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 int r; 108 109 if (!n) 110 return -ENOMEM; 111 vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL); 112 if (!vqs) { 113 kfree(n); 114 return -ENOMEM; 115 } 116 117 dev = &n->dev; 118 vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ]; 119 n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick; 120 r = vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX); 121 if (r < 0) { 122 kfree(vqs); 123 kfree(n); 124 return r; 125 } 126 127 f->private_data = n; 128 129 return 0; 130 } 131 132 static void *vhost_test_stop_vq(struct vhost_test *n, 133 struct vhost_virtqueue *vq) 134 { 135 void *private; 136 137 mutex_lock(&vq->mutex); 138 private = vq->private_data; 139 vq->private_data = NULL; 140 mutex_unlock(&vq->mutex); 141 return private; 142 } 143 144 static void vhost_test_stop(struct vhost_test *n, void **privatep) 145 { 146 *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ); 147 } 148 149 static void vhost_test_flush_vq(struct vhost_test *n, int index) 150 { 151 vhost_poll_flush(&n->vqs[index].poll); 152 } 153 154 static void vhost_test_flush(struct vhost_test *n) 155 { 156 vhost_test_flush_vq(n, VHOST_TEST_VQ); 157 } 158 159 static int vhost_test_release(struct inode *inode, struct file *f) 160 { 161 struct vhost_test *n = f->private_data; 162 void *private; 163 164 vhost_test_stop(n, &private); 165 vhost_test_flush(n); 166 vhost_dev_cleanup(&n->dev, false); 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_init_used(&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_memory *memory; 230 231 mutex_lock(&n->dev.mutex); 232 err = vhost_dev_check_owner(&n->dev); 233 if (err) 234 goto done; 235 memory = vhost_dev_reset_owner_prepare(); 236 if (!memory) { 237 err = -ENOMEM; 238 goto done; 239 } 240 vhost_test_stop(n, &priv); 241 vhost_test_flush(n); 242 vhost_dev_reset_owner(&n->dev, memory); 243 done: 244 mutex_unlock(&n->dev.mutex); 245 return err; 246 } 247 248 static int vhost_test_set_features(struct vhost_test *n, u64 features) 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 n->dev.acked_features = features; 257 smp_wmb(); 258 vhost_test_flush(n); 259 mutex_unlock(&n->dev.mutex); 260 return 0; 261 } 262 263 static long vhost_test_ioctl(struct file *f, unsigned int ioctl, 264 unsigned long arg) 265 { 266 struct vhost_test *n = f->private_data; 267 void __user *argp = (void __user *)arg; 268 u64 __user *featurep = argp; 269 int test; 270 u64 features; 271 int r; 272 switch (ioctl) { 273 case VHOST_TEST_RUN: 274 if (copy_from_user(&test, argp, sizeof test)) 275 return -EFAULT; 276 return vhost_test_run(n, test); 277 case VHOST_GET_FEATURES: 278 features = VHOST_FEATURES; 279 if (copy_to_user(featurep, &features, sizeof features)) 280 return -EFAULT; 281 return 0; 282 case VHOST_SET_FEATURES: 283 if (copy_from_user(&features, featurep, sizeof features)) 284 return -EFAULT; 285 if (features & ~VHOST_FEATURES) 286 return -EOPNOTSUPP; 287 return vhost_test_set_features(n, features); 288 case VHOST_RESET_OWNER: 289 return vhost_test_reset_owner(n); 290 default: 291 mutex_lock(&n->dev.mutex); 292 r = vhost_dev_ioctl(&n->dev, ioctl, argp); 293 if (r == -ENOIOCTLCMD) 294 r = vhost_vring_ioctl(&n->dev, ioctl, argp); 295 vhost_test_flush(n); 296 mutex_unlock(&n->dev.mutex); 297 return r; 298 } 299 } 300 301 #ifdef CONFIG_COMPAT 302 static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl, 303 unsigned long arg) 304 { 305 return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); 306 } 307 #endif 308 309 static const struct file_operations vhost_test_fops = { 310 .owner = THIS_MODULE, 311 .release = vhost_test_release, 312 .unlocked_ioctl = vhost_test_ioctl, 313 #ifdef CONFIG_COMPAT 314 .compat_ioctl = vhost_test_compat_ioctl, 315 #endif 316 .open = vhost_test_open, 317 .llseek = noop_llseek, 318 }; 319 320 static struct miscdevice vhost_test_misc = { 321 MISC_DYNAMIC_MINOR, 322 "vhost-test", 323 &vhost_test_fops, 324 }; 325 326 static int vhost_test_init(void) 327 { 328 return misc_register(&vhost_test_misc); 329 } 330 module_init(vhost_test_init); 331 332 static void vhost_test_exit(void) 333 { 334 misc_deregister(&vhost_test_misc); 335 } 336 module_exit(vhost_test_exit); 337 338 MODULE_VERSION("0.0.1"); 339 MODULE_LICENSE("GPL v2"); 340 MODULE_AUTHOR("Michael S. Tsirkin"); 341 MODULE_DESCRIPTION("Host kernel side for virtio simulator"); 342