tools: virtio: introduce vhost_net_test

introduce vhost_net_test for both vhost_net tx and rx basing
on virtio_test to test vhost_net changing in the kernel.

Steps for vhost_net tx testing:
1. Prepare a out buf.
2. Kick the vhost_net to do tx processing.
3. Do the receiving in the tun side.
4. verify the data received by tun is correct.

Steps for vhost_net rx testing:
1. Prepare a in buf.
2. Do the sending in the tun side.
3. Kick the vhost_net to do rx processing.
4. verify the data received by vhost_net is correct.

Signed-off-by: Yunsheng Lin <[e-mail]>
Acked-by: Michael S. Tsirkin <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

tools/virtio/.gitignore

···
 # SPDX-License-Identifier: GPL-2.0-only
 *.d
 virtio_test
+vhost_net_test
 vringh_test
 virtio-trace/trace-agent

tools/virtio/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 all: test mod
-test: virtio_test vringh_test
+test: virtio_test vringh_test vhost_net_test
 virtio_test: virtio_ring.o virtio_test.o
 vringh_test: vringh_test.o vringh.o virtio_ring.o
+vhost_net_test: virtio_ring.o vhost_net_test.o
 
 try-run = $(shell set -e;		\
 	if ($(1)) >/dev/null 2>&1;	\
···
 
 .PHONY: all test mod clean vhost oot oot-clean oot-build
 clean:
-	${RM} *.o vringh_test virtio_test vhost_test/*.o vhost_test/.*.cmd \
-              vhost_test/Module.symvers vhost_test/modules.order *.d
+	${RM} *.o vringh_test virtio_test vhost_net_test vhost_test/*.o \
+              vhost_test/.*.cmd vhost_test/Module.symvers \
+              vhost_test/modules.order *.d
 -include *.d

tools/virtio/linux/virtio_config.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_VIRTIO_CONFIG_H
+#define LINUX_VIRTIO_CONFIG_H
 #include <linux/virtio_byteorder.h>
 #include <linux/virtio.h>
 #include <uapi/linux/virtio_config.h>
···
 {
 	return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
 }
+
+#endif

tools/virtio/vhost_net_test.c

···
+// 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;
+}