linux/tools/virtio/virtio_test.c
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   1#define _GNU_SOURCE
   2#include <getopt.h>
   3#include <string.h>
   4#include <poll.h>
   5#include <sys/eventfd.h>
   6#include <stdlib.h>
   7#include <assert.h>
   8#include <unistd.h>
   9#include <sys/ioctl.h>
  10#include <sys/stat.h>
  11#include <sys/types.h>
  12#include <fcntl.h>
  13#include <linux/vhost.h>
  14#include <linux/virtio.h>
  15#include <linux/virtio_ring.h>
  16#include "../../drivers/vhost/test.h"
  17
  18struct vq_info {
  19        int kick;
  20        int call;
  21        int num;
  22        int idx;
  23        void *ring;
  24        /* copy used for control */
  25        struct vring vring;
  26        struct virtqueue *vq;
  27};
  28
  29struct vdev_info {
  30        struct virtio_device vdev;
  31        int control;
  32        struct pollfd fds[1];
  33        struct vq_info vqs[1];
  34        int nvqs;
  35        void *buf;
  36        size_t buf_size;
  37        struct vhost_memory *mem;
  38};
  39
  40void vq_notify(struct virtqueue *vq)
  41{
  42        struct vq_info *info = vq->priv;
  43        unsigned long long v = 1;
  44        int r;
  45        r = write(info->kick, &v, sizeof v);
  46        assert(r == sizeof v);
  47}
  48
  49void vq_callback(struct virtqueue *vq)
  50{
  51}
  52
  53
  54void vhost_vq_setup(struct vdev_info *dev, struct vq_info *info)
  55{
  56        struct vhost_vring_state state = { .index = info->idx };
  57        struct vhost_vring_file file = { .index = info->idx };
  58        unsigned long long features = dev->vdev.features[0];
  59        struct vhost_vring_addr addr = {
  60                .index = info->idx,
  61                .desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
  62                .avail_user_addr = (uint64_t)(unsigned long)info->vring.avail,
  63                .used_user_addr = (uint64_t)(unsigned long)info->vring.used,
  64        };
  65        int r;
  66        r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
  67        assert(r >= 0);
  68        state.num = info->vring.num;
  69        r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
  70        assert(r >= 0);
  71        state.num = 0;
  72        r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
  73        assert(r >= 0);
  74        r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
  75        assert(r >= 0);
  76        file.fd = info->kick;
  77        r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
  78        assert(r >= 0);
  79        file.fd = info->call;
  80        r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
  81        assert(r >= 0);
  82}
  83
  84static void vq_info_add(struct vdev_info *dev, int num)
  85{
  86        struct vq_info *info = &dev->vqs[dev->nvqs];
  87        int r;
  88        info->idx = dev->nvqs;
  89        info->kick = eventfd(0, EFD_NONBLOCK);
  90        info->call = eventfd(0, EFD_NONBLOCK);
  91        r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
  92        assert(r >= 0);
  93        memset(info->ring, 0, vring_size(num, 4096));
  94        vring_init(&info->vring, num, info->ring, 4096);
  95        info->vq = vring_new_virtqueue(info->vring.num, 4096, &dev->vdev, info->ring,
  96                                       vq_notify, vq_callback, "test");
  97        assert(info->vq);
  98        info->vq->priv = info;
  99        vhost_vq_setup(dev, info);
 100        dev->fds[info->idx].fd = info->call;
 101        dev->fds[info->idx].events = POLLIN;
 102        dev->nvqs++;
 103}
 104
 105static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
 106{
 107        int r;
 108        memset(dev, 0, sizeof *dev);
 109        dev->vdev.features[0] = features;
 110        dev->vdev.features[1] = features >> 32;
 111        dev->buf_size = 1024;
 112        dev->buf = malloc(dev->buf_size);
 113        assert(dev->buf);
 114        dev->control = open("/dev/vhost-test", O_RDWR);
 115        assert(dev->control >= 0);
 116        r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
 117        assert(r >= 0);
 118        dev->mem = malloc(offsetof(struct vhost_memory, regions) +
 119                          sizeof dev->mem->regions[0]);
 120        assert(dev->mem);
 121        memset(dev->mem, 0, offsetof(struct vhost_memory, regions) +
 122                          sizeof dev->mem->regions[0]);
 123        dev->mem->nregions = 1;
 124        dev->mem->regions[0].guest_phys_addr = (long)dev->buf;
 125        dev->mem->regions[0].userspace_addr = (long)dev->buf;
 126        dev->mem->regions[0].memory_size = dev->buf_size;
 127        r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
 128        assert(r >= 0);
 129}
 130
 131/* TODO: this is pretty bad: we get a cache line bounce
 132 * for the wait queue on poll and another one on read,
 133 * plus the read which is there just to clear the
 134 * current state. */
 135static void wait_for_interrupt(struct vdev_info *dev)
 136{
 137        int i;
 138        unsigned long long val;
 139        poll(dev->fds, dev->nvqs, -1);
 140        for (i = 0; i < dev->nvqs; ++i)
 141                if (dev->fds[i].revents & POLLIN) {
 142                        read(dev->fds[i].fd, &val, sizeof val);
 143                }
 144}
 145
 146static void run_test(struct vdev_info *dev, struct vq_info *vq, int bufs)
 147{
 148        struct scatterlist sl;
 149        long started = 0, completed = 0;
 150        long completed_before;
 151        int r, test = 1;
 152        unsigned len;
 153        long long spurious = 0;
 154        r = ioctl(dev->control, VHOST_TEST_RUN, &test);
 155        assert(r >= 0);
 156        for (;;) {
 157                virtqueue_disable_cb(vq->vq);
 158                completed_before = completed;
 159                do {
 160                        if (started < bufs) {
 161                                sg_init_one(&sl, dev->buf, dev->buf_size);
 162                                r = virtqueue_add_buf(vq->vq, &sl, 1, 0,
 163                                                      dev->buf + started);
 164                                if (likely(r >= 0)) {
 165                                        ++started;
 166                                        virtqueue_kick(vq->vq);
 167                                }
 168                        } else
 169                                r = -1;
 170
 171                        /* Flush out completed bufs if any */
 172                        if (virtqueue_get_buf(vq->vq, &len)) {
 173                                ++completed;
 174                                r = 0;
 175                        }
 176
 177                } while (r >= 0);
 178                if (completed == completed_before)
 179                        ++spurious;
 180                assert(completed <= bufs);
 181                assert(started <= bufs);
 182                if (completed == bufs)
 183                        break;
 184                if (virtqueue_enable_cb(vq->vq)) {
 185                        wait_for_interrupt(dev);
 186                }
 187        }
 188        test = 0;
 189        r = ioctl(dev->control, VHOST_TEST_RUN, &test);
 190        assert(r >= 0);
 191        fprintf(stderr, "spurious wakeus: 0x%llx\n", spurious);
 192}
 193
 194const char optstring[] = "h";
 195const struct option longopts[] = {
 196        {
 197                .name = "help",
 198                .val = 'h',
 199        },
 200        {
 201                .name = "indirect",
 202                .val = 'I',
 203        },
 204        {
 205                .name = "no-indirect",
 206                .val = 'i',
 207        },
 208        {
 209        }
 210};
 211
 212static void help()
 213{
 214        fprintf(stderr, "Usage: virtio_test [--help] [--no-indirect]\n");
 215}
 216
 217int main(int argc, char **argv)
 218{
 219        struct vdev_info dev;
 220        unsigned long long features = 1ULL << VIRTIO_RING_F_INDIRECT_DESC;
 221        int o;
 222
 223        for (;;) {
 224                o = getopt_long(argc, argv, optstring, longopts, NULL);
 225                switch (o) {
 226                case -1:
 227                        goto done;
 228                case '?':
 229                        help();
 230                        exit(2);
 231                case 'h':
 232                        help();
 233                        goto done;
 234                case 'i':
 235                        features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
 236                        break;
 237                default:
 238                        assert(0);
 239                        break;
 240                }
 241        }
 242
 243done:
 244        vdev_info_init(&dev, features);
 245        vq_info_add(&dev, 256);
 246        run_test(&dev, &dev.vqs[0], 0x100000);
 247        return 0;
 248}
 249