nvme: introduce function to get nguid

Signed-off-by: Jacek Kalwas <jacek.kalwas@intel.com>
Change-Id: Ida07eca2e3cbc390d8ee481f63b20f5715a53631
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8626
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

include/spdk/nvme.h

@@ -2639,6 +2639,15 @@ enum spdk_nvme_dealloc_logical_block_read_value spdk_nvme_ns_get_dealloc_logical
  */
 uint32_t spdk_nvme_ns_get_optimal_io_boundary(struct spdk_nvme_ns *ns);
 
+/**
+ * Get the NGUID for the given namespace.
+ *
+ * \param ns Namespace to query.
+ *
+ * \return a pointer to namespace NGUID, or NULL if ns does not have a NGUID.
+ */
+const uint8_t *spdk_nvme_ns_get_nguid(const struct spdk_nvme_ns *ns);
+
 /**
  * Get the UUID for the given namespace.
  *

lib/nvme/nvme_ns.c

@@ -406,6 +406,22 @@ nvme_ns_find_id_desc(const struct spdk_nvme_ns *ns, enum spdk_nvme_nidt type, si
 	return NULL;
 }
 
+const uint8_t *
+spdk_nvme_ns_get_nguid(const struct spdk_nvme_ns *ns)
+{
+	const uint8_t *nguid;
+	size_t size;
+
+	nguid = nvme_ns_find_id_desc(ns, SPDK_NVME_NIDT_NGUID, &size);
+	if (nguid && size != sizeof(((struct spdk_nvme_ns_data *)0)->nguid)) {
+		SPDK_WARNLOG("Invalid NIDT_NGUID descriptor length reported: %zu (expected: %zu)\n",
+			     size, sizeof(((struct spdk_nvme_ns_data *)0)->nguid));
+		return NULL;
+	}
+
+	return nguid;
+}
+
 const struct spdk_uuid *
 spdk_nvme_ns_get_uuid(const struct spdk_nvme_ns *ns)
 {

lib/nvme/spdk_nvme.map

@@ -124,6 +124,7 @@
 	spdk_nvme_ns_supports_compare;
 	spdk_nvme_ns_get_dealloc_logical_block_read_value;
 	spdk_nvme_ns_get_optimal_io_boundary;
+	spdk_nvme_ns_get_nguid;
 	spdk_nvme_ns_get_uuid;
 	spdk_nvme_ns_get_csi;
 	spdk_nvme_ns_get_flags;