Adding upstream version 1.8.upstream/1.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 1571 insertions, 0 deletions

diff --git a/examples/discover-loop.c b/examples/discover-loop.c
new file mode 100644
index 0000000..7528067
--- /dev/null
+++ b/examples/discover-loop.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors: Keith Busch <keith.busch@wdc.com>
+ */
+
+/**
+ * discover-loop: Use fabrics commands to discover any loop targets and print
+ * those records. You must have at least one configured nvme loop target on the
+ * system (no existing connection required). The output will look more
+ * interesting with more targets.
+ */
+#define __SANE_USERSPACE_TYPES__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <libnvme.h>
+
+#include <ccan/endian/endian.h>
+
+static void print_discover_log(struct nvmf_discovery_log *log)
+{
+	int i, numrec = le64_to_cpu(log->numrec);
+
+	printf(".\n");
+	printf("|-- genctr:%llx\n", log->genctr);
+	printf("|-- numrec:%x\n", numrec);
+	printf("`-- recfmt:%x\n", log->recfmt);
+
+	for (i = 0; i < numrec; i++) {
+		struct nvmf_disc_log_entry *e = &log->entries[i];
+
+		printf("  %c-- Entry:%d\n", (i < numrec - 1) ? '|' : '`', i);
+		printf("  %c   |-- trtype:%x\n", (i < numrec - 1) ? '|' : ' ', e->trtype);
+		printf("  %c   |-- adrfam:%x\n", (i < numrec - 1) ? '|' : ' ', e->adrfam);
+		printf("  %c   |-- subtype:%x\n", (i < numrec - 1) ? '|' : ' ', e->subtype);
+		printf("  %c   |-- treq:%x\n", (i < numrec - 1) ? '|' : ' ', e->treq);
+		printf("  %c   |-- portid:%x\n", (i < numrec - 1) ? '|' : ' ', e->portid);
+		printf("  %c   |-- cntlid:%x\n", (i < numrec - 1) ? '|' : ' ', e->cntlid);
+		printf("  %c   |-- asqsz:%x\n", (i < numrec - 1) ? '|' : ' ', e->asqsz);
+		printf("  %c   |-- trsvcid:%s\n", (i < numrec - 1) ? '|' : ' ', e->trsvcid);
+		printf("  %c   |-- subnqn:%s\n", (i < numrec - 1) ? '|' : ' ', e->subnqn);
+		printf("  %c   `-- traddr:%s\n", (i < numrec - 1) ? '|' : ' ', e->traddr);
+	}
+}
+
+int main()
+{
+	struct nvmf_discovery_log *log = NULL;
+	nvme_root_t r;
+	nvme_host_t h;
+	nvme_ctrl_t c;
+	int ret;
+	struct nvme_fabrics_config cfg;
+
+	nvmf_default_config(&cfg);
+
+	r = nvme_scan(NULL);
+	h = nvme_default_host(r);
+	if (!h) {
+		fprintf(stderr, "Failed to allocated memory\n");
+		return ENOMEM;
+	}
+	c = nvme_create_ctrl(r, NVME_DISC_SUBSYS_NAME, "loop",
+			     NULL, NULL, NULL, NULL);
+	if (!c) {
+		fprintf(stderr, "Failed to allocate memory\n");
+		return ENOMEM;
+	}
+	ret = nvmf_add_ctrl(h, c, &cfg);
+	if (ret < 0) {
+		fprintf(stderr, "no controller found\n");
+		return errno;
+	}
+
+	ret = nvmf_get_discovery_log(c, &log, 4);
+	nvme_disconnect_ctrl(c);
+	nvme_free_ctrl(c);
+
+	if (ret)
+		fprintf(stderr, "nvmf-discover-log:%x\n", ret);
+	else
+		print_discover_log(log);
+
+	nvme_free_tree(r);
+	free(log);
+	return 0;
+}
diff --git a/examples/discover-loop.py b/examples/discover-loop.py
new file mode 100644
index 0000000..8481e82
--- /dev/null
+++ b/examples/discover-loop.py
@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: Apache-2.0
+'''
+Example script for nvme discovery
+
+Copyright (c) 2021 Hannes Reinecke, SUSE Software Solutions
+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.
+'''
+
+import sys
+import pprint
+from libnvme import nvme
+
+def disc_supp_str(dlp_supp_opts):
+    d = {
+        nvme.NVMF_LOG_DISC_LID_EXTDLPES: "Extended Discovery Log Page Entry Supported (EXTDLPES)",
+        nvme.NVMF_LOG_DISC_LID_PLEOS:    "Port Local Entries Only Supported (PLEOS)",
+        nvme.NVMF_LOG_DISC_LID_ALLSUBES: "All NVM Subsystem Entries Supported (ALLSUBES)",
+    }
+    return [txt for msk, txt in d.items() if dlp_supp_opts & msk]
+
+r = nvme.root()
+h = nvme.host(r)
+c = nvme.ctrl(r, nvme.NVME_DISC_SUBSYS_NAME, 'loop')
+try:
+    c.connect(h)
+except Exception as e:
+    sys.exit(f'Failed to connect: {e}')
+
+print("connected to %s subsys %s" % (c.name, c.subsystem.name))
+
+slp = c.supported_log_pages()
+
+try:
+    dlp_supp_opts = slp[nvme.NVME_LOG_LID_DISCOVER] >> 16
+except (TypeError, IndexError):
+    dlp_supp_opts = 0
+
+print(f"LID {nvme.NVME_LOG_LID_DISCOVER}h (Discovery), supports: {disc_supp_str(dlp_supp_opts)}")
+
+try:
+    lsp = nvme.NVMF_LOG_DISC_LSP_PLEO if dlp_supp_opts & nvme.NVMF_LOG_DISC_LID_PLEOS else 0
+    d = c.discover(lsp=lsp)
+    print(pprint.pformat(d))
+except Exception as e:
+    sys.exit(f'Failed to discover: {e}')
+
+try:
+    c.disconnect()
+except Exception as e:
+    sys.exit(f'Failed to disconnect: {e}')
+
+c = None
+h = None
+r = None
diff --git a/examples/display-columnar.c b/examples/display-columnar.c
new file mode 100644
index 0000000..db98bdf
--- /dev/null
+++ b/examples/display-columnar.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors: Keith Busch <keith.busch@wdc.com>
+ */
+
+/**
+ * display-columnar: Scans the nvme topology, prints each record type in a
+ * column format for easy visual scanning.
+ */
+#include <stdio.h>
+#include <inttypes.h>
+#include <libnvme.h>
+
+static const char dash[101] = {[0 ... 99] = '-'};
+int main()
+{
+	nvme_root_t r;
+	nvme_host_t h;
+	nvme_subsystem_t s;
+	nvme_ctrl_t c;
+	nvme_path_t p;
+	nvme_ns_t n;
+
+	r = nvme_scan(NULL);
+	if (!r)
+		return -1;
+
+
+	printf("%-16s %-96s %-.16s\n", "Subsystem", "Subsystem-NQN", "Controllers");
+	printf("%-.16s %-.96s %-.16s\n", dash, dash, dash);
+
+	nvme_for_each_host(r, h) {
+		nvme_for_each_subsystem(h, s) {
+			bool first = true;
+			printf("%-16s %-96s ", nvme_subsystem_get_name(s),
+			       nvme_subsystem_get_nqn(s));
+
+			nvme_subsystem_for_each_ctrl(s, c) {
+				printf("%s%s", first ? "": ", ",
+				       nvme_ctrl_get_name(c));
+				first = false;
+			}
+			printf("\n");
+		}
+	}
+	printf("\n");
+
+	printf("%-8s %-20s %-40s %-8s %-6s %-14s %-12s %-16s\n", "Device",
+		"SN", "MN", "FR", "TxPort", "Address", "Subsystem", "Namespaces");
+	printf("%-.8s %-.20s %-.40s %-.8s %-.6s %-.14s %-.12s %-.16s\n", dash, dash,
+		dash, dash, dash, dash, dash, dash);
+
+	nvme_for_each_host(r, h) {
+		nvme_for_each_subsystem(h, s) {
+			nvme_subsystem_for_each_ctrl(s, c) {
+				bool first = true;
+
+				printf("%-8s %-20s %-40s %-8s %-6s %-14s %-12s ",
+				       nvme_ctrl_get_name(c),
+				       nvme_ctrl_get_serial(c),
+				       nvme_ctrl_get_model(c),
+				       nvme_ctrl_get_firmware(c),
+				       nvme_ctrl_get_transport(c),
+				       nvme_ctrl_get_address(c),
+				       nvme_subsystem_get_name(s));
+
+				nvme_ctrl_for_each_ns(c, n) {
+					printf("%s%s", first ? "": ", ",
+					       nvme_ns_get_name(n));
+					first = false;
+				}
+
+				nvme_ctrl_for_each_path(c, p) {
+					printf("%s%s", first ? "": ", ",
+					       nvme_ns_get_name(nvme_path_get_ns(p)));
+					first = false;
+				}
+				printf("\n");
+			}
+		}
+	}
+	printf("\n");
+
+ 	printf("%-12s %-8s %-16s %-8s %-16s\n", "Device", "NSID", "Sectors", "Format", "Controllers");
+	printf("%-.12s %-.8s %-.16s %-.8s %-.16s\n", dash, dash, dash, dash, dash);
+
+	nvme_for_each_host(r, h) {
+		nvme_for_each_subsystem(h, s) {
+			nvme_subsystem_for_each_ctrl(s, c) {
+				nvme_ctrl_for_each_ns(c, n)
+					printf("%-12s %-8d %-16" PRIu64 " %-8d %s\n",
+					       nvme_ns_get_name(n),
+					       nvme_ns_get_nsid(n),
+					       nvme_ns_get_lba_count(n),
+					       nvme_ns_get_lba_size(n),
+					       nvme_ctrl_get_name(c));
+			}
+
+			nvme_subsystem_for_each_ns(s, n) {
+				bool first = true;
+
+				printf("%-12s %-8d %-16" PRIu64 " %-8d ",
+				       nvme_ns_get_name(n),
+				       nvme_ns_get_nsid(n),
+				       nvme_ns_get_lba_count(n),
+				       nvme_ns_get_lba_size(n));
+				nvme_subsystem_for_each_ctrl(s, c) {
+					printf("%s%s", first ? "" : ", ",
+					       nvme_ctrl_get_name(c));
+					first = false;
+				}
+				printf("\n");
+			}
+		}
+	}
+	return 0;
+}
+
diff --git a/examples/display-tree.c b/examples/display-tree.c
new file mode 100644
index 0000000..b9ea75f
--- /dev/null
+++ b/examples/display-tree.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors: Keith Busch <keith.busch@wdc.com>
+ */
+
+/**
+ * display-tree: Scans the nvme topology, prints as an ascii tree with some
+ * selected attributes for each component.
+ */
+#include <stdio.h>
+#include <inttypes.h>
+#include <libnvme.h>
+
+int main()
+{
+	nvme_root_t r;
+	nvme_host_t h;
+	nvme_subsystem_t s, _s;
+	nvme_ctrl_t c, _c;
+	nvme_path_t p, _p;
+	nvme_ns_t n, _n;
+
+	r = nvme_scan(NULL);
+	if (!r)
+		return -1;
+
+	printf(".\n");
+	nvme_for_each_host(r, h) {
+		nvme_for_each_subsystem_safe(h, s, _s) {
+			printf("%c-- %s - NQN=%s\n", _s ? '|' : '`',
+			       nvme_subsystem_get_name(s),
+			       nvme_subsystem_get_nqn(s));
+
+			nvme_subsystem_for_each_ns_safe(s, n, _n) {
+				printf("%c   |-- %s lba size:%d lba max:%" PRIu64 "\n",
+				       _s ? '|' : ' ',
+				       nvme_ns_get_name(n),
+				       nvme_ns_get_lba_size(n),
+				       nvme_ns_get_lba_count(n));
+			}
+
+			nvme_subsystem_for_each_ctrl_safe(s, c, _c) {
+				printf("%c   %c-- %s %s %s %s\n",
+				       _s ? '|' : ' ', _c ? '|' : '`',
+				       nvme_ctrl_get_name(c),
+				       nvme_ctrl_get_transport(c),
+				       nvme_ctrl_get_address(c),
+				       nvme_ctrl_get_state(c));
+
+				nvme_ctrl_for_each_ns_safe(c, n, _n)
+					printf("%c   %c   %c-- %s lba size:%d lba max:%" PRIu64 "\n",
+					       _s ? '|' : ' ', _c ? '|' : ' ',
+					       _n ? '|' : '`',
+					       nvme_ns_get_name(n),
+					       nvme_ns_get_lba_size(n),
+					       nvme_ns_get_lba_count(n));
+
+				nvme_ctrl_for_each_path_safe(c, p, _p)
+					printf("%c   %c   %c-- %s %s\n",
+					       _s ? '|' : ' ', _c ? '|' : ' ',
+					       _p ? '|' : '`',
+					       nvme_path_get_name(p),
+					       nvme_path_get_ana_state(p));
+			}
+		}
+	}
+	nvme_free_tree(r);
+	return 0;
+}
diff --git a/examples/meson.build b/examples/meson.build
new file mode 100644
index 0000000..3139311
--- /dev/null
+++ b/examples/meson.build
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# This file is part of libnvme.
+# Copyright (c) 2021 Dell Inc.
+#
+# Authors: Martin Belanger <Martin.Belanger@dell.com>
+#
+executable(
+    'telemetry-listen',
+    ['telemetry-listen.c'],
+    dependencies: libnvme_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
+executable(
+    'display-columnar',
+    ['display-columnar.c'],
+    dependencies: libnvme_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
+executable(
+    'display-tree',
+    ['display-tree.c'],
+    dependencies: libnvme_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
+executable(
+    'discover-loop',
+    ['discover-loop.c'],
+    dependencies: libnvme_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
+executable(
+    'mi-mctp',
+    ['mi-mctp.c'],
+    dependencies: libnvme_mi_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
+if libdbus_dep.found()
+    executable(
+        'mi-conf',
+        ['mi-conf.c'],
+        dependencies: [libnvme_mi_dep, libdbus_dep],
+        include_directories: [incdir, internal_incdir]
+    )
+endif
diff --git a/examples/mi-conf.c b/examples/mi-conf.c
new file mode 100644
index 0000000..4fdd405
--- /dev/null
+++ b/examples/mi-conf.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2022 Code Construct Pty Ltd.
+ *
+ * Authors: Jeremy Kerr <jk@codeconstruct.com.au>
+ */
+
+/**
+ * mi-conf: query a device for optimal MTU and set for both the local MCTP
+ * route (through dbus to mctpd) and the device itself (through NVMe-MI
+ * configuration commands)
+ */
+
+#include <err.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libnvme-mi.h>
+
+#include <ccan/array_size/array_size.h>
+#include <ccan/endian/endian.h>
+
+#include <dbus/dbus.h>
+
+#define MCTP_DBUS_NAME "xyz.openbmc_project.MCTP"
+#define MCTP_DBUS_PATH "/xyz/openbmc_project/mctp"
+#define MCTP_DBUS_EP_IFACE "au.com.CodeConstruct.MCTP.Endpoint"
+
+static int parse_mctp(const char *devstr, unsigned int *net, uint8_t *eid)
+{
+	int rc;
+
+	rc = sscanf(devstr, "mctp:%u,%hhu", net, eid);
+	if (rc != 2)
+		return -1;
+
+	return 0;
+}
+
+int find_port(nvme_mi_ep_t ep, uint8_t *portp, uint16_t *mtup)
+{
+	struct nvme_mi_read_nvm_ss_info ss_info;
+	struct nvme_mi_read_port_info port_info;
+	uint8_t port;
+	bool found;
+	int rc;
+
+	/* query number of ports */
+	rc = nvme_mi_mi_read_mi_data_subsys(ep, &ss_info);
+	if (rc) {
+		warn("Failed reading subsystem info");
+		return -1;
+	}
+
+	found = false;
+	for (port = 0; port <= ss_info.nump; port++) {
+		rc = nvme_mi_mi_read_mi_data_port(ep, port, &port_info);
+		if (rc) {
+			warn("Failed reading port info for port %ud", port);
+			return -1;
+		}
+
+		/* skip non-SMBus ports */
+		if (port_info.portt != 0x2)
+			continue;
+
+		if (found) {
+			warn("Mutliple SMBus ports; skipping duplicate");
+		} else {
+			*portp = port;
+			*mtup = port_info.mmctptus;
+			found = true;
+		}
+	}
+
+	return found ? 0 : 1;
+}
+
+int set_local_mtu(DBusConnection *bus, unsigned int net, uint8_t eid,
+		  uint32_t mtu)
+{
+	DBusMessage *msg, *resp;
+	DBusError berr;
+	char *ep_path;
+	int rc;
+
+	rc = asprintf(&ep_path, "%s/%u/%hhu", MCTP_DBUS_PATH, net, eid);
+	if (rc < 0) {
+		warn("Failed to create dbus path");
+		return -1;
+	}
+
+	/* The NVMe-MI interfaces refer to their MTU as *not* including the
+	 * 4-byte MCTP header, whereas the MCTP specs *do* include it. When
+	 * we're setting the route MTU, we're using to the MCTP-style MTU,
+	 * which needs the extra four bytes included
+	 */
+	mtu += 4;
+
+	rc = -1;
+	dbus_error_init(&berr);
+	msg = dbus_message_new_method_call(MCTP_DBUS_NAME, ep_path,
+					   MCTP_DBUS_EP_IFACE, "SetMTU");
+	if (!msg) {
+		warnx("Can't create D-Bus message");
+		goto out;
+	}
+
+	rc = dbus_message_append_args(msg,
+				      DBUS_TYPE_UINT32, &mtu,
+				      DBUS_TYPE_INVALID);
+	if (!rc) {
+		warnx("Can't construct D-Bus message arguments");
+		goto out_free_msg;
+	}
+
+	resp = dbus_connection_send_with_reply_and_block(bus, msg,
+							 2000, &berr);
+	if (!resp) {
+		warnx("Failed to set local MTU: %s (%s)", berr.message,
+		      berr.name);
+	} else {
+		dbus_message_unref(resp);
+		rc = 0;
+	}
+
+out_free_msg:
+	dbus_message_unref(msg);
+out:
+	dbus_error_free(&berr);
+	return rc;
+}
+
+int main(int argc, char **argv)
+{
+	uint16_t cur_mtu, mtu;
+	DBusConnection *bus;
+	const char *devstr;
+	uint8_t eid, port;
+	nvme_root_t root;
+	unsigned int net;
+	nvme_mi_ep_t ep;
+	DBusError berr;
+	int rc;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s mctp:<net>,<eid>\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	devstr = argv[1];
+	rc = parse_mctp(devstr, &net, &eid);
+	if (rc)
+		errx(EXIT_FAILURE, "can't parse MI device string '%s'", devstr);
+
+	root = nvme_mi_create_root(stderr, DEFAULT_LOGLEVEL);
+	if (!root)
+		err(EXIT_FAILURE, "can't create NVMe root");
+
+	ep = nvme_mi_open_mctp(root, net, eid);
+	if (!ep) {
+		warnx("can't open MCTP endpoint %d:%d", net, eid);
+		goto out_free_root;
+	}
+
+	dbus_error_init(&berr);
+	bus = dbus_bus_get(DBUS_BUS_SYSTEM, &berr);
+	if (!bus) {
+		warnx("Failed opening D-Bus: %s (%s)\n",
+		      berr.message, berr.name);
+		rc = -1;
+		goto out_close_ep;
+	}
+
+	rc = find_port(ep, &port, &mtu);
+	if (rc) {
+		warnx("Can't find SMBus port information");
+		goto out_close_bus;
+	}
+
+	rc = nvme_mi_mi_config_get_mctp_mtu(ep, port, &cur_mtu);
+	if (rc) {
+		cur_mtu = 0;
+		warn("Can't query current MTU; no way to revert on failure");
+	}
+
+	if (mtu == cur_mtu) {
+		printf("Current MTU (%d) is already at max\n", cur_mtu);
+		goto out_close_bus;
+	}
+
+	rc = nvme_mi_mi_config_set_mctp_mtu(ep, port, mtu);
+	if (rc) {
+		warn("Can't set MCTP MTU");
+		goto out_close_bus;
+	}
+
+	rc = set_local_mtu(bus, net, eid, mtu);
+	if (rc) {
+		/* revert if we have an old setting */
+		if (cur_mtu) {
+			rc = nvme_mi_mi_config_set_mctp_mtu(ep, port, cur_mtu);
+			if (rc)
+				warn("Failed to restore previous MTU!");
+			rc = -1;
+		}
+	} else {
+		printf("MTU for port %u set to %d (was %d)\n",
+		       port, mtu, cur_mtu);
+	}
+
+out_close_bus:
+	dbus_connection_unref(bus);
+out_close_ep:
+	dbus_error_free(&berr);
+	nvme_mi_close(ep);
+out_free_root:
+	nvme_mi_free_root(root);
+
+	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
diff --git a/examples/mi-mctp.c b/examples/mi-mctp.c
new file mode 100644
index 0000000..e0b7644
--- /dev/null
+++ b/examples/mi-mctp.c
@@ -0,0 +1,778 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2021 Code Construct Pty Ltd.
+ *
+ * Authors: Jeremy Kerr <jk@codeconstruct.com.au>
+ */
+
+/**
+ * mi-mctp: open a MI connection over MCTP, and query controller info
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <libnvme-mi.h>
+
+#include <ccan/array_size/array_size.h>
+#include <ccan/endian/endian.h>
+
+static void show_port_pcie(struct nvme_mi_read_port_info *port)
+{
+	printf("    PCIe max payload: 0x%x\n", 0x80 << port->pcie.mps);
+	printf("    PCIe link speeds: 0x%02x\n", port->pcie.sls);
+	printf("    PCIe current speed: 0x%02x\n", port->pcie.cls);
+	printf("    PCIe max link width: 0x%02x\n", port->pcie.mlw);
+	printf("    PCIe neg link width: 0x%02x\n", port->pcie.nlw);
+	printf("    PCIe port: 0x%02x\n", port->pcie.pn);
+}
+
+static void show_port_smbus(struct nvme_mi_read_port_info *port)
+{
+	printf("    SMBus address: 0x%02x\n", port->smb.vpd_addr);
+	printf("    VPD access freq: 0x%02x\n", port->smb.mvpd_freq);
+	printf("    MCTP address: 0x%02x\n", port->smb.mme_addr);
+	printf("    MCTP access freq: 0x%02x\n", port->smb.mme_freq);
+	printf("    NVMe basic management: %s\n",
+	       (port->smb.nvmebm & 0x1) ? "enabled" : "disabled");
+}
+
+static struct {
+	int typeid;
+	const char *name;
+	void (*fn)(struct nvme_mi_read_port_info *);
+} port_types[] = {
+	{ 0x00, "inactive", NULL },
+	{ 0x01, "PCIe", show_port_pcie },
+	{ 0x02, "SMBus", show_port_smbus },
+};
+
+static int show_port(nvme_mi_ep_t ep, int portid)
+{
+	void (*show_fn)(struct nvme_mi_read_port_info *);
+	struct nvme_mi_read_port_info port;
+	const char *typestr;
+	int rc;
+
+	rc = nvme_mi_mi_read_mi_data_port(ep, portid, &port);
+	if (rc)
+		return rc;
+
+	if (port.portt < ARRAY_SIZE(port_types)) {
+		show_fn = port_types[port.portt].fn;
+		typestr = port_types[port.portt].name;
+	} else {
+		show_fn = NULL;
+		typestr = "INVALID";
+	}
+
+	printf("  port %d\n", portid);
+	printf("    type %s[%d]\n", typestr, port.portt);
+	printf("    MCTP MTU: %d\n", port.mmctptus);
+	printf("    MEB size: %d\n", port.meb);
+
+	if (show_fn)
+		show_fn(&port);
+
+	return 0;
+}
+
+int do_info(nvme_mi_ep_t ep)
+{
+	struct nvme_mi_nvm_ss_health_status ss_health;
+	struct nvme_mi_read_nvm_ss_info ss_info;
+	int i, rc;
+
+	rc = nvme_mi_mi_read_mi_data_subsys(ep, &ss_info);
+	if (rc) {
+		warn("can't perform Read MI Data operation");
+		return -1;
+	}
+
+	printf("NVMe MI subsys info:\n");
+	printf(" num ports: %d\n", ss_info.nump + 1);
+	printf(" major ver: %d\n", ss_info.mjr);
+	printf(" minor ver: %d\n", ss_info.mnr);
+
+	printf("NVMe MI port info:\n");
+	for (i = 0; i <= ss_info.nump; i++)
+		show_port(ep, i);
+
+	rc = nvme_mi_mi_subsystem_health_status_poll(ep, true, &ss_health);
+	if (rc)
+		err(EXIT_FAILURE, "can't perform Health Status Poll operation");
+
+	printf("NVMe MI subsys health:\n");
+	printf(" subsystem status:  0x%x\n", ss_health.nss);
+	printf(" smart warnings:    0x%x\n", ss_health.sw);
+	printf(" composite temp:    %d\n", ss_health.ctemp);
+	printf(" drive life used:   %d%%\n", ss_health.pdlu);
+	printf(" controller status: 0x%04x\n", le16_to_cpu(ss_health.ccs));
+
+	return 0;
+}
+
+static int show_ctrl(nvme_mi_ep_t ep, uint16_t ctrl_id)
+{
+	struct nvme_mi_read_ctrl_info ctrl;
+	int rc;
+
+	rc = nvme_mi_mi_read_mi_data_ctrl(ep, ctrl_id, &ctrl);
+	if (rc)
+		return rc;
+
+	printf("  Controller id: %d\n", ctrl_id);
+	printf("    port id: %d\n", ctrl.portid);
+	if (ctrl.prii & 0x1) {
+		uint16_t bdfn = le16_to_cpu(ctrl.pri);
+		printf("    PCIe routing valid\n");
+		printf("    PCIe bus: 0x%02x\n", bdfn >> 8);
+		printf("    PCIe dev: 0x%02x\n", bdfn >> 3 & 0x1f);
+		printf("    PCIe fn : 0x%02x\n", bdfn & 0x7);
+	} else {
+		printf("    PCIe routing invalid\n");
+	}
+	printf("    PCI vendor: %04x\n", le16_to_cpu(ctrl.vid));
+	printf("    PCI device: %04x\n", le16_to_cpu(ctrl.did));
+	printf("    PCI subsys vendor: %04x\n", le16_to_cpu(ctrl.ssvid));
+	printf("    PCI subsys device: %04x\n", le16_to_cpu(ctrl.ssvid));
+
+	return 0;
+}
+
+static int do_controllers(nvme_mi_ep_t ep)
+{
+	struct nvme_ctrl_list ctrl_list;
+	int rc, i;
+
+	rc = nvme_mi_mi_read_mi_data_ctrl_list(ep, 0, &ctrl_list);
+	if (rc) {
+		warnx("Can't perform Controller List operation");
+		return rc;
+	}
+
+	printf("NVMe controller list:\n");
+	for (i = 0; i < le16_to_cpu(ctrl_list.num); i++) {
+		uint16_t id = le16_to_cpu(ctrl_list.identifier[i]);
+		show_ctrl(ep, id);
+	}
+	return 0;
+}
+
+static const char *__copy_id_str(const void *field, size_t size,
+				 char *buf, size_t buf_size)
+{
+	assert(size < buf_size);
+	strncpy(buf, field, size);
+	buf[size] = '\0';
+	return buf;
+}
+
+#define copy_id_str(f,b) __copy_id_str(f, sizeof(f), b, sizeof(b))
+
+int do_identify(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	struct nvme_identify_args id_args = { 0 };
+	struct nvme_mi_ctrl *ctrl;
+	struct nvme_id_ctrl id;
+	uint16_t ctrl_id;
+	char buf[41];
+	bool partial;
+	int rc, tmp;
+
+	if (argc < 2) {
+		fprintf(stderr, "no controller ID specified\n");
+		return -1;
+	}
+
+	tmp = atoi(argv[1]);
+	if (tmp < 0 || tmp > 0xffff) {
+		fprintf(stderr, "invalid controller ID\n");
+		return -1;
+	}
+
+	ctrl_id = tmp & 0xffff;
+
+	partial = argc > 2 && !strcmp(argv[2], "--partial");
+
+	ctrl = nvme_mi_init_ctrl(ep, ctrl_id);
+	if (!ctrl) {
+		warn("can't create controller");
+		return -1;
+	}
+
+	id_args.data = &id;
+	id_args.args_size = sizeof(id_args);
+	id_args.cns = NVME_IDENTIFY_CNS_CTRL;
+	id_args.nsid = NVME_NSID_NONE;
+	id_args.cntid = 0;
+	id_args.csi = NVME_CSI_NVM;
+
+	/* for this example code, we can either do a full or partial identify;
+	 * since we're only printing the fields before the 'rab' member,
+	 * these will be equivalent, aside from the size of the MI
+	 * response.
+	 */
+	if (partial) {
+		rc = nvme_mi_admin_identify_partial(ctrl, &id_args, 0,
+					    offsetof(struct nvme_id_ctrl, rab));
+	} else {
+		rc = nvme_mi_admin_identify(ctrl, &id_args);
+	}
+
+	if (rc) {
+		warn("can't perform Admin Identify command");
+		return -1;
+	}
+
+	printf("NVMe Controller %d identify\n", ctrl_id);
+	printf(" PCI vendor: %04x\n", le16_to_cpu(id.vid));
+	printf(" PCI subsys vendor: %04x\n", le16_to_cpu(id.ssvid));
+	printf(" Serial number: %s\n", copy_id_str(id.sn, buf));
+	printf(" Model number: %s\n", copy_id_str(id.mn, buf));
+	printf(" Firmware rev: %s\n", copy_id_str(id.fr, buf));
+
+	return 0;
+}
+
+void fhexdump(FILE *fp, const unsigned char *buf, int len)
+{
+	const int row_len = 16;
+	int i, j;
+
+	for (i = 0; i < len; i += row_len) {
+		char hbuf[row_len * strlen("00 ") + 1];
+		char cbuf[row_len + strlen("|") + 1];
+
+		for (j = 0; (j < row_len) && ((i+j) < len); j++) {
+			unsigned char c = buf[i + j];
+
+			sprintf(hbuf + j * 3, "%02x ", c);
+
+			if (!isprint(c))
+				c = '.';
+
+			sprintf(cbuf + j, "%c", c);
+		}
+
+		strcat(cbuf, "|");
+
+		fprintf(fp, "%08x  %*s |%s\n", i,
+				0 - (int)sizeof(hbuf) + 1, hbuf, cbuf);
+	}
+}
+
+void hexdump(const unsigned char *buf, int len)
+{
+	fhexdump(stdout, buf, len);
+}
+
+int do_get_log_page(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	struct nvme_get_log_args args = { 0 };
+	struct nvme_mi_ctrl *ctrl;
+	uint8_t buf[512];
+	uint16_t ctrl_id;
+	int rc, tmp;
+
+	if (argc < 2) {
+		fprintf(stderr, "no controller ID specified\n");
+		return -1;
+	}
+
+	tmp = atoi(argv[1]);
+	if (tmp < 0 || tmp > 0xffff) {
+		fprintf(stderr, "invalid controller ID\n");
+		return -1;
+	}
+
+	ctrl_id = tmp & 0xffff;
+
+	args.args_size = sizeof(args);
+	args.log = buf;
+	args.len = sizeof(buf);
+
+	if (argc > 2) {
+		tmp = atoi(argv[2]);
+		args.lid = tmp & 0xff;
+	} else {
+		args.lid = 0x1;
+	}
+
+	ctrl = nvme_mi_init_ctrl(ep, ctrl_id);
+	if (!ctrl) {
+		warn("can't create controller");
+		return -1;
+	}
+
+	rc = nvme_mi_admin_get_log(ctrl, &args);
+	if (rc) {
+		warn("can't perform Get Log page command");
+		return -1;
+	}
+
+	printf("Get log page (log id = 0x%02x) data:\n", args.lid);
+	hexdump(buf, args.len);
+
+	return 0;
+}
+
+int do_admin_raw(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	struct nvme_mi_admin_req_hdr req;
+	struct nvme_mi_admin_resp_hdr *resp;
+	struct nvme_mi_ctrl *ctrl;
+	size_t resp_data_len;
+	unsigned long tmp;
+	uint8_t buf[512];
+	uint16_t ctrl_id;
+	uint8_t opcode;
+	__le32 *cdw;
+	int i, rc;
+
+	if (argc < 2) {
+		fprintf(stderr, "no controller ID specified\n");
+		return -1;
+	}
+
+	if (argc < 3) {
+		fprintf(stderr, "no opcode specified\n");
+		return -1;
+	}
+
+	tmp = atoi(argv[1]);
+	if (tmp > 0xffff) {
+		fprintf(stderr, "invalid controller ID\n");
+		return -1;
+	}
+	ctrl_id = tmp & 0xffff;
+
+	tmp = atoi(argv[2]);
+	if (tmp > 0xff) {
+		fprintf(stderr, "invalid opcode\n");
+		return -1;
+	}
+	opcode = tmp & 0xff;
+
+	memset(&req, 0, sizeof(req));
+	req.opcode = opcode;
+	req.ctrl_id = cpu_to_le16(ctrl_id);
+
+	/* The cdw10 - cdw16 fields are contiguous in req; set from argv. */
+	cdw = (void *)&req + offsetof(typeof(req), cdw10);
+	for (i = 0; i < 6; i++) {
+		if (argc >= 4 + i)
+			tmp = strtoul(argv[3 + i], NULL, 0);
+		else
+			tmp = 0;
+		*cdw = cpu_to_le32(tmp & 0xffffffff);
+		cdw++;
+	}
+
+	printf("Admin request:\n");
+	printf(" opcode: 0x%02x\n", req.opcode);
+	printf(" ctrl:   0x%04x\n", le16_to_cpu(req.ctrl_id));
+	printf(" cdw10:   0x%08x\n", le32_to_cpu(req.cdw10));
+	printf(" cdw11:   0x%08x\n", le32_to_cpu(req.cdw11));
+	printf(" cdw12:   0x%08x\n", le32_to_cpu(req.cdw12));
+	printf(" cdw13:   0x%08x\n", le32_to_cpu(req.cdw13));
+	printf(" cdw14:   0x%08x\n", le32_to_cpu(req.cdw14));
+	printf(" cdw15:   0x%08x\n", le32_to_cpu(req.cdw15));
+	printf(" raw:\n");
+	hexdump((void *)&req, sizeof(req));
+
+	memset(buf, 0, sizeof(buf));
+	resp = (void *)buf;
+
+	ctrl = nvme_mi_init_ctrl(ep, ctrl_id);
+	if (!ctrl) {
+		warn("can't create controller");
+		return -1;
+	}
+
+	resp_data_len = sizeof(buf) - sizeof(*resp);
+
+	rc = nvme_mi_admin_xfer(ctrl, &req, 0, resp, 0, &resp_data_len);
+	if (rc) {
+		warn("nvme_admin_xfer failed: %d", rc);
+		return -1;
+	}
+
+	printf("Admin response:\n");
+	printf(" Status: 0x%02x\n", resp->status);
+	printf(" cdw0:   0x%08x\n", le32_to_cpu(resp->cdw0));
+	printf(" cdw1:   0x%08x\n", le32_to_cpu(resp->cdw1));
+	printf(" cdw3:   0x%08x\n", le32_to_cpu(resp->cdw3));
+	printf(" data [%zd bytes]\n", resp_data_len);
+
+	hexdump(buf + sizeof(*resp), resp_data_len);
+	return 0;
+}
+
+static struct {
+	uint8_t id;
+	const char *name;
+} sec_protos[] = {
+	{ 0x00, "Security protocol information" },
+	{ 0xea, "NVMe" },
+	{ 0xec, "JEDEC Universal Flash Storage" },
+	{ 0xed, "SDCard TrustedFlash Security" },
+	{ 0xee, "IEEE 1667" },
+	{ 0xef, "ATA Device Server Password Security" },
+};
+
+static const char *sec_proto_description(uint8_t id)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(sec_protos); i++) {
+		if (sec_protos[i].id == id)
+			return sec_protos[i].name;
+	}
+
+	if (id >= 0xf0)
+		return "Vendor specific";
+
+	return "unknown";
+}
+
+int do_security_info(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	struct nvme_security_receive_args args = { 0 };
+	nvme_mi_ctrl_t ctrl;
+	int i, rc, n_proto;
+	unsigned long tmp;
+	uint16_t ctrl_id;
+	struct {
+		uint8_t		rsvd[6];
+		uint16_t	len;
+		uint8_t		protocols[256];
+	} proto_info;
+
+	if (argc != 2) {
+		fprintf(stderr, "no controller ID specified\n");
+		return -1;
+	}
+
+	tmp = atoi(argv[1]);
+	if (tmp > 0xffff) {
+		fprintf(stderr, "invalid controller ID\n");
+		return -1;
+	}
+
+	ctrl_id = tmp & 0xffff;
+
+	ctrl = nvme_mi_init_ctrl(ep, ctrl_id);
+	if (!ctrl) {
+		warn("can't create controller");
+		return -1;
+	}
+
+	/* protocol 0x00, spsp 0x0000: retrieve supported protocols */
+	args.args_size = sizeof(args);
+	args.data = &proto_info;
+	args.data_len = sizeof(proto_info);
+
+	rc = nvme_mi_admin_security_recv(ctrl, &args);
+	if (rc) {
+		warnx("can't perform Security Receive command: rc %d", rc);
+		return -1;
+	}
+
+	if (args.data_len < 6) {
+		warnx("Short response in security receive command (%d bytes)",
+		      args.data_len);
+		return -1;
+	}
+
+	n_proto = be16_to_cpu(proto_info.len);
+	if (args.data_len < 6 + n_proto) {
+		warnx("Short response in security receive command (%d bytes), "
+		      "for %d protocols", args.data_len, n_proto);
+		return -1;
+	}
+
+	printf("Supported protocols:\n");
+	for (i = 0; i < n_proto; i++) {
+		uint8_t id = proto_info.protocols[i];
+		printf("  0x%02x: %s\n", id, sec_proto_description(id));
+	}
+
+	return 0;
+}
+
+struct {
+	enum nvme_mi_config_smbus_freq id;
+	const char *str;
+} smbus_freqs[] = {
+	{ NVME_MI_CONFIG_SMBUS_FREQ_100kHz, "100k" },
+	{ NVME_MI_CONFIG_SMBUS_FREQ_400kHz, "400k" },
+	{ NVME_MI_CONFIG_SMBUS_FREQ_1MHz,   "1M" },
+};
+
+static const char *smbus_freq_str(enum nvme_mi_config_smbus_freq freq)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(smbus_freqs); i++) {
+		if (smbus_freqs[i].id == freq)
+			return smbus_freqs[i].str;
+	}
+
+	return NULL;
+}
+
+static int smbus_freq_val(const char *str, enum nvme_mi_config_smbus_freq *freq)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(smbus_freqs); i++) {
+		if (!strcmp(smbus_freqs[i].str, str)) {
+			*freq = smbus_freqs[i].id;
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+int do_config_get(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	enum nvme_mi_config_smbus_freq freq;
+	uint16_t mtu;
+	uint8_t port;
+	int rc;
+
+	if (argc > 1)
+		port = atoi(argv[1]) & 0xff;
+	else
+		port = 0;
+
+	rc = nvme_mi_mi_config_get_smbus_freq(ep, port, &freq);
+	if (rc) {
+		warn("can't query SMBus freq for port %d\n", port);
+	} else {
+		const char *fstr = smbus_freq_str(freq);
+		printf("SMBus access frequency (port %d): %s [0x%x]\n", port,
+		       fstr ?: "unknown", freq);
+	}
+
+	rc = nvme_mi_mi_config_get_mctp_mtu(ep, port, &mtu);
+	if (rc)
+		warn("can't query MCTP MTU for port %d\n", port);
+	else
+		printf("MCTP MTU (port %d): %d\n", port, mtu);
+
+	return 0;
+}
+
+int do_config_set(nvme_mi_ep_t ep, int argc, char **argv)
+{
+	const char *name, *val;
+	uint8_t port;
+	int rc;
+
+	if (argc != 4) {
+		fprintf(stderr, "config set requires <port> <type> <val>\n");
+		return -1;
+	}
+
+	port = atoi(argv[1]) & 0xff;
+	name = argv[2];
+	val = argv[3];
+
+	if (!strcmp(name, "freq")) {
+		enum nvme_mi_config_smbus_freq freq;
+		rc = smbus_freq_val(val, &freq);
+		if (rc) {
+			fprintf(stderr, "unknown SMBus freq %s. "
+				"Try 100k, 400k or 1M\n", val);
+			return -1;
+		}
+		rc = nvme_mi_mi_config_set_smbus_freq(ep, port, freq);
+
+	} else if (!strcmp(name, "mtu")) {
+		uint16_t mtu;
+		mtu = atoi(val) & 0xffff;
+		/* controllers should reject this, but prevent the potential
+		 * footgun of disabling futher comunication with the device
+		 */
+		if (mtu < 64) {
+			fprintf(stderr, "MTU value too small\n");
+			return -1;
+		}
+		rc = nvme_mi_mi_config_set_mctp_mtu(ep, port, mtu);
+
+	} else {
+		fprintf(stderr, "Invalid configuration '%s', "
+			"try freq or mtu\n", name);
+		return -1;
+	}
+
+	if (rc)
+		fprintf(stderr, "config set failed with status %d\n", rc);
+
+	return rc;
+}
+
+enum action {
+	ACTION_INFO,
+	ACTION_CONTROLLERS,
+	ACTION_IDENTIFY,
+	ACTION_GET_LOG_PAGE,
+	ACTION_ADMIN_RAW,
+	ACTION_SECURITY_INFO,
+	ACTION_CONFIG_GET,
+	ACTION_CONFIG_SET,
+};
+
+static int do_action_endpoint(enum action action, nvme_mi_ep_t ep, int argc, char** argv)
+{
+	int rc;
+
+	switch (action) {
+	case ACTION_INFO:
+		rc = do_info(ep);
+		break;
+	case ACTION_CONTROLLERS:
+		rc = do_controllers(ep);
+		break;
+	case ACTION_IDENTIFY:
+		rc = do_identify(ep, argc, argv);
+		break;
+	case ACTION_GET_LOG_PAGE:
+		rc = do_get_log_page(ep, argc, argv);
+		break;
+	case ACTION_ADMIN_RAW:
+		rc = do_admin_raw(ep, argc, argv);
+		break;
+	case ACTION_SECURITY_INFO:
+		rc = do_security_info(ep, argc, argv);
+		break;
+	case ACTION_CONFIG_GET:
+		rc = do_config_get(ep, argc, argv);
+		break;
+	case ACTION_CONFIG_SET:
+		rc = do_config_set(ep, argc, argv);
+		break;
+	default:
+		/* This shouldn't be possible, as we should be covering all
+		 * of the enum action options above. Hoever, keep the compilers
+		 * happy and fail gracefully. */
+		fprintf(stderr, "invalid action %d?\n", action);
+		rc = -1;
+	}
+	return rc;
+}
+
+int main(int argc, char **argv)
+{
+	enum action action;
+	nvme_root_t root;
+	nvme_mi_ep_t ep;
+	bool dbus = false, usage = true;
+	uint8_t eid;
+	int rc = 0, net;
+
+	if (argc >= 2 && strcmp(argv[1], "dbus") == 0) {
+		usage = false;
+		dbus= true;
+		argv += 1;
+		argc -= 1;
+	} else if (argc >= 3) {
+		usage = false;
+		net = atoi(argv[1]);
+		eid = atoi(argv[2]) & 0xff;
+		argv += 2;
+		argc -= 2;
+	}
+
+	if (usage) {
+		fprintf(stderr,
+			"usage: %s <net> <eid> [action] [action args]\n"
+			"       %s 'dbus'      [action] [action args]\n",
+			argv[0], argv[0]);
+		fprintf(stderr, "where action is:\n"
+			"  info\n"
+			"  controllers\n"
+			"  identify <controller-id> [--partial]\n"
+			"  get-log-page <controller-id> [<log-id>]\n"
+			"  admin <controller-id> <opcode> [<cdw10>, <cdw11>, ...]\n"
+			"  security-info <controller-id>\n"
+			"  get-config [port]\n"
+			"  set-config <port> <type> <val>\n"
+			"\n"
+			"  'dbus' target will query D-Bus for known MCTP endpoints\n"
+			);
+		return EXIT_FAILURE;
+	}
+
+	if (argc == 1) {
+		action = ACTION_INFO;
+	} else {
+		char *action_str = argv[1];
+		argc--;
+		argv++;
+
+		if (!strcmp(action_str, "info")) {
+			action = ACTION_INFO;
+		} else if (!strcmp(action_str, "controllers")) {
+			action = ACTION_CONTROLLERS;
+		} else if (!strcmp(action_str, "identify")) {
+			action = ACTION_IDENTIFY;
+		} else if (!strcmp(action_str, "get-log-page")) {
+			action = ACTION_GET_LOG_PAGE;
+		} else if (!strcmp(action_str, "admin")) {
+			action = ACTION_ADMIN_RAW;
+		} else if (!strcmp(action_str, "security-info")) {
+			action = ACTION_SECURITY_INFO;
+		} else if (!strcmp(action_str, "get-config")) {
+			action = ACTION_CONFIG_GET;
+		} else if (!strcmp(action_str, "set-config")) {
+			action = ACTION_CONFIG_SET;
+		} else {
+			fprintf(stderr, "invalid action '%s'\n", action_str);
+			return EXIT_FAILURE;
+		}
+	}
+	if (dbus) {
+		nvme_root_t root;
+		int i = 0;
+
+		root = nvme_mi_scan_mctp();
+		if (!root)
+			errx(EXIT_FAILURE, "can't scan D-Bus entries");
+
+		nvme_mi_for_each_endpoint(root, ep) i++;
+		printf("Found %d endpoints in D-Bus:\n", i);
+		nvme_mi_for_each_endpoint(root, ep) {
+			char *desc = nvme_mi_endpoint_desc(ep);
+			printf("%s\n", desc);
+			rc = do_action_endpoint(action, ep, argc, argv);
+			printf("---\n");
+			free(desc);
+		}
+		nvme_mi_free_root(root);
+	} else {
+		root = nvme_mi_create_root(stderr, DEFAULT_LOGLEVEL);
+		if (!root)
+			err(EXIT_FAILURE, "can't create NVMe root");
+
+		ep = nvme_mi_open_mctp(root, net, eid);
+		if (!ep)
+			errx(EXIT_FAILURE, "can't open MCTP endpoint %d:%d", net, eid);
+		rc = do_action_endpoint(action, ep, argc, argv);
+		nvme_mi_close(ep);
+		nvme_mi_free_root(root);
+	}
+
+	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
+
diff --git a/examples/telemetry-listen.c b/examples/telemetry-listen.c
new file mode 100644
index 0000000..ec5edb3
--- /dev/null
+++ b/examples/telemetry-listen.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors: Keith Busch <keith.busch@wdc.com>
+ */
+
+/**
+ * Open all nvme controller's uevent and listen for changes. If NVME_AEN event
+ * is observed with controller telemetry data, read the log and save it to a
+ * file in /var/log/ with the device's unique name and epoch timestamp.
+ */
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <libnvme.h>
+
+#include <ccan/endian/endian.h>
+
+struct events {
+	nvme_ctrl_t c;
+	int uevent_fd;
+};
+
+static int open_uevent(nvme_ctrl_t c)
+{
+	char buf[0x1000];
+	if (snprintf(buf, sizeof(buf), "%s/uevent", nvme_ctrl_get_sysfs_dir(c)) < 0)
+		return -1;
+	return open(buf, O_RDONLY);
+}
+
+static void save_telemetry(nvme_ctrl_t c)
+{
+	char buf[0x1000];
+	size_t log_size;
+	int ret, fd;
+	struct nvme_telemetry_log *log;
+	time_t s;
+
+	/* Clear the log (rae == false) at the end to see new telemetry events later */
+	ret = nvme_get_ctrl_telemetry(nvme_ctrl_get_fd(c), false, &log, NVME_TELEMETRY_DA_3, &log_size);
+	if (ret)
+		return;
+
+	s = time(NULL);
+	ret = snprintf(buf, sizeof(buf), "/var/log/%s-telemetry-%ld",
+		nvme_ctrl_get_subsysnqn(c), s);
+	if (ret < 0) {
+		free(log);
+		return;
+	}
+
+	fd = open(buf, O_CREAT|O_WRONLY, S_IRUSR|S_IRGRP);
+	if (fd < 0) {
+		free(log);
+		return;
+	}
+
+	ret = write(fd, log, log_size);
+	if (ret < 0)
+		printf("failed to write telemetry log\n");
+	else
+		printf("telemetry log save as %s, wrote:%d size:%zd\n", buf,
+			ret, log_size);
+	close(fd);
+	free(log);
+}
+
+static void check_telemetry(nvme_ctrl_t c, int ufd)
+{
+	char buf[0x1000] = { 0 };
+	char *p, *ptr;
+	int len;
+
+	len = read(ufd, buf, sizeof(buf) - 1);
+	if (len < 0)
+		return;
+
+	ptr = buf;
+	while ((p = strsep(&ptr, "\n")) != NULL) {
+		__u32 aen, type, info, lid;
+
+		if (sscanf(p, "NVME_AEN=0x%08x", &aen) != 1)
+			continue;
+
+		type = aen & 0x07;
+		info = (aen >> 8) & 0xff;
+		lid = (aen >> 16) & 0xff;
+
+		printf("%s: aen type:%x info:%x lid:%d\n",
+			nvme_ctrl_get_name(c), type, info, lid);
+		if (type == NVME_AER_NOTICE &&
+		    info == NVME_AER_NOTICE_TELEMETRY)
+			save_telemetry(c);
+	}
+}
+
+static void wait_events(fd_set *fds, struct events *e, int nr)
+{
+	int ret, i;
+
+	for (i = 0; i < nr; i++)
+		check_telemetry(e[i].c, e[i].uevent_fd);
+
+	while (1) {
+		ret = select(nr, fds, NULL, NULL, NULL);
+		if (ret < 0)
+			return;
+
+		for (i = 0; i < nr; i++) {
+			if (!FD_ISSET(e[i].uevent_fd, fds))
+				continue;
+			check_telemetry(e[i].c, e[i].uevent_fd);
+		}
+	}
+}
+
+int main()
+{
+	struct events *e;
+	fd_set fds;
+	int i = 0;
+
+	nvme_subsystem_t s;
+	nvme_ctrl_t c;
+	nvme_host_t h;
+	nvme_root_t r;
+
+	r = nvme_scan(NULL);
+	if (!r)
+		return EXIT_FAILURE;
+
+	nvme_for_each_host(r, h)
+		nvme_for_each_subsystem(h, s)
+			nvme_subsystem_for_each_ctrl(s, c)
+				i++;
+
+	e = calloc(i, sizeof(struct events));
+	FD_ZERO(&fds);
+	i = 0;
+
+	nvme_for_each_host(r, h) {
+		nvme_for_each_subsystem(h, s) {
+			nvme_subsystem_for_each_ctrl(s, c) {
+				int fd = open_uevent(c);
+
+				if (fd < 0)
+					continue;
+				FD_SET(fd, &fds);
+				e[i].uevent_fd = fd;
+				e[i].c = c;
+				i++;
+			}
+		}
+	}
+
+	wait_events(&fds, e, i);
+	nvme_free_tree(r);
+	free(e);
+
+	return EXIT_SUCCESS;
+}