tools/virtio/vhost_net_test.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #define _GNU_SOURCE
 #include <getopt.h>
 #include <limits.h>
 #include <string.h>
 #include <poll.h>
 #include <sys/eventfd.h>
 #include <stdlib.h>
 #include <assert.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <stdbool.h>
 #include <linux/vhost.h>
 #include <linux/if.h>
 #include <linux/if_tun.h>
 #include <linux/in.h>
 #include <linux/if_packet.h>
 #include <linux/virtio_net.h>
 #include <netinet/ether.h>

 #define HDR_LEN		sizeof(struct virtio_net_hdr_mrg_rxbuf)
 #define TEST_BUF_LEN	256
 #define TEST_PTYPE	ETH_P_LOOPBACK
 #define DESC_NUM	256

 /* Used by implementation of kmalloc() in tools/virtio/linux/kernel.h */
 void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;

 struct vq_info {
 	int kick;
 	int call;
 	int idx;
 	long started;
 	long completed;
 	struct pollfd fds;
 	void *ring;
 	/* copy used for control */
 	struct vring vring;
 	struct virtqueue *vq;
 };

 struct vdev_info {
 	struct virtio_device vdev;
 	int control;
 	struct vq_info vqs[2];
 	int nvqs;
 	void *buf;
 	size_t buf_size;
 	char *test_buf;
 	char *res_buf;
 	struct vhost_memory *mem;
 	int sock;
 	int ifindex;
 	unsigned char mac[ETHER_ADDR_LEN];
 };

 static int tun_alloc(struct vdev_info *dev, char *tun_name)
 {
 	struct ifreq ifr;
 	int len = HDR_LEN;
 	int fd, e;

 	fd = open("/dev/net/tun", O_RDWR);
 	if (fd < 0) {
 		perror("Cannot open /dev/net/tun");
 		return fd;
 	}

 	memset(&ifr, 0, sizeof(ifr));

 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
 	strncpy(ifr.ifr_name, tun_name, IFNAMSIZ);

 	e = ioctl(fd, TUNSETIFF, &ifr);
 	if (e < 0) {
 		perror("ioctl[TUNSETIFF]");
 		close(fd);
 		return e;
 	}

 	e = ioctl(fd, TUNSETVNETHDRSZ, &len);
 	if (e < 0) {
 		perror("ioctl[TUNSETVNETHDRSZ]");
 		close(fd);
 		return e;
 	}

 	e = ioctl(fd, SIOCGIFHWADDR, &ifr);
 	if (e < 0) {
 		perror("ioctl[SIOCGIFHWADDR]");
 		close(fd);
 		return e;
 	}

 	memcpy(dev->mac, &ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 	return fd;
 }

 static void vdev_create_socket(struct vdev_info *dev, char *tun_name)
 {
 	struct ifreq ifr;

 	dev->sock = socket(AF_PACKET, SOCK_RAW, htons(TEST_PTYPE));
 	assert(dev->sock != -1);

 	strncpy(ifr.ifr_name, tun_name, IFNAMSIZ);
 	assert(ioctl(dev->sock, SIOCGIFINDEX, &ifr) >= 0);

 	dev->ifindex = ifr.ifr_ifindex;

 	/* Set the flags that bring the device up */
 	assert(ioctl(dev->sock, SIOCGIFFLAGS, &ifr) >= 0);
 	ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
 	assert(ioctl(dev->sock, SIOCSIFFLAGS, &ifr) >= 0);
 }

 static void vdev_send_packet(struct vdev_info *dev)
 {
 	char *sendbuf = dev->test_buf + HDR_LEN;
 	struct sockaddr_ll saddrll = {0};
 	int sockfd = dev->sock;
 	int ret;

 	saddrll.sll_family = PF_PACKET;
 	saddrll.sll_ifindex = dev->ifindex;
 	saddrll.sll_halen = ETH_ALEN;
 	saddrll.sll_protocol = htons(TEST_PTYPE);

 	ret = sendto(sockfd, sendbuf, TEST_BUF_LEN, 0,
 		     (struct sockaddr *)&saddrll,
 		     sizeof(struct sockaddr_ll));
 	assert(ret >= 0);
 }

 static bool vq_notify(struct virtqueue *vq)
 {
 	struct vq_info *info = vq->priv;
 	unsigned long long v = 1;
 	int r;

 	r = write(info->kick, &v, sizeof(v));
 	assert(r == sizeof(v));

 	return true;
 }

 static void vhost_vq_setup(struct vdev_info *dev, struct vq_info *info)
 {
 	struct vhost_vring_addr addr = {
 		.index = info->idx,
 		.desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
 		.avail_user_addr = (uint64_t)(unsigned long)info->vring.avail,
 		.used_user_addr = (uint64_t)(unsigned long)info->vring.used,
 	};
 	struct vhost_vring_state state = { .index = info->idx };
 	struct vhost_vring_file file = { .index = info->idx };
 	int r;

 	state.num = info->vring.num;
 	r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
 	assert(r >= 0);

 	state.num = 0;
 	r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
 	assert(r >= 0);

 	r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
 	assert(r >= 0);

 	file.fd = info->kick;
 	r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
 	assert(r >= 0);
 }

 static void vq_reset(struct vq_info *info, int num, struct virtio_device *vdev)
 {
 	if (info->vq)
 		vring_del_virtqueue(info->vq);

 	memset(info->ring, 0, vring_size(num, 4096));
 	vring_init(&info->vring, num, info->ring, 4096);
 	info->vq = vring_new_virtqueue(info->idx, num, 4096, vdev, true, false,
 				       info->ring, vq_notify, NULL, "test");
 	assert(info->vq);
 	info->vq->priv = info;
 }

 static void vq_info_add(struct vdev_info *dev, int idx, int num, int fd)
 {
 	struct vhost_vring_file backend = { .index = idx, .fd = fd };
 	struct vq_info *info = &dev->vqs[idx];
 	int r;

 	info->idx = idx;
 	info->kick = eventfd(0, EFD_NONBLOCK);
 	r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
 	assert(r >= 0);
 	vq_reset(info, num, &dev->vdev);
 	vhost_vq_setup(dev, info);

 	r = ioctl(dev->control, VHOST_NET_SET_BACKEND, &backend);
 	assert(!r);
 }

 static void vdev_info_init(struct vdev_info *dev, unsigned long long features)
 {
 	struct ether_header *eh;
 	int i, r;

 	dev->vdev.features = features;
 	INIT_LIST_HEAD(&dev->vdev.vqs);
 	spin_lock_init(&dev->vdev.vqs_list_lock);

 	dev->buf_size = (HDR_LEN + TEST_BUF_LEN) * 2;
 	dev->buf = malloc(dev->buf_size);
 	assert(dev->buf);
 	dev->test_buf = dev->buf;
 	dev->res_buf = dev->test_buf + HDR_LEN + TEST_BUF_LEN;

 	memset(dev->test_buf, 0, HDR_LEN + TEST_BUF_LEN);
 	eh = (struct ether_header *)(dev->test_buf + HDR_LEN);
 	eh->ether_type = htons(TEST_PTYPE);
 	memcpy(eh->ether_dhost, dev->mac, ETHER_ADDR_LEN);
 	memcpy(eh->ether_shost, dev->mac, ETHER_ADDR_LEN);

 	for (i = sizeof(*eh); i < TEST_BUF_LEN; i++)
 		dev->test_buf[i + HDR_LEN] = (char)i;

 	dev->control = open("/dev/vhost-net", O_RDWR);
 	assert(dev->control >= 0);

 	r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
 	assert(r >= 0);

 	dev->mem = malloc(offsetof(struct vhost_memory, regions) +
 			  sizeof(dev->mem->regions[0]));
 	assert(dev->mem);
 	memset(dev->mem, 0, offsetof(struct vhost_memory, regions) +
 	       sizeof(dev->mem->regions[0]));
 	dev->mem->nregions = 1;
 	dev->mem->regions[0].guest_phys_addr = (long)dev->buf;
 	dev->mem->regions[0].userspace_addr = (long)dev->buf;
 	dev->mem->regions[0].memory_size = dev->buf_size;

 	r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
 	assert(r >= 0);

 	r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
 	assert(r >= 0);

 	dev->nvqs = 2;
 }

 static void wait_for_interrupt(struct vq_info *vq)
 {
 	unsigned long long val;

 	poll(&vq->fds, 1, 100);

 	if (vq->fds.revents & POLLIN)
 		read(vq->fds.fd, &val, sizeof(val));
 }

 static void verify_res_buf(char *res_buf)
 {
 	int i;

 	for (i = ETHER_HDR_LEN; i < TEST_BUF_LEN; i++)
 		assert(res_buf[i] == (char)i);
 }

 static void run_tx_test(struct vdev_info *dev, struct vq_info *vq,
 			bool delayed, int bufs)
 {
 	long long spurious = 0;
 	struct scatterlist sl;
 	unsigned int len;
 	int r;

 	for (;;) {
 		long started_before = vq->started;
 		long completed_before = vq->completed;

 		virtqueue_disable_cb(vq->vq);
 		do {
 			while (vq->started < bufs &&
 			       (vq->started - vq->completed) < 1) {
 				sg_init_one(&sl, dev->test_buf, HDR_LEN + TEST_BUF_LEN);
 				r = virtqueue_add_outbuf(vq->vq, &sl, 1,
 							 dev->test_buf + vq->started,
 							 GFP_ATOMIC);
 				if (unlikely(r != 0))
 					break;

 				++vq->started;

 				if (unlikely(!virtqueue_kick(vq->vq))) {
 					r = -1;
 					break;
 				}
 			}

 			if (vq->started >= bufs)
 				r = -1;

 			/* Flush out completed bufs if any */
 			while (virtqueue_get_buf(vq->vq, &len)) {
 				int n;

 				n = recvfrom(dev->sock, dev->res_buf, TEST_BUF_LEN, 0, NULL, NULL);
 				assert(n == TEST_BUF_LEN);
 				verify_res_buf(dev->res_buf);

 				++vq->completed;
 				r = 0;
 			}
 		} while (r == 0);

 		if (vq->completed == completed_before && vq->started == started_before)
 			++spurious;

 		assert(vq->completed <= bufs);
 		assert(vq->started <= bufs);
 		if (vq->completed == bufs)
 			break;

 		if (delayed) {
 			if (virtqueue_enable_cb_delayed(vq->vq))
 				wait_for_interrupt(vq);
 		} else {
 			if (virtqueue_enable_cb(vq->vq))
 				wait_for_interrupt(vq);
 		}
 	}
 	printf("TX spurious wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
 	       spurious, vq->started, vq->completed);
 }

 static void run_rx_test(struct vdev_info *dev, struct vq_info *vq,
 			bool delayed, int bufs)
 {
 	long long spurious = 0;
 	struct scatterlist sl;
 	unsigned int len;
 	int r;

 	for (;;) {
 		long started_before = vq->started;
 		long completed_before = vq->completed;

 		do {
 			while (vq->started < bufs &&
 			       (vq->started - vq->completed) < 1) {
 				sg_init_one(&sl, dev->res_buf, HDR_LEN + TEST_BUF_LEN);

 				r = virtqueue_add_inbuf(vq->vq, &sl, 1,
 							dev->res_buf + vq->started,
 							GFP_ATOMIC);
 				if (unlikely(r != 0))
 					break;

 				++vq->started;

 				vdev_send_packet(dev);

 				if (unlikely(!virtqueue_kick(vq->vq))) {
 					r = -1;
 					break;
 				}
 			}

 			if (vq->started >= bufs)
 				r = -1;

 			/* Flush out completed bufs if any */
 			while (virtqueue_get_buf(vq->vq, &len)) {
 				struct ether_header *eh;

 				eh = (struct ether_header *)(dev->res_buf + HDR_LEN);

 				/* tun netdev is up and running, only handle the
 				 * TEST_PTYPE packet.
 				 */
 				if (eh->ether_type == htons(TEST_PTYPE)) {
 					assert(len == TEST_BUF_LEN + HDR_LEN);
 					verify_res_buf(dev->res_buf + HDR_LEN);
 				}

 				++vq->completed;
 				r = 0;
 			}
 		} while (r == 0);

 		if (vq->completed == completed_before && vq->started == started_before)
 			++spurious;

 		assert(vq->completed <= bufs);
 		assert(vq->started <= bufs);
 		if (vq->completed == bufs)
 			break;
 	}

 	printf("RX spurious wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
 	       spurious, vq->started, vq->completed);
 }

 static const char optstring[] = "h";
 static const struct option longopts[] = {
 	{
 		.name = "help",
 		.val = 'h',
 	},
 	{
 		.name = "event-idx",
 		.val = 'E',
 	},
 	{
 		.name = "no-event-idx",
 		.val = 'e',
 	},
 	{
 		.name = "indirect",
 		.val = 'I',
 	},
 	{
 		.name = "no-indirect",
 		.val = 'i',
 	},
 	{
 		.name = "virtio-1",
 		.val = '1',
 	},
 	{
 		.name = "no-virtio-1",
 		.val = '0',
 	},
 	{
 		.name = "delayed-interrupt",
 		.val = 'D',
 	},
 	{
 		.name = "no-delayed-interrupt",
 		.val = 'd',
 	},
 	{
 		.name = "buf-num",
 		.val = 'n',
 		.has_arg = required_argument,
 	},
 	{
 		.name = "batch",
 		.val = 'b',
 		.has_arg = required_argument,
 	},
 	{
 	}
 };

 static void help(int status)
 {
 	fprintf(stderr, "Usage: vhost_net_test [--help]"
 		" [--no-indirect]"
 		" [--no-event-idx]"
 		" [--no-virtio-1]"
 		" [--delayed-interrupt]"
 		" [--buf-num]"
 		"\n");

 	exit(status);
 }

 int main(int argc, char **argv)
 {
 	unsigned long long features = (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
 		(1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VIRTIO_F_VERSION_1);
 	char tun_name[IFNAMSIZ];
 	long nbufs = 0x100000;
 	struct vdev_info dev;
 	bool delayed = false;
 	int o, fd;

 	for (;;) {
 		o = getopt_long(argc, argv, optstring, longopts, NULL);
 		switch (o) {
 		case -1:
 			goto done;
 		case '?':
 			help(2);
 		case 'e':
 			features &= ~(1ULL << VIRTIO_RING_F_EVENT_IDX);
 			break;
 		case 'h':
 			help(0);
 		case 'i':
 			features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
 			break;
 		case '0':
 			features &= ~(1ULL << VIRTIO_F_VERSION_1);
 			break;
 		case 'D':
 			delayed = true;
 			break;
 		case 'n':
 			nbufs = strtol(optarg, NULL, 10);
 			assert(nbufs > 0);
 			break;
 		default:
 			assert(0);
 			break;
 		}
 	}

 done:
 	memset(&dev, 0, sizeof(dev));
 	snprintf(tun_name, IFNAMSIZ, "tun_%d", getpid());

 	fd = tun_alloc(&dev, tun_name);
 	assert(fd >= 0);

 	vdev_info_init(&dev, features);
 	vq_info_add(&dev, 0, DESC_NUM, fd);
 	vq_info_add(&dev, 1, DESC_NUM, fd);
 	vdev_create_socket(&dev, tun_name);

 	run_rx_test(&dev, &dev.vqs[0], delayed, nbufs);
 	run_tx_test(&dev, &dev.vqs[1], delayed, nbufs);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	#define _GNU_SOURCE
	#include <getopt.h>
	#include <limits.h>
	#include <string.h>
	#include <poll.h>
	#include <sys/eventfd.h>
	#include <stdlib.h>
	#include <assert.h>
	#include <unistd.h>
	#include <sys/ioctl.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <fcntl.h>
	#include <stdbool.h>
	#include <linux/vhost.h>
	#include <linux/if.h>
	#include <linux/if_tun.h>
	#include <linux/in.h>
	#include <linux/if_packet.h>
	#include <linux/virtio_net.h>
	#include <netinet/ether.h>

	#define HDR_LEN sizeof(struct virtio_net_hdr_mrg_rxbuf)
	#define TEST_BUF_LEN 256
	#define TEST_PTYPE ETH_P_LOOPBACK
	#define DESC_NUM 256

	/* Used by implementation of kmalloc() in tools/virtio/linux/kernel.h */
	void __kmalloc_fake, __kfree_ignore_start, *__kfree_ignore_end;

	struct vq_info {
	int kick;
	int call;
	int idx;
	long started;
	long completed;
	struct pollfd fds;
	void *ring;
	/* copy used for control */
	struct vring vring;
	struct virtqueue *vq;
	};

	struct vdev_info {
	struct virtio_device vdev;
	int control;
	struct vq_info vqs[2];
	int nvqs;
	void *buf;
	size_t buf_size;
	char *test_buf;
	char *res_buf;
	struct vhost_memory *mem;
	int sock;
	int ifindex;
	unsigned char mac[ETHER_ADDR_LEN];
	};

	static int tun_alloc(struct vdev_info dev, char tun_name)
	{
	struct ifreq ifr;
	int len = HDR_LEN;
	int fd, e;

	fd = open("/dev/net/tun", O_RDWR);
	if (fd < 0) {
	perror("Cannot open /dev/net/tun");
	return fd;
	}

	memset(&ifr, 0, sizeof(ifr));

	ifr.ifr_flags = IFF_TAP \| IFF_NO_PI \| IFF_VNET_HDR;
	strncpy(ifr.ifr_name, tun_name, IFNAMSIZ);

	e = ioctl(fd, TUNSETIFF, &ifr);
	if (e < 0) {
	perror("ioctl[TUNSETIFF]");
	close(fd);
	return e;
	}

	e = ioctl(fd, TUNSETVNETHDRSZ, &len);
	if (e < 0) {
	perror("ioctl[TUNSETVNETHDRSZ]");
	close(fd);
	return e;
	}

	e = ioctl(fd, SIOCGIFHWADDR, &ifr);
	if (e < 0) {
	perror("ioctl[SIOCGIFHWADDR]");
	close(fd);
	return e;
	}

	memcpy(dev->mac, &ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
	return fd;
	}

	static void vdev_create_socket(struct vdev_info dev, char tun_name)
	{
	struct ifreq ifr;

	dev->sock = socket(AF_PACKET, SOCK_RAW, htons(TEST_PTYPE));
	assert(dev->sock != -1);

	strncpy(ifr.ifr_name, tun_name, IFNAMSIZ);
	assert(ioctl(dev->sock, SIOCGIFINDEX, &ifr) >= 0);

	dev->ifindex = ifr.ifr_ifindex;

	/* Set the flags that bring the device up */
	assert(ioctl(dev->sock, SIOCGIFFLAGS, &ifr) >= 0);
	ifr.ifr_flags \|= (IFF_UP \| IFF_RUNNING);
	assert(ioctl(dev->sock, SIOCSIFFLAGS, &ifr) >= 0);
	}

	static void vdev_send_packet(struct vdev_info *dev)
	{
	char *sendbuf = dev->test_buf + HDR_LEN;
	struct sockaddr_ll saddrll = {0};
	int sockfd = dev->sock;
	int ret;

	saddrll.sll_family = PF_PACKET;
	saddrll.sll_ifindex = dev->ifindex;
	saddrll.sll_halen = ETH_ALEN;
	saddrll.sll_protocol = htons(TEST_PTYPE);

	ret = sendto(sockfd, sendbuf, TEST_BUF_LEN, 0,
	(struct sockaddr *)&saddrll,
	sizeof(struct sockaddr_ll));
	assert(ret >= 0);
	}

	static bool vq_notify(struct virtqueue *vq)
	{
	struct vq_info *info = vq->priv;
	unsigned long long v = 1;
	int r;

	r = write(info->kick, &v, sizeof(v));
	assert(r == sizeof(v));

	return true;
	}

	static void vhost_vq_setup(struct vdev_info dev, struct vq_info info)
	{
	struct vhost_vring_addr addr = {
	.index = info->idx,
	.desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
	.avail_user_addr = (uint64_t)(unsigned long)info->vring.avail,
	.used_user_addr = (uint64_t)(unsigned long)info->vring.used,
	};
	struct vhost_vring_state state = { .index = info->idx };
	struct vhost_vring_file file = { .index = info->idx };
	int r;

	state.num = info->vring.num;
	r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
	assert(r >= 0);

	state.num = 0;
	r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
	assert(r >= 0);

	r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
	assert(r >= 0);

	file.fd = info->kick;
	r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
	assert(r >= 0);
	}

	static void vq_reset(struct vq_info info, int num, struct virtio_device vdev)
	{
	if (info->vq)
	vring_del_virtqueue(info->vq);

	memset(info->ring, 0, vring_size(num, 4096));
	vring_init(&info->vring, num, info->ring, 4096);
	info->vq = vring_new_virtqueue(info->idx, num, 4096, vdev, true, false,
	info->ring, vq_notify, NULL, "test");
	assert(info->vq);
	info->vq->priv = info;
	}

	static void vq_info_add(struct vdev_info *dev, int idx, int num, int fd)
	{
	struct vhost_vring_file backend = { .index = idx, .fd = fd };
	struct vq_info *info = &dev->vqs[idx];
	int r;

	info->idx = idx;
	info->kick = eventfd(0, EFD_NONBLOCK);
	r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
	assert(r >= 0);
	vq_reset(info, num, &dev->vdev);
	vhost_vq_setup(dev, info);

	r = ioctl(dev->control, VHOST_NET_SET_BACKEND, &backend);
	assert(!r);
	}

	static void vdev_info_init(struct vdev_info *dev, unsigned long long features)
	{
	struct ether_header *eh;
	int i, r;

	dev->vdev.features = features;
	INIT_LIST_HEAD(&dev->vdev.vqs);
	spin_lock_init(&dev->vdev.vqs_list_lock);

	dev->buf_size = (HDR_LEN + TEST_BUF_LEN) * 2;
	dev->buf = malloc(dev->buf_size);
	assert(dev->buf);
	dev->test_buf = dev->buf;
	dev->res_buf = dev->test_buf + HDR_LEN + TEST_BUF_LEN;

	memset(dev->test_buf, 0, HDR_LEN + TEST_BUF_LEN);
	eh = (struct ether_header *)(dev->test_buf + HDR_LEN);
	eh->ether_type = htons(TEST_PTYPE);
	memcpy(eh->ether_dhost, dev->mac, ETHER_ADDR_LEN);
	memcpy(eh->ether_shost, dev->mac, ETHER_ADDR_LEN);

	for (i = sizeof(*eh); i < TEST_BUF_LEN; i++)
	dev->test_buf[i + HDR_LEN] = (char)i;

	dev->control = open("/dev/vhost-net", O_RDWR);
	assert(dev->control >= 0);

	r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
	assert(r >= 0);

	dev->mem = malloc(offsetof(struct vhost_memory, regions) +
	sizeof(dev->mem->regions[0]));
	assert(dev->mem);
	memset(dev->mem, 0, offsetof(struct vhost_memory, regions) +
	sizeof(dev->mem->regions[0]));
	dev->mem->nregions = 1;
	dev->mem->regions[0].guest_phys_addr = (long)dev->buf;
	dev->mem->regions[0].userspace_addr = (long)dev->buf;
	dev->mem->regions[0].memory_size = dev->buf_size;

	r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
	assert(r >= 0);

	r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
	assert(r >= 0);

	dev->nvqs = 2;
	}

	static void wait_for_interrupt(struct vq_info *vq)
	{
	unsigned long long val;

	poll(&vq->fds, 1, 100);

	if (vq->fds.revents & POLLIN)
	read(vq->fds.fd, &val, sizeof(val));
	}

	static void verify_res_buf(char *res_buf)
	{
	int i;

	for (i = ETHER_HDR_LEN; i < TEST_BUF_LEN; i++)
	assert(res_buf[i] == (char)i);
	}

	static void run_tx_test(struct vdev_info dev, struct vq_info vq,
	bool delayed, int bufs)
	{
	long long spurious = 0;
	struct scatterlist sl;
	unsigned int len;
	int r;

	for (;;) {
	long started_before = vq->started;
	long completed_before = vq->completed;

	virtqueue_disable_cb(vq->vq);
	do {
	while (vq->started < bufs &&
	(vq->started - vq->completed) < 1) {
	sg_init_one(&sl, dev->test_buf, HDR_LEN + TEST_BUF_LEN);
	r = virtqueue_add_outbuf(vq->vq, &sl, 1,
	dev->test_buf + vq->started,
	GFP_ATOMIC);
	if (unlikely(r != 0))
	break;

	++vq->started;

	if (unlikely(!virtqueue_kick(vq->vq))) {
	r = -1;
	break;
	}
	}

	if (vq->started >= bufs)
	r = -1;

	/* Flush out completed bufs if any */
	while (virtqueue_get_buf(vq->vq, &len)) {
	int n;

	n = recvfrom(dev->sock, dev->res_buf, TEST_BUF_LEN, 0, NULL, NULL);
	assert(n == TEST_BUF_LEN);
	verify_res_buf(dev->res_buf);

	++vq->completed;
	r = 0;
	}
	} while (r == 0);

	if (vq->completed == completed_before && vq->started == started_before)
	++spurious;

	assert(vq->completed <= bufs);
	assert(vq->started <= bufs);
	if (vq->completed == bufs)
	break;

	if (delayed) {
	if (virtqueue_enable_cb_delayed(vq->vq))
	wait_for_interrupt(vq);
	} else {
	if (virtqueue_enable_cb(vq->vq))
	wait_for_interrupt(vq);
	}
	}
	printf("TX spurious wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
	spurious, vq->started, vq->completed);
	}

	static void run_rx_test(struct vdev_info dev, struct vq_info vq,
	bool delayed, int bufs)
	{
	long long spurious = 0;
	struct scatterlist sl;
	unsigned int len;
	int r;

	for (;;) {
	long started_before = vq->started;
	long completed_before = vq->completed;

	do {
	while (vq->started < bufs &&
	(vq->started - vq->completed) < 1) {
	sg_init_one(&sl, dev->res_buf, HDR_LEN + TEST_BUF_LEN);

	r = virtqueue_add_inbuf(vq->vq, &sl, 1,
	dev->res_buf + vq->started,
	GFP_ATOMIC);
	if (unlikely(r != 0))
	break;

	++vq->started;

	vdev_send_packet(dev);

	if (unlikely(!virtqueue_kick(vq->vq))) {
	r = -1;
	break;
	}
	}

	if (vq->started >= bufs)
	r = -1;

	/* Flush out completed bufs if any */
	while (virtqueue_get_buf(vq->vq, &len)) {
	struct ether_header *eh;

	eh = (struct ether_header *)(dev->res_buf + HDR_LEN);

	/* tun netdev is up and running, only handle the
	* TEST_PTYPE packet.
	*/
	if (eh->ether_type == htons(TEST_PTYPE)) {
	assert(len == TEST_BUF_LEN + HDR_LEN);
	verify_res_buf(dev->res_buf + HDR_LEN);
	}

	++vq->completed;
	r = 0;
	}
	} while (r == 0);

	if (vq->completed == completed_before && vq->started == started_before)
	++spurious;

	assert(vq->completed <= bufs);
	assert(vq->started <= bufs);
	if (vq->completed == bufs)
	break;
	}

	printf("RX spurious wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
	spurious, vq->started, vq->completed);
	}

	static const char optstring[] = "h";
	static const struct option longopts[] = {
	{
	.name = "help",
	.val = 'h',
	},
	{
	.name = "event-idx",
	.val = 'E',
	},
	{
	.name = "no-event-idx",
	.val = 'e',
	},
	{
	.name = "indirect",
	.val = 'I',
	},
	{
	.name = "no-indirect",
	.val = 'i',
	},
	{
	.name = "virtio-1",
	.val = '1',
	},
	{
	.name = "no-virtio-1",
	.val = '0',
	},
	{
	.name = "delayed-interrupt",
	.val = 'D',
	},
	{
	.name = "no-delayed-interrupt",
	.val = 'd',
	},
	{
	.name = "buf-num",
	.val = 'n',
	.has_arg = required_argument,
	},
	{
	.name = "batch",
	.val = 'b',
	.has_arg = required_argument,
	},
	{
	}
	};

	static void help(int status)
	{
	fprintf(stderr, "Usage: vhost_net_test [--help]"
	" [--no-indirect]"
	" [--no-event-idx]"
	" [--no-virtio-1]"
	" [--delayed-interrupt]"
	" [--buf-num]"
	"\n");

	exit(status);
	}

	int main(int argc, char **argv)
	{
	unsigned long long features = (1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	(1ULL << VIRTIO_RING_F_EVENT_IDX) \| (1ULL << VIRTIO_F_VERSION_1);
	char tun_name[IFNAMSIZ];
	long nbufs = 0x100000;
	struct vdev_info dev;
	bool delayed = false;
	int o, fd;

	for (;;) {
	o = getopt_long(argc, argv, optstring, longopts, NULL);
	switch (o) {
	case -1:
	goto done;
	case '?':
	help(2);
	case 'e':
	features &= ~(1ULL << VIRTIO_RING_F_EVENT_IDX);
	break;
	case 'h':
	help(0);
	case 'i':
	features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
	break;
	case '0':
	features &= ~(1ULL << VIRTIO_F_VERSION_1);
	break;
	case 'D':
	delayed = true;
	break;
	case 'n':
	nbufs = strtol(optarg, NULL, 10);
	assert(nbufs > 0);
	break;
	default:
	assert(0);
	break;
	}
	}

	done:
	memset(&dev, 0, sizeof(dev));
	snprintf(tun_name, IFNAMSIZ, "tun_%d", getpid());

	fd = tun_alloc(&dev, tun_name);
	assert(fd >= 0);

	vdev_info_init(&dev, features);
	vq_info_add(&dev, 0, DESC_NUM, fd);
	vq_info_add(&dev, 1, DESC_NUM, fd);
	vdev_create_socket(&dev, tun_name);

	run_rx_test(&dev, &dev.vqs[0], delayed, nbufs);
	run_tx_test(&dev, &dev.vqs[1], delayed, nbufs);

	return 0;
	}