drivers/vhost/test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (C) 2009 Red Hat, Inc.
   3  * Author: Michael S. Tsirkin <mst@redhat.com>
   4  *
   5  * test virtio server in host kernel.
   6  */
   7
   8 #include <linux/compat.h>
   9 #include <linux/eventfd.h>
  10 #include <linux/vhost.h>
  11 #include <linux/miscdevice.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/workqueue.h>
  15 #include <linux/file.h>
  16 #include <linux/slab.h>
  17
  18 #include "test.h"
  19 #include "vhost.h"
  20
  21 /* Max number of bytes transferred before requeueing the job.
  22  * Using this limit prevents one virtqueue from starving others. */
  23 #define VHOST_TEST_WEIGHT 0x80000
  24
  25 /* Max number of packets transferred before requeueing the job.
  26  * Using this limit prevents one virtqueue from starving others with
  27  * pkts.
  28  */
  29 #define VHOST_TEST_PKT_WEIGHT 256
  30
  31 enum {
  32         VHOST_TEST_VQ = 0,
  33         VHOST_TEST_VQ_MAX = 1,
  34 };
  35
  36 struct vhost_test {
  37         struct vhost_dev dev;
  38         struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
  39 };
  40
  41 /* Expects to be always run from workqueue - which acts as
  42  * read-size critical section for our kind of RCU. */
  43 static void handle_vq(struct vhost_test *n)
  44 {
  45         struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
  46         unsigned out, in;
  47         int head;
  48         size_t len, total_len = 0;
  49         void *private;
  50
  51         mutex_lock(&vq->mutex);
  52         private = vq->private_data;
  53         if (!private) {
  54                 mutex_unlock(&vq->mutex);
  55                 return;
  56         }
  57
  58         vhost_disable_notify(&n->dev, vq);
  59
  60         for (;;) {
  61                 head = vhost_get_vq_desc(vq, vq->iov,
  62                                          ARRAY_SIZE(vq->iov),
  63                                          &out, &in,
  64                                          NULL, NULL);
  65                 /* On error, stop handling until the next kick. */
  66                 if (unlikely(head < 0))
  67                         break;
  68                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
  69                 if (head == vq->num) {
  70                         if (unlikely(vhost_enable_notify(&n->dev, vq))) {
  71                                 vhost_disable_notify(&n->dev, vq);
  72                                 continue;
  73                         }
  74                         break;
  75                 }
  76                 if (in) {
  77                         vq_err(vq, "Unexpected descriptor format for TX: "
  78                                "out %d, int %d\n", out, in);
  79                         break;
  80                 }
  81                 len = iov_length(vq->iov, out);
  82                 /* Sanity check */
  83                 if (!len) {
  84                         vq_err(vq, "Unexpected 0 len for TX\n");
  85                         break;
  86                 }
  87                 vhost_add_used_and_signal(&n->dev, vq, head, 0);
  88                 total_len += len;
  89                 if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))
  90                         break;
  91         }
  92
  93         mutex_unlock(&vq->mutex);
  94 }
  95
  96 static void handle_vq_kick(struct vhost_work *work)
  97 {
  98         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
  99                                                   poll.work);
 100         struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
 101
 102         handle_vq(n);
 103 }
 104
 105 static int vhost_test_open(struct inode *inode, struct file *f)
 106 {
 107         struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
 108         struct vhost_dev *dev;
 109         struct vhost_virtqueue **vqs;
 110
 111         if (!n)
 112                 return -ENOMEM;
 113         vqs = kmalloc_array(VHOST_TEST_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
 114         if (!vqs) {
 115                 kfree(n);
 116                 return -ENOMEM;
 117         }
 118
 119         dev = &n->dev;
 120         vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
 121         n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
 122         vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
 123                        VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT);
 124
 125         f->private_data = n;
 126
 127         return 0;
 128 }
 129
 130 static void *vhost_test_stop_vq(struct vhost_test *n,
 131                                 struct vhost_virtqueue *vq)
 132 {
 133         void *private;
 134
 135         mutex_lock(&vq->mutex);
 136         private = vq->private_data;
 137         vq->private_data = NULL;
 138         mutex_unlock(&vq->mutex);
 139         return private;
 140 }
 141
 142 static void vhost_test_stop(struct vhost_test *n, void **privatep)
 143 {
 144         *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
 145 }
 146
 147 static void vhost_test_flush_vq(struct vhost_test *n, int index)
 148 {
 149         vhost_poll_flush(&n->vqs[index].poll);
 150 }
 151
 152 static void vhost_test_flush(struct vhost_test *n)
 153 {
 154         vhost_test_flush_vq(n, VHOST_TEST_VQ);
 155 }
 156
 157 static int vhost_test_release(struct inode *inode, struct file *f)
 158 {
 159         struct vhost_test *n = f->private_data;
 160         void  *private;
 161
 162         vhost_test_stop(n, &private);
 163         vhost_test_flush(n);
 164         vhost_dev_cleanup(&n->dev);
 165         /* We do an extra flush before freeing memory,
 166          * since jobs can re-queue themselves. */
 167         vhost_test_flush(n);
 168         kfree(n);
 169         return 0;
 170 }
 171
 172 static long vhost_test_run(struct vhost_test *n, int test)
 173 {
 174         void *priv, *oldpriv;
 175         struct vhost_virtqueue *vq;
 176         int r, index;
 177
 178         if (test < 0 || test > 1)
 179                 return -EINVAL;
 180
 181         mutex_lock(&n->dev.mutex);
 182         r = vhost_dev_check_owner(&n->dev);
 183         if (r)
 184                 goto err;
 185
 186         for (index = 0; index < n->dev.nvqs; ++index) {
 187                 /* Verify that ring has been setup correctly. */
 188                 if (!vhost_vq_access_ok(&n->vqs[index])) {
 189                         r = -EFAULT;
 190                         goto err;
 191                 }
 192         }
 193
 194         for (index = 0; index < n->dev.nvqs; ++index) {
 195                 vq = n->vqs + index;
 196                 mutex_lock(&vq->mutex);
 197                 priv = test ? n : NULL;
 198
 199                 /* start polling new socket */
 200                 oldpriv = vq->private_data;
 201                 vq->private_data = priv;
 202
 203                 r = vhost_vq_init_access(&n->vqs[index]);
 204
 205                 mutex_unlock(&vq->mutex);
 206
 207                 if (r)
 208                         goto err;
 209
 210                 if (oldpriv) {
 211                         vhost_test_flush_vq(n, index);
 212                 }
 213         }
 214
 215         mutex_unlock(&n->dev.mutex);
 216         return 0;
 217
 218 err:
 219         mutex_unlock(&n->dev.mutex);
 220         return r;
 221 }
 222
 223 static long vhost_test_reset_owner(struct vhost_test *n)
 224 {
 225         void *priv = NULL;
 226         long err;
 227         struct vhost_umem *umem;
 228
 229         mutex_lock(&n->dev.mutex);
 230         err = vhost_dev_check_owner(&n->dev);
 231         if (err)
 232                 goto done;
 233         umem = vhost_dev_reset_owner_prepare();
 234         if (!umem) {
 235                 err = -ENOMEM;
 236                 goto done;
 237         }
 238         vhost_test_stop(n, &priv);
 239         vhost_test_flush(n);
 240         vhost_dev_reset_owner(&n->dev, umem);
 241 done:
 242         mutex_unlock(&n->dev.mutex);
 243         return err;
 244 }
 245
 246 static int vhost_test_set_features(struct vhost_test *n, u64 features)
 247 {
 248         struct vhost_virtqueue *vq;
 249
 250         mutex_lock(&n->dev.mutex);
 251         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 252             !vhost_log_access_ok(&n->dev)) {
 253                 mutex_unlock(&n->dev.mutex);
 254                 return -EFAULT;
 255         }
 256         vq = &n->vqs[VHOST_TEST_VQ];
 257         mutex_lock(&vq->mutex);
 258         vq->acked_features = features;
 259         mutex_unlock(&vq->mutex);
 260         mutex_unlock(&n->dev.mutex);
 261         return 0;
 262 }
 263
 264 static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
 265                              unsigned long arg)
 266 {
 267         struct vhost_test *n = f->private_data;
 268         void __user *argp = (void __user *)arg;
 269         u64 __user *featurep = argp;
 270         int test;
 271         u64 features;
 272         int r;
 273         switch (ioctl) {
 274         case VHOST_TEST_RUN:
 275                 if (copy_from_user(&test, argp, sizeof test))
 276                         return -EFAULT;
 277                 return vhost_test_run(n, test);
 278         case VHOST_GET_FEATURES:
 279                 features = VHOST_FEATURES;
 280                 if (copy_to_user(featurep, &features, sizeof features))
 281                         return -EFAULT;
 282                 return 0;
 283         case VHOST_SET_FEATURES:
 284                 printk(KERN_ERR "1\n");
 285                 if (copy_from_user(&features, featurep, sizeof features))
 286                         return -EFAULT;
 287                 printk(KERN_ERR "2\n");
 288                 if (features & ~VHOST_FEATURES)
 289                         return -EOPNOTSUPP;
 290                 printk(KERN_ERR "3\n");
 291                 return vhost_test_set_features(n, features);
 292         case VHOST_RESET_OWNER:
 293                 return vhost_test_reset_owner(n);
 294         default:
 295                 mutex_lock(&n->dev.mutex);
 296                 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
 297                 if (r == -ENOIOCTLCMD)
 298                         r = vhost_vring_ioctl(&n->dev, ioctl, argp);
 299                 vhost_test_flush(n);
 300                 mutex_unlock(&n->dev.mutex);
 301                 return r;
 302         }
 303 }
 304
 305 #ifdef CONFIG_COMPAT
 306 static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl,
 307                                    unsigned long arg)
 308 {
 309         return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
 310 }
 311 #endif
 312
 313 static const struct file_operations vhost_test_fops = {
 314         .owner          = THIS_MODULE,
 315         .release        = vhost_test_release,
 316         .unlocked_ioctl = vhost_test_ioctl,
 317 #ifdef CONFIG_COMPAT
 318         .compat_ioctl   = vhost_test_compat_ioctl,
 319 #endif
 320         .open           = vhost_test_open,
 321         .llseek         = noop_llseek,
 322 };
 323
 324 static struct miscdevice vhost_test_misc = {
 325         MISC_DYNAMIC_MINOR,
 326         "vhost-test",
 327         &vhost_test_fops,
 328 };
 329 module_misc_device(vhost_test_misc);
 330
 331 MODULE_VERSION("0.0.1");
 332 MODULE_LICENSE("GPL v2");
 333 MODULE_AUTHOR("Michael S. Tsirkin");
 334 MODULE_DESCRIPTION("Host kernel side for virtio simulator");