Adding upstream version 18.2.2.upstream/18.2.2

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

4 files changed, 998 insertions, 0 deletions

diff --git a/src/spdk/test/external_code/passthru/Makefile b/src/spdk/test/external_code/passthru/Makefile
new file mode 100644
index 000000000..e8560ace4
--- /dev/null
+++ b/src/spdk/test/external_code/passthru/Makefile
@@ -0,0 +1,43 @@
+#
+#  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.
+#
+
+src=vbdev_passthru_rpc.c vbdev_passthru.c
+shared:
+	$(CC) $(COMMON_CFLAGS) -c -fPIC ./vbdev_passthru_rpc.c -o ./vbdev_passthru_rpc.o
+	$(CC) $(COMMON_CFLAGS) -c -fPIC ./vbdev_passthru.c -o ./vbdev_passthru.o
+	$(CC) $(COMMON_CFLAGS) -shared ./vbdev_passthru_rpc.o ./vbdev_passthru.o -o ./libpassthru_external.so
+
+static:
+	$(CC) $(COMMON_CFLAGS) -c ./vbdev_passthru_rpc.c -o ./vbdev_passthru_rpc.o
+	$(CC) $(COMMON_CFLAGS) -c ./vbdev_passthru.c -o ./vbdev_passthru.o
+	$(AR) rcs ./libpassthru_external.a ./vbdev_passthru_rpc.o ./vbdev_passthru.o
diff --git a/src/spdk/test/external_code/passthru/vbdev_passthru.c b/src/spdk/test/external_code/passthru/vbdev_passthru.c
new file mode 100644
index 000000000..cecc8f701
--- /dev/null
+++ b/src/spdk/test/external_code/passthru/vbdev_passthru.c
@@ -0,0 +1,748 @@
+/*-
+ *   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.
+ */
+
+/*
+ * This is a simple example of a virtual block device module that passes IO
+ * down to a bdev (or bdevs) that its configured to attach to.
+ */
+
+#include "vbdev_passthru.h"
+#include "spdk/env.h"
+#include "spdk/conf.h"
+#include "spdk/endian.h"
+#include "spdk/thread.h"
+
+
+static int vbdev_ext_passthru_init(void);
+static void vbdev_ext_passthru_get_spdk_running_config(FILE *fp);
+static int vbdev_ext_passthru_get_ctx_size(void);
+static void vbdev_ext_passthru_examine(struct spdk_bdev *bdev);
+static void vbdev_ext_passthru_finish(void);
+static int vbdev_ext_passthru_config_json(struct spdk_json_write_ctx *w);
+
+static struct spdk_bdev_module passthru_if_external = {
+	.name = "passthru_external",
+	.module_init = vbdev_ext_passthru_init,
+	.config_text = vbdev_ext_passthru_get_spdk_running_config,
+	.get_ctx_size = vbdev_ext_passthru_get_ctx_size,
+	.examine_config = vbdev_ext_passthru_examine,
+	.module_fini = vbdev_ext_passthru_finish,
+	.config_json = vbdev_ext_passthru_config_json
+};
+
+SPDK_BDEV_MODULE_REGISTER(passthru, &passthru_if_external)
+
+/* List of pt_bdev names and their base bdevs via configuration file.
+ * Used so we can parse the conf once at init and use this list in examine().
+ */
+struct bdev_names {
+	char			*vbdev_name;
+	char			*bdev_name;
+	TAILQ_ENTRY(bdev_names)	link;
+};
+static TAILQ_HEAD(, bdev_names) g_bdev_names = TAILQ_HEAD_INITIALIZER(g_bdev_names);
+
+/* List of virtual bdevs and associated info for each. */
+struct vbdev_passthru {
+	struct spdk_bdev		*base_bdev; /* the thing we're attaching to */
+	struct spdk_bdev_desc		*base_desc; /* its descriptor we get from open */
+	struct spdk_bdev		pt_bdev;    /* the PT virtual bdev */
+	TAILQ_ENTRY(vbdev_passthru)	link;
+};
+static TAILQ_HEAD(, vbdev_passthru) g_pt_nodes = TAILQ_HEAD_INITIALIZER(g_pt_nodes);
+
+/* The pt vbdev channel struct. It is allocated and freed on my behalf by the io channel code.
+ * If this vbdev needed to implement a poller or a queue for IO, this is where those things
+ * would be defined. This passthru bdev doesn't actually need to allocate a channel, it could
+ * simply pass back the channel of the bdev underneath it but for example purposes we will
+ * present its own to the upper layers.
+ */
+struct pt_io_channel {
+	struct spdk_io_channel	*base_ch; /* IO channel of base device */
+};
+
+/* Just for fun, this pt_bdev module doesn't need it but this is essentially a per IO
+ * context that we get handed by the bdev layer.
+ */
+struct passthru_bdev_io {
+	uint8_t test;
+
+	/* bdev related */
+	struct spdk_io_channel *ch;
+
+	/* for bdev_io_wait */
+	struct spdk_bdev_io_wait_entry bdev_io_wait;
+};
+
+static void
+vbdev_passthru_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io);
+
+
+/* Callback for unregistering the IO device. */
+static void
+_device_unregister_cb(void *io_device)
+{
+	struct vbdev_passthru *pt_node  = io_device;
+
+	/* Done with this pt_node. */
+	free(pt_node->pt_bdev.name);
+	free(pt_node);
+}
+
+/* Called after we've unregistered following a hot remove callback.
+ * Our finish entry point will be called next.
+ */
+static int
+vbdev_passthru_destruct(void *ctx)
+{
+	struct vbdev_passthru *pt_node = (struct vbdev_passthru *)ctx;
+
+	/* It is important to follow this exact sequence of steps for destroying
+	 * a vbdev...
+	 */
+
+	TAILQ_REMOVE(&g_pt_nodes, pt_node, link);
+
+	/* Unclaim the underlying bdev. */
+	spdk_bdev_module_release_bdev(pt_node->base_bdev);
+
+	/* Close the underlying bdev. */
+	spdk_bdev_close(pt_node->base_desc);
+
+	/* Unregister the io_device. */
+	spdk_io_device_unregister(pt_node, _device_unregister_cb);
+
+	return 0;
+}
+
+/* Completion callback for IO that were issued from this bdev. The original bdev_io
+ * is passed in as an arg so we'll complete that one with the appropriate status
+ * and then free the one that this module issued.
+ */
+static void
+_pt_complete_io(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
+{
+	struct spdk_bdev_io *orig_io = cb_arg;
+	int status = success ? SPDK_BDEV_IO_STATUS_SUCCESS : SPDK_BDEV_IO_STATUS_FAILED;
+	struct passthru_bdev_io *io_ctx = (struct passthru_bdev_io *)orig_io->driver_ctx;
+
+	/* We setup this value in the submission routine, just showing here that it is
+	 * passed back to us.
+	 */
+	if (io_ctx->test != 0x5a) {
+		SPDK_ERRLOG("Error, original IO device_ctx is wrong! 0x%x\n",
+			    io_ctx->test);
+	}
+
+	/* Complete the original IO and then free the one that we created here
+	 * as a result of issuing an IO via submit_reqeust.
+	 */
+	spdk_bdev_io_complete(orig_io, status);
+	spdk_bdev_free_io(bdev_io);
+}
+
+static void
+vbdev_passthru_resubmit_io(void *arg)
+{
+	struct spdk_bdev_io *bdev_io = (struct spdk_bdev_io *)arg;
+	struct passthru_bdev_io *io_ctx = (struct passthru_bdev_io *)bdev_io->driver_ctx;
+
+	vbdev_passthru_submit_request(io_ctx->ch, bdev_io);
+}
+
+static void
+vbdev_passthru_queue_io(struct spdk_bdev_io *bdev_io)
+{
+	struct passthru_bdev_io *io_ctx = (struct passthru_bdev_io *)bdev_io->driver_ctx;
+	int rc;
+
+	io_ctx->bdev_io_wait.bdev = bdev_io->bdev;
+	io_ctx->bdev_io_wait.cb_fn = vbdev_passthru_resubmit_io;
+	io_ctx->bdev_io_wait.cb_arg = bdev_io;
+
+	rc = spdk_bdev_queue_io_wait(bdev_io->bdev, io_ctx->ch, &io_ctx->bdev_io_wait);
+	if (rc != 0) {
+		SPDK_ERRLOG("Queue io failed in vbdev_passthru_queue_io, rc=%d.\n", rc);
+		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+	}
+}
+
+/* Callback for getting a buf from the bdev pool in the event that the caller passed
+ * in NULL, we need to own the buffer so it doesn't get freed by another vbdev module
+ * beneath us before we're done with it. That won't happen in this example but it could
+ * if this example were used as a template for something more complex.
+ */
+static void
+pt_read_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
+{
+	struct vbdev_passthru *pt_node = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_passthru,
+					 pt_bdev);
+	struct pt_io_channel *pt_ch = spdk_io_channel_get_ctx(ch);
+	struct passthru_bdev_io *io_ctx = (struct passthru_bdev_io *)bdev_io->driver_ctx;
+	int rc;
+
+	if (!success) {
+		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+		return;
+	}
+
+	if (bdev_io->u.bdev.md_buf == NULL) {
+		rc = spdk_bdev_readv_blocks(pt_node->base_desc, pt_ch->base_ch, bdev_io->u.bdev.iovs,
+					    bdev_io->u.bdev.iovcnt, bdev_io->u.bdev.offset_blocks,
+					    bdev_io->u.bdev.num_blocks, _pt_complete_io,
+					    bdev_io);
+	} else {
+		rc = spdk_bdev_readv_blocks_with_md(pt_node->base_desc, pt_ch->base_ch,
+						    bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
+						    bdev_io->u.bdev.md_buf,
+						    bdev_io->u.bdev.offset_blocks,
+						    bdev_io->u.bdev.num_blocks,
+						    _pt_complete_io, bdev_io);
+	}
+
+	if (rc != 0) {
+		if (rc == -ENOMEM) {
+			SPDK_ERRLOG("No memory, start to queue io for passthru.\n");
+			io_ctx->ch = ch;
+			vbdev_passthru_queue_io(bdev_io);
+		} else {
+			SPDK_ERRLOG("ERROR on bdev_io submission!\n");
+			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+		}
+	}
+}
+
+/* Called when someone above submits IO to this pt vbdev. We're simply passing it on here
+ * via SPDK IO calls which in turn allocate another bdev IO and call our cpl callback provided
+ * below along with the original bdiv_io so that we can complete it once this IO completes.
+ */
+static void
+vbdev_passthru_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
+{
+	struct vbdev_passthru *pt_node = SPDK_CONTAINEROF(bdev_io->bdev, struct vbdev_passthru, pt_bdev);
+	struct pt_io_channel *pt_ch = spdk_io_channel_get_ctx(ch);
+	struct passthru_bdev_io *io_ctx = (struct passthru_bdev_io *)bdev_io->driver_ctx;
+	int rc = 0;
+
+	/* Setup a per IO context value; we don't do anything with it in the vbdev other
+	 * than confirm we get the same thing back in the completion callback just to
+	 * demonstrate.
+	 */
+	io_ctx->test = 0x5a;
+
+	switch (bdev_io->type) {
+	case SPDK_BDEV_IO_TYPE_READ:
+		spdk_bdev_io_get_buf(bdev_io, pt_read_get_buf_cb,
+				     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
+		break;
+	case SPDK_BDEV_IO_TYPE_WRITE:
+		if (bdev_io->u.bdev.md_buf == NULL) {
+			rc = spdk_bdev_writev_blocks(pt_node->base_desc, pt_ch->base_ch, bdev_io->u.bdev.iovs,
+						     bdev_io->u.bdev.iovcnt, bdev_io->u.bdev.offset_blocks,
+						     bdev_io->u.bdev.num_blocks, _pt_complete_io,
+						     bdev_io);
+		} else {
+			rc = spdk_bdev_writev_blocks_with_md(pt_node->base_desc, pt_ch->base_ch,
+							     bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
+							     bdev_io->u.bdev.md_buf,
+							     bdev_io->u.bdev.offset_blocks,
+							     bdev_io->u.bdev.num_blocks,
+							     _pt_complete_io, bdev_io);
+		}
+		break;
+	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
+		rc = spdk_bdev_write_zeroes_blocks(pt_node->base_desc, pt_ch->base_ch,
+						   bdev_io->u.bdev.offset_blocks,
+						   bdev_io->u.bdev.num_blocks,
+						   _pt_complete_io, bdev_io);
+		break;
+	case SPDK_BDEV_IO_TYPE_UNMAP:
+		rc = spdk_bdev_unmap_blocks(pt_node->base_desc, pt_ch->base_ch,
+					    bdev_io->u.bdev.offset_blocks,
+					    bdev_io->u.bdev.num_blocks,
+					    _pt_complete_io, bdev_io);
+		break;
+	case SPDK_BDEV_IO_TYPE_FLUSH:
+		rc = spdk_bdev_flush_blocks(pt_node->base_desc, pt_ch->base_ch,
+					    bdev_io->u.bdev.offset_blocks,
+					    bdev_io->u.bdev.num_blocks,
+					    _pt_complete_io, bdev_io);
+		break;
+	case SPDK_BDEV_IO_TYPE_RESET:
+		rc = spdk_bdev_reset(pt_node->base_desc, pt_ch->base_ch,
+				     _pt_complete_io, bdev_io);
+		break;
+	default:
+		SPDK_ERRLOG("passthru: unknown I/O type %d\n", bdev_io->type);
+		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+		return;
+	}
+	if (rc != 0) {
+		if (rc == -ENOMEM) {
+			SPDK_ERRLOG("No memory, start to queue io for passthru.\n");
+			io_ctx->ch = ch;
+			vbdev_passthru_queue_io(bdev_io);
+		} else {
+			SPDK_ERRLOG("ERROR on bdev_io submission!\n");
+			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
+		}
+	}
+}
+
+/* We'll just call the base bdev and let it answer however if we were more
+ * restrictive for some reason (or less) we could get the response back
+ * and modify according to our purposes.
+ */
+static bool
+vbdev_passthru_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
+{
+	struct vbdev_passthru *pt_node = (struct vbdev_passthru *)ctx;
+
+	return spdk_bdev_io_type_supported(pt_node->base_bdev, io_type);
+}
+
+/* We supplied this as an entry point for upper layers who want to communicate to this
+ * bdev.  This is how they get a channel. We are passed the same context we provided when
+ * we created our PT vbdev in examine() which, for this bdev, is the address of one of
+ * our context nodes. From here we'll ask the SPDK channel code to fill out our channel
+ * struct and we'll keep it in our PT node.
+ */
+static struct spdk_io_channel *
+vbdev_passthru_get_io_channel(void *ctx)
+{
+	struct vbdev_passthru *pt_node = (struct vbdev_passthru *)ctx;
+	struct spdk_io_channel *pt_ch = NULL;
+
+	/* The IO channel code will allocate a channel for us which consists of
+	 * the SPDK channel structure plus the size of our pt_io_channel struct
+	 * that we passed in when we registered our IO device. It will then call
+	 * our channel create callback to populate any elements that we need to
+	 * update.
+	 */
+	pt_ch = spdk_get_io_channel(pt_node);
+
+	return pt_ch;
+}
+
+/* This is the output for get_bdevs() for this vbdev */
+static int
+vbdev_passthru_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
+{
+	struct vbdev_passthru *pt_node = (struct vbdev_passthru *)ctx;
+
+	spdk_json_write_name(w, "passthru");
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "name", spdk_bdev_get_name(&pt_node->pt_bdev));
+	spdk_json_write_named_string(w, "base_bdev_name", spdk_bdev_get_name(pt_node->base_bdev));
+	spdk_json_write_object_end(w);
+
+	return 0;
+}
+
+/* This is used to generate JSON that can configure this module to its current state. */
+static int
+vbdev_ext_passthru_config_json(struct spdk_json_write_ctx *w)
+{
+	struct vbdev_passthru *pt_node;
+
+	TAILQ_FOREACH(pt_node, &g_pt_nodes, link) {
+		spdk_json_write_object_begin(w);
+		spdk_json_write_named_string(w, "method", "construct_passthru_bdev");
+		spdk_json_write_named_object_begin(w, "params");
+		spdk_json_write_named_string(w, "base_bdev_name", spdk_bdev_get_name(pt_node->base_bdev));
+		spdk_json_write_named_string(w, "name", spdk_bdev_get_name(&pt_node->pt_bdev));
+		spdk_json_write_object_end(w);
+		spdk_json_write_object_end(w);
+	}
+	return 0;
+}
+
+/* We provide this callback for the SPDK channel code to create a channel using
+ * the channel struct we provided in our module get_io_channel() entry point. Here
+ * we get and save off an underlying base channel of the device below us so that
+ * we can communicate with the base bdev on a per channel basis.  If we needed
+ * our own poller for this vbdev, we'd register it here.
+ */
+static int
+pt_bdev_ch_create_cb(void *io_device, void *ctx_buf)
+{
+	struct pt_io_channel *pt_ch = ctx_buf;
+	struct vbdev_passthru *pt_node = io_device;
+
+	pt_ch->base_ch = spdk_bdev_get_io_channel(pt_node->base_desc);
+
+	return 0;
+}
+
+/* We provide this callback for the SPDK channel code to destroy a channel
+ * created with our create callback. We just need to undo anything we did
+ * when we created. If this bdev used its own poller, we'd unregsiter it here.
+ */
+static void
+pt_bdev_ch_destroy_cb(void *io_device, void *ctx_buf)
+{
+	struct pt_io_channel *pt_ch = ctx_buf;
+
+	spdk_put_io_channel(pt_ch->base_ch);
+}
+
+/* Create the passthru association from the bdev and vbdev name and insert
+ * on the global list. */
+static int
+vbdev_passthru_insert_name(const char *bdev_name, const char *vbdev_name)
+{
+	struct bdev_names *name;
+
+	TAILQ_FOREACH(name, &g_bdev_names, link) {
+		if (strcmp(vbdev_name, name->vbdev_name) == 0) {
+			SPDK_ERRLOG("passthru bdev %s already exists\n", vbdev_name);
+			return -EEXIST;
+		}
+	}
+
+	name = calloc(1, sizeof(struct bdev_names));
+	if (!name) {
+		SPDK_ERRLOG("could not allocate bdev_names\n");
+		return -ENOMEM;
+	}
+
+	name->bdev_name = strdup(bdev_name);
+	if (!name->bdev_name) {
+		SPDK_ERRLOG("could not allocate name->bdev_name\n");
+		free(name);
+		return -ENOMEM;
+	}
+
+	name->vbdev_name = strdup(vbdev_name);
+	if (!name->vbdev_name) {
+		SPDK_ERRLOG("could not allocate name->vbdev_name\n");
+		free(name->bdev_name);
+		free(name);
+		return -ENOMEM;
+	}
+
+	TAILQ_INSERT_TAIL(&g_bdev_names, name, link);
+
+	return 0;
+}
+
+/* On init, just parse config file and build list of pt vbdevs and bdev name pairs. */
+static int
+vbdev_ext_passthru_init(void)
+{
+	struct spdk_conf_section *sp = NULL;
+	const char *conf_bdev_name = NULL;
+	const char *conf_vbdev_name = NULL;
+	struct bdev_names *name;
+	int i, rc;
+
+	sp = spdk_conf_find_section(NULL, "Ext_Pt");
+	if (sp == NULL) {
+		return 0;
+	}
+
+	for (i = 0; ; i++) {
+		if (!spdk_conf_section_get_nval(sp, "PTE", i)) {
+			break;
+		}
+
+		conf_bdev_name = spdk_conf_section_get_nmval(sp, "PTE", i, 0);
+		if (!conf_bdev_name) {
+			SPDK_ERRLOG("Passthru configuration missing bdev name\n");
+			break;
+		}
+
+		conf_vbdev_name = spdk_conf_section_get_nmval(sp, "PTE", i, 1);
+		if (!conf_vbdev_name) {
+			SPDK_ERRLOG("Passthru configuration missing pt_bdev name\n");
+			break;
+		}
+
+		rc = vbdev_passthru_insert_name(conf_bdev_name, conf_vbdev_name);
+		if (rc != 0) {
+			return rc;
+		}
+	}
+	TAILQ_FOREACH(name, &g_bdev_names, link) {
+		SPDK_NOTICELOG("conf parse matched: %s\n", name->bdev_name);
+	}
+	return 0;
+}
+
+/* Called when the entire module is being torn down. */
+static void
+vbdev_ext_passthru_finish(void)
+{
+	struct bdev_names *name;
+
+	while ((name = TAILQ_FIRST(&g_bdev_names))) {
+		TAILQ_REMOVE(&g_bdev_names, name, link);
+		free(name->bdev_name);
+		free(name->vbdev_name);
+		free(name);
+	}
+}
+
+/* During init we'll be asked how much memory we'd like passed to us
+ * in bev_io structures as context. Here's where we specify how
+ * much context we want per IO.
+ */
+static int
+vbdev_ext_passthru_get_ctx_size(void)
+{
+	return sizeof(struct passthru_bdev_io);
+}
+
+/* Called when SPDK wants to save the current config of this vbdev module to
+ * a file.
+ */
+static void
+vbdev_ext_passthru_get_spdk_running_config(FILE *fp)
+{
+	struct bdev_names *names = NULL;
+
+	fprintf(fp, "\n[Ext_Pt]\n");
+	TAILQ_FOREACH(names, &g_bdev_names, link) {
+		fprintf(fp, "  PTE %s %s\n", names->bdev_name, names->vbdev_name);
+	}
+	fprintf(fp, "\n");
+}
+
+/* Where vbdev_ext_passthru_config_json() is used to generate per module JSON config data, this
+ * function is called to output any per bdev specific methods. For the PT module, there are
+ * none.
+ */
+static void
+vbdev_passthru_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
+{
+	/* No config per bdev needed */
+}
+
+/* When we register our bdev this is how we specify our entry points. */
+static const struct spdk_bdev_fn_table vbdev_passthru_fn_table = {
+	.destruct		= vbdev_passthru_destruct,
+	.submit_request		= vbdev_passthru_submit_request,
+	.io_type_supported	= vbdev_passthru_io_type_supported,
+	.get_io_channel		= vbdev_passthru_get_io_channel,
+	.dump_info_json		= vbdev_passthru_dump_info_json,
+	.write_config_json	= vbdev_passthru_write_config_json,
+};
+
+/* Called when the underlying base bdev goes away. */
+static void
+vbdev_passthru_base_bdev_hotremove_cb(void *ctx)
+{
+	struct vbdev_passthru *pt_node, *tmp;
+	struct spdk_bdev *bdev_find = ctx;
+
+	TAILQ_FOREACH_SAFE(pt_node, &g_pt_nodes, link, tmp) {
+		if (bdev_find == pt_node->base_bdev) {
+			spdk_bdev_unregister(&pt_node->pt_bdev, NULL, NULL);
+		}
+	}
+}
+
+/* Create and register the passthru vbdev if we find it in our list of bdev names.
+ * This can be called either by the examine path or RPC method.
+ */
+static int
+vbdev_passthru_register(struct spdk_bdev *bdev)
+{
+	struct bdev_names *name;
+	struct vbdev_passthru *pt_node;
+	int rc = 0;
+
+	/* Check our list of names from config versus this bdev and if
+	 * there's a match, create the pt_node & bdev accordingly.
+	 */
+	TAILQ_FOREACH(name, &g_bdev_names, link) {
+		if (strcmp(name->bdev_name, bdev->name) != 0) {
+			continue;
+		}
+
+		SPDK_NOTICELOG("Match on %s\n", bdev->name);
+		pt_node = calloc(1, sizeof(struct vbdev_passthru));
+		if (!pt_node) {
+			rc = -ENOMEM;
+			SPDK_ERRLOG("could not allocate pt_node\n");
+			break;
+		}
+
+		/* The base bdev that we're attaching to. */
+		pt_node->base_bdev = bdev;
+		pt_node->pt_bdev.name = strdup(name->vbdev_name);
+		if (!pt_node->pt_bdev.name) {
+			rc = -ENOMEM;
+			SPDK_ERRLOG("could not allocate pt_bdev name\n");
+			free(pt_node);
+			break;
+		}
+		pt_node->pt_bdev.product_name = "passthru";
+
+		/* Copy some properties from the underlying base bdev. */
+		pt_node->pt_bdev.write_cache = bdev->write_cache;
+		pt_node->pt_bdev.required_alignment = bdev->required_alignment;
+		pt_node->pt_bdev.optimal_io_boundary = bdev->optimal_io_boundary;
+		pt_node->pt_bdev.blocklen = bdev->blocklen;
+		pt_node->pt_bdev.blockcnt = bdev->blockcnt;
+
+		pt_node->pt_bdev.md_interleave = bdev->md_interleave;
+		pt_node->pt_bdev.md_len = bdev->md_len;
+		pt_node->pt_bdev.dif_type = bdev->dif_type;
+		pt_node->pt_bdev.dif_is_head_of_md = bdev->dif_is_head_of_md;
+		pt_node->pt_bdev.dif_check_flags = bdev->dif_check_flags;
+
+		/* This is the context that is passed to us when the bdev
+		 * layer calls in so we'll save our pt_bdev node here.
+		 */
+		pt_node->pt_bdev.ctxt = pt_node;
+		pt_node->pt_bdev.fn_table = &vbdev_passthru_fn_table;
+		pt_node->pt_bdev.module = &passthru_if_external;
+		TAILQ_INSERT_TAIL(&g_pt_nodes, pt_node, link);
+
+		spdk_io_device_register(pt_node, pt_bdev_ch_create_cb, pt_bdev_ch_destroy_cb,
+					sizeof(struct pt_io_channel),
+					name->vbdev_name);
+		SPDK_NOTICELOG("io_device created at: 0x%p\n", pt_node);
+
+		rc = spdk_bdev_open(bdev, true, vbdev_passthru_base_bdev_hotremove_cb,
+				    bdev, &pt_node->base_desc);
+		if (rc) {
+			SPDK_ERRLOG("could not open bdev %s\n", spdk_bdev_get_name(bdev));
+			TAILQ_REMOVE(&g_pt_nodes, pt_node, link);
+			spdk_io_device_unregister(pt_node, NULL);
+			free(pt_node->pt_bdev.name);
+			free(pt_node);
+			break;
+		}
+		SPDK_NOTICELOG("bdev opened\n");
+
+		rc = spdk_bdev_module_claim_bdev(bdev, pt_node->base_desc, pt_node->pt_bdev.module);
+		if (rc) {
+			SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(bdev));
+			spdk_bdev_close(pt_node->base_desc);
+			TAILQ_REMOVE(&g_pt_nodes, pt_node, link);
+			spdk_io_device_unregister(pt_node, NULL);
+			free(pt_node->pt_bdev.name);
+			free(pt_node);
+			break;
+		}
+		SPDK_NOTICELOG("bdev claimed\n");
+
+		rc = spdk_bdev_register(&pt_node->pt_bdev);
+		if (rc) {
+			SPDK_ERRLOG("could not register pt_bdev\n");
+			spdk_bdev_module_release_bdev(&pt_node->pt_bdev);
+			spdk_bdev_close(pt_node->base_desc);
+			TAILQ_REMOVE(&g_pt_nodes, pt_node, link);
+			spdk_io_device_unregister(pt_node, NULL);
+			free(pt_node->pt_bdev.name);
+			free(pt_node);
+			break;
+		}
+		SPDK_NOTICELOG("ext_pt_bdev registered\n");
+		SPDK_NOTICELOG("created ext_pt_bdev for: %s\n", name->vbdev_name);
+	}
+
+	return rc;
+}
+
+/* Create the passthru disk from the given bdev and vbdev name. */
+int
+create_passthru_disk(const char *bdev_name, const char *vbdev_name)
+{
+	struct spdk_bdev *bdev = NULL;
+	int rc = 0;
+
+	/* Insert the bdev into our global name list even if it doesn't exist yet,
+	 * it may show up soon...
+	 */
+	rc = vbdev_passthru_insert_name(bdev_name, vbdev_name);
+	if (rc) {
+		return rc;
+	}
+
+	bdev = spdk_bdev_get_by_name(bdev_name);
+	if (!bdev) {
+		/* This is not an error, we tracked the name above and it still
+		 * may show up later.
+		 */
+		SPDK_NOTICELOG("vbdev creation deferred pending base bdev arrival\n");
+		return 0;
+	}
+
+	return vbdev_passthru_register(bdev);
+}
+
+void
+delete_passthru_disk(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn, void *cb_arg)
+{
+	struct bdev_names *name;
+
+	if (!bdev || bdev->module != &passthru_if_external) {
+		cb_fn(cb_arg, -ENODEV);
+		return;
+	}
+
+	/* Remove the association (vbdev, bdev) from g_bdev_names. This is required so that the
+	 * vbdev does not get re-created if the same bdev is constructed at some other time,
+	 * unless the underlying bdev was hot-removed.
+	 */
+	TAILQ_FOREACH(name, &g_bdev_names, link) {
+		if (strcmp(name->vbdev_name, bdev->name) == 0) {
+			TAILQ_REMOVE(&g_bdev_names, name, link);
+			free(name->bdev_name);
+			free(name->vbdev_name);
+			free(name);
+			break;
+		}
+	}
+
+	/* Additional cleanup happens in the destruct callback. */
+	spdk_bdev_unregister(bdev, cb_fn, cb_arg);
+}
+
+/* Because we specified this function in our pt bdev function table when we
+ * registered our pt bdev, we'll get this call anytime a new bdev shows up.
+ * Here we need to decide if we care about it and if so what to do. We
+ * parsed the config file at init so we check the new bdev against the list
+ * we built up at that time and if the user configured us to attach to this
+ * bdev, here's where we do it.
+ */
+static void
+vbdev_ext_passthru_examine(struct spdk_bdev *bdev)
+{
+	vbdev_passthru_register(bdev);
+
+	spdk_bdev_module_examine_done(&passthru_if_external);
+}
diff --git a/src/spdk/test/external_code/passthru/vbdev_passthru.h b/src/spdk/test/external_code/passthru/vbdev_passthru.h
new file mode 100644
index 000000000..db6ad8e8f
--- /dev/null
+++ b/src/spdk/test/external_code/passthru/vbdev_passthru.h
@@ -0,0 +1,65 @@
+/*-
+ *   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.
+ */
+
+#ifndef SPDK_VBDEV_PASSTHRU_H
+#define SPDK_VBDEV_PASSTHRU_H
+
+#include "spdk/stdinc.h"
+
+#include "spdk/bdev.h"
+#include "spdk/bdev_module.h"
+#include "spdk/log.h"
+#include "spdk/rpc.h"
+#include "spdk/string.h"
+#include "spdk/util.h"
+
+/**
+ * Create new pass through bdev.
+ *
+ * \param bdev_name Bdev on which pass through vbdev will be created.
+ * \param vbdev_name Name of the pass through bdev.
+ * \return 0 on success, other on failure.
+ */
+int create_passthru_disk(const char *bdev_name, const char *vbdev_name);
+
+/**
+ * Delete passthru bdev.
+ *
+ * \param bdev Pointer to pass through bdev.
+ * \param cb_fn Function to call after deletion.
+ * \param cb_arg Argument to pass to cb_fn.
+ */
+void delete_passthru_disk(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn,
+			  void *cb_arg);
+
+#endif /* SPDK_VBDEV_PASSTHRU_H */
diff --git a/src/spdk/test/external_code/passthru/vbdev_passthru_rpc.c b/src/spdk/test/external_code/passthru/vbdev_passthru_rpc.c
new file mode 100644
index 000000000..a50be08ed
--- /dev/null
+++ b/src/spdk/test/external_code/passthru/vbdev_passthru_rpc.c
@@ -0,0 +1,142 @@
+/*-
+ *   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 "vbdev_passthru.h"
+
+/* Structure to hold the parameters for this RPC method. */
+struct rpc_construct_passthru {
+	char *base_bdev_name;
+	char *name;
+};
+
+/* Free the allocated memory resource after the RPC handling. */
+static void
+free_rpc_construct_passthru(struct rpc_construct_passthru *r)
+{
+	free(r->base_bdev_name);
+	free(r->name);
+}
+
+/* Structure to decode the input parameters for this RPC method. */
+static const struct spdk_json_object_decoder rpc_construct_passthru_decoders[] = {
+	{"base_bdev_name", offsetof(struct rpc_construct_passthru, base_bdev_name), spdk_json_decode_string},
+	{"name", offsetof(struct rpc_construct_passthru, name), spdk_json_decode_string},
+};
+
+/* Decode the parameters for this RPC method and properly construct the passthru
+ * device. Error status returned in the failed cases.
+ */
+static void
+spdk_rpc_construct_passthru_bdev(struct spdk_jsonrpc_request *request,
+				 const struct spdk_json_val *params)
+{
+	struct rpc_construct_passthru req = {NULL};
+	struct spdk_json_write_ctx *w;
+	int rc;
+
+	if (spdk_json_decode_object(params, rpc_construct_passthru_decoders,
+				    SPDK_COUNTOF(rpc_construct_passthru_decoders),
+				    &req)) {
+		SPDK_ERRLOG("spdk_json_decode_object failed\n");
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
+						 "spdk_json_decode_object failed");
+		goto cleanup;
+	}
+
+	rc = create_passthru_disk(req.base_bdev_name, req.name);
+	if (rc != 0) {
+		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
+		goto cleanup;
+	}
+
+	w = spdk_jsonrpc_begin_result(request);
+	spdk_json_write_string(w, req.name);
+	spdk_jsonrpc_end_result(request, w);
+
+cleanup:
+	free_rpc_construct_passthru(&req);
+}
+SPDK_RPC_REGISTER("construct_ext_passthru_bdev", spdk_rpc_construct_passthru_bdev, SPDK_RPC_RUNTIME)
+
+struct rpc_delete_passthru {
+	char *name;
+};
+
+static void
+free_rpc_delete_passthru(struct rpc_delete_passthru *req)
+{
+	free(req->name);
+}
+
+static const struct spdk_json_object_decoder rpc_delete_passthru_decoders[] = {
+	{"name", offsetof(struct rpc_delete_passthru, name), spdk_json_decode_string},
+};
+
+static void
+_spdk_rpc_delete_passthru_bdev_cb(void *cb_arg, int bdeverrno)
+{
+	struct spdk_jsonrpc_request *request = cb_arg;
+	struct spdk_json_write_ctx *w;
+
+	w = spdk_jsonrpc_begin_result(request);
+	spdk_json_write_bool(w, bdeverrno == 0);
+	spdk_jsonrpc_end_result(request, w);
+}
+
+static void
+spdk_rpc_delete_passthru_bdev(struct spdk_jsonrpc_request *request,
+			      const struct spdk_json_val *params)
+{
+	struct rpc_delete_passthru req = {NULL};
+	struct spdk_bdev *bdev;
+
+	if (spdk_json_decode_object(params, rpc_delete_passthru_decoders,
+				    SPDK_COUNTOF(rpc_delete_passthru_decoders),
+				    &req)) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
+						 "spdk_json_decode_object failed");
+		goto cleanup;
+	}
+
+	bdev = spdk_bdev_get_by_name(req.name);
+	if (bdev == NULL) {
+		spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
+		goto cleanup;
+	}
+
+	delete_passthru_disk(bdev, _spdk_rpc_delete_passthru_bdev_cb, request);
+
+cleanup:
+	free_rpc_delete_passthru(&req);
+}
+SPDK_RPC_REGISTER("delete_ext_passthru_bdev", spdk_rpc_delete_passthru_bdev, SPDK_RPC_RUNTIME)