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 = vhost_vq_get_backend(vq); 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, true, NULL); 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 = vhost_vq_get_backend(vq); 137 vhost_vq_set_backend(vq, 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(struct vhost_test *n) 148 { 149 vhost_dev_flush(&n->dev); 150 } 151 152 static int vhost_test_release(struct inode *inode, struct file *f) 153 { 154 struct vhost_test *n = f->private_data; 155 void *private; 156 157 vhost_test_stop(n, &private); 158 vhost_test_flush(n); 159 vhost_dev_stop(&n->dev); 160 vhost_dev_cleanup(&n->dev); 161 kfree(n->dev.vqs); 162 kfree(n); 163 return 0; 164 } 165 166 static long vhost_test_run(struct vhost_test *n, int test) 167 { 168 void *priv, *oldpriv; 169 struct vhost_virtqueue *vq; 170 int r, index; 171 172 if (test < 0 || test > 1) 173 return -EINVAL; 174 175 mutex_lock(&n->dev.mutex); 176 r = vhost_dev_check_owner(&n->dev); 177 if (r) 178 goto err; 179 180 for (index = 0; index < n->dev.nvqs; ++index) { 181 /* Verify that ring has been setup correctly. */ 182 if (!vhost_vq_access_ok(&n->vqs[index])) { 183 r = -EFAULT; 184 goto err; 185 } 186 } 187 188 for (index = 0; index < n->dev.nvqs; ++index) { 189 vq = n->vqs + index; 190 mutex_lock(&vq->mutex); 191 priv = test ? n : NULL; 192 193 /* start polling new socket */ 194 oldpriv = vhost_vq_get_backend(vq); 195 vhost_vq_set_backend(vq, priv); 196 197 r = vhost_vq_init_access(&n->vqs[index]); 198 199 mutex_unlock(&vq->mutex); 200 201 if (r) 202 goto err; 203 204 if (oldpriv) { 205 vhost_test_flush(n); 206 } 207 } 208 209 mutex_unlock(&n->dev.mutex); 210 return 0; 211 212 err: 213 mutex_unlock(&n->dev.mutex); 214 return r; 215 } 216 217 static long vhost_test_reset_owner(struct vhost_test *n) 218 { 219 void *priv = NULL; 220 long err; 221 struct vhost_iotlb *umem; 222 223 mutex_lock(&n->dev.mutex); 224 err = vhost_dev_check_owner(&n->dev); 225 if (err) 226 goto done; 227 umem = vhost_dev_reset_owner_prepare(); 228 if (!umem) { 229 err = -ENOMEM; 230 goto done; 231 } 232 vhost_test_stop(n, &priv); 233 vhost_test_flush(n); 234 vhost_dev_stop(&n->dev); 235 vhost_dev_reset_owner(&n->dev, umem); 236 done: 237 mutex_unlock(&n->dev.mutex); 238 return err; 239 } 240 241 static int vhost_test_set_features(struct vhost_test *n, u64 features) 242 { 243 struct vhost_virtqueue *vq; 244 245 mutex_lock(&n->dev.mutex); 246 if ((features & (1 << VHOST_F_LOG_ALL)) && 247 !vhost_log_access_ok(&n->dev)) { 248 mutex_unlock(&n->dev.mutex); 249 return -EFAULT; 250 } 251 vq = &n->vqs[VHOST_TEST_VQ]; 252 mutex_lock(&vq->mutex); 253 vq->acked_features = features; 254 mutex_unlock(&vq->mutex); 255 mutex_unlock(&n->dev.mutex); 256 return 0; 257 } 258 259 static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd) 260 { 261 static void *backend; 262 263 const bool enable = fd != -1; 264 struct vhost_virtqueue *vq; 265 int r; 266 267 mutex_lock(&n->dev.mutex); 268 r = vhost_dev_check_owner(&n->dev); 269 if (r) 270 goto err; 271 272 if (index >= VHOST_TEST_VQ_MAX) { 273 r = -ENOBUFS; 274 goto err; 275 } 276 vq = &n->vqs[index]; 277 mutex_lock(&vq->mutex); 278 279 /* Verify that ring has been setup correctly. */ 280 if (!vhost_vq_access_ok(vq)) { 281 r = -EFAULT; 282 goto err_vq; 283 } 284 if (!enable) { 285 vhost_poll_stop(&vq->poll); 286 backend = vhost_vq_get_backend(vq); 287 vhost_vq_set_backend(vq, NULL); 288 } else { 289 vhost_vq_set_backend(vq, backend); 290 r = vhost_vq_init_access(vq); 291 if (r == 0) 292 r = vhost_poll_start(&vq->poll, vq->kick); 293 } 294 295 mutex_unlock(&vq->mutex); 296 297 if (enable) { 298 vhost_test_flush(n); 299 } 300 301 mutex_unlock(&n->dev.mutex); 302 return 0; 303 304 err_vq: 305 mutex_unlock(&vq->mutex); 306 err: 307 mutex_unlock(&n->dev.mutex); 308 return r; 309 } 310 311 static long vhost_test_ioctl(struct file *f, unsigned int ioctl, 312 unsigned long arg) 313 { 314 struct vhost_vring_file backend; 315 struct vhost_test *n = f->private_data; 316 void __user *argp = (void __user *)arg; 317 u64 __user *featurep = argp; 318 int test; 319 u64 features; 320 int r; 321 switch (ioctl) { 322 case VHOST_TEST_RUN: 323 if (copy_from_user(&test, argp, sizeof test)) 324 return -EFAULT; 325 return vhost_test_run(n, test); 326 case VHOST_TEST_SET_BACKEND: 327 if (copy_from_user(&backend, argp, sizeof backend)) 328 return -EFAULT; 329 return vhost_test_set_backend(n, backend.index, backend.fd); 330 case VHOST_GET_FEATURES: 331 features = VHOST_FEATURES; 332 if (copy_to_user(featurep, &features, sizeof features)) 333 return -EFAULT; 334 return 0; 335 case VHOST_SET_FEATURES: 336 if (copy_from_user(&features, featurep, sizeof features)) 337 return -EFAULT; 338 if (features & ~VHOST_FEATURES) 339 return -EOPNOTSUPP; 340 return vhost_test_set_features(n, features); 341 case VHOST_RESET_OWNER: 342 return vhost_test_reset_owner(n); 343 default: 344 mutex_lock(&n->dev.mutex); 345 r = vhost_dev_ioctl(&n->dev, ioctl, argp); 346 if (r == -ENOIOCTLCMD) 347 r = vhost_vring_ioctl(&n->dev, ioctl, argp); 348 vhost_test_flush(n); 349 mutex_unlock(&n->dev.mutex); 350 return r; 351 } 352 } 353 354 static const struct file_operations vhost_test_fops = { 355 .owner = THIS_MODULE, 356 .release = vhost_test_release, 357 .unlocked_ioctl = vhost_test_ioctl, 358 .compat_ioctl = compat_ptr_ioctl, 359 .open = vhost_test_open, 360 .llseek = noop_llseek, 361 }; 362 363 static struct miscdevice vhost_test_misc = { 364 MISC_DYNAMIC_MINOR, 365 "vhost-test", 366 &vhost_test_fops, 367 }; 368 module_misc_device(vhost_test_misc); 369 370 MODULE_VERSION("0.0.1"); 371 MODULE_LICENSE("GPL v2"); 372 MODULE_AUTHOR("Michael S. Tsirkin"); 373 MODULE_DESCRIPTION("Host kernel side for virtio simulator"); 374