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