374 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/* 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 0x8000024 25/* Max number of packets transferred before requeueing the job.26 * Using this limit prevents one virtqueue from starving others with27 * pkts.28 */29#define VHOST_TEST_PKT_WEIGHT 25630 31enum {32 VHOST_TEST_VQ = 0,33 VHOST_TEST_VQ_MAX = 1,34};35 36struct 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 as42 * read-size critical section for our kind of RCU. */43static 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 96static 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 105static 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 130static 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 142static 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 147static void vhost_test_flush(struct vhost_test *n)148{149 vhost_dev_flush(&n->dev);150}151 152static 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 166static 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 212err:213 mutex_unlock(&n->dev.mutex);214 return r;215}216 217static 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);236done:237 mutex_unlock(&n->dev.mutex);238 return err;239}240 241static 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 259static 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 304err_vq:305 mutex_unlock(&vq->mutex);306err:307 mutex_unlock(&n->dev.mutex);308 return r;309}310 311static 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 354static 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 363static struct miscdevice vhost_test_misc = {364 MISC_DYNAMIC_MINOR,365 "vhost-test",366 &vhost_test_fops,367};368module_misc_device(vhost_test_misc);369 370MODULE_VERSION("0.0.1");371MODULE_LICENSE("GPL v2");372MODULE_AUTHOR("Michael S. Tsirkin");373MODULE_DESCRIPTION("Host kernel side for virtio simulator");374