Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1 | /* Copyright (C) 2009 Red Hat, Inc. |
| 2 | * Copyright (C) 2006 Rusty Russell IBM Corporation |
| 3 | * |
| 4 | * Author: Michael S. Tsirkin <mst@redhat.com> |
| 5 | * |
| 6 | * Inspiration, some code, and most witty comments come from |
Rob Landley | 6151658 | 2011-05-06 09:27:36 -0700 | [diff] [blame] | 7 | * Documentation/virtual/lguest/lguest.c, by Rusty Russell |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2. |
| 10 | * |
| 11 | * Generic code for virtio server in host kernel. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/eventfd.h> |
| 15 | #include <linux/vhost.h> |
| 16 | #include <linux/virtio_net.h> |
| 17 | #include <linux/mm.h> |
Michael S. Tsirkin | 64e1c80 | 2010-10-06 15:34:45 +0200 | [diff] [blame] | 18 | #include <linux/mmu_context.h> |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 19 | #include <linux/miscdevice.h> |
| 20 | #include <linux/mutex.h> |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 21 | #include <linux/rcupdate.h> |
| 22 | #include <linux/poll.h> |
| 23 | #include <linux/file.h> |
| 24 | #include <linux/highmem.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 25 | #include <linux/slab.h> |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 26 | #include <linux/kthread.h> |
Michael S. Tsirkin | 9e3d195 | 2010-07-27 22:56:50 +0300 | [diff] [blame] | 27 | #include <linux/cgroup.h> |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 28 | |
| 29 | #include <linux/net.h> |
| 30 | #include <linux/if_packet.h> |
| 31 | #include <linux/if_arp.h> |
| 32 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 33 | #include "vhost.h" |
| 34 | |
| 35 | enum { |
| 36 | VHOST_MEMORY_MAX_NREGIONS = 64, |
| 37 | VHOST_MEMORY_F_LOG = 0x1, |
| 38 | }; |
| 39 | |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 40 | static unsigned vhost_zcopy_mask __read_mostly; |
| 41 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 42 | #define vhost_used_event(vq) ((u16 __user *)&vq->avail->ring[vq->num]) |
| 43 | #define vhost_avail_event(vq) ((u16 __user *)&vq->used->ring[vq->num]) |
| 44 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 45 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
| 46 | poll_table *pt) |
| 47 | { |
| 48 | struct vhost_poll *poll; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 49 | |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 50 | poll = container_of(pt, struct vhost_poll, table); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 51 | poll->wqh = wqh; |
| 52 | add_wait_queue(wqh, &poll->wait); |
| 53 | } |
| 54 | |
| 55 | static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync, |
| 56 | void *key) |
| 57 | { |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 58 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
| 59 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 60 | if (!((unsigned long)key & poll->mask)) |
| 61 | return 0; |
| 62 | |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 63 | vhost_poll_queue(poll); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 64 | return 0; |
| 65 | } |
| 66 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 67 | static void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 68 | { |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 69 | INIT_LIST_HEAD(&work->node); |
| 70 | work->fn = fn; |
| 71 | init_waitqueue_head(&work->done); |
| 72 | work->flushing = 0; |
| 73 | work->queue_seq = work->done_seq = 0; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 74 | } |
| 75 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 76 | /* Init poll structure */ |
| 77 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
| 78 | unsigned long mask, struct vhost_dev *dev) |
| 79 | { |
| 80 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
| 81 | init_poll_funcptr(&poll->table, vhost_poll_func); |
| 82 | poll->mask = mask; |
| 83 | poll->dev = dev; |
| 84 | |
| 85 | vhost_work_init(&poll->work, fn); |
| 86 | } |
| 87 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 88 | /* Start polling a file. We add ourselves to file's wait queue. The caller must |
| 89 | * keep a reference to a file until after vhost_poll_stop is called. */ |
| 90 | void vhost_poll_start(struct vhost_poll *poll, struct file *file) |
| 91 | { |
| 92 | unsigned long mask; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 93 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 94 | mask = file->f_op->poll(file, &poll->table); |
| 95 | if (mask) |
| 96 | vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask); |
| 97 | } |
| 98 | |
| 99 | /* Stop polling a file. After this function returns, it becomes safe to drop the |
| 100 | * file reference. You must also flush afterwards. */ |
| 101 | void vhost_poll_stop(struct vhost_poll *poll) |
| 102 | { |
| 103 | remove_wait_queue(poll->wqh, &poll->wait); |
| 104 | } |
| 105 | |
Michael S. Tsirkin | 0174b0c | 2011-01-10 10:03:20 +0200 | [diff] [blame] | 106 | static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work, |
| 107 | unsigned seq) |
| 108 | { |
| 109 | int left; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 110 | |
Michael S. Tsirkin | 0174b0c | 2011-01-10 10:03:20 +0200 | [diff] [blame] | 111 | spin_lock_irq(&dev->work_lock); |
| 112 | left = seq - work->done_seq; |
| 113 | spin_unlock_irq(&dev->work_lock); |
| 114 | return left <= 0; |
| 115 | } |
| 116 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 117 | static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 118 | { |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 119 | unsigned seq; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 120 | int flushing; |
| 121 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 122 | spin_lock_irq(&dev->work_lock); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 123 | seq = work->queue_seq; |
| 124 | work->flushing++; |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 125 | spin_unlock_irq(&dev->work_lock); |
Michael S. Tsirkin | 0174b0c | 2011-01-10 10:03:20 +0200 | [diff] [blame] | 126 | wait_event(work->done, vhost_work_seq_done(dev, work, seq)); |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 127 | spin_lock_irq(&dev->work_lock); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 128 | flushing = --work->flushing; |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 129 | spin_unlock_irq(&dev->work_lock); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 130 | BUG_ON(flushing < 0); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 131 | } |
| 132 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 133 | /* Flush any work that has been scheduled. When calling this, don't hold any |
| 134 | * locks that are also used by the callback. */ |
| 135 | void vhost_poll_flush(struct vhost_poll *poll) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 136 | { |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 137 | vhost_work_flush(poll->dev, &poll->work); |
| 138 | } |
| 139 | |
| 140 | static inline void vhost_work_queue(struct vhost_dev *dev, |
| 141 | struct vhost_work *work) |
| 142 | { |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 143 | unsigned long flags; |
| 144 | |
| 145 | spin_lock_irqsave(&dev->work_lock, flags); |
| 146 | if (list_empty(&work->node)) { |
| 147 | list_add_tail(&work->node, &dev->work_list); |
| 148 | work->queue_seq++; |
| 149 | wake_up_process(dev->worker); |
| 150 | } |
| 151 | spin_unlock_irqrestore(&dev->work_lock, flags); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 152 | } |
| 153 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 154 | void vhost_poll_queue(struct vhost_poll *poll) |
| 155 | { |
| 156 | vhost_work_queue(poll->dev, &poll->work); |
| 157 | } |
| 158 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 159 | static void vhost_vq_reset(struct vhost_dev *dev, |
| 160 | struct vhost_virtqueue *vq) |
| 161 | { |
| 162 | vq->num = 1; |
| 163 | vq->desc = NULL; |
| 164 | vq->avail = NULL; |
| 165 | vq->used = NULL; |
| 166 | vq->last_avail_idx = 0; |
| 167 | vq->avail_idx = 0; |
| 168 | vq->last_used_idx = 0; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 169 | vq->signalled_used = 0; |
| 170 | vq->signalled_used_valid = false; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 171 | vq->used_flags = 0; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 172 | vq->log_used = false; |
| 173 | vq->log_addr = -1ull; |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 174 | vq->vhost_hlen = 0; |
| 175 | vq->sock_hlen = 0; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 176 | vq->private_data = NULL; |
| 177 | vq->log_base = NULL; |
| 178 | vq->error_ctx = NULL; |
| 179 | vq->error = NULL; |
| 180 | vq->kick = NULL; |
| 181 | vq->call_ctx = NULL; |
| 182 | vq->call = NULL; |
Michael S. Tsirkin | 73a99f0 | 2010-02-23 11:23:45 +0200 | [diff] [blame] | 183 | vq->log_ctx = NULL; |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 184 | vq->upend_idx = 0; |
| 185 | vq->done_idx = 0; |
| 186 | vq->ubufs = NULL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 187 | } |
| 188 | |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 189 | static int vhost_worker(void *data) |
| 190 | { |
| 191 | struct vhost_dev *dev = data; |
| 192 | struct vhost_work *work = NULL; |
| 193 | unsigned uninitialized_var(seq); |
| 194 | |
Michael S. Tsirkin | 64e1c80 | 2010-10-06 15:34:45 +0200 | [diff] [blame] | 195 | use_mm(dev->mm); |
| 196 | |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 197 | for (;;) { |
| 198 | /* mb paired w/ kthread_stop */ |
| 199 | set_current_state(TASK_INTERRUPTIBLE); |
| 200 | |
| 201 | spin_lock_irq(&dev->work_lock); |
| 202 | if (work) { |
| 203 | work->done_seq = seq; |
| 204 | if (work->flushing) |
| 205 | wake_up_all(&work->done); |
| 206 | } |
| 207 | |
| 208 | if (kthread_should_stop()) { |
| 209 | spin_unlock_irq(&dev->work_lock); |
| 210 | __set_current_state(TASK_RUNNING); |
Michael S. Tsirkin | 64e1c80 | 2010-10-06 15:34:45 +0200 | [diff] [blame] | 211 | break; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 212 | } |
| 213 | if (!list_empty(&dev->work_list)) { |
| 214 | work = list_first_entry(&dev->work_list, |
| 215 | struct vhost_work, node); |
| 216 | list_del_init(&work->node); |
| 217 | seq = work->queue_seq; |
| 218 | } else |
| 219 | work = NULL; |
| 220 | spin_unlock_irq(&dev->work_lock); |
| 221 | |
| 222 | if (work) { |
| 223 | __set_current_state(TASK_RUNNING); |
| 224 | work->fn(work); |
Nadav Har'El | d550dda | 2012-02-27 15:07:29 +0200 | [diff] [blame] | 225 | if (need_resched()) |
| 226 | schedule(); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 227 | } else |
| 228 | schedule(); |
| 229 | |
| 230 | } |
Michael S. Tsirkin | 64e1c80 | 2010-10-06 15:34:45 +0200 | [diff] [blame] | 231 | unuse_mm(dev->mm); |
| 232 | return 0; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 233 | } |
| 234 | |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 235 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
| 236 | { |
| 237 | kfree(vq->indirect); |
| 238 | vq->indirect = NULL; |
| 239 | kfree(vq->log); |
| 240 | vq->log = NULL; |
| 241 | kfree(vq->heads); |
| 242 | vq->heads = NULL; |
| 243 | kfree(vq->ubuf_info); |
| 244 | vq->ubuf_info = NULL; |
| 245 | } |
| 246 | |
| 247 | void vhost_enable_zcopy(int vq) |
| 248 | { |
| 249 | vhost_zcopy_mask |= 0x1 << vq; |
| 250 | } |
| 251 | |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 252 | /* Helper to allocate iovec buffers for all vqs. */ |
| 253 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) |
| 254 | { |
| 255 | int i; |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 256 | bool zcopy; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 257 | |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 258 | for (i = 0; i < dev->nvqs; ++i) { |
| 259 | dev->vqs[i].indirect = kmalloc(sizeof *dev->vqs[i].indirect * |
| 260 | UIO_MAXIOV, GFP_KERNEL); |
| 261 | dev->vqs[i].log = kmalloc(sizeof *dev->vqs[i].log * UIO_MAXIOV, |
| 262 | GFP_KERNEL); |
| 263 | dev->vqs[i].heads = kmalloc(sizeof *dev->vqs[i].heads * |
| 264 | UIO_MAXIOV, GFP_KERNEL); |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 265 | zcopy = vhost_zcopy_mask & (0x1 << i); |
| 266 | if (zcopy) |
| 267 | dev->vqs[i].ubuf_info = |
| 268 | kmalloc(sizeof *dev->vqs[i].ubuf_info * |
| 269 | UIO_MAXIOV, GFP_KERNEL); |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 270 | if (!dev->vqs[i].indirect || !dev->vqs[i].log || |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 271 | !dev->vqs[i].heads || |
| 272 | (zcopy && !dev->vqs[i].ubuf_info)) |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 273 | goto err_nomem; |
| 274 | } |
| 275 | return 0; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 276 | |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 277 | err_nomem: |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 278 | for (; i >= 0; --i) |
| 279 | vhost_vq_free_iovecs(&dev->vqs[i]); |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 280 | return -ENOMEM; |
| 281 | } |
| 282 | |
| 283 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) |
| 284 | { |
| 285 | int i; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 286 | |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 287 | for (i = 0; i < dev->nvqs; ++i) |
| 288 | vhost_vq_free_iovecs(&dev->vqs[i]); |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 289 | } |
| 290 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 291 | long vhost_dev_init(struct vhost_dev *dev, |
| 292 | struct vhost_virtqueue *vqs, int nvqs) |
| 293 | { |
| 294 | int i; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 295 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 296 | dev->vqs = vqs; |
| 297 | dev->nvqs = nvqs; |
| 298 | mutex_init(&dev->mutex); |
| 299 | dev->log_ctx = NULL; |
| 300 | dev->log_file = NULL; |
| 301 | dev->memory = NULL; |
| 302 | dev->mm = NULL; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 303 | spin_lock_init(&dev->work_lock); |
| 304 | INIT_LIST_HEAD(&dev->work_list); |
| 305 | dev->worker = NULL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 306 | |
| 307 | for (i = 0; i < dev->nvqs; ++i) { |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 308 | dev->vqs[i].log = NULL; |
| 309 | dev->vqs[i].indirect = NULL; |
| 310 | dev->vqs[i].heads = NULL; |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 311 | dev->vqs[i].ubuf_info = NULL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 312 | dev->vqs[i].dev = dev; |
| 313 | mutex_init(&dev->vqs[i].mutex); |
| 314 | vhost_vq_reset(dev, dev->vqs + i); |
| 315 | if (dev->vqs[i].handle_kick) |
| 316 | vhost_poll_init(&dev->vqs[i].poll, |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 317 | dev->vqs[i].handle_kick, POLLIN, dev); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 318 | } |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 319 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 320 | return 0; |
| 321 | } |
| 322 | |
| 323 | /* Caller should have device mutex */ |
| 324 | long vhost_dev_check_owner(struct vhost_dev *dev) |
| 325 | { |
| 326 | /* Are you the owner? If not, I don't think you mean to do that */ |
| 327 | return dev->mm == current->mm ? 0 : -EPERM; |
| 328 | } |
| 329 | |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 330 | struct vhost_attach_cgroups_struct { |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 331 | struct vhost_work work; |
| 332 | struct task_struct *owner; |
| 333 | int ret; |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 334 | }; |
| 335 | |
| 336 | static void vhost_attach_cgroups_work(struct vhost_work *work) |
| 337 | { |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 338 | struct vhost_attach_cgroups_struct *s; |
| 339 | |
| 340 | s = container_of(work, struct vhost_attach_cgroups_struct, work); |
| 341 | s->ret = cgroup_attach_task_all(s->owner, current); |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 342 | } |
| 343 | |
| 344 | static int vhost_attach_cgroups(struct vhost_dev *dev) |
| 345 | { |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 346 | struct vhost_attach_cgroups_struct attach; |
| 347 | |
| 348 | attach.owner = current; |
| 349 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); |
| 350 | vhost_work_queue(dev, &attach.work); |
| 351 | vhost_work_flush(dev, &attach.work); |
| 352 | return attach.ret; |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 353 | } |
| 354 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 355 | /* Caller should have device mutex */ |
| 356 | static long vhost_dev_set_owner(struct vhost_dev *dev) |
| 357 | { |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 358 | struct task_struct *worker; |
| 359 | int err; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 360 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 361 | /* Is there an owner already? */ |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 362 | if (dev->mm) { |
| 363 | err = -EBUSY; |
| 364 | goto err_mm; |
| 365 | } |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 366 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 367 | /* No owner, become one */ |
| 368 | dev->mm = get_task_mm(current); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 369 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
| 370 | if (IS_ERR(worker)) { |
| 371 | err = PTR_ERR(worker); |
| 372 | goto err_worker; |
| 373 | } |
| 374 | |
| 375 | dev->worker = worker; |
Michael S. Tsirkin | 87d6a41 | 2010-09-02 14:05:30 +0300 | [diff] [blame] | 376 | wake_up_process(worker); /* avoid contributing to loadavg */ |
| 377 | |
| 378 | err = vhost_attach_cgroups(dev); |
Michael S. Tsirkin | 9e3d195 | 2010-07-27 22:56:50 +0300 | [diff] [blame] | 379 | if (err) |
| 380 | goto err_cgroup; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 381 | |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 382 | err = vhost_dev_alloc_iovecs(dev); |
| 383 | if (err) |
| 384 | goto err_cgroup; |
| 385 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 386 | return 0; |
Michael S. Tsirkin | 9e3d195 | 2010-07-27 22:56:50 +0300 | [diff] [blame] | 387 | err_cgroup: |
| 388 | kthread_stop(worker); |
Michael S. Tsirkin | 615cc22 | 2010-09-02 14:16:36 +0300 | [diff] [blame] | 389 | dev->worker = NULL; |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 390 | err_worker: |
| 391 | if (dev->mm) |
| 392 | mmput(dev->mm); |
| 393 | dev->mm = NULL; |
| 394 | err_mm: |
| 395 | return err; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 396 | } |
| 397 | |
| 398 | /* Caller should have device mutex */ |
| 399 | long vhost_dev_reset_owner(struct vhost_dev *dev) |
| 400 | { |
| 401 | struct vhost_memory *memory; |
| 402 | |
| 403 | /* Restore memory to default empty mapping. */ |
| 404 | memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL); |
| 405 | if (!memory) |
| 406 | return -ENOMEM; |
| 407 | |
Michael S. Tsirkin | ea5d404 | 2011-11-27 19:05:58 +0200 | [diff] [blame] | 408 | vhost_dev_cleanup(dev, true); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 409 | |
| 410 | memory->nregions = 0; |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 411 | RCU_INIT_POINTER(dev->memory, memory); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 412 | return 0; |
| 413 | } |
| 414 | |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 415 | /* In case of DMA done not in order in lower device driver for some reason. |
| 416 | * upend_idx is used to track end of used idx, done_idx is used to track head |
| 417 | * of used idx. Once lower device DMA done contiguously, we will signal KVM |
| 418 | * guest used idx. |
| 419 | */ |
| 420 | int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq) |
| 421 | { |
| 422 | int i; |
| 423 | int j = 0; |
| 424 | |
| 425 | for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) { |
| 426 | if ((vq->heads[i].len == VHOST_DMA_DONE_LEN)) { |
| 427 | vq->heads[i].len = VHOST_DMA_CLEAR_LEN; |
| 428 | vhost_add_used_and_signal(vq->dev, vq, |
| 429 | vq->heads[i].id, 0); |
| 430 | ++j; |
| 431 | } else |
| 432 | break; |
| 433 | } |
| 434 | if (j) |
| 435 | vq->done_idx = i; |
| 436 | return j; |
| 437 | } |
| 438 | |
Michael S. Tsirkin | ea5d404 | 2011-11-27 19:05:58 +0200 | [diff] [blame] | 439 | /* Caller should have device mutex if and only if locked is set */ |
| 440 | void vhost_dev_cleanup(struct vhost_dev *dev, bool locked) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 441 | { |
| 442 | int i; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 443 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 444 | for (i = 0; i < dev->nvqs; ++i) { |
| 445 | if (dev->vqs[i].kick && dev->vqs[i].handle_kick) { |
| 446 | vhost_poll_stop(&dev->vqs[i].poll); |
| 447 | vhost_poll_flush(&dev->vqs[i].poll); |
| 448 | } |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 449 | /* Wait for all lower device DMAs done. */ |
| 450 | if (dev->vqs[i].ubufs) |
| 451 | vhost_ubuf_put_and_wait(dev->vqs[i].ubufs); |
| 452 | |
| 453 | /* Signal guest as appropriate. */ |
| 454 | vhost_zerocopy_signal_used(&dev->vqs[i]); |
| 455 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 456 | if (dev->vqs[i].error_ctx) |
| 457 | eventfd_ctx_put(dev->vqs[i].error_ctx); |
| 458 | if (dev->vqs[i].error) |
| 459 | fput(dev->vqs[i].error); |
| 460 | if (dev->vqs[i].kick) |
| 461 | fput(dev->vqs[i].kick); |
| 462 | if (dev->vqs[i].call_ctx) |
| 463 | eventfd_ctx_put(dev->vqs[i].call_ctx); |
| 464 | if (dev->vqs[i].call) |
| 465 | fput(dev->vqs[i].call); |
| 466 | vhost_vq_reset(dev, dev->vqs + i); |
| 467 | } |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 468 | vhost_dev_free_iovecs(dev); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 469 | if (dev->log_ctx) |
| 470 | eventfd_ctx_put(dev->log_ctx); |
| 471 | dev->log_ctx = NULL; |
| 472 | if (dev->log_file) |
| 473 | fput(dev->log_file); |
| 474 | dev->log_file = NULL; |
| 475 | /* No one will access memory at this point */ |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 476 | kfree(rcu_dereference_protected(dev->memory, |
Michael S. Tsirkin | ea5d404 | 2011-11-27 19:05:58 +0200 | [diff] [blame] | 477 | locked == |
| 478 | lockdep_is_held(&dev->mutex))); |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 479 | RCU_INIT_POINTER(dev->memory, NULL); |
Tejun Heo | c23f344 | 2010-06-02 20:40:00 +0200 | [diff] [blame] | 480 | WARN_ON(!list_empty(&dev->work_list)); |
Eric Dumazet | 78b620c | 2010-08-31 02:05:57 +0000 | [diff] [blame] | 481 | if (dev->worker) { |
| 482 | kthread_stop(dev->worker); |
| 483 | dev->worker = NULL; |
| 484 | } |
Michael S. Tsirkin | 533a19b | 2010-10-06 15:34:38 +0200 | [diff] [blame] | 485 | if (dev->mm) |
| 486 | mmput(dev->mm); |
| 487 | dev->mm = NULL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 488 | } |
| 489 | |
| 490 | static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
| 491 | { |
| 492 | u64 a = addr / VHOST_PAGE_SIZE / 8; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 493 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 494 | /* Make sure 64 bit math will not overflow. */ |
| 495 | if (a > ULONG_MAX - (unsigned long)log_base || |
| 496 | a + (unsigned long)log_base > ULONG_MAX) |
Dan Carpenter | 6d97e55 | 2010-10-11 19:24:19 +0200 | [diff] [blame] | 497 | return 0; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 498 | |
| 499 | return access_ok(VERIFY_WRITE, log_base + a, |
| 500 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
| 501 | } |
| 502 | |
| 503 | /* Caller should have vq mutex and device mutex. */ |
| 504 | static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem, |
| 505 | int log_all) |
| 506 | { |
| 507 | int i; |
Jeff Dike | 179b284 | 2010-04-07 09:59:10 -0400 | [diff] [blame] | 508 | |
Michael S. Tsirkin | f8322fb | 2010-05-27 12:28:03 +0300 | [diff] [blame] | 509 | if (!mem) |
| 510 | return 0; |
Jeff Dike | 179b284 | 2010-04-07 09:59:10 -0400 | [diff] [blame] | 511 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 512 | for (i = 0; i < mem->nregions; ++i) { |
| 513 | struct vhost_memory_region *m = mem->regions + i; |
| 514 | unsigned long a = m->userspace_addr; |
| 515 | if (m->memory_size > ULONG_MAX) |
| 516 | return 0; |
| 517 | else if (!access_ok(VERIFY_WRITE, (void __user *)a, |
| 518 | m->memory_size)) |
| 519 | return 0; |
| 520 | else if (log_all && !log_access_ok(log_base, |
| 521 | m->guest_phys_addr, |
| 522 | m->memory_size)) |
| 523 | return 0; |
| 524 | } |
| 525 | return 1; |
| 526 | } |
| 527 | |
| 528 | /* Can we switch to this memory table? */ |
| 529 | /* Caller should have device mutex but not vq mutex */ |
| 530 | static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, |
| 531 | int log_all) |
| 532 | { |
| 533 | int i; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 534 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 535 | for (i = 0; i < d->nvqs; ++i) { |
| 536 | int ok; |
| 537 | mutex_lock(&d->vqs[i].mutex); |
| 538 | /* If ring is inactive, will check when it's enabled. */ |
| 539 | if (d->vqs[i].private_data) |
| 540 | ok = vq_memory_access_ok(d->vqs[i].log_base, mem, |
| 541 | log_all); |
| 542 | else |
| 543 | ok = 1; |
| 544 | mutex_unlock(&d->vqs[i].mutex); |
| 545 | if (!ok) |
| 546 | return 0; |
| 547 | } |
| 548 | return 1; |
| 549 | } |
| 550 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 551 | static int vq_access_ok(struct vhost_dev *d, unsigned int num, |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 552 | struct vring_desc __user *desc, |
| 553 | struct vring_avail __user *avail, |
| 554 | struct vring_used __user *used) |
| 555 | { |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 556 | size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 557 | return access_ok(VERIFY_READ, desc, num * sizeof *desc) && |
| 558 | access_ok(VERIFY_READ, avail, |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 559 | sizeof *avail + num * sizeof *avail->ring + s) && |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 560 | access_ok(VERIFY_WRITE, used, |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 561 | sizeof *used + num * sizeof *used->ring + s); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 562 | } |
| 563 | |
| 564 | /* Can we log writes? */ |
| 565 | /* Caller should have device mutex but not vq mutex */ |
| 566 | int vhost_log_access_ok(struct vhost_dev *dev) |
| 567 | { |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 568 | struct vhost_memory *mp; |
| 569 | |
| 570 | mp = rcu_dereference_protected(dev->memory, |
| 571 | lockdep_is_held(&dev->mutex)); |
| 572 | return memory_access_ok(dev, mp, 1); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 573 | } |
| 574 | |
| 575 | /* Verify access for write logging. */ |
| 576 | /* Caller should have vq mutex and device mutex */ |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 577 | static int vq_log_access_ok(struct vhost_dev *d, struct vhost_virtqueue *vq, |
| 578 | void __user *log_base) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 579 | { |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 580 | struct vhost_memory *mp; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 581 | size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 582 | |
| 583 | mp = rcu_dereference_protected(vq->dev->memory, |
| 584 | lockdep_is_held(&vq->mutex)); |
| 585 | return vq_memory_access_ok(log_base, mp, |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 586 | vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) && |
| 587 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
| 588 | sizeof *vq->used + |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 589 | vq->num * sizeof *vq->used->ring + s)); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 590 | } |
| 591 | |
| 592 | /* Can we start vq? */ |
| 593 | /* Caller should have vq mutex and device mutex */ |
| 594 | int vhost_vq_access_ok(struct vhost_virtqueue *vq) |
| 595 | { |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 596 | return vq_access_ok(vq->dev, vq->num, vq->desc, vq->avail, vq->used) && |
| 597 | vq_log_access_ok(vq->dev, vq, vq->log_base); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 598 | } |
| 599 | |
| 600 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
| 601 | { |
| 602 | struct vhost_memory mem, *newmem, *oldmem; |
| 603 | unsigned long size = offsetof(struct vhost_memory, regions); |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 604 | |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 605 | if (copy_from_user(&mem, m, size)) |
| 606 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 607 | if (mem.padding) |
| 608 | return -EOPNOTSUPP; |
| 609 | if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS) |
| 610 | return -E2BIG; |
| 611 | newmem = kmalloc(size + mem.nregions * sizeof *m->regions, GFP_KERNEL); |
| 612 | if (!newmem) |
| 613 | return -ENOMEM; |
| 614 | |
| 615 | memcpy(newmem, &mem, size); |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 616 | if (copy_from_user(newmem->regions, m->regions, |
| 617 | mem.nregions * sizeof *m->regions)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 618 | kfree(newmem); |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 619 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 620 | } |
| 621 | |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 622 | if (!memory_access_ok(d, newmem, |
| 623 | vhost_has_feature(d, VHOST_F_LOG_ALL))) { |
Takuya Yoshikawa | a02c378 | 2010-05-27 19:03:56 +0900 | [diff] [blame] | 624 | kfree(newmem); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 625 | return -EFAULT; |
Takuya Yoshikawa | a02c378 | 2010-05-27 19:03:56 +0900 | [diff] [blame] | 626 | } |
Arnd Bergmann | 28457ee | 2010-03-09 19:24:45 +0100 | [diff] [blame] | 627 | oldmem = rcu_dereference_protected(d->memory, |
| 628 | lockdep_is_held(&d->mutex)); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 629 | rcu_assign_pointer(d->memory, newmem); |
| 630 | synchronize_rcu(); |
| 631 | kfree(oldmem); |
| 632 | return 0; |
| 633 | } |
| 634 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 635 | static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) |
| 636 | { |
| 637 | struct file *eventfp, *filep = NULL, |
| 638 | *pollstart = NULL, *pollstop = NULL; |
| 639 | struct eventfd_ctx *ctx = NULL; |
| 640 | u32 __user *idxp = argp; |
| 641 | struct vhost_virtqueue *vq; |
| 642 | struct vhost_vring_state s; |
| 643 | struct vhost_vring_file f; |
| 644 | struct vhost_vring_addr a; |
| 645 | u32 idx; |
| 646 | long r; |
| 647 | |
| 648 | r = get_user(idx, idxp); |
| 649 | if (r < 0) |
| 650 | return r; |
Krishna Kumar | 0f3d9a1 | 2010-05-25 11:10:36 +0530 | [diff] [blame] | 651 | if (idx >= d->nvqs) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 652 | return -ENOBUFS; |
| 653 | |
| 654 | vq = d->vqs + idx; |
| 655 | |
| 656 | mutex_lock(&vq->mutex); |
| 657 | |
| 658 | switch (ioctl) { |
| 659 | case VHOST_SET_VRING_NUM: |
| 660 | /* Resizing ring with an active backend? |
| 661 | * You don't want to do that. */ |
| 662 | if (vq->private_data) { |
| 663 | r = -EBUSY; |
| 664 | break; |
| 665 | } |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 666 | if (copy_from_user(&s, argp, sizeof s)) { |
| 667 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 668 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 669 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 670 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { |
| 671 | r = -EINVAL; |
| 672 | break; |
| 673 | } |
| 674 | vq->num = s.num; |
| 675 | break; |
| 676 | case VHOST_SET_VRING_BASE: |
| 677 | /* Moving base with an active backend? |
| 678 | * You don't want to do that. */ |
| 679 | if (vq->private_data) { |
| 680 | r = -EBUSY; |
| 681 | break; |
| 682 | } |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 683 | if (copy_from_user(&s, argp, sizeof s)) { |
| 684 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 685 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 686 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 687 | if (s.num > 0xffff) { |
| 688 | r = -EINVAL; |
| 689 | break; |
| 690 | } |
| 691 | vq->last_avail_idx = s.num; |
| 692 | /* Forget the cached index value. */ |
| 693 | vq->avail_idx = vq->last_avail_idx; |
| 694 | break; |
| 695 | case VHOST_GET_VRING_BASE: |
| 696 | s.index = idx; |
| 697 | s.num = vq->last_avail_idx; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 698 | if (copy_to_user(argp, &s, sizeof s)) |
| 699 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 700 | break; |
| 701 | case VHOST_SET_VRING_ADDR: |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 702 | if (copy_from_user(&a, argp, sizeof a)) { |
| 703 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 704 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 705 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 706 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { |
| 707 | r = -EOPNOTSUPP; |
| 708 | break; |
| 709 | } |
| 710 | /* For 32bit, verify that the top 32bits of the user |
| 711 | data are set to zero. */ |
| 712 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || |
| 713 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || |
| 714 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { |
| 715 | r = -EFAULT; |
| 716 | break; |
| 717 | } |
| 718 | if ((a.avail_user_addr & (sizeof *vq->avail->ring - 1)) || |
| 719 | (a.used_user_addr & (sizeof *vq->used->ring - 1)) || |
| 720 | (a.log_guest_addr & (sizeof *vq->used->ring - 1))) { |
| 721 | r = -EINVAL; |
| 722 | break; |
| 723 | } |
| 724 | |
| 725 | /* We only verify access here if backend is configured. |
| 726 | * If it is not, we don't as size might not have been setup. |
| 727 | * We will verify when backend is configured. */ |
| 728 | if (vq->private_data) { |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 729 | if (!vq_access_ok(d, vq->num, |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 730 | (void __user *)(unsigned long)a.desc_user_addr, |
| 731 | (void __user *)(unsigned long)a.avail_user_addr, |
| 732 | (void __user *)(unsigned long)a.used_user_addr)) { |
| 733 | r = -EINVAL; |
| 734 | break; |
| 735 | } |
| 736 | |
| 737 | /* Also validate log access for used ring if enabled. */ |
| 738 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && |
| 739 | !log_access_ok(vq->log_base, a.log_guest_addr, |
| 740 | sizeof *vq->used + |
| 741 | vq->num * sizeof *vq->used->ring)) { |
| 742 | r = -EINVAL; |
| 743 | break; |
| 744 | } |
| 745 | } |
| 746 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 747 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
| 748 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; |
| 749 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; |
| 750 | vq->log_addr = a.log_guest_addr; |
| 751 | vq->used = (void __user *)(unsigned long)a.used_user_addr; |
| 752 | break; |
| 753 | case VHOST_SET_VRING_KICK: |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 754 | if (copy_from_user(&f, argp, sizeof f)) { |
| 755 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 756 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 757 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 758 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
Michael S. Tsirkin | 535297a | 2010-03-17 16:06:11 +0200 | [diff] [blame] | 759 | if (IS_ERR(eventfp)) { |
| 760 | r = PTR_ERR(eventfp); |
| 761 | break; |
| 762 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 763 | if (eventfp != vq->kick) { |
| 764 | pollstop = filep = vq->kick; |
| 765 | pollstart = vq->kick = eventfp; |
| 766 | } else |
| 767 | filep = eventfp; |
| 768 | break; |
| 769 | case VHOST_SET_VRING_CALL: |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 770 | if (copy_from_user(&f, argp, sizeof f)) { |
| 771 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 772 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 773 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 774 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
Michael S. Tsirkin | 535297a | 2010-03-17 16:06:11 +0200 | [diff] [blame] | 775 | if (IS_ERR(eventfp)) { |
| 776 | r = PTR_ERR(eventfp); |
| 777 | break; |
| 778 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 779 | if (eventfp != vq->call) { |
| 780 | filep = vq->call; |
| 781 | ctx = vq->call_ctx; |
| 782 | vq->call = eventfp; |
| 783 | vq->call_ctx = eventfp ? |
| 784 | eventfd_ctx_fileget(eventfp) : NULL; |
| 785 | } else |
| 786 | filep = eventfp; |
| 787 | break; |
| 788 | case VHOST_SET_VRING_ERR: |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 789 | if (copy_from_user(&f, argp, sizeof f)) { |
| 790 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 791 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 792 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 793 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
Michael S. Tsirkin | 535297a | 2010-03-17 16:06:11 +0200 | [diff] [blame] | 794 | if (IS_ERR(eventfp)) { |
| 795 | r = PTR_ERR(eventfp); |
| 796 | break; |
| 797 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 798 | if (eventfp != vq->error) { |
| 799 | filep = vq->error; |
| 800 | vq->error = eventfp; |
| 801 | ctx = vq->error_ctx; |
| 802 | vq->error_ctx = eventfp ? |
| 803 | eventfd_ctx_fileget(eventfp) : NULL; |
| 804 | } else |
| 805 | filep = eventfp; |
| 806 | break; |
| 807 | default: |
| 808 | r = -ENOIOCTLCMD; |
| 809 | } |
| 810 | |
| 811 | if (pollstop && vq->handle_kick) |
| 812 | vhost_poll_stop(&vq->poll); |
| 813 | |
| 814 | if (ctx) |
| 815 | eventfd_ctx_put(ctx); |
| 816 | if (filep) |
| 817 | fput(filep); |
| 818 | |
| 819 | if (pollstart && vq->handle_kick) |
| 820 | vhost_poll_start(&vq->poll, vq->kick); |
| 821 | |
| 822 | mutex_unlock(&vq->mutex); |
| 823 | |
| 824 | if (pollstop && vq->handle_kick) |
| 825 | vhost_poll_flush(&vq->poll); |
| 826 | return r; |
| 827 | } |
| 828 | |
| 829 | /* Caller must have device mutex */ |
| 830 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg) |
| 831 | { |
| 832 | void __user *argp = (void __user *)arg; |
| 833 | struct file *eventfp, *filep = NULL; |
| 834 | struct eventfd_ctx *ctx = NULL; |
| 835 | u64 p; |
| 836 | long r; |
| 837 | int i, fd; |
| 838 | |
| 839 | /* If you are not the owner, you can become one */ |
| 840 | if (ioctl == VHOST_SET_OWNER) { |
| 841 | r = vhost_dev_set_owner(d); |
| 842 | goto done; |
| 843 | } |
| 844 | |
| 845 | /* You must be the owner to do anything else */ |
| 846 | r = vhost_dev_check_owner(d); |
| 847 | if (r) |
| 848 | goto done; |
| 849 | |
| 850 | switch (ioctl) { |
| 851 | case VHOST_SET_MEM_TABLE: |
| 852 | r = vhost_set_memory(d, argp); |
| 853 | break; |
| 854 | case VHOST_SET_LOG_BASE: |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 855 | if (copy_from_user(&p, argp, sizeof p)) { |
| 856 | r = -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 857 | break; |
Takuya Yoshikawa | 7ad9c9d | 2010-05-27 18:58:03 +0900 | [diff] [blame] | 858 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 859 | if ((u64)(unsigned long)p != p) { |
| 860 | r = -EFAULT; |
| 861 | break; |
| 862 | } |
| 863 | for (i = 0; i < d->nvqs; ++i) { |
| 864 | struct vhost_virtqueue *vq; |
| 865 | void __user *base = (void __user *)(unsigned long)p; |
| 866 | vq = d->vqs + i; |
| 867 | mutex_lock(&vq->mutex); |
| 868 | /* If ring is inactive, will check when it's enabled. */ |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 869 | if (vq->private_data && !vq_log_access_ok(d, vq, base)) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 870 | r = -EFAULT; |
| 871 | else |
| 872 | vq->log_base = base; |
| 873 | mutex_unlock(&vq->mutex); |
| 874 | } |
| 875 | break; |
| 876 | case VHOST_SET_LOG_FD: |
| 877 | r = get_user(fd, (int __user *)argp); |
| 878 | if (r < 0) |
| 879 | break; |
| 880 | eventfp = fd == -1 ? NULL : eventfd_fget(fd); |
| 881 | if (IS_ERR(eventfp)) { |
| 882 | r = PTR_ERR(eventfp); |
| 883 | break; |
| 884 | } |
| 885 | if (eventfp != d->log_file) { |
| 886 | filep = d->log_file; |
| 887 | ctx = d->log_ctx; |
| 888 | d->log_ctx = eventfp ? |
| 889 | eventfd_ctx_fileget(eventfp) : NULL; |
| 890 | } else |
| 891 | filep = eventfp; |
| 892 | for (i = 0; i < d->nvqs; ++i) { |
| 893 | mutex_lock(&d->vqs[i].mutex); |
| 894 | d->vqs[i].log_ctx = d->log_ctx; |
| 895 | mutex_unlock(&d->vqs[i].mutex); |
| 896 | } |
| 897 | if (ctx) |
| 898 | eventfd_ctx_put(ctx); |
| 899 | if (filep) |
| 900 | fput(filep); |
| 901 | break; |
| 902 | default: |
| 903 | r = vhost_set_vring(d, ioctl, argp); |
| 904 | break; |
| 905 | } |
| 906 | done: |
| 907 | return r; |
| 908 | } |
| 909 | |
| 910 | static const struct vhost_memory_region *find_region(struct vhost_memory *mem, |
| 911 | __u64 addr, __u32 len) |
| 912 | { |
| 913 | struct vhost_memory_region *reg; |
| 914 | int i; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 915 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 916 | /* linear search is not brilliant, but we really have on the order of 6 |
| 917 | * regions in practice */ |
| 918 | for (i = 0; i < mem->nregions; ++i) { |
| 919 | reg = mem->regions + i; |
| 920 | if (reg->guest_phys_addr <= addr && |
| 921 | reg->guest_phys_addr + reg->memory_size - 1 >= addr) |
| 922 | return reg; |
| 923 | } |
| 924 | return NULL; |
| 925 | } |
| 926 | |
| 927 | /* TODO: This is really inefficient. We need something like get_user() |
| 928 | * (instruction directly accesses the data, with an exception table entry |
| 929 | * returning -EFAULT). See Documentation/x86/exception-tables.txt. |
| 930 | */ |
| 931 | static int set_bit_to_user(int nr, void __user *addr) |
| 932 | { |
| 933 | unsigned long log = (unsigned long)addr; |
| 934 | struct page *page; |
| 935 | void *base; |
| 936 | int bit = nr + (log % PAGE_SIZE) * 8; |
| 937 | int r; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 938 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 939 | r = get_user_pages_fast(log, 1, 1, &page); |
Michael S. Tsirkin | d6db3f5 | 2010-02-23 11:25:23 +0200 | [diff] [blame] | 940 | if (r < 0) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 941 | return r; |
Michael S. Tsirkin | d6db3f5 | 2010-02-23 11:25:23 +0200 | [diff] [blame] | 942 | BUG_ON(r != 1); |
Cong Wang | c6daa7f | 2011-11-25 23:14:26 +0800 | [diff] [blame] | 943 | base = kmap_atomic(page); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 944 | set_bit(bit, base); |
Cong Wang | c6daa7f | 2011-11-25 23:14:26 +0800 | [diff] [blame] | 945 | kunmap_atomic(base); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 946 | set_page_dirty_lock(page); |
| 947 | put_page(page); |
| 948 | return 0; |
| 949 | } |
| 950 | |
| 951 | static int log_write(void __user *log_base, |
| 952 | u64 write_address, u64 write_length) |
| 953 | { |
Michael S. Tsirkin | 28831ee | 2010-11-29 10:22:10 +0200 | [diff] [blame] | 954 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 955 | int r; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 956 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 957 | if (!write_length) |
| 958 | return 0; |
Michael S. Tsirkin | 3bf9be4 | 2010-11-29 10:19:07 +0200 | [diff] [blame] | 959 | write_length += write_address % VHOST_PAGE_SIZE; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 960 | for (;;) { |
| 961 | u64 base = (u64)(unsigned long)log_base; |
Michael S. Tsirkin | 28831ee | 2010-11-29 10:22:10 +0200 | [diff] [blame] | 962 | u64 log = base + write_page / 8; |
| 963 | int bit = write_page % 8; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 964 | if ((u64)(unsigned long)log != log) |
| 965 | return -EFAULT; |
| 966 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); |
| 967 | if (r < 0) |
| 968 | return r; |
| 969 | if (write_length <= VHOST_PAGE_SIZE) |
| 970 | break; |
| 971 | write_length -= VHOST_PAGE_SIZE; |
Michael S. Tsirkin | 28831ee | 2010-11-29 10:22:10 +0200 | [diff] [blame] | 972 | write_page += 1; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 973 | } |
| 974 | return r; |
| 975 | } |
| 976 | |
| 977 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
| 978 | unsigned int log_num, u64 len) |
| 979 | { |
| 980 | int i, r; |
| 981 | |
| 982 | /* Make sure data written is seen before log. */ |
Michael S. Tsirkin | 5659338 | 2010-02-01 07:21:02 +0000 | [diff] [blame] | 983 | smp_wmb(); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 984 | for (i = 0; i < log_num; ++i) { |
| 985 | u64 l = min(log[i].len, len); |
| 986 | r = log_write(vq->log_base, log[i].addr, l); |
| 987 | if (r < 0) |
| 988 | return r; |
| 989 | len -= l; |
Michael S. Tsirkin | 5786aee | 2010-09-22 12:31:53 +0200 | [diff] [blame] | 990 | if (!len) { |
| 991 | if (vq->log_ctx) |
| 992 | eventfd_signal(vq->log_ctx, 1); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 993 | return 0; |
Michael S. Tsirkin | 5786aee | 2010-09-22 12:31:53 +0200 | [diff] [blame] | 994 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 995 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 996 | /* Length written exceeds what we have stored. This is a bug. */ |
| 997 | BUG(); |
| 998 | return 0; |
| 999 | } |
| 1000 | |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1001 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
| 1002 | { |
| 1003 | void __user *used; |
Michael S. Tsirkin | b834226 | 2011-07-19 17:15:43 +0300 | [diff] [blame] | 1004 | if (__put_user(vq->used_flags, &vq->used->flags) < 0) |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1005 | return -EFAULT; |
| 1006 | if (unlikely(vq->log_used)) { |
| 1007 | /* Make sure the flag is seen before log. */ |
| 1008 | smp_wmb(); |
| 1009 | /* Log used flag write. */ |
| 1010 | used = &vq->used->flags; |
| 1011 | log_write(vq->log_base, vq->log_addr + |
| 1012 | (used - (void __user *)vq->used), |
| 1013 | sizeof vq->used->flags); |
| 1014 | if (vq->log_ctx) |
| 1015 | eventfd_signal(vq->log_ctx, 1); |
| 1016 | } |
| 1017 | return 0; |
| 1018 | } |
| 1019 | |
| 1020 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) |
| 1021 | { |
Michael S. Tsirkin | b834226 | 2011-07-19 17:15:43 +0300 | [diff] [blame] | 1022 | if (__put_user(vq->avail_idx, vhost_avail_event(vq))) |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1023 | return -EFAULT; |
| 1024 | if (unlikely(vq->log_used)) { |
| 1025 | void __user *used; |
| 1026 | /* Make sure the event is seen before log. */ |
| 1027 | smp_wmb(); |
| 1028 | /* Log avail event write */ |
| 1029 | used = vhost_avail_event(vq); |
| 1030 | log_write(vq->log_base, vq->log_addr + |
| 1031 | (used - (void __user *)vq->used), |
| 1032 | sizeof *vhost_avail_event(vq)); |
| 1033 | if (vq->log_ctx) |
| 1034 | eventfd_signal(vq->log_ctx, 1); |
| 1035 | } |
| 1036 | return 0; |
| 1037 | } |
| 1038 | |
| 1039 | int vhost_init_used(struct vhost_virtqueue *vq) |
| 1040 | { |
| 1041 | int r; |
| 1042 | if (!vq->private_data) |
| 1043 | return 0; |
| 1044 | |
| 1045 | r = vhost_update_used_flags(vq); |
| 1046 | if (r) |
| 1047 | return r; |
| 1048 | vq->signalled_used_valid = false; |
| 1049 | return get_user(vq->last_used_idx, &vq->used->idx); |
| 1050 | } |
| 1051 | |
Christoph Hellwig | a8d3782 | 2010-04-13 14:11:25 -0400 | [diff] [blame] | 1052 | static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, |
| 1053 | struct iovec iov[], int iov_size) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1054 | { |
| 1055 | const struct vhost_memory_region *reg; |
| 1056 | struct vhost_memory *mem; |
| 1057 | struct iovec *_iov; |
| 1058 | u64 s = 0; |
| 1059 | int ret = 0; |
| 1060 | |
| 1061 | rcu_read_lock(); |
| 1062 | |
| 1063 | mem = rcu_dereference(dev->memory); |
| 1064 | while ((u64)len > s) { |
| 1065 | u64 size; |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1066 | if (unlikely(ret >= iov_size)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1067 | ret = -ENOBUFS; |
| 1068 | break; |
| 1069 | } |
| 1070 | reg = find_region(mem, addr, len); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1071 | if (unlikely(!reg)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1072 | ret = -EFAULT; |
| 1073 | break; |
| 1074 | } |
| 1075 | _iov = iov + ret; |
| 1076 | size = reg->memory_size - addr + reg->guest_phys_addr; |
| 1077 | _iov->iov_len = min((u64)len, size); |
Christoph Hellwig | a8d3782 | 2010-04-13 14:11:25 -0400 | [diff] [blame] | 1078 | _iov->iov_base = (void __user *)(unsigned long) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1079 | (reg->userspace_addr + addr - reg->guest_phys_addr); |
| 1080 | s += size; |
| 1081 | addr += size; |
| 1082 | ++ret; |
| 1083 | } |
| 1084 | |
| 1085 | rcu_read_unlock(); |
| 1086 | return ret; |
| 1087 | } |
| 1088 | |
| 1089 | /* Each buffer in the virtqueues is actually a chain of descriptors. This |
| 1090 | * function returns the next descriptor in the chain, |
| 1091 | * or -1U if we're at the end. */ |
| 1092 | static unsigned next_desc(struct vring_desc *desc) |
| 1093 | { |
| 1094 | unsigned int next; |
| 1095 | |
| 1096 | /* If this descriptor says it doesn't chain, we're done. */ |
| 1097 | if (!(desc->flags & VRING_DESC_F_NEXT)) |
| 1098 | return -1U; |
| 1099 | |
| 1100 | /* Check they're not leading us off end of descriptors. */ |
| 1101 | next = desc->next; |
| 1102 | /* Make sure compiler knows to grab that: we don't want it changing! */ |
| 1103 | /* We will use the result as an index in an array, so most |
| 1104 | * architectures only need a compiler barrier here. */ |
| 1105 | read_barrier_depends(); |
| 1106 | |
| 1107 | return next; |
| 1108 | } |
| 1109 | |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1110 | static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, |
| 1111 | struct iovec iov[], unsigned int iov_size, |
| 1112 | unsigned int *out_num, unsigned int *in_num, |
| 1113 | struct vhost_log *log, unsigned int *log_num, |
| 1114 | struct vring_desc *indirect) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1115 | { |
| 1116 | struct vring_desc desc; |
| 1117 | unsigned int i = 0, count, found = 0; |
| 1118 | int ret; |
| 1119 | |
| 1120 | /* Sanity check */ |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1121 | if (unlikely(indirect->len % sizeof desc)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1122 | vq_err(vq, "Invalid length in indirect descriptor: " |
| 1123 | "len 0x%llx not multiple of 0x%zx\n", |
| 1124 | (unsigned long long)indirect->len, |
| 1125 | sizeof desc); |
| 1126 | return -EINVAL; |
| 1127 | } |
| 1128 | |
| 1129 | ret = translate_desc(dev, indirect->addr, indirect->len, vq->indirect, |
Jason Wang | e0e9b40 | 2010-09-14 23:53:05 +0800 | [diff] [blame] | 1130 | UIO_MAXIOV); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1131 | if (unlikely(ret < 0)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1132 | vq_err(vq, "Translation failure %d in indirect.\n", ret); |
| 1133 | return ret; |
| 1134 | } |
| 1135 | |
| 1136 | /* We will use the result as an address to read from, so most |
| 1137 | * architectures only need a compiler barrier here. */ |
| 1138 | read_barrier_depends(); |
| 1139 | |
| 1140 | count = indirect->len / sizeof desc; |
| 1141 | /* Buffers are chained via a 16 bit next field, so |
| 1142 | * we can have at most 2^16 of these. */ |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1143 | if (unlikely(count > USHRT_MAX + 1)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1144 | vq_err(vq, "Indirect buffer length too big: %d\n", |
| 1145 | indirect->len); |
| 1146 | return -E2BIG; |
| 1147 | } |
| 1148 | |
| 1149 | do { |
| 1150 | unsigned iov_count = *in_num + *out_num; |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1151 | if (unlikely(++found > count)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1152 | vq_err(vq, "Loop detected: last one at %u " |
| 1153 | "indirect size %u\n", |
| 1154 | i, count); |
| 1155 | return -EINVAL; |
| 1156 | } |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 1157 | if (unlikely(memcpy_fromiovec((unsigned char *)&desc, |
| 1158 | vq->indirect, sizeof desc))) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1159 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
| 1160 | i, (size_t)indirect->addr + i * sizeof desc); |
| 1161 | return -EINVAL; |
| 1162 | } |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1163 | if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1164 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
| 1165 | i, (size_t)indirect->addr + i * sizeof desc); |
| 1166 | return -EINVAL; |
| 1167 | } |
| 1168 | |
| 1169 | ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, |
| 1170 | iov_size - iov_count); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1171 | if (unlikely(ret < 0)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1172 | vq_err(vq, "Translation failure %d indirect idx %d\n", |
| 1173 | ret, i); |
| 1174 | return ret; |
| 1175 | } |
| 1176 | /* If this is an input descriptor, increment that count. */ |
| 1177 | if (desc.flags & VRING_DESC_F_WRITE) { |
| 1178 | *in_num += ret; |
| 1179 | if (unlikely(log)) { |
| 1180 | log[*log_num].addr = desc.addr; |
| 1181 | log[*log_num].len = desc.len; |
| 1182 | ++*log_num; |
| 1183 | } |
| 1184 | } else { |
| 1185 | /* If it's an output descriptor, they're all supposed |
| 1186 | * to come before any input descriptors. */ |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1187 | if (unlikely(*in_num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1188 | vq_err(vq, "Indirect descriptor " |
| 1189 | "has out after in: idx %d\n", i); |
| 1190 | return -EINVAL; |
| 1191 | } |
| 1192 | *out_num += ret; |
| 1193 | } |
| 1194 | } while ((i = next_desc(&desc)) != -1); |
| 1195 | return 0; |
| 1196 | } |
| 1197 | |
| 1198 | /* This looks in the virtqueue and for the first available buffer, and converts |
| 1199 | * it to an iovec for convenient access. Since descriptors consist of some |
| 1200 | * number of output then some number of input descriptors, it's actually two |
| 1201 | * iovecs, but we pack them into one and note how many of each there were. |
| 1202 | * |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1203 | * This function returns the descriptor number found, or vq->num (which is |
| 1204 | * never a valid descriptor number) if none was found. A negative code is |
| 1205 | * returned on error. */ |
| 1206 | int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, |
| 1207 | struct iovec iov[], unsigned int iov_size, |
| 1208 | unsigned int *out_num, unsigned int *in_num, |
| 1209 | struct vhost_log *log, unsigned int *log_num) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1210 | { |
| 1211 | struct vring_desc desc; |
| 1212 | unsigned int i, head, found = 0; |
| 1213 | u16 last_avail_idx; |
| 1214 | int ret; |
| 1215 | |
| 1216 | /* Check it isn't doing very strange things with descriptor numbers. */ |
| 1217 | last_avail_idx = vq->last_avail_idx; |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1218 | if (unlikely(__get_user(vq->avail_idx, &vq->avail->idx))) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1219 | vq_err(vq, "Failed to access avail idx at %p\n", |
| 1220 | &vq->avail->idx); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1221 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1222 | } |
| 1223 | |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1224 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1225 | vq_err(vq, "Guest moved used index from %u to %u", |
| 1226 | last_avail_idx, vq->avail_idx); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1227 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1228 | } |
| 1229 | |
| 1230 | /* If there's nothing new since last we looked, return invalid. */ |
| 1231 | if (vq->avail_idx == last_avail_idx) |
| 1232 | return vq->num; |
| 1233 | |
| 1234 | /* Only get avail ring entries after they have been exposed by guest. */ |
Michael S. Tsirkin | 5659338 | 2010-02-01 07:21:02 +0000 | [diff] [blame] | 1235 | smp_rmb(); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1236 | |
| 1237 | /* Grab the next descriptor number they're advertising, and increment |
| 1238 | * the index we've seen. */ |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1239 | if (unlikely(__get_user(head, |
| 1240 | &vq->avail->ring[last_avail_idx % vq->num]))) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1241 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
| 1242 | last_avail_idx, |
| 1243 | &vq->avail->ring[last_avail_idx % vq->num]); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1244 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1245 | } |
| 1246 | |
| 1247 | /* If their number is silly, that's an error. */ |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1248 | if (unlikely(head >= vq->num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1249 | vq_err(vq, "Guest says index %u > %u is available", |
| 1250 | head, vq->num); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1251 | return -EINVAL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1252 | } |
| 1253 | |
| 1254 | /* When we start there are none of either input nor output. */ |
| 1255 | *out_num = *in_num = 0; |
| 1256 | if (unlikely(log)) |
| 1257 | *log_num = 0; |
| 1258 | |
| 1259 | i = head; |
| 1260 | do { |
| 1261 | unsigned iov_count = *in_num + *out_num; |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1262 | if (unlikely(i >= vq->num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1263 | vq_err(vq, "Desc index is %u > %u, head = %u", |
| 1264 | i, vq->num, head); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1265 | return -EINVAL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1266 | } |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1267 | if (unlikely(++found > vq->num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1268 | vq_err(vq, "Loop detected: last one at %u " |
| 1269 | "vq size %u head %u\n", |
| 1270 | i, vq->num, head); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1271 | return -EINVAL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1272 | } |
Michael S. Tsirkin | fcc042a | 2011-03-06 13:33:49 +0200 | [diff] [blame] | 1273 | ret = __copy_from_user(&desc, vq->desc + i, sizeof desc); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1274 | if (unlikely(ret)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1275 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
| 1276 | i, vq->desc + i); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1277 | return -EFAULT; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1278 | } |
| 1279 | if (desc.flags & VRING_DESC_F_INDIRECT) { |
| 1280 | ret = get_indirect(dev, vq, iov, iov_size, |
| 1281 | out_num, in_num, |
| 1282 | log, log_num, &desc); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1283 | if (unlikely(ret < 0)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1284 | vq_err(vq, "Failure detected " |
| 1285 | "in indirect descriptor at idx %d\n", i); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1286 | return ret; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1287 | } |
| 1288 | continue; |
| 1289 | } |
| 1290 | |
| 1291 | ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, |
| 1292 | iov_size - iov_count); |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1293 | if (unlikely(ret < 0)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1294 | vq_err(vq, "Translation failure %d descriptor idx %d\n", |
| 1295 | ret, i); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1296 | return ret; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1297 | } |
| 1298 | if (desc.flags & VRING_DESC_F_WRITE) { |
| 1299 | /* If this is an input descriptor, |
| 1300 | * increment that count. */ |
| 1301 | *in_num += ret; |
| 1302 | if (unlikely(log)) { |
| 1303 | log[*log_num].addr = desc.addr; |
| 1304 | log[*log_num].len = desc.len; |
| 1305 | ++*log_num; |
| 1306 | } |
| 1307 | } else { |
| 1308 | /* If it's an output descriptor, they're all supposed |
| 1309 | * to come before any input descriptors. */ |
Michael S. Tsirkin | 7b3384f | 2010-07-01 18:40:12 +0300 | [diff] [blame] | 1310 | if (unlikely(*in_num)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1311 | vq_err(vq, "Descriptor has out after in: " |
| 1312 | "idx %d\n", i); |
Michael S. Tsirkin | d5675bd | 2010-06-24 16:59:59 +0300 | [diff] [blame] | 1313 | return -EINVAL; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1314 | } |
| 1315 | *out_num += ret; |
| 1316 | } |
| 1317 | } while ((i = next_desc(&desc)) != -1); |
| 1318 | |
| 1319 | /* On success, increment avail index. */ |
| 1320 | vq->last_avail_idx++; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1321 | |
| 1322 | /* Assume notifications from guest are disabled at this point, |
| 1323 | * if they aren't we would need to update avail_event index. */ |
| 1324 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1325 | return head; |
| 1326 | } |
| 1327 | |
| 1328 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1329 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1330 | { |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1331 | vq->last_avail_idx -= n; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1332 | } |
| 1333 | |
| 1334 | /* After we've used one of their buffers, we tell them about it. We'll then |
| 1335 | * want to notify the guest, using eventfd. */ |
| 1336 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) |
| 1337 | { |
Christoph Hellwig | a8d3782 | 2010-04-13 14:11:25 -0400 | [diff] [blame] | 1338 | struct vring_used_elem __user *used; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1339 | |
| 1340 | /* The virtqueue contains a ring of used buffers. Get a pointer to the |
| 1341 | * next entry in that used ring. */ |
| 1342 | used = &vq->used->ring[vq->last_used_idx % vq->num]; |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1343 | if (__put_user(head, &used->id)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1344 | vq_err(vq, "Failed to write used id"); |
| 1345 | return -EFAULT; |
| 1346 | } |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1347 | if (__put_user(len, &used->len)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1348 | vq_err(vq, "Failed to write used len"); |
| 1349 | return -EFAULT; |
| 1350 | } |
| 1351 | /* Make sure buffer is written before we update index. */ |
Michael S. Tsirkin | 5659338 | 2010-02-01 07:21:02 +0000 | [diff] [blame] | 1352 | smp_wmb(); |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1353 | if (__put_user(vq->last_used_idx + 1, &vq->used->idx)) { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1354 | vq_err(vq, "Failed to increment used idx"); |
| 1355 | return -EFAULT; |
| 1356 | } |
| 1357 | if (unlikely(vq->log_used)) { |
| 1358 | /* Make sure data is seen before log. */ |
Michael S. Tsirkin | 5659338 | 2010-02-01 07:21:02 +0000 | [diff] [blame] | 1359 | smp_wmb(); |
Michael S. Tsirkin | 86e9424 | 2010-02-17 19:11:33 +0200 | [diff] [blame] | 1360 | /* Log used ring entry write. */ |
| 1361 | log_write(vq->log_base, |
Christoph Hellwig | a8d3782 | 2010-04-13 14:11:25 -0400 | [diff] [blame] | 1362 | vq->log_addr + |
| 1363 | ((void __user *)used - (void __user *)vq->used), |
Michael S. Tsirkin | 86e9424 | 2010-02-17 19:11:33 +0200 | [diff] [blame] | 1364 | sizeof *used); |
| 1365 | /* Log used index update. */ |
| 1366 | log_write(vq->log_base, |
| 1367 | vq->log_addr + offsetof(struct vring_used, idx), |
| 1368 | sizeof vq->used->idx); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1369 | if (vq->log_ctx) |
| 1370 | eventfd_signal(vq->log_ctx, 1); |
| 1371 | } |
| 1372 | vq->last_used_idx++; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1373 | /* If the driver never bothers to signal in a very long while, |
| 1374 | * used index might wrap around. If that happens, invalidate |
| 1375 | * signalled_used index we stored. TODO: make sure driver |
| 1376 | * signals at least once in 2^16 and remove this. */ |
| 1377 | if (unlikely(vq->last_used_idx == vq->signalled_used)) |
| 1378 | vq->signalled_used_valid = false; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1379 | return 0; |
| 1380 | } |
| 1381 | |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1382 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
| 1383 | struct vring_used_elem *heads, |
| 1384 | unsigned count) |
| 1385 | { |
| 1386 | struct vring_used_elem __user *used; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1387 | u16 old, new; |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1388 | int start; |
| 1389 | |
| 1390 | start = vq->last_used_idx % vq->num; |
| 1391 | used = vq->used->ring + start; |
Michael S. Tsirkin | dfe5ac5 | 2010-09-21 14:18:01 +0200 | [diff] [blame] | 1392 | if (__copy_to_user(used, heads, count * sizeof *used)) { |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1393 | vq_err(vq, "Failed to write used"); |
| 1394 | return -EFAULT; |
| 1395 | } |
| 1396 | if (unlikely(vq->log_used)) { |
| 1397 | /* Make sure data is seen before log. */ |
| 1398 | smp_wmb(); |
| 1399 | /* Log used ring entry write. */ |
| 1400 | log_write(vq->log_base, |
| 1401 | vq->log_addr + |
| 1402 | ((void __user *)used - (void __user *)vq->used), |
| 1403 | count * sizeof *used); |
| 1404 | } |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1405 | old = vq->last_used_idx; |
| 1406 | new = (vq->last_used_idx += count); |
| 1407 | /* If the driver never bothers to signal in a very long while, |
| 1408 | * used index might wrap around. If that happens, invalidate |
| 1409 | * signalled_used index we stored. TODO: make sure driver |
| 1410 | * signals at least once in 2^16 and remove this. */ |
| 1411 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) |
| 1412 | vq->signalled_used_valid = false; |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1413 | return 0; |
| 1414 | } |
| 1415 | |
| 1416 | /* After we've used one of their buffers, we tell them about it. We'll then |
| 1417 | * want to notify the guest, using eventfd. */ |
| 1418 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, |
| 1419 | unsigned count) |
| 1420 | { |
| 1421 | int start, n, r; |
| 1422 | |
| 1423 | start = vq->last_used_idx % vq->num; |
| 1424 | n = vq->num - start; |
| 1425 | if (n < count) { |
| 1426 | r = __vhost_add_used_n(vq, heads, n); |
| 1427 | if (r < 0) |
| 1428 | return r; |
| 1429 | heads += n; |
| 1430 | count -= n; |
| 1431 | } |
| 1432 | r = __vhost_add_used_n(vq, heads, count); |
| 1433 | |
| 1434 | /* Make sure buffer is written before we update index. */ |
| 1435 | smp_wmb(); |
| 1436 | if (put_user(vq->last_used_idx, &vq->used->idx)) { |
| 1437 | vq_err(vq, "Failed to increment used idx"); |
| 1438 | return -EFAULT; |
| 1439 | } |
| 1440 | if (unlikely(vq->log_used)) { |
| 1441 | /* Log used index update. */ |
| 1442 | log_write(vq->log_base, |
| 1443 | vq->log_addr + offsetof(struct vring_used, idx), |
| 1444 | sizeof vq->used->idx); |
| 1445 | if (vq->log_ctx) |
| 1446 | eventfd_signal(vq->log_ctx, 1); |
| 1447 | } |
| 1448 | return r; |
| 1449 | } |
| 1450 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1451 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1452 | { |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1453 | __u16 old, new, event; |
| 1454 | bool v; |
Michael S. Tsirkin | 0d49935 | 2010-05-11 19:44:17 +0300 | [diff] [blame] | 1455 | /* Flush out used index updates. This is paired |
| 1456 | * with the barrier that the Guest executes when enabling |
| 1457 | * interrupts. */ |
| 1458 | smp_mb(); |
| 1459 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1460 | if (vhost_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) && |
| 1461 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
| 1462 | return true; |
| 1463 | |
| 1464 | if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { |
| 1465 | __u16 flags; |
| 1466 | if (__get_user(flags, &vq->avail->flags)) { |
| 1467 | vq_err(vq, "Failed to get flags"); |
| 1468 | return true; |
| 1469 | } |
| 1470 | return !(flags & VRING_AVAIL_F_NO_INTERRUPT); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1471 | } |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1472 | old = vq->signalled_used; |
| 1473 | v = vq->signalled_used_valid; |
| 1474 | new = vq->signalled_used = vq->last_used_idx; |
| 1475 | vq->signalled_used_valid = true; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1476 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1477 | if (unlikely(!v)) |
| 1478 | return true; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1479 | |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1480 | if (get_user(event, vhost_used_event(vq))) { |
| 1481 | vq_err(vq, "Failed to get used event idx"); |
| 1482 | return true; |
| 1483 | } |
| 1484 | return vring_need_event(event, new, old); |
| 1485 | } |
| 1486 | |
| 1487 | /* This actually signals the guest, using eventfd. */ |
| 1488 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
| 1489 | { |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1490 | /* Signal the Guest tell them we used something up. */ |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1491 | if (vq->call_ctx && vhost_notify(dev, vq)) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1492 | eventfd_signal(vq->call_ctx, 1); |
| 1493 | } |
| 1494 | |
| 1495 | /* And here's the combo meal deal. Supersize me! */ |
| 1496 | void vhost_add_used_and_signal(struct vhost_dev *dev, |
| 1497 | struct vhost_virtqueue *vq, |
| 1498 | unsigned int head, int len) |
| 1499 | { |
| 1500 | vhost_add_used(vq, head, len); |
| 1501 | vhost_signal(dev, vq); |
| 1502 | } |
| 1503 | |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1504 | /* multi-buffer version of vhost_add_used_and_signal */ |
| 1505 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, |
| 1506 | struct vhost_virtqueue *vq, |
| 1507 | struct vring_used_elem *heads, unsigned count) |
| 1508 | { |
| 1509 | vhost_add_used_n(vq, heads, count); |
| 1510 | vhost_signal(dev, vq); |
| 1511 | } |
| 1512 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1513 | /* OK, now we need to know about added descriptors. */ |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1514 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1515 | { |
| 1516 | u16 avail_idx; |
| 1517 | int r; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 1518 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1519 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
| 1520 | return false; |
| 1521 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1522 | if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1523 | r = vhost_update_used_flags(vq); |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1524 | if (r) { |
| 1525 | vq_err(vq, "Failed to enable notification at %p: %d\n", |
| 1526 | &vq->used->flags, r); |
| 1527 | return false; |
| 1528 | } |
| 1529 | } else { |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1530 | r = vhost_update_avail_event(vq, vq->avail_idx); |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1531 | if (r) { |
| 1532 | vq_err(vq, "Failed to update avail event index at %p: %d\n", |
| 1533 | vhost_avail_event(vq), r); |
| 1534 | return false; |
| 1535 | } |
| 1536 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1537 | /* They could have slipped one in as we were doing that: make |
| 1538 | * sure it's written, then check again. */ |
Michael S. Tsirkin | 5659338 | 2010-02-01 07:21:02 +0000 | [diff] [blame] | 1539 | smp_mb(); |
Michael S. Tsirkin | 8b7347a | 2010-09-19 15:56:30 +0200 | [diff] [blame] | 1540 | r = __get_user(avail_idx, &vq->avail->idx); |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1541 | if (r) { |
| 1542 | vq_err(vq, "Failed to check avail idx at %p: %d\n", |
| 1543 | &vq->avail->idx, r); |
| 1544 | return false; |
| 1545 | } |
| 1546 | |
David Stevens | 8dd014a | 2010-07-27 18:52:21 +0300 | [diff] [blame] | 1547 | return avail_idx != vq->avail_idx; |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1548 | } |
| 1549 | |
| 1550 | /* We don't need to be notified again. */ |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1551 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1552 | { |
| 1553 | int r; |
Krishna Kumar | d47effe | 2011-03-01 17:06:37 +0530 | [diff] [blame] | 1554 | |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1555 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
| 1556 | return; |
| 1557 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1558 | if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { |
Jason Wang | 2723fea | 2011-06-21 18:04:38 +0800 | [diff] [blame] | 1559 | r = vhost_update_used_flags(vq); |
Michael S. Tsirkin | 8ea8cf8 | 2011-05-20 02:10:54 +0300 | [diff] [blame] | 1560 | if (r) |
| 1561 | vq_err(vq, "Failed to enable notification at %p: %d\n", |
| 1562 | &vq->used->flags, r); |
| 1563 | } |
Michael S. Tsirkin | 3a4d5c9 | 2010-01-14 06:17:27 +0000 | [diff] [blame] | 1564 | } |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 1565 | |
| 1566 | static void vhost_zerocopy_done_signal(struct kref *kref) |
| 1567 | { |
| 1568 | struct vhost_ubuf_ref *ubufs = container_of(kref, struct vhost_ubuf_ref, |
| 1569 | kref); |
| 1570 | wake_up(&ubufs->wait); |
| 1571 | } |
| 1572 | |
| 1573 | struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *vq, |
| 1574 | bool zcopy) |
| 1575 | { |
| 1576 | struct vhost_ubuf_ref *ubufs; |
| 1577 | /* No zero copy backend? Nothing to count. */ |
| 1578 | if (!zcopy) |
| 1579 | return NULL; |
| 1580 | ubufs = kmalloc(sizeof *ubufs, GFP_KERNEL); |
| 1581 | if (!ubufs) |
| 1582 | return ERR_PTR(-ENOMEM); |
| 1583 | kref_init(&ubufs->kref); |
Michael S. Tsirkin | bab632d | 2011-07-18 03:48:46 +0000 | [diff] [blame] | 1584 | init_waitqueue_head(&ubufs->wait); |
| 1585 | ubufs->vq = vq; |
| 1586 | return ubufs; |
| 1587 | } |
| 1588 | |
| 1589 | void vhost_ubuf_put(struct vhost_ubuf_ref *ubufs) |
| 1590 | { |
| 1591 | kref_put(&ubufs->kref, vhost_zerocopy_done_signal); |
| 1592 | } |
| 1593 | |
| 1594 | void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs) |
| 1595 | { |
| 1596 | kref_put(&ubufs->kref, vhost_zerocopy_done_signal); |
| 1597 | wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount)); |
| 1598 | kfree(ubufs); |
| 1599 | } |
| 1600 | |
| 1601 | void vhost_zerocopy_callback(void *arg) |
| 1602 | { |
| 1603 | struct ubuf_info *ubuf = arg; |
| 1604 | struct vhost_ubuf_ref *ubufs = ubuf->arg; |
| 1605 | struct vhost_virtqueue *vq = ubufs->vq; |
| 1606 | |
| 1607 | /* set len = 1 to mark this desc buffers done DMA */ |
| 1608 | vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN; |
| 1609 | kref_put(&ubufs->kref, vhost_zerocopy_done_signal); |
| 1610 | } |