[ovs-dev,v2] dpdk: Add commands to configure log levels.

diff --git a/NEWS b/NEWS
index e52e862e1e..243ddeb562 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,8 @@  Post-v2.13.0
      * Add hardware offload support for matching IPv6 protocol (experimental).
      * Add hardware offload support for set of IPv6 src/dst/ttl
        and tunnel push-output actions (experimental).
+     * Add 'ovs-appctl dpdk/log-list' and 'ovs-appctl dpdk/log-set' commands
+       to list and change log levels in DPDK components.
    - Linux datapath:
      * Support for kernel versions up to 5.5.x.
    - AF_XDP:
diff --git a/lib/automake.mk b/lib/automake.mk
index 86940ccd2f..d2dd03d120 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -519,6 +519,7 @@  MAN_FRAGMENTS += \
 	lib/daemon-syn.man \
 	lib/db-ctl-base.man \
 	lib/dpctl.man \
+	lib/dpdk-unixctl.man \
 	lib/memory-unixctl.man \
 	lib/netdev-dpdk-unixctl.man \
 	lib/dpif-netdev-unixctl.man \
diff --git a/lib/dpdk-unixctl.man b/lib/dpdk-unixctl.man
new file mode 100644
index 0000000000..2d6d576f24
--- /dev/null
+++ b/lib/dpdk-unixctl.man
@@ -0,0 +1,14 @@ 
+.SS "DPDK COMMANDS"
+These commands manage DPDK components.
+.IP "\fBdpdk/log-list\fR"
+Lists all DPDK components that emit logs and their logging levels.
+.IP "\fBdpdk/log-set\fR [\fIspec\fR]"
+Sets DPDK components logging level. Without any \fIspec\fR, sets the logging
+\fBlevel\fR for all DPDK components to \fBdebug\fR. Otherwise, \fIspec\fR is a
+list of words separated by spaces: a word can be either a logging \fBlevel\fR
+(\fBemergency\fR, \fBalert\fR, \fBcritical\fR, \fBerror\fR, \fBwarning\fR,
+\fBnotice\fR, \fBinfo\fR or \fBdebug\fR) or a \fBpattern\fR matching DPDK
+components (see \fBdpdk/log-list\fR command on \fBovs\-appctl\fR(8)) separated
+by a colon from the logging \fBlevel\fR to apply.
+.RE
+.
diff --git a/lib/dpdk.c b/lib/dpdk.c
index 31450d4708..c603430d14 100644
--- a/lib/dpdk.c
+++ b/lib/dpdk.c
@@ -36,6 +36,7 @@ 
 #include "ovs-numa.h"
 #include "smap.h"
 #include "svec.h"
+#include "unixctl.h"
 #include "util.h"
 #include "vswitch-idl.h"
 
@@ -261,6 +262,99 @@  static cookie_io_functions_t dpdk_log_func = {
     .write = dpdk_log_write,
 };
 
+static void
+dpdk_unixctl_mem_stream(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                        const char *argv[] OVS_UNUSED, void *aux)
+{
+    void (*callback)(FILE *) = aux;
+    char *response = NULL;
+    FILE *stream;
+    size_t size;
+
+    stream = open_memstream(&response, &size);
+    if (!stream) {
+        response = xasprintf("Unable to open memstream: %s.",
+                             ovs_strerror(errno));
+        unixctl_command_reply_error(conn, response);
+        goto out;
+    }
+
+    callback(stream);
+    fclose(stream);
+    unixctl_command_reply(conn, response);
+out:
+    free(response);
+}
+
+static int
+dpdk_parse_log_level(const char *s)
+{
+    static const char * const levels[] = {
+        [RTE_LOG_EMERG]   = "emergency",
+        [RTE_LOG_ALERT]   = "alert",
+        [RTE_LOG_CRIT]    = "critical",
+        [RTE_LOG_ERR]     = "error",
+        [RTE_LOG_WARNING] = "warning",
+        [RTE_LOG_NOTICE]  = "notice",
+        [RTE_LOG_INFO]    = "info",
+        [RTE_LOG_DEBUG]   = "debug",
+    };
+    int i;
+
+    for (i = 1; i < ARRAY_SIZE(levels); ++i) {
+        if (!strcmp(s, levels[i])) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+static void
+dpdk_unixctl_log_set(struct unixctl_conn *conn, int argc, const char *argv[],
+                     void *aux OVS_UNUSED)
+{
+    int i;
+
+    /* With no argument, set all components level to 'debug'. */
+    if (argc == 1) {
+        rte_log_set_level_pattern("*", RTE_LOG_DEBUG);
+    }
+    for (i = 1; i < argc; i++) {
+        char *err_msg = NULL;
+        char *level_string;
+        char *pattern;
+        char *s;
+        int level;
+
+        s = xstrdup(argv[i]);
+        level_string = strchr(s, ':');
+        if (level_string == NULL) {
+            pattern = "*";
+            level_string = s;
+        } else {
+            pattern = s;
+            level_string[0] = '\0';
+            level_string++;
+        }
+
+        level = dpdk_parse_log_level(level_string);
+        if (level == -1) {
+            err_msg = xasprintf("invalid log level: '%s'", level_string);
+        } else if (rte_log_set_level_pattern(pattern, level) < 0) {
+            err_msg = xasprintf("cannot set log level for '%s'", argv[i]);
+        }
+
+        if (err_msg) {
+            unixctl_command_reply_error(conn, err_msg);
+            free(err_msg);
+            free(s);
+            return;
+        }
+        free(s);
+    }
+    unixctl_command_reply(conn, NULL);
+}
+
 static bool
 dpdk_init__(const struct smap *ovs_other_config)
 {
@@ -413,18 +507,24 @@  dpdk_init__(const struct smap *ovs_other_config)
         FILE *stream = open_memstream(&response, &size);
 
         if (stream) {
+            fprintf(stream, "rte_memzone_dump:\n");
             rte_memzone_dump(stream);
+            fprintf(stream, "rte_log_dump:\n");
+            rte_log_dump(stream);
             fclose(stream);
-            if (size) {
-                VLOG_DBG("rte_memzone_dump:\n%s", response);
-            }
+            VLOG_DBG("%s", response);
             free(response);
         } else {
-            VLOG_DBG("Could not dump memzone. Unable to open memstream: %s.",
-                     ovs_strerror(errno));
+            VLOG_DBG("Could not dump memzone and log levels. "
+                     "Unable to open memstream: %s.", ovs_strerror(errno));
         }
     }
 
+    unixctl_command_register("dpdk/log-list", "", 0, 0,
+                             dpdk_unixctl_mem_stream, rte_log_dump);
+    unixctl_command_register("dpdk/log-set", "{level | pattern:level}", 0,
+                             INT_MAX, dpdk_unixctl_log_set, NULL);
+
     /* We are called from the main thread here */
     RTE_PER_LCORE(_lcore_id) = NON_PMD_CORE_ID;
 
diff --git a/vswitchd/ovs-vswitchd.8.in b/vswitchd/ovs-vswitchd.8.in
index 0ad8bd2bc4..c064529289 100644
--- a/vswitchd/ovs-vswitchd.8.in
+++ b/vswitchd/ovs-vswitchd.8.in
@@ -272,6 +272,7 @@  type).
 ..
 .so lib/dpctl.man
 .
+.so lib/dpdk-unixctl.man
 .so lib/dpif-netdev-unixctl.man
 .so lib/netdev-dpdk-unixctl.man
 .so ofproto/ofproto-dpif-unixctl.man