[dpdk-dev] [RFC PATCH v2 02/14] create vhost_cuse sub-directory create vhost_cuse directory move vhost-net-cdev.c to vhost_cuse directory

[Huawei Xie <huawei.xie@intel.com>]

vhost-cuse functionality will be divided into two parts:
	cuse driver specific logic and common logic.

cuse driver specific logic will be in vhost_cuse logic.
vhost ioctl message is pre-processed there and then sent to virtio-net
module if necessary.

virtio-net provides common message handling for both vhost-cuse and vhost-user.

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
---
 lib/librte_vhost/Makefile                    |   4 +-
 lib/librte_vhost/vhost-net-cdev.c            | 389 ---------------------------
 lib/librte_vhost/vhost_cuse/vhost-net-cdev.c | 389 +++++++++++++++++++++++++++
 3 files changed, 391 insertions(+), 391 deletions(-)
 delete mode 100644 lib/librte_vhost/vhost-net-cdev.c
 create mode 100644 lib/librte_vhost/vhost_cuse/vhost-net-cdev.c

diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
index c008d64..0b2f08f 100644
--- a/lib/librte_vhost/Makefile
+++ b/lib/librte_vhost/Makefile
@@ -34,10 +34,10 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_vhost.a
 
-CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 -lfuse
+CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -I vhost_cuse -O3 -D_FILE_OFFSET_BITS=64 -lfuse
 LDFLAGS += -lfuse
 # all source are stored in SRCS-y
-SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := vhost-net-cdev.c virtio-net.c vhost_rxtx.c
+SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := vhost_cuse/vhost-net-cdev.c virtio-net.c vhost_rxtx.c
 
 # install includes
 SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_virtio_net.h
diff --git a/lib/librte_vhost/vhost-net-cdev.c b/lib/librte_vhost/vhost-net-cdev.c
deleted file mode 100644
index 57c76cb..0000000
--- a/lib/librte_vhost/vhost-net-cdev.c
+++ /dev/null
@@ -1,389 +0,0 @@
-/*-
- *   BSD LICENSE
- *
- *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
- *   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 <errno.h>
-#include <fuse/cuse_lowlevel.h>
-#include <linux/limits.h>
-#include <linux/vhost.h>
-#include <stdint.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <rte_ethdev.h>
-#include <rte_log.h>
-#include <rte_string_fns.h>
-#include <rte_virtio_net.h>
-
-#include "vhost-net-cdev.h"
-
-#define FUSE_OPT_DUMMY "\0\0"
-#define FUSE_OPT_FORE  "-f\0\0"
-#define FUSE_OPT_NOMULTI "-s\0\0"
-
-static const uint32_t default_major = 231;
-static const uint32_t default_minor = 1;
-static const char cuse_device_name[] = "/dev/cuse";
-static const char default_cdev[] = "vhost-net";
-
-static struct fuse_session *session;
-static struct vhost_net_device_ops const *ops;
-
-/*
- * Returns vhost_device_ctx from given fuse_req_t. The index is populated later
- * when the device is added to the device linked list.
- */
-static struct vhost_device_ctx
-fuse_req_to_vhost_ctx(fuse_req_t req, struct fuse_file_info *fi)
-{
-	struct vhost_device_ctx ctx;
-	struct fuse_ctx const *const req_ctx = fuse_req_ctx(req);
-
-	ctx.pid = req_ctx->pid;
-	ctx.fh = fi->fh;
-
-	return ctx;
-}
-
-/*
- * When the device is created in QEMU it gets initialised here and
- * added to the device linked list.
- */
-static void
-vhost_net_open(fuse_req_t req, struct fuse_file_info *fi)
-{
-	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
-	int err = 0;
-
-	err = ops->new_device(ctx);
-	if (err == -1) {
-		fuse_reply_err(req, EPERM);
-		return;
-	}
-
-	fi->fh = err;
-
-	RTE_LOG(INFO, VHOST_CONFIG,
-		"(%"PRIu64") Device configuration started\n", fi->fh);
-	fuse_reply_open(req, fi);
-}
-
-/*
- * When QEMU is shutdown or killed the device gets released.
- */
-static void
-vhost_net_release(fuse_req_t req, struct fuse_file_info *fi)
-{
-	int err = 0;
-	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
-
-	ops->destroy_device(ctx);
-	RTE_LOG(INFO, VHOST_CONFIG, "(%"PRIu64") Device released\n", ctx.fh);
-	fuse_reply_err(req, err);
-}
-
-/*
- * Boilerplate code for CUSE IOCTL
- * Implicit arguments: ctx, req, result.
- */
-#define VHOST_IOCTL(func) do {	\
-	result = (func)(ctx);	\
-	fuse_reply_ioctl(req, result, NULL, 0);	\
-} while (0)
-
-/*
- * Boilerplate IOCTL RETRY
- * Implicit arguments: req.
- */
-#define VHOST_IOCTL_RETRY(size_r, size_w) do {	\
-	struct iovec iov_r = { arg, (size_r) };	\
-	struct iovec iov_w = { arg, (size_w) };	\
-	fuse_reply_ioctl_retry(req, &iov_r,	\
-		(size_r) ? 1 : 0, &iov_w, (size_w) ? 1 : 0);\
-} while (0)
-
-/*
- * Boilerplate code for CUSE Read IOCTL
- * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
- */
-#define VHOST_IOCTL_R(type, var, func) do {	\
-	if (!in_bufsz) {	\
-		VHOST_IOCTL_RETRY(sizeof(type), 0);\
-	} else {	\
-		(var) = *(const type*)in_buf;	\
-		result = func(ctx, &(var));	\
-		fuse_reply_ioctl(req, result, NULL, 0);\
-	}	\
-} while (0)
-
-/*
- * Boilerplate code for CUSE Write IOCTL
- * Implicit arguments: ctx, req, result, out_bufsz.
- */
-#define VHOST_IOCTL_W(type, var, func) do {	\
-	if (!out_bufsz) {	\
-		VHOST_IOCTL_RETRY(0, sizeof(type));\
-	} else {	\
-		result = (func)(ctx, &(var));\
-		fuse_reply_ioctl(req, result, &(var), sizeof(type));\
-	} \
-} while (0)
-
-/*
- * Boilerplate code for CUSE Read/Write IOCTL
- * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
- */
-#define VHOST_IOCTL_RW(type1, var1, type2, var2, func) do {	\
-	if (!in_bufsz) {	\
-		VHOST_IOCTL_RETRY(sizeof(type1), sizeof(type2));\
-	} else {	\
-		(var1) = *(const type1*) (in_buf);	\
-		result = (func)(ctx, (var1), &(var2));	\
-		fuse_reply_ioctl(req, result, &(var2), sizeof(type2));\
-	}	\
-} while (0)
-
-/*
- * The IOCTLs are handled using CUSE/FUSE in userspace. Depending on the type
- * of IOCTL a buffer is requested to read or to write. This request is handled
- * by FUSE and the buffer is then given to CUSE.
- */
-static void
-vhost_net_ioctl(fuse_req_t req, int cmd, void *arg,
-		struct fuse_file_info *fi, __rte_unused unsigned flags,
-		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
-{
-	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
-	struct vhost_vring_file file;
-	struct vhost_vring_state state;
-	struct vhost_vring_addr addr;
-	uint64_t features;
-	uint32_t index;
-	int result = 0;
-
-	switch (cmd) {
-	case VHOST_NET_SET_BACKEND:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_NET_SET_BACKEND\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_file, file, ops->set_backend);
-		break;
-
-	case VHOST_GET_FEATURES:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_GET_FEATURES\n", ctx.fh);
-		VHOST_IOCTL_W(uint64_t, features, ops->get_features);
-		break;
-
-	case VHOST_SET_FEATURES:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_FEATURES\n", ctx.fh);
-		VHOST_IOCTL_R(uint64_t, features, ops->set_features);
-		break;
-
-	case VHOST_RESET_OWNER:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_RESET_OWNER\n", ctx.fh);
-		VHOST_IOCTL(ops->reset_owner);
-		break;
-
-	case VHOST_SET_OWNER:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_OWNER\n", ctx.fh);
-		VHOST_IOCTL(ops->set_owner);
-		break;
-
-	case VHOST_SET_MEM_TABLE:
-		/*TODO fix race condition.*/
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_MEM_TABLE\n", ctx.fh);
-		static struct vhost_memory mem_temp;
-
-		switch (in_bufsz) {
-		case 0:
-			VHOST_IOCTL_RETRY(sizeof(struct vhost_memory), 0);
-			break;
-
-		case sizeof(struct vhost_memory):
-			mem_temp = *(const struct vhost_memory *) in_buf;
-
-			if (mem_temp.nregions > 0) {
-				VHOST_IOCTL_RETRY(sizeof(struct vhost_memory) +
-					(sizeof(struct vhost_memory_region) *
-						mem_temp.nregions), 0);
-			} else {
-				result = -1;
-				fuse_reply_ioctl(req, result, NULL, 0);
-			}
-			break;
-
-		default:
-			result = ops->set_mem_table(ctx,
-					in_buf, mem_temp.nregions);
-			if (result)
-				fuse_reply_err(req, EINVAL);
-			else
-				fuse_reply_ioctl(req, result, NULL, 0);
-		}
-		break;
-
-	case VHOST_SET_VRING_NUM:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_VRING_NUM\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_state, state,
-			ops->set_vring_num);
-		break;
-
-	case VHOST_SET_VRING_BASE:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_VRING_BASE\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_state, state,
-			ops->set_vring_base);
-		break;
-
-	case VHOST_GET_VRING_BASE:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_GET_VRING_BASE\n", ctx.fh);
-		VHOST_IOCTL_RW(uint32_t, index,
-			struct vhost_vring_state, state, ops->get_vring_base);
-		break;
-
-	case VHOST_SET_VRING_ADDR:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_VRING_ADDR\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_addr, addr,
-			ops->set_vring_addr);
-		break;
-
-	case VHOST_SET_VRING_KICK:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_VRING_KICK\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_file, file,
-			ops->set_vring_kick);
-		break;
-
-	case VHOST_SET_VRING_CALL:
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: VHOST_SET_VRING_CALL\n", ctx.fh);
-		VHOST_IOCTL_R(struct vhost_vring_file, file,
-			ops->set_vring_call);
-		break;
-
-	default:
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: DOESN NOT EXIST\n", ctx.fh);
-		result = -1;
-		fuse_reply_ioctl(req, result, NULL, 0);
-	}
-
-	if (result < 0)
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: FAIL\n", ctx.fh);
-	else
-		LOG_DEBUG(VHOST_CONFIG,
-			"(%"PRIu64") IOCTL: SUCCESS\n", ctx.fh);
-}
-
-/*
- * Structure handling open, release and ioctl function pointers is populated.
- */
-static const struct cuse_lowlevel_ops vhost_net_ops = {
-	.open		= vhost_net_open,
-	.release	= vhost_net_release,
-	.ioctl		= vhost_net_ioctl,
-};
-
-/*
- * cuse_info is populated and used to register the cuse device.
- * vhost_net_device_ops are also passed when the device is registered in app.
- */
-int
-rte_vhost_driver_register(const char *dev_name)
-{
-	struct cuse_info cuse_info;
-	char device_name[PATH_MAX] = "";
-	char char_device_name[PATH_MAX] = "";
-	const char *device_argv[] = { device_name };
-
-	char fuse_opt_dummy[] = FUSE_OPT_DUMMY;
-	char fuse_opt_fore[] = FUSE_OPT_FORE;
-	char fuse_opt_nomulti[] = FUSE_OPT_NOMULTI;
-	char *fuse_argv[] = {fuse_opt_dummy, fuse_opt_fore, fuse_opt_nomulti};
-
-	if (access(cuse_device_name, R_OK | W_OK) < 0) {
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"char device %s can't be accessed, maybe not exist\n",
-			cuse_device_name);
-		return -1;
-	}
-
-	/*
-	 * The device name is created. This is passed to QEMU so that it can
-	 * register the device with our application.
-	 */
-	snprintf(device_name, PATH_MAX, "DEVNAME=%s", dev_name);
-	snprintf(char_device_name, PATH_MAX, "/dev/%s", dev_name);
-
-	/* Check if device already exists. */
-	if (access(char_device_name, F_OK) != -1) {
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"char device %s already exists\n", char_device_name);
-		return -1;
-	}
-
-	memset(&cuse_info, 0, sizeof(cuse_info));
-	cuse_info.dev_major = default_major;
-	cuse_info.dev_minor = default_minor;
-	cuse_info.dev_info_argc = 1;
-	cuse_info.dev_info_argv = device_argv;
-	cuse_info.flags = CUSE_UNRESTRICTED_IOCTL;
-
-	ops = get_virtio_net_callbacks();
-
-	session = cuse_lowlevel_setup(3, fuse_argv,
-			&cuse_info, &vhost_net_ops, 0, NULL);
-	if (session == NULL)
-		return -1;
-
-	return 0;
-}
-
-/**
- * The CUSE session is launched allowing the application to receive open,
- * release and ioctl calls.
- */
-int
-rte_vhost_driver_session_start(void)
-{
-	fuse_session_loop(session);
-
-	return 0;
-}
diff --git a/lib/librte_vhost/vhost_cuse/vhost-net-cdev.c b/lib/librte_vhost/vhost_cuse/vhost-net-cdev.c
new file mode 100644
index 0000000..57c76cb
--- /dev/null
+++ b/lib/librte_vhost/vhost_cuse/vhost-net-cdev.c
@@ -0,0 +1,389 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   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 <errno.h>
+#include <fuse/cuse_lowlevel.h>
+#include <linux/limits.h>
+#include <linux/vhost.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rte_ethdev.h>
+#include <rte_log.h>
+#include <rte_string_fns.h>
+#include <rte_virtio_net.h>
+
+#include "vhost-net-cdev.h"
+
+#define FUSE_OPT_DUMMY "\0\0"
+#define FUSE_OPT_FORE  "-f\0\0"
+#define FUSE_OPT_NOMULTI "-s\0\0"
+
+static const uint32_t default_major = 231;
+static const uint32_t default_minor = 1;
+static const char cuse_device_name[] = "/dev/cuse";
+static const char default_cdev[] = "vhost-net";
+
+static struct fuse_session *session;
+static struct vhost_net_device_ops const *ops;
+
+/*
+ * Returns vhost_device_ctx from given fuse_req_t. The index is populated later
+ * when the device is added to the device linked list.
+ */
+static struct vhost_device_ctx
+fuse_req_to_vhost_ctx(fuse_req_t req, struct fuse_file_info *fi)
+{
+	struct vhost_device_ctx ctx;
+	struct fuse_ctx const *const req_ctx = fuse_req_ctx(req);
+
+	ctx.pid = req_ctx->pid;
+	ctx.fh = fi->fh;
+
+	return ctx;
+}
+
+/*
+ * When the device is created in QEMU it gets initialised here and
+ * added to the device linked list.
+ */
+static void
+vhost_net_open(fuse_req_t req, struct fuse_file_info *fi)
+{
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+	int err = 0;
+
+	err = ops->new_device(ctx);
+	if (err == -1) {
+		fuse_reply_err(req, EPERM);
+		return;
+	}
+
+	fi->fh = err;
+
+	RTE_LOG(INFO, VHOST_CONFIG,
+		"(%"PRIu64") Device configuration started\n", fi->fh);
+	fuse_reply_open(req, fi);
+}
+
+/*
+ * When QEMU is shutdown or killed the device gets released.
+ */
+static void
+vhost_net_release(fuse_req_t req, struct fuse_file_info *fi)
+{
+	int err = 0;
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+
+	ops->destroy_device(ctx);
+	RTE_LOG(INFO, VHOST_CONFIG, "(%"PRIu64") Device released\n", ctx.fh);
+	fuse_reply_err(req, err);
+}
+
+/*
+ * Boilerplate code for CUSE IOCTL
+ * Implicit arguments: ctx, req, result.
+ */
+#define VHOST_IOCTL(func) do {	\
+	result = (func)(ctx);	\
+	fuse_reply_ioctl(req, result, NULL, 0);	\
+} while (0)
+
+/*
+ * Boilerplate IOCTL RETRY
+ * Implicit arguments: req.
+ */
+#define VHOST_IOCTL_RETRY(size_r, size_w) do {	\
+	struct iovec iov_r = { arg, (size_r) };	\
+	struct iovec iov_w = { arg, (size_w) };	\
+	fuse_reply_ioctl_retry(req, &iov_r,	\
+		(size_r) ? 1 : 0, &iov_w, (size_w) ? 1 : 0);\
+} while (0)
+
+/*
+ * Boilerplate code for CUSE Read IOCTL
+ * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
+ */
+#define VHOST_IOCTL_R(type, var, func) do {	\
+	if (!in_bufsz) {	\
+		VHOST_IOCTL_RETRY(sizeof(type), 0);\
+	} else {	\
+		(var) = *(const type*)in_buf;	\
+		result = func(ctx, &(var));	\
+		fuse_reply_ioctl(req, result, NULL, 0);\
+	}	\
+} while (0)
+
+/*
+ * Boilerplate code for CUSE Write IOCTL
+ * Implicit arguments: ctx, req, result, out_bufsz.
+ */
+#define VHOST_IOCTL_W(type, var, func) do {	\
+	if (!out_bufsz) {	\
+		VHOST_IOCTL_RETRY(0, sizeof(type));\
+	} else {	\
+		result = (func)(ctx, &(var));\
+		fuse_reply_ioctl(req, result, &(var), sizeof(type));\
+	} \
+} while (0)
+
+/*
+ * Boilerplate code for CUSE Read/Write IOCTL
+ * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
+ */
+#define VHOST_IOCTL_RW(type1, var1, type2, var2, func) do {	\
+	if (!in_bufsz) {	\
+		VHOST_IOCTL_RETRY(sizeof(type1), sizeof(type2));\
+	} else {	\
+		(var1) = *(const type1*) (in_buf);	\
+		result = (func)(ctx, (var1), &(var2));	\
+		fuse_reply_ioctl(req, result, &(var2), sizeof(type2));\
+	}	\
+} while (0)
+
+/*
+ * The IOCTLs are handled using CUSE/FUSE in userspace. Depending on the type
+ * of IOCTL a buffer is requested to read or to write. This request is handled
+ * by FUSE and the buffer is then given to CUSE.
+ */
+static void
+vhost_net_ioctl(fuse_req_t req, int cmd, void *arg,
+		struct fuse_file_info *fi, __rte_unused unsigned flags,
+		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+	struct vhost_vring_file file;
+	struct vhost_vring_state state;
+	struct vhost_vring_addr addr;
+	uint64_t features;
+	uint32_t index;
+	int result = 0;
+
+	switch (cmd) {
+	case VHOST_NET_SET_BACKEND:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_NET_SET_BACKEND\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file, ops->set_backend);
+		break;
+
+	case VHOST_GET_FEATURES:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_GET_FEATURES\n", ctx.fh);
+		VHOST_IOCTL_W(uint64_t, features, ops->get_features);
+		break;
+
+	case VHOST_SET_FEATURES:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_FEATURES\n", ctx.fh);
+		VHOST_IOCTL_R(uint64_t, features, ops->set_features);
+		break;
+
+	case VHOST_RESET_OWNER:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_RESET_OWNER\n", ctx.fh);
+		VHOST_IOCTL(ops->reset_owner);
+		break;
+
+	case VHOST_SET_OWNER:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_OWNER\n", ctx.fh);
+		VHOST_IOCTL(ops->set_owner);
+		break;
+
+	case VHOST_SET_MEM_TABLE:
+		/*TODO fix race condition.*/
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_MEM_TABLE\n", ctx.fh);
+		static struct vhost_memory mem_temp;
+
+		switch (in_bufsz) {
+		case 0:
+			VHOST_IOCTL_RETRY(sizeof(struct vhost_memory), 0);
+			break;
+
+		case sizeof(struct vhost_memory):
+			mem_temp = *(const struct vhost_memory *) in_buf;
+
+			if (mem_temp.nregions > 0) {
+				VHOST_IOCTL_RETRY(sizeof(struct vhost_memory) +
+					(sizeof(struct vhost_memory_region) *
+						mem_temp.nregions), 0);
+			} else {
+				result = -1;
+				fuse_reply_ioctl(req, result, NULL, 0);
+			}
+			break;
+
+		default:
+			result = ops->set_mem_table(ctx,
+					in_buf, mem_temp.nregions);
+			if (result)
+				fuse_reply_err(req, EINVAL);
+			else
+				fuse_reply_ioctl(req, result, NULL, 0);
+		}
+		break;
+
+	case VHOST_SET_VRING_NUM:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_VRING_NUM\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_state, state,
+			ops->set_vring_num);
+		break;
+
+	case VHOST_SET_VRING_BASE:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_VRING_BASE\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_state, state,
+			ops->set_vring_base);
+		break;
+
+	case VHOST_GET_VRING_BASE:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_GET_VRING_BASE\n", ctx.fh);
+		VHOST_IOCTL_RW(uint32_t, index,
+			struct vhost_vring_state, state, ops->get_vring_base);
+		break;
+
+	case VHOST_SET_VRING_ADDR:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_VRING_ADDR\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_addr, addr,
+			ops->set_vring_addr);
+		break;
+
+	case VHOST_SET_VRING_KICK:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_VRING_KICK\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file,
+			ops->set_vring_kick);
+		break;
+
+	case VHOST_SET_VRING_CALL:
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: VHOST_SET_VRING_CALL\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file,
+			ops->set_vring_call);
+		break;
+
+	default:
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: DOESN NOT EXIST\n", ctx.fh);
+		result = -1;
+		fuse_reply_ioctl(req, result, NULL, 0);
+	}
+
+	if (result < 0)
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: FAIL\n", ctx.fh);
+	else
+		LOG_DEBUG(VHOST_CONFIG,
+			"(%"PRIu64") IOCTL: SUCCESS\n", ctx.fh);
+}
+
+/*
+ * Structure handling open, release and ioctl function pointers is populated.
+ */
+static const struct cuse_lowlevel_ops vhost_net_ops = {
+	.open		= vhost_net_open,
+	.release	= vhost_net_release,
+	.ioctl		= vhost_net_ioctl,
+};
+
+/*
+ * cuse_info is populated and used to register the cuse device.
+ * vhost_net_device_ops are also passed when the device is registered in app.
+ */
+int
+rte_vhost_driver_register(const char *dev_name)
+{
+	struct cuse_info cuse_info;
+	char device_name[PATH_MAX] = "";
+	char char_device_name[PATH_MAX] = "";
+	const char *device_argv[] = { device_name };
+
+	char fuse_opt_dummy[] = FUSE_OPT_DUMMY;
+	char fuse_opt_fore[] = FUSE_OPT_FORE;
+	char fuse_opt_nomulti[] = FUSE_OPT_NOMULTI;
+	char *fuse_argv[] = {fuse_opt_dummy, fuse_opt_fore, fuse_opt_nomulti};
+
+	if (access(cuse_device_name, R_OK | W_OK) < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"char device %s can't be accessed, maybe not exist\n",
+			cuse_device_name);
+		return -1;
+	}
+
+	/*
+	 * The device name is created. This is passed to QEMU so that it can
+	 * register the device with our application.
+	 */
+	snprintf(device_name, PATH_MAX, "DEVNAME=%s", dev_name);
+	snprintf(char_device_name, PATH_MAX, "/dev/%s", dev_name);
+
+	/* Check if device already exists. */
+	if (access(char_device_name, F_OK) != -1) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"char device %s already exists\n", char_device_name);
+		return -1;
+	}
+
+	memset(&cuse_info, 0, sizeof(cuse_info));
+	cuse_info.dev_major = default_major;
+	cuse_info.dev_minor = default_minor;
+	cuse_info.dev_info_argc = 1;
+	cuse_info.dev_info_argv = device_argv;
+	cuse_info.flags = CUSE_UNRESTRICTED_IOCTL;
+
+	ops = get_virtio_net_callbacks();
+
+	session = cuse_lowlevel_setup(3, fuse_argv,
+			&cuse_info, &vhost_net_ops, 0, NULL);
+	if (session == NULL)
+		return -1;
+
+	return 0;
+}
+
+/**
+ * The CUSE session is launched allowing the application to receive open,
+ * release and ioctl calls.
+ */
+int
+rte_vhost_driver_session_start(void)
+{
+	fuse_session_loop(session);
+
+	return 0;
+}
-- 
1.8.1.4