drivers/vhost/test.c

   1 /* Copyright (C) 2009 Red Hat, Inc.
   2  * Author: Michael S. Tsirkin <mst@redhat.com>
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2.
   5  *
   6  * test virtio server in host kernel.
   7  */
   8
   9 #include <linux/compat.h>
  10 #include <linux/eventfd.h>
  11 #include <linux/vhost.h>
  12 #include <linux/miscdevice.h>
  13 #include <linux/module.h>
  14 #include <linux/mutex.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/file.h>
  17 #include <linux/slab.h>
  18
  19 #include "test.h"
  20 #include "vhost.h"
  21
  22 /* Max number of bytes transferred before requeueing the job.
  23  * Using this limit prevents one virtqueue from starving others. */
  24 #define VHOST_TEST_WEIGHT 0x80000
  25
  26 /* Max number of packets transferred before requeueing the job.
  27  * Using this limit prevents one virtqueue from starving others with
  28  * pkts.
  29  */
  30 #define VHOST_TEST_PKT_WEIGHT 256
  31
  32 enum {
  33         VHOST_TEST_VQ = 0,
  34         VHOST_TEST_VQ_MAX = 1,
  35 };
  36
  37 struct vhost_test {
  38         struct vhost_dev dev;
  39         struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
  40 };
  41
  42 /* Expects to be always run from workqueue - which acts as
  43  * read-size critical section for our kind of RCU. */
  44 static void handle_vq(struct vhost_test *n)
  45 {
  46         struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
  47         unsigned out, in;
  48         int head;
  49         size_t len, total_len = 0;
  50         void *private;
  51
  52         mutex_lock(&vq->mutex);
  53         private = vq->private_data;
  54         if (!private) {
  55                 mutex_unlock(&vq->mutex);
  56                 return;
  57         }
  58
  59         vhost_disable_notify(&n->dev, vq);
  60
  61         for (;;) {
  62                 head = vhost_get_vq_desc(vq, vq->iov,
  63                                          ARRAY_SIZE(vq->iov),
  64                                          &out, &in,
  65                                          NULL, NULL);
  66                 /* On error, stop handling until the next kick. */
  67                 if (unlikely(head < 0))
  68                         break;
  69                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
  70                 if (head == vq->num) {
  71                         if (unlikely(vhost_enable_notify(&n->dev, vq))) {
  72                                 vhost_disable_notify(&n->dev, vq);
  73                                 continue;
  74                         }
  75                         break;
  76                 }
  77                 if (in) {
  78                         vq_err(vq, "Unexpected descriptor format for TX: "
  79                                "out %d, int %d\n", out, in);
  80                         break;
  81                 }
  82                 len = iov_length(vq->iov, out);
  83                 /* Sanity check */
  84                 if (!len) {
  85                         vq_err(vq, "Unexpected 0 len for TX\n");
  86                         break;
  87                 }
  88                 vhost_add_used_and_signal(&n->dev, vq, head, 0);
  89                 total_len += len;
  90                 if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))
  91                         break;
  92         }
  93
  94         mutex_unlock(&vq->mutex);
  95 }
  96
  97 static void handle_vq_kick(struct vhost_work *work)
  98 {
  99         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 100                                                   poll.work);
 101         struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
 102
 103         handle_vq(n);
 104 }
 105
 106 static int vhost_test_open(struct inode *inode, struct file *f)
 107 {
 108         struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
 109         struct vhost_dev *dev;
 110         struct vhost_virtqueue **vqs;
 111
 112         if (!n)
 113                 return -ENOMEM;
 114         vqs = kmalloc_array(VHOST_TEST_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
 115         if (!vqs) {
 116                 kfree(n);
 117                 return -ENOMEM;
 118         }
 119
 120         dev = &n->dev;
 121         vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
 122         n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
 123         vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
 124                        VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT);
 125
 126         f->private_data = n;
 127
 128         return 0;
 129 }
 130
 131 static void *vhost_test_stop_vq(struct vhost_test *n,
 132                                 struct vhost_virtqueue *vq)
 133 {
 134         void *private;
 135
 136         mutex_lock(&vq->mutex);
 137         private = vq->private_data;
 138         vq->private_data = NULL;
 139         mutex_unlock(&vq->mutex);
 140         return private;
 141 }
 142
 143 static void vhost_test_stop(struct vhost_test *n, void **privatep)
 144 {
 145         *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
 146 }
 147
 148 static void vhost_test_flush_vq(struct vhost_test *n, int index)
 149 {
 150         vhost_poll_flush(&n->vqs[index].poll);
 151 }
 152
 153 static void vhost_test_flush(struct vhost_test *n)
 154 {
 155         vhost_test_flush_vq(n, VHOST_TEST_VQ);
 156 }
 157
 158 static int vhost_test_release(struct inode *inode, struct file *f)
 159 {
 160         struct vhost_test *n = f->private_data;
 161         void  *private;
 162
 163         vhost_test_stop(n, &private);
 164         vhost_test_flush(n);
 165         vhost_dev_stop(&n->dev);
 166         vhost_dev_cleanup(&n->dev);
 167         /* We do an extra flush before freeing memory,
 168          * since jobs can re-queue themselves. */
 169         vhost_test_flush(n);
 170         kfree(n);
 171         return 0;
 172 }
 173
 174 static long vhost_test_run(struct vhost_test *n, int test)
 175 {
 176         void *priv, *oldpriv;
 177         struct vhost_virtqueue *vq;
 178         int r, index;
 179
 180         if (test < 0 || test > 1)
 181                 return -EINVAL;
 182
 183         mutex_lock(&n->dev.mutex);
 184         r = vhost_dev_check_owner(&n->dev);
 185         if (r)
 186                 goto err;
 187
 188         for (index = 0; index < n->dev.nvqs; ++index) {
 189                 /* Verify that ring has been setup correctly. */
 190                 if (!vhost_vq_access_ok(&n->vqs[index])) {
 191                         r = -EFAULT;
 192                         goto err;
 193                 }
 194         }
 195
 196         for (index = 0; index < n->dev.nvqs; ++index) {
 197                 vq = n->vqs + index;
 198                 mutex_lock(&vq->mutex);
 199                 priv = test ? n : NULL;
 200
 201                 /* start polling new socket */
 202                 oldpriv = vq->private_data;
 203                 vq->private_data = priv;
 204
 205                 r = vhost_vq_init_access(&n->vqs[index]);
 206
 207                 mutex_unlock(&vq->mutex);
 208
 209                 if (r)
 210                         goto err;
 211
 212                 if (oldpriv) {
 213                         vhost_test_flush_vq(n, index);
 214                 }
 215         }
 216
 217         mutex_unlock(&n->dev.mutex);
 218         return 0;
 219
 220 err:
 221         mutex_unlock(&n->dev.mutex);
 222         return r;
 223 }
 224
 225 static long vhost_test_reset_owner(struct vhost_test *n)
 226 {
 227         void *priv = NULL;
 228         long err;
 229         struct vhost_umem *umem;
 230
 231         mutex_lock(&n->dev.mutex);
 232         err = vhost_dev_check_owner(&n->dev);
 233         if (err)
 234                 goto done;
 235         umem = vhost_dev_reset_owner_prepare();
 236         if (!umem) {
 237                 err = -ENOMEM;
 238                 goto done;
 239         }
 240         vhost_test_stop(n, &priv);
 241         vhost_test_flush(n);
 242         vhost_dev_stop(&n->dev);
 243         vhost_dev_reset_owner(&n->dev, umem);
 244 done:
 245         mutex_unlock(&n->dev.mutex);
 246         return err;
 247 }
 248
 249 static int vhost_test_set_features(struct vhost_test *n, u64 features)
 250 {
 251         struct vhost_virtqueue *vq;
 252
 253         mutex_lock(&n->dev.mutex);
 254         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 255             !vhost_log_access_ok(&n->dev)) {
 256                 mutex_unlock(&n->dev.mutex);
 257                 return -EFAULT;
 258         }
 259         vq = &n->vqs[VHOST_TEST_VQ];
 260         mutex_lock(&vq->mutex);
 261         vq->acked_features = features;
 262         mutex_unlock(&vq->mutex);
 263         mutex_unlock(&n->dev.mutex);
 264         return 0;
 265 }
 266
 267 static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
 268                              unsigned long arg)
 269 {
 270         struct vhost_test *n = f->private_data;
 271         void __user *argp = (void __user *)arg;
 272         u64 __user *featurep = argp;
 273         int test;
 274         u64 features;
 275         int r;
 276         switch (ioctl) {
 277         case VHOST_TEST_RUN:
 278                 if (copy_from_user(&test, argp, sizeof test))
 279                         return -EFAULT;
 280                 return vhost_test_run(n, test);
 281         case VHOST_GET_FEATURES:
 282                 features = VHOST_FEATURES;
 283                 if (copy_to_user(featurep, &features, sizeof features))
 284                         return -EFAULT;
 285                 return 0;
 286         case VHOST_SET_FEATURES:
 287                 printk(KERN_ERR "1\n");
 288                 if (copy_from_user(&features, featurep, sizeof features))
 289                         return -EFAULT;
 290                 printk(KERN_ERR "2\n");
 291                 if (features & ~VHOST_FEATURES)
 292                         return -EOPNOTSUPP;
 293                 printk(KERN_ERR "3\n");
 294                 return vhost_test_set_features(n, features);
 295         case VHOST_RESET_OWNER:
 296                 return vhost_test_reset_owner(n);
 297         default:
 298                 mutex_lock(&n->dev.mutex);
 299                 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
 300                 if (r == -ENOIOCTLCMD)
 301                         r = vhost_vring_ioctl(&n->dev, ioctl, argp);
 302                 vhost_test_flush(n);
 303                 mutex_unlock(&n->dev.mutex);
 304                 return r;
 305         }
 306 }
 307
 308 #ifdef CONFIG_COMPAT
 309 static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl,
 310                                    unsigned long arg)
 311 {
 312         return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
 313 }
 314 #endif
 315
 316 static const struct file_operations vhost_test_fops = {
 317         .owner          = THIS_MODULE,
 318         .release        = vhost_test_release,
 319         .unlocked_ioctl = vhost_test_ioctl,
 320 #ifdef CONFIG_COMPAT
 321         .compat_ioctl   = vhost_test_compat_ioctl,
 322 #endif
 323         .open           = vhost_test_open,
 324         .llseek         = noop_llseek,
 325 };
 326
 327 static struct miscdevice vhost_test_misc = {
 328         MISC_DYNAMIC_MINOR,
 329         "vhost-test",
 330         &vhost_test_fops,
 331 };
 332 module_misc_device(vhost_test_misc);
 333
 334 MODULE_VERSION("0.0.1");
 335 MODULE_LICENSE("GPL v2");
 336 MODULE_AUTHOR("Michael S. Tsirkin");
 337 MODULE_DESCRIPTION("Host kernel side for virtio simulator");