mi: Introduce asynchronous event message handling

Added new functionality to mi.c and mi-mctp.c to handle AEMs.  Included
new example mi-mctp-ae.c for usage.

Signed-off-by: Chuck Horkin <chorkin@microsoft.com>

Author: chorkin

examples/meson.build

@@ -40,6 +40,13 @@ executable(
     include_directories: [incdir, internal_incdir]
 )
 
+executable(
+    'mi-mctp-ae',
+    ['mi-mctp-ae.c'],
+    dependencies: libnvme_mi_dep,
+    include_directories: [incdir, internal_incdir]
+)
+
 if libdbus_dep.found()
     executable(
         'mi-conf',

examples/mi-mctp-ae.c

@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * This file is part of libnvme.
+ */
+
+/**
+ * mi-mctp-ae: open a MI connection over MCTP, supporting asynchronous event messages
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h> // for usleep
+
+#include <libnvme-mi.h>
+#include <poll.h>
+
+#include <ccan/array_size/array_size.h>
+#include <ccan/endian/endian.h>
+#include <sys/select.h>
+
+// Function to print the byte array
+static void print_byte_array(void *data, size_t len)
+{
+	uint8_t *byte_data = (uint8_t *)data;
+
+	for (size_t i = 0; i < len; ++i)
+		printf("%02X ", byte_data[i]);
+	printf("\n");
+}
+
+static void print_event_info(struct nvme_mi_event *event)
+{
+	printf("aeoi: %02X\n", event->aeoi);
+	printf("aeocidi: %04X\n", event->aeocidi);
+	printf("aessi: %02X\n", event->aessi);
+
+	printf("specific_info: ");
+	if (event->spec_info_len && event->spec_info)
+		print_byte_array(event->spec_info, event->spec_info_len);
+	else
+		printf("EMPTY\n");
+
+	printf("vendor_specific_info: ");
+	if (event->vend_spec_info_len && event->vend_spec_info)
+		print_byte_array(event->vend_spec_info, event->vend_spec_info_len);
+	else
+		printf("EMPTY\n");
+}
+
+enum nvme_mi_aem_handler_next_action aem_handler(nvme_mi_ep_t ep, size_t num_events, void *userdata)
+{
+	uint32_t *count = (uint32_t *) userdata;
+	*count = *count+1;
+
+	printf("Received notification #%d with %zu events:\n", *count, num_events);
+	for (int i = 0; i < num_events; i++) {
+		struct nvme_mi_event *event = nvme_mi_aem_get_next_event(ep);
+
+		if (event == NULL)
+			printf("Unexpected NULL event\n");
+		else {
+			printf("Event:\n");
+			print_event_info(event);
+			printf("\n");
+		}
+	}
+
+	return NVME_MI_AEM_HNA_ACK;
+}
+
+int main(int argc, char **argv)
+{
+	nvme_root_t root;
+	nvme_mi_ep_t ep;
+	bool usage = true;
+	uint8_t eid = 0;
+	int rc = 0, net = 0;
+	struct nvme_mi_aem_callbacks aem_cb_info = {0};
+	uint32_t notification_counter = 0;
+
+	const uint8_t AEM_FD_INDEX = 0;
+	const uint8_t STD_IN_FD_INDEX = 1;
+
+	if (argc > 3) {
+		usage = false;
+		net = atoi(argv[1]);
+		eid = atoi(argv[2]) & 0xff;
+		argv += 2;
+		argc -= 2;
+
+		int event_count = argc - 1;
+
+		for (int i = 0; i < event_count; i++) {
+			int event = atoi(argv[1+i]);
+
+			aem_cb_info.enabled[event] = true;
+		}
+	}
+
+	if (usage) {
+		fprintf(stderr,
+			"usage: %s <net> <eid> [AE #s separated by spaces]\n",
+			argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	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);
+
+	aem_cb_info.aem_handler = aem_handler;
+
+	rc = nvme_mi_enable_aem(ep, true, true, true, 1, 4, &aem_cb_info, &notification_counter);
+	if (rc)
+		errx(EXIT_FAILURE, "Can't enable aem:%d (%d)", rc, errno);
+
+	struct pollfd fds[2];
+
+	fds[AEM_FD_INDEX].fd = nvme_mi_get_aem_fd(ep);
+	if (fds[AEM_FD_INDEX].fd < 0)
+		errx(EXIT_FAILURE, "Can't get aem fd\n");
+
+	fds[STD_IN_FD_INDEX].fd = STDIN_FILENO;
+
+	fds[AEM_FD_INDEX].events = POLLIN;
+	fds[STD_IN_FD_INDEX].events = POLLIN;
+
+	printf("Press any key to exit\n");
+	while (1) {
+		int poll_timeout = 500; // Timeout in milliseconds
+
+		rc = poll(fds, 2, poll_timeout);
+
+		if (rc == -1) {
+			perror("poll");
+			break;
+		} else if (rc == 0) {
+			//printf("No data within %d milliseconds.\n", timeout);
+		} else {
+			//Time to do the work
+			if (fds[AEM_FD_INDEX].revents & POLLIN) {
+				rc = nvme_mi_aem_process(ep, &notification_counter);
+				if (rc)
+					errx(EXIT_FAILURE,
+						"nvme_mi_aem_process failed with:%d (%d)",
+						rc,
+						errno);
+			}
+			if (fds[STD_IN_FD_INDEX].revents & POLLIN)
+				break;//we are done
+		}
+	}
+
+	//Cleanup
+	nvme_mi_disable_aem(ep);
+	nvme_mi_close(ep);
+	nvme_mi_free_root(root);
+
+	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
+

src/libnvme-mi.map

@@ -1,6 +1,11 @@
 LIBNVME_MI_1_12 {
 	global:
 		nvme_mi_mi_xfer;
+		nvme_mi_get_aem_fd;
+		nvme_mi_enable_aem;
+		nvme_mi_aem_process;
+		nvme_mi_disable_aem;
+		nvme_mi_aem_get_next_event;
 };
 
 LIBNVME_MI_1_11 {