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"); 335