examples/vhost_blk: introduce vhost storage sample

A Vhost-blk example that support inflight feature. It uses the
new APIs that introduced in the first patch, so it can show how these
APIs work to support inflight feature.

Signed-off-by: Jin Yu <jin.yu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

MAINTAINERS

@@ -839,6 +839,8 @@ F: lib/librte_vhost/
 F: doc/guides/prog_guide/vhost_lib.rst
 F: examples/vhost/
 F: doc/guides/sample_app_ug/vhost.rst
+F: examples/vhost_blk/
+F: doc/guides/sample_app_ug/vhost_blk.rst
 F: examples/vhost_crypto/
 F: examples/vdpa/
 F: doc/guides/sample_app_ug/vdpa.rst

doc/guides/sample_app_ug/index.rst

@@ -41,6 +41,7 @@ Sample Applications User Guides
     packet_ordering
     vmdq_dcb_forwarding
     vhost
+    vhost_blk
     vhost_crypto
     vdpa
     ip_pipeline

doc/guides/sample_app_ug/vhost_blk.rst

@@ -0,0 +1,63 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2010-2017 Intel Corporation.
+
+Vhost_blk Sample Application
+=============================
+
+The vhost_blk sample application implemented a simple block device,
+which used as the  backend of Qemu vhost-user-blk device. Users can extend
+the exist example to use other type of block device(e.g. AIO) besides
+memory based block device. Similar with vhost-user-net device, the sample
+application used domain socket to communicate with Qemu, and the virtio
+ring (split or packed format) was processed by vhost_blk sample application.
+
+The sample application reuse lots codes from SPDK(Storage Performance
+Development Kit, https://github.com/spdk/spdk) vhost-user-blk target,
+for DPDK vhost library used in storage area, user can take SPDK as
+reference as well.
+
+Testing steps
+-------------
+
+This section shows the steps how to start a VM with the block device as
+fast data path for critical application.
+
+Compiling the Application
+-------------------------
+
+To compile the sample application see :doc:`compiling`.
+
+The application is located in the ``examples`` sub-directory.
+
+You will also need to build DPDK both on the host and inside the guest
+
+Start the vhost_blk example
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: console
+
+        ./vhost_blk -m 1024
+
+.. _vhost_blk_app_run_vm:
+
+Start the VM
+~~~~~~~~~~~~
+
+.. code-block:: console
+
+    qemu-system-x86_64 -machine accel=kvm \
+        -m $mem -object memory-backend-file,id=mem,size=$mem,\
+        mem-path=/dev/hugepages,share=on -numa node,memdev=mem \
+        -drive file=os.img,if=none,id=disk \
+        -device ide-hd,drive=disk,bootindex=0 \
+        -chardev socket,id=char0,reconnect=1,path=/tmp/vhost.socket \
+        -device vhost-user-blk-pci,ring_packed=1,chardev=char0,num-queues=1 \
+        ...
+
+.. note::
+    You must check whether your Qemu can support "vhost-user-blk" or not,
+    Qemu v4.0 or newer version is required.
+    reconnect=1 means live recovery support that qemu can reconnect vhost_blk
+    after we restart vhost_blk example.
+    ring_packed=1 means the device support packed ring but need the guest kernel
+    version >= 5.0

examples/Makefile

@@ -68,7 +68,7 @@ ifeq ($(CONFIG_RTE_LIBRTE_HASH),y)
 DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += tep_termination
 endif
 DIRS-$(CONFIG_RTE_LIBRTE_TIMER) += timer
-DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vdpa
+DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vdpa vhost_blk
 ifeq ($(CONFIG_RTE_LIBRTE_CRYPTODEV),y)
 DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost_crypto
 endif

examples/meson.build

@@ -42,7 +42,7 @@ all_examples = [
 	'skeleton', 'tep_termination',
 	'timer', 'vdpa',
 	'vhost', 'vhost_crypto',
-	'vm_power_manager',
+	'vhost_blk', 'vm_power_manager',
 	'vm_power_manager/guest_cli',
 	'vmdq', 'vmdq_dcb',
 ]

examples/vhost_blk/Makefile

@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2010-2014 Intel Corporation
+
+# binary name
+APP = vhost-blk
+
+# all source are stored in SRCS-y
+SRCS-y := blk.c vhost_blk.c vhost_blk_compat.c
+
+# Build using pkg-config variables if possible
+$(shell pkg-config --exists libdpdk)
+ifeq ($(.SHELLSTATUS),0)
+
+all: shared
+.PHONY: shared static
+shared: build/$(APP)-shared
+	ln -sf $(APP)-shared build/$(APP)
+static: build/$(APP)-static
+	ln -sf $(APP)-static build/$(APP)
+
+LDFLAGS += -pthread
+
+PC_FILE := $(shell pkg-config --path libdpdk)
+CFLAGS += -O3 $(shell pkg-config --cflags libdpdk)
+LDFLAGS_SHARED = $(shell pkg-config --libs libdpdk)
+LDFLAGS_STATIC = -Wl,-Bstatic $(shell pkg-config --static --libs libdpdk)
+
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
+build/$(APP)-shared: $(SRCS-y) Makefile $(PC_FILE) | build
+	$(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_SHARED)
+
+build/$(APP)-static: $(SRCS-y) Makefile $(PC_FILE) | build
+	$(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS) $(LDFLAGS_STATIC)
+
+build:
+	@mkdir -p $@
+
+.PHONY: clean
+clean:
+	rm -f build/$(APP) build/$(APP)-static build/$(APP)-shared
+	test -d build && rmdir -p build || true
+
+else # Build using legacy build system
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, detect a build directory, by looking for a path with a .config
+RTE_TARGET ?= $(notdir $(abspath $(dir $(firstword $(wildcard $(RTE_SDK)/*/.config)))))
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+ifneq ($(CONFIG_RTE_EXEC_ENV_LINUX),y)
+$(info This application can only operate in a linux environment, \
+please change the definition of the RTE_TARGET environment variable)
+all:
+else
+
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
+CFLAGS += $(WERROR_FLAGS)
+
+include $(RTE_SDK)/mk/rte.extapp.mk
+
+endif
+endif

examples/vhost_blk/blk.c

@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2019 Intel Corporation
+ */
+
+/**
+ * This work is largely based on the "vhost-user-blk" implementation by
+ * SPDK(https://github.com/spdk/spdk).
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <assert.h>
+#include <ctype.h>
+#include <string.h>
+#include <stddef.h>
+
+#include <rte_atomic.h>
+#include <rte_cycles.h>
+#include <rte_log.h>
+#include <rte_malloc.h>
+#include <rte_byteorder.h>
+#include <rte_string_fns.h>
+
+#include "vhost_blk.h"
+#include "blk_spec.h"
+
+static void
+vhost_strcpy_pad(void *dst, const char *src, size_t size, int pad)
+{
+	size_t len;
+
+	len = strlen(src);
+	if (len < size) {
+		memcpy(dst, src, len);
+		memset((char *)dst + len, pad, size - len);
+	} else {
+		memcpy(dst, src, size);
+	}
+}
+
+static int
+vhost_bdev_blk_readwrite(struct vhost_block_dev *bdev,
+			  struct vhost_blk_task *task,
+			  uint64_t lba_512, __rte_unused uint32_t xfer_len)
+{
+	uint32_t i;
+	uint64_t offset;
+	uint32_t nbytes = 0;
+
+	offset = lba_512 * 512;
+
+	for (i = 0; i < task->iovs_cnt; i++) {
+		if (task->dxfer_dir == BLK_DIR_TO_DEV)
+			memcpy(bdev->data + offset, task->iovs[i].iov_base,
+			       task->iovs[i].iov_len);
+		else
+			memcpy(task->iovs[i].iov_base, bdev->data + offset,
+			       task->iovs[i].iov_len);
+		offset += task->iovs[i].iov_len;
+		nbytes += task->iovs[i].iov_len;
+	}
+
+	return nbytes;
+}
+
+int
+vhost_bdev_process_blk_commands(struct vhost_block_dev *bdev,
+				 struct vhost_blk_task *task)
+{
+	int used_len;
+
+	if (unlikely(task->data_len > (bdev->blockcnt * bdev->blocklen))) {
+		fprintf(stderr, "read or write beyond capacity\n");
+		return VIRTIO_BLK_S_UNSUPP;
+	}
+
+	switch (task->req->type) {
+	case VIRTIO_BLK_T_IN:
+		if (unlikely(task->data_len == 0 ||
+			(task->data_len & (512 - 1)) != 0)) {
+			fprintf(stderr,
+				"%s - passed IO buffer is not multiple of 512b"
+				"(req_idx = %"PRIu16").\n",
+				task->req->type ? "WRITE" : "READ",
+				task->head_idx);
+			return VIRTIO_BLK_S_UNSUPP;
+		}
+
+		task->dxfer_dir = BLK_DIR_FROM_DEV;
+		vhost_bdev_blk_readwrite(bdev, task,
+					 task->req->sector, task->data_len);
+		break;
+	case VIRTIO_BLK_T_OUT:
+		if (unlikely(task->data_len == 0 ||
+			(task->data_len & (512 - 1)) != 0)) {
+			fprintf(stderr,
+				"%s - passed IO buffer is not multiple of 512b"
+				"(req_idx = %"PRIu16").\n",
+				task->req->type ? "WRITE" : "READ",
+				task->head_idx);
+			return VIRTIO_BLK_S_UNSUPP;
+		}
+
+		if (task->readtype) {
+			fprintf(stderr, "type isn't right\n");
+			return VIRTIO_BLK_S_IOERR;
+		}
+		task->dxfer_dir = BLK_DIR_TO_DEV;
+		vhost_bdev_blk_readwrite(bdev, task,
+					 task->req->sector, task->data_len);
+		break;
+	case VIRTIO_BLK_T_GET_ID:
+		if (!task->iovs_cnt || task->data_len)
+			return VIRTIO_BLK_S_UNSUPP;
+		used_len = min(VIRTIO_BLK_ID_BYTES, task->data_len);
+		vhost_strcpy_pad(task->iovs[0].iov_base,
+				 bdev->product_name, used_len, ' ');
+		break;
+	default:
+		fprintf(stderr, "unsupported cmd\n");
+		return VIRTIO_BLK_S_UNSUPP;
+	}
+
+	return VIRTIO_BLK_S_OK;
+}

examples/vhost_blk/blk_spec.h

@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2019 Intel Corporation
+ */
+
+#ifndef _BLK_SPEC_H
+#define _BLK_SPEC_H
+
+#include <stdint.h>
+
+#ifndef VHOST_USER_MEMORY_MAX_NREGIONS
+#define VHOST_USER_MEMORY_MAX_NREGIONS		8
+#endif
+
+#ifndef VHOST_USER_MAX_CONFIG_SIZE
+#define VHOST_USER_MAX_CONFIG_SIZE		256
+#endif
+
+#ifndef VHOST_USER_PROTOCOL_F_CONFIG
+#define VHOST_USER_PROTOCOL_F_CONFIG		9
+#endif
+
+#ifndef VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD
+#define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD	12
+#endif
+
+#define VIRTIO_BLK_ID_BYTES	20	/* ID string length */
+
+#define VIRTIO_BLK_T_IN			0
+#define VIRTIO_BLK_T_OUT		1
+#define VIRTIO_BLK_T_FLUSH		4
+#define VIRTIO_BLK_T_GET_ID		8
+#define VIRTIO_BLK_T_DISCARD		11
+#define VIRTIO_BLK_T_WRITE_ZEROES	13
+
+#define VIRTIO_BLK_S_OK			0
+#define VIRTIO_BLK_S_IOERR		1
+#define VIRTIO_BLK_S_UNSUPP		2
+
+enum vhost_user_request {
+	VHOST_USER_NONE = 0,
+	VHOST_USER_GET_FEATURES = 1,
+	VHOST_USER_SET_FEATURES = 2,
+	VHOST_USER_SET_OWNER = 3,
+	VHOST_USER_RESET_OWNER = 4,
+	VHOST_USER_SET_MEM_TABLE = 5,
+	VHOST_USER_SET_LOG_BASE = 6,
+	VHOST_USER_SET_LOG_FD = 7,
+	VHOST_USER_SET_VRING_NUM = 8,
+	VHOST_USER_SET_VRING_ADDR = 9,
+	VHOST_USER_SET_VRING_BASE = 10,
+	VHOST_USER_GET_VRING_BASE = 11,
+	VHOST_USER_SET_VRING_KICK = 12,
+	VHOST_USER_SET_VRING_CALL = 13,
+	VHOST_USER_SET_VRING_ERR = 14,
+	VHOST_USER_GET_PROTOCOL_FEATURES = 15,
+	VHOST_USER_SET_PROTOCOL_FEATURES = 16,
+	VHOST_USER_GET_QUEUE_NUM = 17,
+	VHOST_USER_SET_VRING_ENABLE = 18,
+	VHOST_USER_MAX
+};
+
+/** Get/set config msg payload */
+struct vhost_user_config {
+	uint32_t offset;
+	uint32_t size;
+	uint32_t flags;
+	uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+};
+
+/** Fixed-size vhost_memory struct */
+struct vhost_memory_padded {
+	uint32_t nregions;
+	uint32_t padding;
+	struct vhost_memory_region regions[VHOST_USER_MEMORY_MAX_NREGIONS];
+};
+
+struct vhost_user_msg {
+	enum vhost_user_request request;
+
+#define VHOST_USER_VERSION_MASK     0x3
+#define VHOST_USER_REPLY_MASK       (0x1 << 2)
+	uint32_t flags;
+	uint32_t size; /**< the following payload size */
+	union {
+#define VHOST_USER_VRING_IDX_MASK   0xff
+#define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
+		uint64_t u64;
+		struct vhost_vring_state state;
+		struct vhost_vring_addr addr;
+		struct vhost_memory_padded memory;
+		struct vhost_user_config cfg;
+	} payload;
+} __attribute((packed));
+
+#endif

examples/vhost_blk/meson.build

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2017 Intel Corporation
+
+# meson file, for building this example as part of a main DPDK build.
+#
+# To build this example as a standalone application with an already-installed
+# DPDK instance, use 'make'
+
+if not is_linux
+	build = false
+endif
+
+if not cc.has_header('linux/virtio_blk.h')
+	build = false
+endif
+
+deps += 'vhost'
+allow_experimental_apis = true
+sources = files(
+	'blk.c', 'vhost_blk.c', 'vhost_blk_compat.c'
+)

examples/vhost_blk/vhost_blk.h

@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2017 Intel Corporation
+ */
+
+#ifndef _VHOST_BLK_H_
+#define _VHOST_BLK_H_
+
+#include <stdio.h>
+#include <sys/uio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_ring.h>
+
+#include <rte_vhost.h>
+
+#ifndef VIRTIO_F_RING_PACKED
+#define VIRTIO_F_RING_PACKED 34
+
+struct vring_packed_desc {
+	/* Buffer Address. */
+	__le64 addr;
+	/* Buffer Length. */
+	__le32 len;
+	/* Buffer ID. */
+	__le16 id;
+	/* The flags depending on descriptor type. */
+	__le16 flags;
+};
+#endif
+
+struct vhost_blk_queue {
+	struct rte_vhost_vring vq;
+	struct rte_vhost_ring_inflight inflight_vq;
+	uint16_t last_avail_idx;
+	uint16_t last_used_idx;
+	bool avail_wrap_counter;
+	bool used_wrap_counter;
+};
+
+#define NUM_OF_BLK_QUEUES 1
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+
+struct vhost_block_dev {
+	/** ID for vhost library. */
+	int vid;
+	/** Queues for the block device */
+	struct vhost_blk_queue queues[NUM_OF_BLK_QUEUES];
+	/** Unique name for this block device. */
+	char name[64];
+
+	/** Unique product name for this kind of block device. */
+	char product_name[256];
+
+	/** Size in bytes of a logical block for the backend */
+	uint32_t blocklen;
+
+	/** Number of blocks */
+	uint64_t blockcnt;
+
+	/** write cache enabled, not used at the moment */
+	int write_cache;
+
+	/** use memory as disk storage space */
+	uint8_t *data;
+};
+
+struct vhost_blk_ctrlr {
+	uint8_t started;
+	uint8_t packed_ring;
+	uint8_t need_restart;
+	/** Only support 1 LUN for the example */
+	struct vhost_block_dev *bdev;
+	/** VM memory region */
+	struct rte_vhost_memory *mem;
+} __rte_cache_aligned;
+
+#define VHOST_BLK_MAX_IOVS 128
+
+enum blk_data_dir {
+	BLK_DIR_NONE = 0,
+	BLK_DIR_TO_DEV = 1,
+	BLK_DIR_FROM_DEV = 2,
+};
+
+struct vhost_blk_task {
+	uint8_t readtype;
+	uint8_t req_idx;
+	uint16_t head_idx;
+	uint16_t last_idx;
+	uint16_t inflight_idx;
+	uint16_t buffer_id;
+	uint32_t dxfer_dir;
+	uint32_t data_len;
+	struct virtio_blk_outhdr *req;
+
+	volatile uint8_t *status;
+
+	struct iovec iovs[VHOST_BLK_MAX_IOVS];
+	uint32_t iovs_cnt;
+	struct vring_packed_desc *desc_packed;
+	struct vring_desc *desc_split;
+	struct rte_vhost_vring *vq;
+	struct vhost_block_dev *bdev;
+	struct vhost_blk_ctrlr *ctrlr;
+};
+
+struct inflight_blk_task {
+	struct vhost_blk_task blk_task;
+	struct rte_vhost_inflight_desc_packed *inflight_desc;
+	struct rte_vhost_inflight_info_packed *inflight_packed;
+};
+
+struct vhost_blk_ctrlr *g_vhost_ctrlr;
+struct vhost_device_ops vhost_blk_device_ops;
+
+int vhost_bdev_process_blk_commands(struct vhost_block_dev *bdev,
+				     struct vhost_blk_task *task);
+
+void vhost_session_install_rte_compat_hooks(uint32_t vid);
+
+void vhost_dev_install_rte_compat_hooks(const char *path);
+
+struct vhost_blk_ctrlr *vhost_blk_ctrlr_find(const char *ctrlr_name);
+
+#endif /* _VHOST_blk_H_ */

examples/vhost_blk/vhost_blk_compat.c

@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2019 Intel Corporation
+ */
+
+#ifndef _VHOST_BLK_COMPAT_H_
+#define _VHOST_BLK_COMPAT_H_
+
+#include <sys/uio.h>
+#include <stdint.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_ring.h>
+
+#include <rte_vhost.h>
+#include "vhost_blk.h"
+#include "blk_spec.h"
+
+#define VHOST_MAX_VQUEUES	256
+#define SPDK_VHOST_MAX_VQ_SIZE	1024
+
+#define VHOST_USER_GET_CONFIG	24
+#define VHOST_USER_SET_CONFIG	25
+
+static int
+vhost_blk_get_config(struct vhost_block_dev *bdev, uint8_t *config,
+			  uint32_t len)
+{
+	struct virtio_blk_config blkcfg;
+	uint32_t blk_size;
+	uint64_t blkcnt;
+
+	if (bdev == NULL) {
+		/* We can't just return -1 here as this GET_CONFIG message might
+		 * be caused by a QEMU VM reboot. Returning -1 will indicate an
+		 * error to QEMU, who might then decide to terminate itself.
+		 * We don't want that. A simple reboot shouldn't break the
+		 * system.
+		 *
+		 * Presenting a block device with block size 0 and block count 0
+		 * doesn't cause any problems on QEMU side and the virtio-pci
+		 * device is even still available inside the VM, but there will
+		 * be no block device created for it - the kernel drivers will
+		 * silently reject it.
+		 */
+		blk_size = 0;
+		blkcnt = 0;
+	} else {
+		blk_size = bdev->blocklen;
+		blkcnt = bdev->blockcnt;
+	}
+
+	memset(&blkcfg, 0, sizeof(blkcfg));
+	blkcfg.blk_size = blk_size;
+	/* minimum I/O size in blocks */
+	blkcfg.min_io_size = 1;
+	/* expressed in 512 Bytes sectors */
+	blkcfg.capacity = (blkcnt * blk_size) / 512;
+	/* QEMU can overwrite this value when started */
+	blkcfg.num_queues = VHOST_MAX_VQUEUES;
+
+	fprintf(stdout, "block device:blk_size = %d, blkcnt = %"PRIx64"\n",
+		blk_size, blkcnt);
+
+	memcpy(config, &blkcfg, min(len, sizeof(blkcfg)));
+
+	return 0;
+}
+
+static enum rte_vhost_msg_result
+extern_vhost_pre_msg_handler(int vid, void *_msg)
+{
+	char path[PATH_MAX];
+	struct vhost_blk_ctrlr *ctrlr;
+	struct vhost_user_msg *msg = _msg;
+	int ret;
+
+	ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+	if (ret) {
+		fprintf(stderr, "Cannot get socket name\n");
+		return -1;
+	}
+
+	ctrlr = vhost_blk_ctrlr_find(path);
+	if (!ctrlr) {
+		fprintf(stderr, "Controller is not ready\n");
+		return -1;
+	}
+
+	switch ((int)msg->request) {
+	case VHOST_USER_GET_VRING_BASE:
+	case VHOST_USER_SET_VRING_BASE:
+	case VHOST_USER_SET_VRING_ADDR:
+	case VHOST_USER_SET_VRING_NUM:
+	case VHOST_USER_SET_VRING_KICK:
+	case VHOST_USER_SET_VRING_CALL:
+	case VHOST_USER_SET_MEM_TABLE:
+		break;
+	case VHOST_USER_GET_CONFIG: {
+		int rc = 0;
+
+		rc = vhost_blk_get_config(ctrlr->bdev,
+					  msg->payload.cfg.region,
+					  msg->payload.cfg.size);
+		if (rc != 0)
+			msg->size = 0;
+
+		return RTE_VHOST_MSG_RESULT_REPLY;
+	}
+	case VHOST_USER_SET_CONFIG:
+	default:
+		break;
+	}
+
+	return RTE_VHOST_MSG_RESULT_NOT_HANDLED;
+}
+
+static enum rte_vhost_msg_result
+extern_vhost_post_msg_handler(int vid, void *_msg)
+{
+	char path[PATH_MAX];
+	struct vhost_blk_ctrlr *ctrlr;
+	struct vhost_user_msg *msg = _msg;
+	int ret;
+
+	ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
+	if (ret) {
+		fprintf(stderr, "Cannot get socket name\n");
+		return -1;
+	}
+
+	ctrlr = vhost_blk_ctrlr_find(path);
+	if (!ctrlr) {
+		fprintf(stderr, "Controller is not ready\n");
+		return -1;
+	}
+
+	switch (msg->request) {
+	case VHOST_USER_SET_FEATURES:
+	case VHOST_USER_SET_VRING_KICK:
+	default:
+		break;
+	}
+
+	return RTE_VHOST_MSG_RESULT_NOT_HANDLED;
+}
+
+struct rte_vhost_user_extern_ops g_extern_vhost_ops = {
+	.pre_msg_handle = extern_vhost_pre_msg_handler,
+	.post_msg_handle = extern_vhost_post_msg_handler,
+};
+
+void
+vhost_session_install_rte_compat_hooks(uint32_t vid)
+{
+	int rc;
+
+	rc = rte_vhost_extern_callback_register(vid, &g_extern_vhost_ops, NULL);
+	if (rc != 0)
+		fprintf(stderr,
+			"rte_vhost_extern_callback_register() failed for vid = %d\n",
+			vid);
+}
+
+void
+vhost_dev_install_rte_compat_hooks(const char *path)
+{
+	uint64_t protocol_features = 0;
+
+	rte_vhost_driver_get_protocol_features(path, &protocol_features);
+	protocol_features |= (1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
+	protocol_features |= (1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD);
+	rte_vhost_driver_set_protocol_features(path, protocol_features);
+}
+
+#endif