lib/nvme: implement external IO processing

This patch allows to send IO requests from external module to the nvme
device.

External module should call nvme_io_msg_ctrlr_start() to start IO message
producer on the controller and enable sending messages.

nvme_io_msg_send() is used to send IO to NVMe driver thread context,
where passed function will be called. Allowing the external module to
issue IO as needed.

NVMe driver users should poll spdk_nvme_io_msg_process() to move forward,
sending IO from external module and process their completions.

Change-Id: Ie59abac69870c4e4daa50120c747f3b620395921
Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
Signed-off-by: Maciej Szwed <maciej.szwed@intel.com>
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/471386
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

include/spdk/nvme.h

@@ -1244,6 +1244,26 @@ int spdk_nvme_ctrlr_cmd_io_raw_with_md(struct spdk_nvme_ctrlr *ctrlr,
 int32_t spdk_nvme_qpair_process_completions(struct spdk_nvme_qpair *qpair,
 		uint32_t max_completions);
 
+/**
+ * Process IO message sent to controller from external module.
+ *
+ * This call process requests from the ring, send IO to an allocated qpair or
+ * admin commands in its context. This call is non-blocking and intended to be
+ * polled by SPDK thread to provide safe environment for NVMe request
+ * completition sent by external module to controller.
+ *
+ * The caller must ensure that each controller is polled by only one thread at
+ * a time.
+ *
+ * This function may be called at any point while the controller is attached to
+ * the SPDK NVMe driver.
+ *
+ * \param ctrlr Opaque handle to NVMe controller.
+ *
+ * \return number of processed external IO messages.
+ */
+int spdk_nvme_io_msg_process(struct spdk_nvme_ctrlr *ctrlr);
+
 /**
  * Send the given admin command to the NVMe controller.
  *

lib/nvme/Makefile

@@ -35,7 +35,7 @@ SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
 C_SRCS = nvme_ctrlr_cmd.c nvme_ctrlr.c nvme_fabric.c nvme_ns_cmd.c nvme_ns.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_ns_ocssd_cmd.c nvme_tcp.c nvme_opal.c nvme_io_msg.c
 C_SRCS-$(CONFIG_RDMA) += nvme_rdma.c
 LIBNAME = nvme
 LOCAL_SYS_LIBS = -luuid

lib/nvme/nvme.c

@@ -33,6 +33,7 @@
 
 #include "spdk/nvmf_spec.h"
 #include "nvme_internal.h"
+#include "nvme_io_msg.h"
 
 #define SPDK_NVME_DRIVER_NAME "spdk_nvme_driver"
 
@@ -68,6 +69,7 @@ spdk_nvme_detach(struct spdk_nvme_ctrlr *ctrlr)
 	nvme_ctrlr_proc_put_ref(ctrlr);
 
 	if (nvme_ctrlr_get_ref_count(ctrlr) == 0) {
+		nvme_io_msg_ctrlr_stop(ctrlr, NULL, true);
 		if (nvme_ctrlr_shared(ctrlr)) {
 			TAILQ_REMOVE(&g_spdk_nvme_driver->shared_attached_ctrlrs, ctrlr, tailq);
 		} else {
@@ -458,6 +460,8 @@ nvme_ctrlr_poll_internal(struct spdk_nvme_ctrlr *ctrlr,
 		return 0;
 	}
 
+	STAILQ_INIT(&ctrlr->io_producers);
+
 	/*
 	 * Controller has been initialized.
 	 *  Move it to the attached_ctrlrs list.

lib/nvme/nvme_internal.h

@@ -714,6 +714,12 @@ struct spdk_nvme_ctrlr {
 	/* CB to notify the user when the ctrlr is removed/failed. */
 	spdk_nvme_remove_cb			remove_cb;
 	void					*cb_ctx;
+
+	struct spdk_nvme_qpair		*external_io_msgs_qpair;
+	pthread_mutex_t			external_io_msgs_lock;
+	struct spdk_ring		*external_io_msgs;
+
+	STAILQ_HEAD(, nvme_io_msg_producer) io_producers;
 };
 
 struct spdk_nvme_probe_ctx {

lib/nvme/nvme_io_msg.c

@@ -0,0 +1,172 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "nvme_internal.h"
+#include "nvme_io_msg.h"
+
+#define SPDK_NVME_MSG_IO_PROCESS_SIZE 8
+
+/**
+ * Send message to IO queue.
+ */
+int
+nvme_io_msg_send(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, spdk_nvme_io_msg_fn fn,
+		 void *arg)
+{
+	int rc;
+	struct spdk_nvme_io_msg *io;
+
+	/* Protect requests ring against preemptive producers */
+	pthread_mutex_lock(&ctrlr->external_io_msgs_lock);
+
+	io = (struct spdk_nvme_io_msg *)calloc(1, sizeof(struct spdk_nvme_io_msg));
+	if (!io) {
+		SPDK_ERRLOG("IO msg allocation failed.");
+		pthread_mutex_unlock(&ctrlr->external_io_msgs_lock);
+		return -ENOMEM;
+	}
+
+	io->ctrlr = ctrlr;
+	io->nsid = nsid;
+	io->fn = fn;
+	io->arg = arg;
+
+	rc = spdk_ring_enqueue(ctrlr->external_io_msgs, (void **)&io, 1, NULL);
+	if (rc != 1) {
+		assert(false);
+		pthread_mutex_unlock(&ctrlr->external_io_msgs_lock);
+		return -ENOMEM;
+	}
+
+	pthread_mutex_unlock(&ctrlr->external_io_msgs_lock);
+
+	return 0;
+}
+
+int
+spdk_nvme_io_msg_process(struct spdk_nvme_ctrlr *ctrlr)
+{
+	int i;
+	int count;
+	struct spdk_nvme_io_msg *io;
+	void *requests[SPDK_NVME_MSG_IO_PROCESS_SIZE];
+
+	if (!ctrlr->external_io_msgs || !ctrlr->external_io_msgs_qpair) {
+		/* Not ready or pending reset */
+		return 0;
+	}
+
+	spdk_nvme_qpair_process_completions(ctrlr->external_io_msgs_qpair, 0);
+
+	count = spdk_ring_dequeue(ctrlr->external_io_msgs, requests,
+				  SPDK_NVME_MSG_IO_PROCESS_SIZE);
+	if (count == 0) {
+		return 0;
+	}
+
+	for (i = 0; i < count; i++) {
+		io = requests[i];
+
+		assert(io != NULL);
+
+		io->fn(io->ctrlr, io->nsid, io->arg);
+		free(io);
+	}
+
+	return count;
+}
+
+int
+nvme_io_msg_ctrlr_start(struct spdk_nvme_ctrlr *ctrlr, struct nvme_io_msg_producer *io_msg_producer)
+{
+	if (io_msg_producer == NULL) {
+		SPDK_ERRLOG("io_msg_producer cannot be NULL\n");
+		return -EINVAL;
+	}
+
+	if (!STAILQ_EMPTY(&ctrlr->io_producers) || ctrlr->is_resetting) {
+		/* There are registered producers - IO messaging already started */
+		STAILQ_INSERT_TAIL(&ctrlr->io_producers, io_msg_producer, link);
+		return 0;
+	}
+
+	pthread_mutex_init(&ctrlr->external_io_msgs_lock, NULL);
+
+	/**
+	 * Initialize ring and qpair for controller
+	 */
+	ctrlr->external_io_msgs = spdk_ring_create(SPDK_RING_TYPE_MP_SC, 65536, SPDK_ENV_SOCKET_ID_ANY);
+	if (!ctrlr->external_io_msgs) {
+		SPDK_ERRLOG("Unable to allocate memory for message ring\n");
+		return -ENOMEM;
+	}
+
+	ctrlr->external_io_msgs_qpair = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, NULL, 0);
+	if (ctrlr->external_io_msgs_qpair == NULL) {
+		SPDK_ERRLOG("spdk_nvme_ctrlr_alloc_io_qpair() failed\n");
+		spdk_ring_free(ctrlr->external_io_msgs);
+		return -1;
+	}
+
+	STAILQ_INSERT_TAIL(&ctrlr->io_producers, io_msg_producer, link);
+
+	return 0;
+}
+
+void
+nvme_io_msg_ctrlr_stop(struct spdk_nvme_ctrlr *ctrlr, struct nvme_io_msg_producer *io_msg_producer,
+		       bool shutdown)
+{
+	if (STAILQ_EMPTY(&ctrlr->io_producers) && shutdown) {
+		/* Shutdown path with no producers registered = io msg ctrlr not started */
+		return;
+	}
+
+	if (io_msg_producer != NULL) {
+		STAILQ_REMOVE(&ctrlr->io_producers, io_msg_producer, nvme_io_msg_producer, link);
+	}
+
+	if (!STAILQ_EMPTY(&ctrlr->io_producers) && !shutdown) {
+		/* There are still some registered producers */
+		return;
+	}
+
+	assert(ctrlr->external_io_msgs);
+	spdk_ring_free(ctrlr->external_io_msgs);
+
+	if (ctrlr->external_io_msgs_qpair) {
+		spdk_nvme_ctrlr_free_io_qpair(ctrlr->external_io_msgs_qpair);
+	}
+
+	pthread_mutex_destroy(&ctrlr->external_io_msgs_lock);
+}

lib/nvme/nvme_io_msg.h

@@ -0,0 +1,66 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file
+ * SPDK cuse
+ */
+
+
+#ifndef SPDK_NVME_IO_MSG_H_
+#define SPDK_NVME_IO_MSG_H_
+
+typedef void (*spdk_nvme_io_msg_fn)(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid,
+				    void *arg);
+
+struct spdk_nvme_io_msg {
+	struct spdk_nvme_ctrlr	*ctrlr;
+	uint32_t		nsid;
+
+	spdk_nvme_io_msg_fn	fn;
+	void			*arg;
+};
+
+struct nvme_io_msg_producer {
+	const char *name;
+	STAILQ_ENTRY(nvme_io_msg_producer) link;
+};
+
+int nvme_io_msg_send(struct spdk_nvme_ctrlr *ctrlr, uint32_t nsid, spdk_nvme_io_msg_fn fn,
+		     void *arg);
+
+int nvme_io_msg_ctrlr_start(struct spdk_nvme_ctrlr *ctrlr,
+			    struct nvme_io_msg_producer *io_msg_producer);
+void nvme_io_msg_ctrlr_stop(struct spdk_nvme_ctrlr *ctrlr,
+			    struct nvme_io_msg_producer *io_msg_producer, bool shutdown);
+
+#endif /* SPDK_NVME_IO_MSG_H_ */

test/unit/lib/nvme/nvme.c/nvme_ut.c

@@ -60,6 +60,8 @@ DEFINE_STUB(nvme_transport_ctrlr_construct, struct spdk_nvme_ctrlr *,
 	    (const struct spdk_nvme_transport_id *trid,
 	     const struct spdk_nvme_ctrlr_opts *opts,
 	     void *devhandle), NULL);
+DEFINE_STUB_V(nvme_io_msg_ctrlr_stop, (struct spdk_nvme_ctrlr *ctrlr,
+				       struct nvme_io_msg_producer *io_msg_producer, bool shutdown));
 
 static bool ut_destruct_called = false;
 void