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 enum { 26 VHOST_TEST_VQ = 0, 27 VHOST_TEST_VQ_MAX = 1, 28 }; 29 30 struct vhost_test { 31 struct vhost_dev dev; 32 struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX]; 33 }; 34 35 /* Expects to be always run from workqueue - which acts as 36 * read-size critical section for our kind of RCU. */ 37 static void handle_vq(struct vhost_test *n) 38 { 39 struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ]; 40 unsigned out, in; 41 int head; 42 size_t len, total_len = 0; 43 void *private; 44 45 mutex_lock(&vq->mutex); 46 private = vq->private_data; 47 if (!private) { 48 mutex_unlock(&vq->mutex); 49 return; 50 } 51 52 vhost_disable_notify(&n->dev, vq); 53 54 for (;;) { 55 head = vhost_get_vq_desc(vq, vq->iov, 56 ARRAY_SIZE(vq->iov), 57 &out, &in, 58 NULL, NULL); 59 /* On error, stop handling until the next kick. */ 60 if (unlikely(head < 0)) 61 break; 62 /* Nothing new? Wait for eventfd to tell us they refilled. */ 63 if (head == vq->num) { 64 if (unlikely(vhost_enable_notify(&n->dev, vq))) { 65 vhost_disable_notify(&n->dev, vq); 66 continue; 67 } 68 break; 69 } 70 if (in) { 71 vq_err(vq, "Unexpected descriptor format for TX: " 72 "out %d, int %d\n", out, in); 73 break; 74 } 75 len = iov_length(vq->iov, out); 76 /* Sanity check */ 77 if (!len) { 78 vq_err(vq, "Unexpected 0 len for TX\n"); 79 break; 80 } 81 vhost_add_used_and_signal(&n->dev, vq, head, 0); 82 total_len += len; 83 if (unlikely(total_len >= VHOST_TEST_WEIGHT)) { 84 vhost_poll_queue(&vq->poll); 85 break; 86 } 87 } 88 89 mutex_unlock(&vq->mutex); 90 } 91 92 static void handle_vq_kick(struct vhost_work *work) 93 { 94 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 95 poll.work); 96 struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev); 97 98 handle_vq(n); 99 } 100 101 static int vhost_test_open(struct inode *inode, struct file *f) 102 { 103 struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL); 104 struct vhost_dev *dev; 105 struct vhost_virtqueue **vqs; 106 107 if (!n) 108 return -ENOMEM; 109 vqs = kmalloc_array(VHOST_TEST_VQ_MAX, sizeof(*vqs), GFP_KERNEL); 110 if (!vqs) { 111 kfree(n); 112 return -ENOMEM; 113 } 114 115 dev = &n->dev; 116 vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ]; 117 n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick; 118 vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX); 119 120 f->private_data = n; 121 122 return 0; 123 } 124 125 static void *vhost_test_stop_vq(struct vhost_test *n, 126 struct vhost_virtqueue *vq) 127 { 128 void *private; 129 130 mutex_lock(&vq->mutex); 131 private = vq->private_data; 132 vq->private_data = NULL; 133 mutex_unlock(&vq->mutex); 134 return private; 135 } 136 137 static void vhost_test_stop(struct vhost_test *n, void **privatep) 138 { 139 *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ); 140 } 141 142 static void vhost_test_flush_vq(struct vhost_test *n, int index) 143 { 144 vhost_poll_flush(&n->vqs[index].poll); 145 } 146 147 static void vhost_test_flush(struct vhost_test *n) 148 { 149 vhost_test_flush_vq(n, VHOST_TEST_VQ); 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_cleanup(&n->dev); 160 /* We do an extra flush before freeing memory, 161 * since jobs can re-queue themselves. */ 162 vhost_test_flush(n); 163 kfree(n); 164 return 0; 165 } 166 167 static long vhost_test_run(struct vhost_test *n, int test) 168 { 169 void *priv, *oldpriv; 170 struct vhost_virtqueue *vq; 171 int r, index; 172 173 if (test < 0 || test > 1) 174 return -EINVAL; 175 176 mutex_lock(&n->dev.mutex); 177 r = vhost_dev_check_owner(&n->dev); 178 if (r) 179 goto err; 180 181 for (index = 0; index < n->dev.nvqs; ++index) { 182 /* Verify that ring has been setup correctly. */ 183 if (!vhost_vq_access_ok(&n->vqs[index])) { 184 r = -EFAULT; 185 goto err; 186 } 187 } 188 189 for (index = 0; index < n->dev.nvqs; ++index) { 190 vq = n->vqs + index; 191 mutex_lock(&vq->mutex); 192 priv = test ? n : NULL; 193 194 /* start polling new socket */ 195 oldpriv = vq->private_data; 196 vq->private_data = priv; 197 198 r = vhost_vq_init_access(&n->vqs[index]); 199 200 mutex_unlock(&vq->mutex); 201 202 if (r) 203 goto err; 204 205 if (oldpriv) { 206 vhost_test_flush_vq(n, index); 207 } 208 } 209 210 mutex_unlock(&n->dev.mutex); 211 return 0; 212 213 err: 214 mutex_unlock(&n->dev.mutex); 215 return r; 216 } 217 218 static long vhost_test_reset_owner(struct vhost_test *n) 219 { 220 void *priv = NULL; 221 long err; 222 struct vhost_umem *umem; 223 224 mutex_lock(&n->dev.mutex); 225 err = vhost_dev_check_owner(&n->dev); 226 if (err) 227 goto done; 228 umem = vhost_dev_reset_owner_prepare(); 229 if (!umem) { 230 err = -ENOMEM; 231 goto done; 232 } 233 vhost_test_stop(n, &priv); 234 vhost_test_flush(n); 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_ioctl(struct file *f, unsigned int ioctl, 260 unsigned long arg) 261 { 262 struct vhost_test *n = f->private_data; 263 void __user *argp = (void __user *)arg; 264 u64 __user *featurep = argp; 265 int test; 266 u64 features; 267 int r; 268 switch (ioctl) { 269 case VHOST_TEST_RUN: 270 if (copy_from_user(&test, argp, sizeof test)) 271 return -EFAULT; 272 return vhost_test_run(n, test); 273 case VHOST_GET_FEATURES: 274 features = VHOST_FEATURES; 275 if (copy_to_user(featurep, &features, sizeof features)) 276 return -EFAULT; 277 return 0; 278 case VHOST_SET_FEATURES: 279 printk(KERN_ERR "1\n"); 280 if (copy_from_user(&features, featurep, sizeof features)) 281 return -EFAULT; 282 printk(KERN_ERR "2\n"); 283 if (features & ~VHOST_FEATURES) 284 return -EOPNOTSUPP; 285 printk(KERN_ERR "3\n"); 286 return vhost_test_set_features(n, features); 287 case VHOST_RESET_OWNER: 288 return vhost_test_reset_owner(n); 289 default: 290 mutex_lock(&n->dev.mutex); 291 r = vhost_dev_ioctl(&n->dev, ioctl, argp); 292 if (r == -ENOIOCTLCMD) 293 r = vhost_vring_ioctl(&n->dev, ioctl, argp); 294 vhost_test_flush(n); 295 mutex_unlock(&n->dev.mutex); 296 return r; 297 } 298 } 299 300 #ifdef CONFIG_COMPAT 301 static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl, 302 unsigned long arg) 303 { 304 return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); 305 } 306 #endif 307 308 static const struct file_operations vhost_test_fops = { 309 .owner = THIS_MODULE, 310 .release = vhost_test_release, 311 .unlocked_ioctl = vhost_test_ioctl, 312 #ifdef CONFIG_COMPAT 313 .compat_ioctl = vhost_test_compat_ioctl, 314 #endif 315 .open = vhost_test_open, 316 .llseek = noop_llseek, 317 }; 318 319 static struct miscdevice vhost_test_misc = { 320 MISC_DYNAMIC_MINOR, 321 "vhost-test", 322 &vhost_test_fops, 323 }; 324 module_misc_device(vhost_test_misc); 325 326 MODULE_VERSION("0.0.1"); 327 MODULE_LICENSE("GPL v2"); 328 MODULE_AUTHOR("Michael S. Tsirkin"); 329 MODULE_DESCRIPTION("Host kernel side for virtio simulator"); 330