nvme: Add the interface to get the optimal polling group

This patch is used to add spdk_nvme_poll_group_get_optimal
public API.

Signed-off-by: Ziye Yang <ziye.yang@intel.com>
Change-Id: Iee34c89e0e1ff1f81167b18e198c144ca28f71de
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3311
Community-CI: Broadcom CI
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## v21.04: (Upcoming Release)
 
+### nvme
+
+Added `spdk_nvme_qpair_get_optimal_poll_group` function and `qpair_get_optimal_poll_group`
+function pointer in spdk_nvmf_transport_ops structure in order to add the qpair to the most
+suitable polling group.
+
 ## v21.01:
 
 ### bdev

include/spdk/nvme.h

@@ -2186,6 +2186,15 @@ typedef void (*spdk_nvme_disconnected_qpair_cb)(struct spdk_nvme_qpair *qpair,
  */
 struct spdk_nvme_poll_group *spdk_nvme_poll_group_create(void *ctx);
 
+/**
+ * Get a optimal poll group.
+ *
+ * \param qpair The qpair to get the optimal poll group.
+ *
+ * \return Pointer to the optimal poll group, or NULL if not found.
+ */
+struct spdk_nvme_poll_group *spdk_nvme_qpair_get_optimal_poll_group(struct spdk_nvme_qpair *qpair);
+
 /**
  * Add an spdk_nvme_qpair to a poll group. qpairs may only be added to
  * a poll group if they are in the disconnected state; i.e. either they were
@@ -3408,6 +3417,8 @@ struct spdk_nvme_transport_ops {
 	void (*admin_qpair_abort_aers)(struct spdk_nvme_qpair *qpair);
 
 	struct spdk_nvme_transport_poll_group *(*poll_group_create)(void);
+	struct spdk_nvme_transport_poll_group *(*qpair_get_optimal_poll_group)(
+		struct spdk_nvme_qpair *qpair);
 
 	int (*poll_group_add)(struct spdk_nvme_transport_poll_group *tgroup, struct spdk_nvme_qpair *qpair);
 

lib/nvme/Makefile

@@ -34,8 +34,8 @@
 SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
-SO_VER := 4
+SO_VER := 5
-SO_MINOR := 2
+SO_MINOR := 0
 
 C_SRCS = nvme_ctrlr_cmd.c nvme_ctrlr.c nvme_fabric.c nvme_ns_cmd.c nvme_ns.c nvme_pcie_common.c nvme_pcie.c nvme_qpair.c nvme.c nvme_quirks.c nvme_transport.c nvme_uevent.c \
 	nvme_ctrlr_ocssd_cmd.c nvme_ns_ocssd_cmd.c nvme_tcp.c nvme_opal.c nvme_io_msg.c nvme_poll_group.c nvme_zns.c

lib/nvme/nvme_internal.h

@@ -1315,6 +1315,9 @@ int nvme_transport_qpair_iterate_requests(struct spdk_nvme_qpair *qpair,
 
 struct spdk_nvme_transport_poll_group *nvme_transport_poll_group_create(
 	const struct spdk_nvme_transport *transport);
+struct spdk_nvme_transport_poll_group *nvme_transport_qpair_get_optimal_poll_group(
+	const struct spdk_nvme_transport *transport,
+	struct spdk_nvme_qpair *qpair);
 int nvme_transport_poll_group_add(struct spdk_nvme_transport_poll_group *tgroup,
 				  struct spdk_nvme_qpair *qpair);
 int nvme_transport_poll_group_remove(struct spdk_nvme_transport_poll_group *tgroup,

lib/nvme/nvme_poll_group.c

@@ -50,6 +50,20 @@ spdk_nvme_poll_group_create(void *ctx)
 	return group;
 }
 
+struct spdk_nvme_poll_group *
+spdk_nvme_qpair_get_optimal_poll_group(struct spdk_nvme_qpair *qpair)
+{
+	struct spdk_nvme_transport_poll_group *tgroup;
+
+	tgroup = nvme_transport_qpair_get_optimal_poll_group(qpair->transport, qpair);
+
+	if (tgroup == NULL) {
+		return NULL;
+	}
+
+	return tgroup->group;
+}
+
 int
 spdk_nvme_poll_group_add(struct spdk_nvme_poll_group *group, struct spdk_nvme_qpair *qpair)
 {

lib/nvme/nvme_transport.c

@@ -448,6 +448,17 @@ nvme_transport_poll_group_create(const struct spdk_nvme_transport *transport)
 	return group;
 }
 
+struct spdk_nvme_transport_poll_group *
+nvme_transport_qpair_get_optimal_poll_group(const struct spdk_nvme_transport *transport,
+		struct spdk_nvme_qpair *qpair)
+{
+	if (transport->ops.qpair_get_optimal_poll_group) {
+		return transport->ops.qpair_get_optimal_poll_group(qpair);
+	} else {
+		return NULL;
+	}
+}
+
 int
 nvme_transport_poll_group_add(struct spdk_nvme_transport_poll_group *tgroup,
 			      struct spdk_nvme_qpair *qpair)

lib/nvme/spdk_nvme.map

@@ -141,6 +141,7 @@
 	spdk_nvme_ns_cmd_comparev_with_md;
 	spdk_nvme_ns_cmd_compare_with_md;
 
+	spdk_nvme_qpair_get_optimal_poll_group;
 	spdk_nvme_qpair_process_completions;
 	spdk_nvme_qpair_get_failure_reason;
 	spdk_nvme_qpair_add_cmd_error_injection;

test/unit/lib/nvme/nvme_poll_group.c/nvme_poll_group_ut.c

@@ -63,6 +63,12 @@ int g_destroy_return_value = 0;
 TAILQ_HEAD(nvme_transport_list, spdk_nvme_transport) g_spdk_nvme_transports =
 	TAILQ_HEAD_INITIALIZER(g_spdk_nvme_transports);
 
+DEFINE_STUB(nvme_transport_qpair_get_optimal_poll_group,
+	    struct spdk_nvme_transport_poll_group *,
+	    (const struct spdk_nvme_transport *transport,
+	     struct spdk_nvme_qpair *qpair),
+	    NULL);
+
 static void
 unit_test_disconnected_qpair_cb(struct spdk_nvme_qpair *qpair, void *poll_group_ctx)
 {