-netdev-unixctl.man b/lib/dpif-netdev-unixctl.man
index b348940b0..534823879 100644
--- a/lib/dpif-netdev-unixctl.man
+++ b/lib/dpif-netdev-unixctl.man
@@ -227,5 +227,8 @@ When this is the case, the above command prints the load-balancing information
 of the bonds configured in datapath \fIdp\fR showing the interface associated
 with each bucket (hash).
 .
+.IP "\fBdpif-netdev/dpif-get\fR
+Lists the DPIF implementations that are available.
+.
 .IP "\fBdpif-netdev/dpif-set\fR \fIdpif_impl\fR"
 Sets the DPIF to be used to \fIdpif_impl\fR. By default "dpif_scalar" is used.
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 9c234ef3d..59a44a848 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -991,6 +991,27 @@ dpif_netdev_subtable_lookup_set(struct unixctl_conn *conn, int argc,
     ds_destroy(&reply);
 }
 
+static void
+dpif_netdev_impl_get(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
+{
+    const struct dpif_netdev_impl_info_t *dpif_impls;
+    uint32_t count = dp_netdev_impl_get(&dpif_impls);
+    if (count == 0) {
+        unixctl_command_reply_error(conn, "error getting dpif names");
+        return;
+    }
+
+    /* Add all dpif functions to reply string. */
+    struct ds reply = DS_EMPTY_INITIALIZER;
+    ds_put_cstr(&reply, "Available DPIF implementations:\n");
+    for (uint32_t i = 0; i < count; i++) {
+        ds_put_format(&reply, "  %s\n", dpif_impls[i].name);
+    }
+    unixctl_command_reply(conn, ds_cstr(&reply));
+    ds_destroy(&reply);
+}
+
 static void
 dpif_netdev_impl_set(struct unixctl_conn *conn, int argc,
                      const char *argv[], void *aux OVS_UNUSED)
@@ -1292,6 +1313,9 @@ dpif_netdev_init(void)
                              "dpif_implementation_name [dp]",
                              1, 2, dpif_netdev_impl_set,
                              NULL);
+    unixctl_command_register("dpif-netdev/dpif-get", "",
+                             0, 0, dpif_netdev_impl_get,
+                             NULL);
     return 0;
 }
 
-- 
2.32.0