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"); 336