Imported Upstream version 17.05

Change-Id: Id1e419c5a214e4a18739663b91f0f9a549f1fdc6
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

7 files changed, 891 insertions, 127 deletions

diff --git a/drivers/net/virtio/virtio_user/vhost.h b/drivers/net/virtio/virtio_user/vhost.h
index 7adb55f5..5c983bd4 100644
--- a/drivers/net/virtio/virtio_user/vhost.h
+++ b/drivers/net/virtio/virtio_user/vhost.h
@@ -42,8 +42,6 @@
 #include "../virtio_logs.h"
 #include "../virtqueue.h"
 
-#define VHOST_MEMORY_MAX_NREGIONS 8
-
 struct vhost_vring_state {
 	unsigned int index;
 	unsigned int num;
@@ -98,6 +96,8 @@ enum vhost_user_request {
 	VHOST_USER_MAX
 };
 
+const char * const vhost_msg_strings[VHOST_USER_MAX];
+
 struct vhost_memory_region {
 	uint64_t guest_phys_addr;
 	uint64_t memory_size; /* bytes */
@@ -105,42 +105,19 @@ struct vhost_memory_region {
 	uint64_t mmap_offset;
 };
 
-struct vhost_memory {
-	uint32_t nregions;
-	uint32_t padding;
-	struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
-};
-
-struct vhost_user_msg {
-	enum vhost_user_request request;
+struct virtio_user_dev;
 
-#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 memory;
-	} payload;
-	int fds[VHOST_MEMORY_MAX_NREGIONS];
-} __attribute((packed));
-
-#define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
-#define VHOST_USER_PAYLOAD_SIZE \
-	(sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
-
-/* The version of the protocol we support */
-#define VHOST_USER_VERSION    0x1
-
-#define VHOST_USER_F_PROTOCOL_FEATURES 30
-#define VHOST_USER_MQ (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
+struct virtio_user_backend_ops {
+	int (*setup)(struct virtio_user_dev *dev);
+	int (*send_request)(struct virtio_user_dev *dev,
+			    enum vhost_user_request req,
+			    void *arg);
+	int (*enable_qp)(struct virtio_user_dev *dev,
+			 uint16_t pair_idx,
+			 int enable);
+};
 
-int vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg);
-int vhost_user_setup(const char *path);
-int vhost_user_enable_queue_pair(int vhostfd, uint16_t pair_idx, int enable);
+struct virtio_user_backend_ops ops_user;
+struct virtio_user_backend_ops ops_kernel;
 
 #endif
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c b/drivers/net/virtio/virtio_user/vhost_kernel.c
new file mode 100644
index 00000000..68d28b13
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
@@ -0,0 +1,403 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2016 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 <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <rte_memory.h>
+#include <rte_eal_memconfig.h>
+
+#include "vhost.h"
+#include "virtio_user_dev.h"
+#include "vhost_kernel_tap.h"
+
+struct vhost_memory_kernel {
+	uint32_t nregions;
+	uint32_t padding;
+	struct vhost_memory_region regions[0];
+};
+
+/* vhost kernel ioctls */
+#define VHOST_VIRTIO 0xAF
+#define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
+#define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
+#define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
+#define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
+#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory_kernel)
+#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
+#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
+#define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
+#define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
+#define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
+#define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
+#define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
+#define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
+#define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
+#define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
+
+static uint64_t max_regions = 64;
+
+static void
+get_vhost_kernel_max_regions(void)
+{
+	int fd;
+	char buf[20] = {'\0'};
+
+	fd = open("/sys/module/vhost/parameters/max_mem_regions", O_RDONLY);
+	if (fd < 0)
+		return;
+
+	if (read(fd, buf, sizeof(buf) - 1) > 0)
+		max_regions = strtoull(buf, NULL, 10);
+
+	close(fd);
+}
+
+static uint64_t vhost_req_user_to_kernel[] = {
+	[VHOST_USER_SET_OWNER] = VHOST_SET_OWNER,
+	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
+	[VHOST_USER_SET_FEATURES] = VHOST_SET_FEATURES,
+	[VHOST_USER_GET_FEATURES] = VHOST_GET_FEATURES,
+	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
+	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
+	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
+	[VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
+	[VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
+	[VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
+	[VHOST_USER_SET_MEM_TABLE] = VHOST_SET_MEM_TABLE,
+};
+
+/* By default, vhost kernel module allows 64 regions, but DPDK allows
+ * 256 segments. As a relief, below function merges those virtually
+ * adjacent memsegs into one region.
+ */
+static struct vhost_memory_kernel *
+prepare_vhost_memory_kernel(void)
+{
+	uint32_t i, j, k = 0;
+	struct rte_memseg *seg;
+	struct vhost_memory_region *mr;
+	struct vhost_memory_kernel *vm;
+
+	vm = malloc(sizeof(struct vhost_memory_kernel) +
+		    max_regions *
+		    sizeof(struct vhost_memory_region));
+	if (!vm)
+		return NULL;
+
+	for (i = 0; i < RTE_MAX_MEMSEG; ++i) {
+		seg = &rte_eal_get_configuration()->mem_config->memseg[i];
+		if (!seg->addr)
+			break;
+
+		int new_region = 1;
+
+		for (j = 0; j < k; ++j) {
+			mr = &vm->regions[j];
+
+			if (mr->userspace_addr + mr->memory_size ==
+			    (uint64_t)(uintptr_t)seg->addr) {
+				mr->memory_size += seg->len;
+				new_region = 0;
+				break;
+			}
+
+			if ((uint64_t)(uintptr_t)seg->addr + seg->len ==
+			    mr->userspace_addr) {
+				mr->guest_phys_addr =
+					(uint64_t)(uintptr_t)seg->addr;
+				mr->userspace_addr =
+					(uint64_t)(uintptr_t)seg->addr;
+				mr->memory_size += seg->len;
+				new_region = 0;
+				break;
+			}
+		}
+
+		if (new_region == 0)
+			continue;
+
+		mr = &vm->regions[k++];
+		/* use vaddr here! */
+		mr->guest_phys_addr = (uint64_t)(uintptr_t)seg->addr;
+		mr->userspace_addr = (uint64_t)(uintptr_t)seg->addr;
+		mr->memory_size = seg->len;
+		mr->mmap_offset = 0;
+
+		if (k >= max_regions) {
+			free(vm);
+			return NULL;
+		}
+	}
+
+	vm->nregions = k;
+	vm->padding = 0;
+	return vm;
+}
+
+/* with below features, vhost kernel does not need to do the checksum and TSO,
+ * these info will be passed to virtio_user through virtio net header.
+ */
+#define VHOST_KERNEL_GUEST_OFFLOADS_MASK	\
+	((1ULL << VIRTIO_NET_F_GUEST_CSUM) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_TSO4) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_TSO6) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_ECN)  |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_UFO))
+
+/* with below features, when flows from virtio_user to vhost kernel
+ * (1) if flows goes up through the kernel networking stack, it does not need
+ * to verify checksum, which can save CPU cycles;
+ * (2) if flows goes through a Linux bridge and outside from an interface
+ * (kernel driver), checksum and TSO will be done by GSO in kernel or even
+ * offloaded into real physical device.
+ */
+#define VHOST_KERNEL_HOST_OFFLOADS_MASK		\
+	((1ULL << VIRTIO_NET_F_HOST_TSO4) |	\
+	 (1ULL << VIRTIO_NET_F_HOST_TSO6) |	\
+	 (1ULL << VIRTIO_NET_F_CSUM))
+
+static int
+tap_supporte_mq(void)
+{
+	int tapfd;
+	unsigned int tap_features;
+
+	tapfd = open(PATH_NET_TUN, O_RDWR);
+	if (tapfd < 0) {
+		PMD_DRV_LOG(ERR, "fail to open %s: %s",
+			    PATH_NET_TUN, strerror(errno));
+		return -1;
+	}
+
+	if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
+		PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
+		close(tapfd);
+		return -1;
+	}
+
+	close(tapfd);
+	return tap_features & IFF_MULTI_QUEUE;
+}
+
+static int
+vhost_kernel_ioctl(struct virtio_user_dev *dev,
+		   enum vhost_user_request req,
+		   void *arg)
+{
+	int ret = -1;
+	unsigned int i;
+	uint64_t req_kernel;
+	struct vhost_memory_kernel *vm = NULL;
+	int vhostfd;
+	unsigned int queue_sel;
+
+	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
+
+	req_kernel = vhost_req_user_to_kernel[req];
+
+	if (req_kernel == VHOST_SET_MEM_TABLE) {
+		vm = prepare_vhost_memory_kernel();
+		if (!vm)
+			return -1;
+		arg = (void *)vm;
+	}
+
+	if (req_kernel == VHOST_SET_FEATURES) {
+		/* We don't need memory protection here */
+		*(uint64_t *)arg &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+		/* VHOST kernel does not know about below flags */
+		*(uint64_t *)arg &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
+		*(uint64_t *)arg &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
+
+		*(uint64_t *)arg &= ~(1ULL << VIRTIO_NET_F_MQ);
+	}
+
+	switch (req_kernel) {
+	case VHOST_SET_VRING_NUM:
+	case VHOST_SET_VRING_ADDR:
+	case VHOST_SET_VRING_BASE:
+	case VHOST_GET_VRING_BASE:
+	case VHOST_SET_VRING_KICK:
+	case VHOST_SET_VRING_CALL:
+		queue_sel = *(unsigned int *)arg;
+		vhostfd = dev->vhostfds[queue_sel / 2];
+		*(unsigned int *)arg = queue_sel % 2;
+		PMD_DRV_LOG(DEBUG, "vhostfd=%d, index=%u",
+			    vhostfd, *(unsigned int *)arg);
+		break;
+	default:
+		vhostfd = -1;
+	}
+	if (vhostfd == -1) {
+		for (i = 0; i < dev->max_queue_pairs; ++i) {
+			if (dev->vhostfds[i] < 0)
+				continue;
+
+			ret = ioctl(dev->vhostfds[i], req_kernel, arg);
+			if (ret < 0)
+				break;
+		}
+	} else {
+		ret = ioctl(vhostfd, req_kernel, arg);
+	}
+
+	if (!ret && req_kernel == VHOST_GET_FEATURES) {
+		/* with tap as the backend, all these features are supported
+		 * but not claimed by vhost-net, so we add them back when
+		 * reporting to upper layer.
+		 */
+		*((uint64_t *)arg) |= VHOST_KERNEL_GUEST_OFFLOADS_MASK;
+		*((uint64_t *)arg) |= VHOST_KERNEL_HOST_OFFLOADS_MASK;
+
+		/* vhost_kernel will not declare this feature, but it does
+		 * support multi-queue.
+		 */
+		if (tap_supporte_mq())
+			*(uint64_t *)arg |= (1ull << VIRTIO_NET_F_MQ);
+	}
+
+	if (vm)
+		free(vm);
+
+	if (ret < 0)
+		PMD_DRV_LOG(ERR, "%s failed: %s",
+			    vhost_msg_strings[req], strerror(errno));
+
+	return ret;
+}
+
+/**
+ * Set up environment to talk with a vhost kernel backend.
+ *
+ * @return
+ *   - (-1) if fail to set up;
+ *   - (>=0) if successful.
+ */
+static int
+vhost_kernel_setup(struct virtio_user_dev *dev)
+{
+	int vhostfd;
+	uint32_t i;
+
+	get_vhost_kernel_max_regions();
+
+	for (i = 0; i < dev->max_queue_pairs; ++i) {
+		vhostfd = open(dev->path, O_RDWR);
+		if (vhostfd < 0) {
+			PMD_DRV_LOG(ERR, "fail to open %s, %s",
+				    dev->path, strerror(errno));
+			return -1;
+		}
+
+		dev->vhostfds[i] = vhostfd;
+	}
+
+	return 0;
+}
+
+static int
+vhost_kernel_set_backend(int vhostfd, int tapfd)
+{
+	struct vhost_vring_file f;
+
+	f.fd = tapfd;
+	f.index = 0;
+	if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
+		PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
+				strerror(errno));
+		return -1;
+	}
+
+	f.index = 1;
+	if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
+		PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
+				strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
+			       uint16_t pair_idx,
+			       int enable)
+{
+	int hdr_size;
+	int vhostfd;
+	int tapfd;
+	int req_mq = (dev->max_queue_pairs > 1);
+
+	vhostfd = dev->vhostfds[pair_idx];
+
+	if (!enable) {
+		if (dev->tapfds[pair_idx] >= 0) {
+			close(dev->tapfds[pair_idx]);
+			dev->tapfds[pair_idx] = -1;
+		}
+		return vhost_kernel_set_backend(vhostfd, -1);
+	} else if (dev->tapfds[pair_idx] >= 0) {
+		return 0;
+	}
+
+	if ((dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
+	    (dev->features & (1ULL << VIRTIO_F_VERSION_1)))
+		hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	else
+		hdr_size = sizeof(struct virtio_net_hdr);
+
+	tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq);
+	if (tapfd < 0) {
+		PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
+		return -1;
+	}
+
+	if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
+		PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
+		close(tapfd);
+		return -1;
+	}
+
+	dev->tapfds[pair_idx] = tapfd;
+	return 0;
+}
+
+struct virtio_user_backend_ops ops_kernel = {
+	.setup = vhost_kernel_setup,
+	.send_request = vhost_kernel_ioctl,
+	.enable_qp = vhost_kernel_enable_queue_pair
+};
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
new file mode 100644
index 00000000..f585de8c
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
@@ -0,0 +1,133 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2016 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 <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <net/if.h>
+#include <errno.h>
+#include <string.h>
+#include <limits.h>
+
+#include "vhost_kernel_tap.h"
+#include "../virtio_logs.h"
+
+int
+vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq)
+{
+	unsigned int tap_features;
+	int sndbuf = INT_MAX;
+	struct ifreq ifr;
+	int tapfd;
+	unsigned int offload =
+			TUN_F_CSUM |
+			TUN_F_TSO4 |
+			TUN_F_TSO6 |
+			TUN_F_TSO_ECN |
+			TUN_F_UFO;
+
+	/* TODO:
+	 * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
+	 * 2. get number of memory regions from vhost module parameter
+	 * max_mem_regions, supported in newer version linux kernel
+	 */
+	tapfd = open(PATH_NET_TUN, O_RDWR);
+	if (tapfd < 0) {
+		PMD_DRV_LOG(ERR, "fail to open %s: %s",
+			    PATH_NET_TUN, strerror(errno));
+		return -1;
+	}
+
+	/* Construct ifr */
+	memset(&ifr, 0, sizeof(ifr));
+	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+
+	if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
+		PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
+		goto error;
+	}
+	if (tap_features & IFF_ONE_QUEUE)
+		ifr.ifr_flags |= IFF_ONE_QUEUE;
+
+	/* Let tap instead of vhost-net handle vnet header, as the latter does
+	 * not support offloading. And in this case, we should not set feature
+	 * bit VHOST_NET_F_VIRTIO_NET_HDR.
+	 */
+	if (tap_features & IFF_VNET_HDR) {
+		ifr.ifr_flags |= IFF_VNET_HDR;
+	} else {
+		PMD_DRV_LOG(ERR, "TAP does not support IFF_VNET_HDR");
+		goto error;
+	}
+
+	if (req_mq)
+		ifr.ifr_flags |= IFF_MULTI_QUEUE;
+
+	if (*p_ifname)
+		strncpy(ifr.ifr_name, *p_ifname, IFNAMSIZ);
+	else
+		strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ);
+	if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
+		PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
+		goto error;
+	}
+
+	fcntl(tapfd, F_SETFL, O_NONBLOCK);
+
+	if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) {
+		PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno));
+		goto error;
+	}
+
+	if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) {
+		PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno));
+		goto error;
+	}
+
+	/* TODO: before set the offload capabilities, we'd better (1) check
+	 * negotiated features to see if necessary to offload; (2) query tap
+	 * to see if it supports the offload capabilities.
+	 */
+	if (ioctl(tapfd, TUNSETOFFLOAD, offload) != 0)
+		PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s",
+			   strerror(errno));
+
+	if (!(*p_ifname))
+		*p_ifname = strdup(ifr.ifr_name);
+
+	return tapfd;
+error:
+	close(tapfd);
+	return -1;
+}
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.h b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
new file mode 100644
index 00000000..eae340cc
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
@@ -0,0 +1,67 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2016 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 <sys/ioctl.h>
+
+/* TUN ioctls */
+#define TUNSETIFF     _IOW('T', 202, int)
+#define TUNGETFEATURES _IOR('T', 207, unsigned int)
+#define TUNSETOFFLOAD  _IOW('T', 208, unsigned int)
+#define TUNGETIFF      _IOR('T', 210, unsigned int)
+#define TUNSETSNDBUF   _IOW('T', 212, int)
+#define TUNGETVNETHDRSZ _IOR('T', 215, int)
+#define TUNSETVNETHDRSZ _IOW('T', 216, int)
+#define TUNSETQUEUE  _IOW('T', 217, int)
+#define TUNSETVNETLE _IOW('T', 220, int)
+#define TUNSETVNETBE _IOW('T', 222, int)
+
+/* TUNSETIFF ifr flags */
+#define IFF_TAP          0x0002
+#define IFF_NO_PI        0x1000
+#define IFF_ONE_QUEUE    0x2000
+#define IFF_VNET_HDR     0x4000
+#define IFF_MULTI_QUEUE  0x0100
+#define IFF_ATTACH_QUEUE 0x0200
+#define IFF_DETACH_QUEUE 0x0400
+
+/* Features for GSO (TUNSETOFFLOAD). */
+#define TUN_F_CSUM	0x01	/* You can hand me unchecksummed packets. */
+#define TUN_F_TSO4	0x02	/* I can handle TSO for IPv4 packets */
+#define TUN_F_TSO6	0x04	/* I can handle TSO for IPv6 packets */
+#define TUN_F_TSO_ECN	0x08	/* I can handle TSO with ECN bits. */
+#define TUN_F_UFO	0x10	/* I can handle UFO packets */
+
+/* Constants */
+#define PATH_NET_TUN	"/dev/net/tun"
+
+int vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq);
diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
index 082e8217..4ad7b21b 100644
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -41,6 +41,39 @@
 #include <errno.h>
 
 #include "vhost.h"
+#include "virtio_user_dev.h"
+
+/* The version of the protocol we support */
+#define VHOST_USER_VERSION    0x1
+
+#define VHOST_MEMORY_MAX_NREGIONS 8
+struct vhost_memory {
+	uint32_t nregions;
+	uint32_t padding;
+	struct vhost_memory_region regions[VHOST_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 memory;
+	} payload;
+	int fds[VHOST_MEMORY_MAX_NREGIONS];
+} __attribute((packed));
+
+#define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
+#define VHOST_USER_PAYLOAD_SIZE \
+	(sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
 
 static int
 vhost_user_write(int fd, void *buf, int len, int *fds, int fd_num)
@@ -223,24 +256,25 @@ prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
 
 static struct vhost_user_msg m;
 
-static const char * const vhost_msg_strings[] = {
-	[VHOST_USER_SET_OWNER] = "VHOST_USER_SET_OWNER",
-	[VHOST_USER_RESET_OWNER] = "VHOST_USER_RESET_OWNER",
-	[VHOST_USER_SET_FEATURES] = "VHOST_USER_SET_FEATURES",
-	[VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
-	[VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
-	[VHOST_USER_SET_VRING_NUM] = "VHOST_USER_SET_VRING_NUM",
-	[VHOST_USER_SET_VRING_BASE] = "VHOST_USER_SET_VRING_BASE",
-	[VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
-	[VHOST_USER_SET_VRING_ADDR] = "VHOST_USER_SET_VRING_ADDR",
-	[VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
-	[VHOST_USER_SET_MEM_TABLE] = "VHOST_USER_SET_MEM_TABLE",
-	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_USER_SET_VRING_ENABLE",
-	NULL,
+const char * const vhost_msg_strings[] = {
+	[VHOST_USER_SET_OWNER] = "VHOST_SET_OWNER",
+	[VHOST_USER_RESET_OWNER] = "VHOST_RESET_OWNER",
+	[VHOST_USER_SET_FEATURES] = "VHOST_SET_FEATURES",
+	[VHOST_USER_GET_FEATURES] = "VHOST_GET_FEATURES",
+	[VHOST_USER_SET_VRING_CALL] = "VHOST_SET_VRING_CALL",
+	[VHOST_USER_SET_VRING_NUM] = "VHOST_SET_VRING_NUM",
+	[VHOST_USER_SET_VRING_BASE] = "VHOST_SET_VRING_BASE",
+	[VHOST_USER_GET_VRING_BASE] = "VHOST_GET_VRING_BASE",
+	[VHOST_USER_SET_VRING_ADDR] = "VHOST_SET_VRING_ADDR",
+	[VHOST_USER_SET_VRING_KICK] = "VHOST_SET_VRING_KICK",
+	[VHOST_USER_SET_MEM_TABLE] = "VHOST_SET_MEM_TABLE",
+	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
 };
 
-int
-vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg)
+static int
+vhost_user_sock(struct virtio_user_dev *dev,
+		enum vhost_user_request req,
+		void *arg)
 {
 	struct vhost_user_msg msg;
 	struct vhost_vring_file *file = 0;
@@ -248,9 +282,9 @@ vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg)
 	int fds[VHOST_MEMORY_MAX_NREGIONS];
 	int fd_num = 0;
 	int i, len;
+	int vhostfd = dev->vhostfd;
 
 	RTE_SET_USED(m);
-	RTE_SET_USED(vhost_msg_strings);
 
 	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 
@@ -371,15 +405,13 @@ vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg)
 
 /**
  * Set up environment to talk with a vhost user backend.
- * @param path
- *   - The path to vhost user unix socket file.
  *
  * @return
- *   - (-1) if fail to set up;
- *   - (>=0) if successful, and it is the fd to vhostfd.
+ *   - (-1) if fail;
+ *   - (0) if succeed.
  */
-int
-vhost_user_setup(const char *path)
+static int
+vhost_user_setup(struct virtio_user_dev *dev)
 {
 	int fd;
 	int flag;
@@ -397,18 +429,21 @@ vhost_user_setup(const char *path)
 
 	memset(&un, 0, sizeof(un));
 	un.sun_family = AF_UNIX;
-	snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
+	snprintf(un.sun_path, sizeof(un.sun_path), "%s", dev->path);
 	if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
 		PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
 		close(fd);
 		return -1;
 	}
 
-	return fd;
+	dev->vhostfd = fd;
+	return 0;
 }
 
-int
-vhost_user_enable_queue_pair(int vhostfd, uint16_t pair_idx, int enable)
+static int
+vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
+			     uint16_t pair_idx,
+			     int enable)
 {
 	int i;
 
@@ -418,10 +453,15 @@ vhost_user_enable_queue_pair(int vhostfd, uint16_t pair_idx, int enable)
 			.num   = enable,
 		};
 
-		if (vhost_user_sock(vhostfd,
-				    VHOST_USER_SET_VRING_ENABLE, &state))
+		if (vhost_user_sock(dev, VHOST_USER_SET_VRING_ENABLE, &state))
 			return -1;
 	}
 
 	return 0;
 }
+
+struct virtio_user_backend_ops ops_user = {
+	.setup = vhost_user_setup,
+	.send_request = vhost_user_sock,
+	.enable_qp = vhost_user_enable_queue_pair
+};
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index a38398b8..450404ba 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -39,6 +39,9 @@
 #include <sys/mman.h>
 #include <unistd.h>
 #include <sys/eventfd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #include "vhost.h"
 #include "virtio_user_dev.h"
@@ -51,21 +54,11 @@ virtio_user_create_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 	 * firstly because vhost depends on this msg to allocate virtqueue
 	 * pair.
 	 */
-	int callfd;
 	struct vhost_vring_file file;
 
-	/* May use invalid flag, but some backend leverages kickfd and callfd as
-	 * criteria to judge if dev is alive. so finally we use real event_fd.
-	 */
-	callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
-	if (callfd < 0) {
-		PMD_DRV_LOG(ERR, "callfd error, %s\n", strerror(errno));
-		return -1;
-	}
 	file.index = queue_sel;
-	file.fd = callfd;
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_VRING_CALL, &file);
-	dev->callfds[queue_sel] = callfd;
+	file.fd = dev->callfds[queue_sel];
+	dev->ops->send_request(dev, VHOST_USER_SET_VRING_CALL, &file);
 
 	return 0;
 }
@@ -73,7 +66,6 @@ virtio_user_create_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 static int
 virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 {
-	int kickfd;
 	struct vhost_vring_file file;
 	struct vhost_vring_state state;
 	struct vring *vring = &dev->vrings[queue_sel];
@@ -88,26 +80,21 @@ virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 
 	state.index = queue_sel;
 	state.num = vring->num;
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_VRING_NUM, &state);
+	dev->ops->send_request(dev, VHOST_USER_SET_VRING_NUM, &state);
 
+	state.index = queue_sel;
 	state.num = 0; /* no reservation */
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_VRING_BASE, &state);
+	dev->ops->send_request(dev, VHOST_USER_SET_VRING_BASE, &state);
 
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_VRING_ADDR, &addr);
+	dev->ops->send_request(dev, VHOST_USER_SET_VRING_ADDR, &addr);
 
 	/* Of all per virtqueue MSGs, make sure VHOST_USER_SET_VRING_KICK comes
 	 * lastly because vhost depends on this msg to judge if
 	 * virtio is ready.
 	 */
-	kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
-	if (kickfd < 0) {
-		PMD_DRV_LOG(ERR, "kickfd error, %s\n", strerror(errno));
-		return -1;
-	}
 	file.index = queue_sel;
-	file.fd = kickfd;
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_VRING_KICK, &file);
-	dev->kickfds[queue_sel] = kickfd;
+	file.fd = dev->kickfds[queue_sel];
+	dev->ops->send_request(dev, VHOST_USER_SET_VRING_KICK, &file);
 
 	return 0;
 }
@@ -146,22 +133,20 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
 		goto error;
 
-	/* Step 1: set features
-	 * Make sure VHOST_USER_F_PROTOCOL_FEATURES is added if mq is enabled,
-	 * VIRTIO_NET_F_MAC and VIRTIO_NET_F_CTRL_VQ is stripped.
-	 */
+	/* Step 1: set features */
 	features = dev->features;
-	if (dev->max_queue_pairs > 1)
-		features |= VHOST_USER_MQ;
+	/* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
 	features &= ~(1ull << VIRTIO_NET_F_MAC);
+	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
 	features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
-	ret = vhost_user_sock(dev->vhostfd, VHOST_USER_SET_FEATURES, &features);
+	features &= ~(1ull << VIRTIO_NET_F_STATUS);
+	ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
 	if (ret < 0)
 		goto error;
 	PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
 
 	/* Step 2: share memory regions */
-	ret = vhost_user_sock(dev->vhostfd, VHOST_USER_SET_MEM_TABLE, NULL);
+	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
 	if (ret < 0)
 		goto error;
 
@@ -172,7 +157,7 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	/* Step 4: enable queues
 	 * we enable the 1st queue pair by default.
 	 */
-	vhost_user_enable_queue_pair(dev->vhostfd, 0, 1);
+	dev->ops->enable_qp(dev, 0, 1);
 
 	return 0;
 error:
@@ -184,13 +169,8 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 {
 	uint32_t i;
 
-	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
-		close(dev->callfds[i]);
-		close(dev->kickfds[i]);
-	}
-
 	for (i = 0; i < dev->max_queue_pairs; ++i)
-		vhost_user_enable_queue_pair(dev->vhostfd, i, 0);
+		dev->ops->enable_qp(dev, i, 0);
 
 	return 0;
 }
@@ -217,35 +197,170 @@ parse_mac(struct virtio_user_dev *dev, const char *mac)
 }
 
 int
-virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
-		     int cq, int queue_size, const char *mac)
+is_vhost_user_by_type(const char *path)
+{
+	struct stat sb;
+
+	if (stat(path, &sb) == -1)
+		return 0;
+
+	return S_ISSOCK(sb.st_mode);
+}
+
+static int
+virtio_user_dev_init_notify(struct virtio_user_dev *dev)
+{
+	uint32_t i, j;
+	int callfd;
+	int kickfd;
+
+	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
+		if (i >= dev->max_queue_pairs * 2) {
+			dev->kickfds[i] = -1;
+			dev->callfds[i] = -1;
+			continue;
+		}
+
+		/* May use invalid flag, but some backend uses kickfd and
+		 * callfd as criteria to judge if dev is alive. so finally we
+		 * use real event_fd.
+		 */
+		callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+		if (callfd < 0) {
+			PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
+			break;
+		}
+		kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+		if (kickfd < 0) {
+			PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
+			break;
+		}
+		dev->callfds[i] = callfd;
+		dev->kickfds[i] = kickfd;
+	}
+
+	if (i < VIRTIO_MAX_VIRTQUEUES) {
+		for (j = 0; j <= i; ++j) {
+			close(dev->callfds[j]);
+			close(dev->kickfds[j]);
+		}
+
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
 {
 	uint32_t i;
+	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
 
+	if (!eth_dev->intr_handle) {
+		eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
+		if (!eth_dev->intr_handle) {
+			PMD_DRV_LOG(ERR, "fail to allocate intr_handle");
+			return -1;
+		}
+		memset(eth_dev->intr_handle, 0, sizeof(*eth_dev->intr_handle));
+	}
+
+	for (i = 0; i < dev->max_queue_pairs; ++i)
+		eth_dev->intr_handle->efds[i] = dev->callfds[i];
+	eth_dev->intr_handle->nb_efd = dev->max_queue_pairs;
+	eth_dev->intr_handle->max_intr = dev->max_queue_pairs + 1;
+	eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
+	if (dev->vhostfd >= 0)
+		eth_dev->intr_handle->fd = dev->vhostfd;
+
+	return 0;
+}
+
+static int
+virtio_user_dev_setup(struct virtio_user_dev *dev)
+{
+	uint32_t q;
+
+	dev->vhostfd = -1;
+	dev->vhostfds = NULL;
+	dev->tapfds = NULL;
+
+	if (is_vhost_user_by_type(dev->path)) {
+		dev->ops = &ops_user;
+	} else {
+		dev->ops = &ops_kernel;
+
+		dev->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
+		dev->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
+		if (!dev->vhostfds || !dev->tapfds) {
+			PMD_INIT_LOG(ERR, "Failed to malloc");
+			return -1;
+		}
+
+		for (q = 0; q < dev->max_queue_pairs; ++q) {
+			dev->vhostfds[q] = -1;
+			dev->tapfds[q] = -1;
+		}
+	}
+
+	if (dev->ops->setup(dev) < 0)
+		return -1;
+
+	if (virtio_user_dev_init_notify(dev) < 0)
+		return -1;
+
+	if (virtio_user_fill_intr_handle(dev) < 0)
+		return -1;
+
+	return 0;
+}
+
+/* Use below macro to filter features from vhost backend */
+#define VIRTIO_USER_SUPPORTED_FEATURES			\
+	(1ULL << VIRTIO_NET_F_MAC		|	\
+	 1ULL << VIRTIO_NET_F_STATUS		|	\
+	 1ULL << VIRTIO_NET_F_MQ		|	\
+	 1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR	|	\
+	 1ULL << VIRTIO_NET_F_CTRL_VQ		|	\
+	 1ULL << VIRTIO_NET_F_CTRL_RX		|	\
+	 1ULL << VIRTIO_NET_F_CTRL_VLAN		|	\
+	 1ULL << VIRTIO_NET_F_CSUM		|	\
+	 1ULL << VIRTIO_NET_F_HOST_TSO4		|	\
+	 1ULL << VIRTIO_NET_F_HOST_TSO6		|	\
+	 1ULL << VIRTIO_NET_F_MRG_RXBUF		|	\
+	 1ULL << VIRTIO_RING_F_INDIRECT_DESC	|	\
+	 1ULL << VIRTIO_NET_F_GUEST_CSUM	|	\
+	 1ULL << VIRTIO_NET_F_GUEST_TSO4	|	\
+	 1ULL << VIRTIO_NET_F_GUEST_TSO6	|	\
+	 1ULL << VIRTIO_F_VERSION_1)
+
+int
+virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
+		     int cq, int queue_size, const char *mac, char **ifname)
+{
 	snprintf(dev->path, PATH_MAX, "%s", path);
 	dev->max_queue_pairs = queues;
 	dev->queue_pairs = 1; /* mq disabled by default */
 	dev->queue_size = queue_size;
 	dev->mac_specified = 0;
 	parse_mac(dev, mac);
-	dev->vhostfd = -1;
 
-	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES * 2 + 1; ++i) {
-		dev->kickfds[i] = -1;
-		dev->callfds[i] = -1;
+	if (*ifname) {
+		dev->ifname = *ifname;
+		*ifname = NULL;
 	}
 
-	dev->vhostfd = vhost_user_setup(dev->path);
-	if (dev->vhostfd < 0) {
+	if (virtio_user_dev_setup(dev) < 0) {
 		PMD_INIT_LOG(ERR, "backend set up fails");
 		return -1;
 	}
-	if (vhost_user_sock(dev->vhostfd, VHOST_USER_SET_OWNER, NULL) < 0) {
+	if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL) < 0) {
 		PMD_INIT_LOG(ERR, "set_owner fails: %s", strerror(errno));
 		return -1;
 	}
 
-	if (vhost_user_sock(dev->vhostfd, VHOST_USER_GET_FEATURES,
+	if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
 			    &dev->device_features) < 0) {
 		PMD_INIT_LOG(ERR, "get_features failed: %s", strerror(errno));
 		return -1;
@@ -268,12 +383,11 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 		dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
 	}
 
-	if (dev->max_queue_pairs > 1) {
-		if (!(dev->features & VHOST_USER_MQ)) {
-			PMD_INIT_LOG(ERR, "MQ not supported by the backend");
-			return -1;
-		}
-	}
+	/* The backend will not report this feature, we add it explicitly */
+	if (is_vhost_user_by_type(dev->path))
+		dev->device_features |= (1ull << VIRTIO_NET_F_STATUS);
+
+	dev->device_features &= VIRTIO_USER_SUPPORTED_FEATURES;
 
 	return 0;
 }
@@ -281,7 +395,25 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 void
 virtio_user_dev_uninit(struct virtio_user_dev *dev)
 {
+	uint32_t i;
+
+	virtio_user_stop_device(dev);
+
+	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
+		close(dev->callfds[i]);
+		close(dev->kickfds[i]);
+	}
+
 	close(dev->vhostfd);
+
+	if (dev->vhostfds) {
+		for (i = 0; i < dev->max_queue_pairs; ++i)
+			close(dev->vhostfds[i]);
+		free(dev->vhostfds);
+		free(dev->tapfds);
+	}
+
+	free(dev->ifname);
 }
 
 static uint8_t
@@ -297,9 +429,9 @@ virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
 	}
 
 	for (i = 0; i < q_pairs; ++i)
-		ret |= vhost_user_enable_queue_pair(dev->vhostfd, i, 1);
+		ret |= dev->ops->enable_qp(dev, i, 1);
 	for (i = q_pairs; i < dev->max_queue_pairs; ++i)
-		ret |= vhost_user_enable_queue_pair(dev->vhostfd, i, 0);
+		ret |= dev->ops->enable_qp(dev, i, 0);
 
 	dev->queue_pairs = q_pairs;
 
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 28fc788e..8361b6bd 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -37,11 +37,20 @@
 #include <limits.h>
 #include "../virtio_pci.h"
 #include "../virtio_ring.h"
+#include "vhost.h"
 
 struct virtio_user_dev {
+	/* for vhost_user backend */
 	int		vhostfd;
-	int		callfds[VIRTIO_MAX_VIRTQUEUES * 2 + 1];
-	int		kickfds[VIRTIO_MAX_VIRTQUEUES * 2 + 1];
+
+	/* for vhost_kernel backend */
+	char		*ifname;
+	int		*vhostfds;
+	int		*tapfds;
+
+	/* for both vhost_user and vhost_kernel */
+	int		callfds[VIRTIO_MAX_VIRTQUEUES];
+	int		kickfds[VIRTIO_MAX_VIRTQUEUES];
 	int		mac_specified;
 	uint32_t	max_queue_pairs;
 	uint32_t	queue_pairs;
@@ -51,15 +60,18 @@ struct virtio_user_dev {
 				   */
 	uint64_t	device_features; /* supported features by device */
 	uint8_t		status;
+	uint8_t		port_id;
 	uint8_t		mac_addr[ETHER_ADDR_LEN];
 	char		path[PATH_MAX];
-	struct vring	vrings[VIRTIO_MAX_VIRTQUEUES * 2 + 1];
+	struct vring	vrings[VIRTIO_MAX_VIRTQUEUES];
+	struct virtio_user_backend_ops *ops;
 };
 
+int is_vhost_user_by_type(const char *path);
 int virtio_user_start_device(struct virtio_user_dev *dev);
 int virtio_user_stop_device(struct virtio_user_dev *dev);
 int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
-			 int cq, int queue_size, const char *mac);
+			 int cq, int queue_size, const char *mac, char **ifname);
 void virtio_user_dev_uninit(struct virtio_user_dev *dev);
 void virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx);
 #endif