blob: c99415a7005136c52b7e1502dfd337581c64bc56 [file] [log] [blame]
Ian Campbellf7116282009-02-06 19:21:19 -08001/******************************************************************************
2 * evtchn.c
3 *
4 * Driver for receiving and demuxing event-channel signals.
5 *
6 * Copyright (c) 2004-2005, K A Fraser
7 * Multi-process extensions Copyright (c) 2004, Steven Smith
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
33
Joe Perches283c0972013-06-28 03:21:41 -070034#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
35
Ian Campbellf7116282009-02-06 19:21:19 -080036#include <linux/module.h>
37#include <linux/kernel.h>
38#include <linux/sched.h>
39#include <linux/slab.h>
40#include <linux/string.h>
41#include <linux/errno.h>
42#include <linux/fs.h>
Ian Campbellf7116282009-02-06 19:21:19 -080043#include <linux/miscdevice.h>
44#include <linux/major.h>
45#include <linux/proc_fs.h>
46#include <linux/stat.h>
47#include <linux/poll.h>
48#include <linux/irq.h>
49#include <linux/init.h>
Ian Campbellf7116282009-02-06 19:21:19 -080050#include <linux/mutex.h>
51#include <linux/cpu.h>
David Vrabel86200152015-11-26 16:14:35 +000052#include <linux/mm.h>
53#include <linux/vmalloc.h>
Jeremy Fitzhardinge1ccbf532009-10-06 15:11:14 -070054
55#include <xen/xen.h>
Ian Campbellf7116282009-02-06 19:21:19 -080056#include <xen/events.h>
57#include <xen/evtchn.h>
Vitaly Kuznetsovcbbb4682016-06-30 17:56:42 +020058#include <xen/xen-ops.h>
Ian Campbellf7116282009-02-06 19:21:19 -080059#include <asm/xen/hypervisor.h>
60
61struct per_user_data {
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -080062 struct mutex bind_mutex; /* serialize bind/unbind operations */
David Vrabel73cc4bb02013-07-19 15:52:00 +010063 struct rb_root evtchns;
David Vrabel86200152015-11-26 16:14:35 +000064 unsigned int nr_evtchns;
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -080065
Ian Campbellf7116282009-02-06 19:21:19 -080066 /* Notification ring, accessed via /dev/xen/evtchn. */
David Vrabel86200152015-11-26 16:14:35 +000067 unsigned int ring_size;
Ian Campbellf7116282009-02-06 19:21:19 -080068 evtchn_port_t *ring;
69 unsigned int ring_cons, ring_prod, ring_overflow;
70 struct mutex ring_cons_mutex; /* protect against concurrent readers */
David Vrabel73cc4bb02013-07-19 15:52:00 +010071 spinlock_t ring_prod_lock; /* product against concurrent interrupts */
Ian Campbellf7116282009-02-06 19:21:19 -080072
73 /* Processes wait on this queue when ring is empty. */
74 wait_queue_head_t evtchn_wait;
75 struct fasync_struct *evtchn_async_queue;
76 const char *name;
David Vrabelfbc872c2016-07-11 15:45:51 +010077
78 domid_t restrict_domid;
Ian Campbellf7116282009-02-06 19:21:19 -080079};
80
David Vrabelfbc872c2016-07-11 15:45:51 +010081#define UNRESTRICTED_DOMID ((domid_t)-1)
82
David Vrabel73cc4bb02013-07-19 15:52:00 +010083struct user_evtchn {
84 struct rb_node node;
85 struct per_user_data *user;
Yan Yankovskyi0102e4e2020-03-23 18:15:11 +020086 evtchn_port_t port;
David Vrabel73cc4bb02013-07-19 15:52:00 +010087 bool enabled;
88};
Ian Campbellf7116282009-02-06 19:21:19 -080089
David Vrabel86200152015-11-26 16:14:35 +000090static void evtchn_free_ring(evtchn_port_t *ring)
91{
92 kvfree(ring);
93}
94
95static unsigned int evtchn_ring_offset(struct per_user_data *u,
96 unsigned int idx)
97{
98 return idx & (u->ring_size - 1);
99}
100
101static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u,
102 unsigned int idx)
103{
104 return u->ring + evtchn_ring_offset(u, idx);
105}
106
David Vrabel73cc4bb02013-07-19 15:52:00 +0100107static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700108{
David Vrabel73cc4bb02013-07-19 15:52:00 +0100109 struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL;
110
David Vrabel86200152015-11-26 16:14:35 +0000111 u->nr_evtchns++;
112
David Vrabel73cc4bb02013-07-19 15:52:00 +0100113 while (*new) {
114 struct user_evtchn *this;
115
Geliang Tang2f60b282016-12-20 22:02:20 +0800116 this = rb_entry(*new, struct user_evtchn, node);
David Vrabel73cc4bb02013-07-19 15:52:00 +0100117
118 parent = *new;
119 if (this->port < evtchn->port)
120 new = &((*new)->rb_left);
121 else if (this->port > evtchn->port)
122 new = &((*new)->rb_right);
123 else
124 return -EEXIST;
125 }
126
127 /* Add new node and rebalance tree. */
128 rb_link_node(&evtchn->node, parent, new);
129 rb_insert_color(&evtchn->node, &u->evtchns);
130
131 return 0;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700132}
133
David Vrabel73cc4bb02013-07-19 15:52:00 +0100134static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700135{
David Vrabel86200152015-11-26 16:14:35 +0000136 u->nr_evtchns--;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100137 rb_erase(&evtchn->node, &u->evtchns);
138 kfree(evtchn);
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700139}
140
Yan Yankovskyi0102e4e2020-03-23 18:15:11 +0200141static struct user_evtchn *find_evtchn(struct per_user_data *u,
142 evtchn_port_t port)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700143{
David Vrabel73cc4bb02013-07-19 15:52:00 +0100144 struct rb_node *node = u->evtchns.rb_node;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700145
David Vrabel73cc4bb02013-07-19 15:52:00 +0100146 while (node) {
147 struct user_evtchn *evtchn;
148
Geliang Tang2f60b282016-12-20 22:02:20 +0800149 evtchn = rb_entry(node, struct user_evtchn, node);
David Vrabel73cc4bb02013-07-19 15:52:00 +0100150
151 if (evtchn->port < port)
152 node = node->rb_left;
153 else if (evtchn->port > port)
154 node = node->rb_right;
155 else
156 return evtchn;
157 }
158 return NULL;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700159}
160
Jeremy Fitzhardinge70697d542010-10-05 11:13:44 -0700161static irqreturn_t evtchn_interrupt(int irq, void *data)
Ian Campbellf7116282009-02-06 19:21:19 -0800162{
David Vrabel73cc4bb02013-07-19 15:52:00 +0100163 struct user_evtchn *evtchn = data;
164 struct per_user_data *u = evtchn->user;
Juergen Gross6977c0b52021-02-19 16:40:30 +0100165 unsigned int prod, cons;
Ian Campbellf7116282009-02-06 19:21:19 -0800166
David Vrabel73cc4bb02013-07-19 15:52:00 +0100167 WARN(!evtchn->enabled,
Yan Yankovskyi0102e4e2020-03-23 18:15:11 +0200168 "Interrupt for port %u, but apparently not enabled; per-user %p\n",
David Vrabel73cc4bb02013-07-19 15:52:00 +0100169 evtchn->port, u);
Ian Campbellf7116282009-02-06 19:21:19 -0800170
David Vrabel73cc4bb02013-07-19 15:52:00 +0100171 evtchn->enabled = false;
172
173 spin_lock(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800174
Juergen Gross6977c0b52021-02-19 16:40:30 +0100175 prod = READ_ONCE(u->ring_prod);
176 cons = READ_ONCE(u->ring_cons);
177
178 if ((prod - cons) < u->ring_size) {
179 *evtchn_ring_entry(u, prod) = evtchn->port;
Juergen Grossd5669952021-02-19 16:40:29 +0100180 smp_wmb(); /* Ensure ring contents visible */
Juergen Gross6977c0b52021-02-19 16:40:30 +0100181 WRITE_ONCE(u->ring_prod, prod + 1);
182 if (cons == prod) {
Ian Campbellf7116282009-02-06 19:21:19 -0800183 wake_up_interruptible(&u->evtchn_wait);
184 kill_fasync(&u->evtchn_async_queue,
185 SIGIO, POLL_IN);
186 }
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700187 } else
Ian Campbellf7116282009-02-06 19:21:19 -0800188 u->ring_overflow = 1;
Ian Campbellf7116282009-02-06 19:21:19 -0800189
David Vrabel73cc4bb02013-07-19 15:52:00 +0100190 spin_unlock(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800191
192 return IRQ_HANDLED;
193}
194
195static ssize_t evtchn_read(struct file *file, char __user *buf,
196 size_t count, loff_t *ppos)
197{
198 int rc;
199 unsigned int c, p, bytes1 = 0, bytes2 = 0;
200 struct per_user_data *u = file->private_data;
201
202 /* Whole number of ports. */
203 count &= ~(sizeof(evtchn_port_t)-1);
204
205 if (count == 0)
206 return 0;
207
208 if (count > PAGE_SIZE)
209 count = PAGE_SIZE;
210
211 for (;;) {
212 mutex_lock(&u->ring_cons_mutex);
213
214 rc = -EFBIG;
215 if (u->ring_overflow)
216 goto unlock_out;
217
Juergen Gross6977c0b52021-02-19 16:40:30 +0100218 c = READ_ONCE(u->ring_cons);
219 p = READ_ONCE(u->ring_prod);
Ian Campbellf7116282009-02-06 19:21:19 -0800220 if (c != p)
221 break;
222
223 mutex_unlock(&u->ring_cons_mutex);
224
225 if (file->f_flags & O_NONBLOCK)
226 return -EAGAIN;
227
228 rc = wait_event_interruptible(u->evtchn_wait,
Juergen Gross6977c0b52021-02-19 16:40:30 +0100229 READ_ONCE(u->ring_cons) != READ_ONCE(u->ring_prod));
Ian Campbellf7116282009-02-06 19:21:19 -0800230 if (rc)
231 return rc;
232 }
233
234 /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
David Vrabel86200152015-11-26 16:14:35 +0000235 if (((c ^ p) & u->ring_size) != 0) {
236 bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) *
Ian Campbellf7116282009-02-06 19:21:19 -0800237 sizeof(evtchn_port_t);
David Vrabel86200152015-11-26 16:14:35 +0000238 bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t);
Ian Campbellf7116282009-02-06 19:21:19 -0800239 } else {
240 bytes1 = (p - c) * sizeof(evtchn_port_t);
241 bytes2 = 0;
242 }
243
244 /* Truncate chunks according to caller's maximum byte count. */
245 if (bytes1 > count) {
246 bytes1 = count;
247 bytes2 = 0;
248 } else if ((bytes1 + bytes2) > count) {
249 bytes2 = count - bytes1;
250 }
251
252 rc = -EFAULT;
Juergen Grossd5669952021-02-19 16:40:29 +0100253 smp_rmb(); /* Ensure that we see the port before we copy it. */
David Vrabel86200152015-11-26 16:14:35 +0000254 if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) ||
Ian Campbellf7116282009-02-06 19:21:19 -0800255 ((bytes2 != 0) &&
256 copy_to_user(&buf[bytes1], &u->ring[0], bytes2)))
257 goto unlock_out;
258
Juergen Gross6977c0b52021-02-19 16:40:30 +0100259 WRITE_ONCE(u->ring_cons, c + (bytes1 + bytes2) / sizeof(evtchn_port_t));
Ian Campbellf7116282009-02-06 19:21:19 -0800260 rc = bytes1 + bytes2;
261
262 unlock_out:
263 mutex_unlock(&u->ring_cons_mutex);
264 return rc;
265}
266
267static ssize_t evtchn_write(struct file *file, const char __user *buf,
268 size_t count, loff_t *ppos)
269{
270 int rc, i;
271 evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL);
272 struct per_user_data *u = file->private_data;
273
274 if (kbuf == NULL)
275 return -ENOMEM;
276
277 /* Whole number of ports. */
278 count &= ~(sizeof(evtchn_port_t)-1);
279
280 rc = 0;
281 if (count == 0)
282 goto out;
283
284 if (count > PAGE_SIZE)
285 count = PAGE_SIZE;
286
287 rc = -EFAULT;
288 if (copy_from_user(kbuf, buf, count) != 0)
289 goto out;
290
David Vrabel73cc4bb02013-07-19 15:52:00 +0100291 mutex_lock(&u->bind_mutex);
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700292
293 for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
Yan Yankovskyi0102e4e2020-03-23 18:15:11 +0200294 evtchn_port_t port = kbuf[i];
David Vrabel73cc4bb02013-07-19 15:52:00 +0100295 struct user_evtchn *evtchn;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700296
David Vrabel73cc4bb02013-07-19 15:52:00 +0100297 evtchn = find_evtchn(u, port);
298 if (evtchn && !evtchn->enabled) {
299 evtchn->enabled = true;
Juergen Grossc44b8492020-09-07 15:47:29 +0200300 xen_irq_lateeoi(irq_from_evtchn(port), 0);
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700301 }
302 }
303
David Vrabel73cc4bb02013-07-19 15:52:00 +0100304 mutex_unlock(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800305
306 rc = count;
307
308 out:
309 free_page((unsigned long)kbuf);
310 return rc;
311}
312
David Vrabel86200152015-11-26 16:14:35 +0000313static int evtchn_resize_ring(struct per_user_data *u)
314{
315 unsigned int new_size;
316 evtchn_port_t *new_ring, *old_ring;
David Vrabel86200152015-11-26 16:14:35 +0000317
318 /*
319 * Ensure the ring is large enough to capture all possible
320 * events. i.e., one free slot for each bound event.
321 */
322 if (u->nr_evtchns <= u->ring_size)
323 return 0;
324
325 if (u->ring_size == 0)
326 new_size = 64;
327 else
328 new_size = 2 * u->ring_size;
329
Kees Cook344476e2018-06-12 14:04:32 -0700330 new_ring = kvmalloc_array(new_size, sizeof(*new_ring), GFP_KERNEL);
David Vrabel86200152015-11-26 16:14:35 +0000331 if (!new_ring)
332 return -ENOMEM;
333
334 old_ring = u->ring;
335
336 /*
337 * Access to the ring contents is serialized by either the
338 * prod /or/ cons lock so take both when resizing.
339 */
340 mutex_lock(&u->ring_cons_mutex);
341 spin_lock_irq(&u->ring_prod_lock);
342
343 /*
344 * Copy the old ring contents to the new ring.
345 *
Jan Beulich27e0e632016-05-04 07:02:36 -0600346 * To take care of wrapping, a full ring, and the new index
347 * pointing into the second half, simply copy the old contents
348 * twice.
David Vrabel86200152015-11-26 16:14:35 +0000349 *
350 * +---------+ +------------------+
Jan Beulich27e0e632016-05-04 07:02:36 -0600351 * |34567 12| -> |34567 1234567 12|
352 * +-----p-c-+ +-------c------p---+
David Vrabel86200152015-11-26 16:14:35 +0000353 */
Jan Beulich27e0e632016-05-04 07:02:36 -0600354 memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring));
355 memcpy(new_ring + u->ring_size, old_ring,
356 u->ring_size * sizeof(*u->ring));
David Vrabel86200152015-11-26 16:14:35 +0000357
358 u->ring = new_ring;
359 u->ring_size = new_size;
360
361 spin_unlock_irq(&u->ring_prod_lock);
362 mutex_unlock(&u->ring_cons_mutex);
363
364 evtchn_free_ring(old_ring);
365
366 return 0;
367}
368
Yan Yankovskyi0102e4e2020-03-23 18:15:11 +0200369static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port)
Ian Campbellf7116282009-02-06 19:21:19 -0800370{
David Vrabel73cc4bb02013-07-19 15:52:00 +0100371 struct user_evtchn *evtchn;
372 struct evtchn_close close;
Ian Campbellf7116282009-02-06 19:21:19 -0800373 int rc = 0;
374
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800375 /*
376 * Ports are never reused, so every caller should pass in a
377 * unique port.
378 *
379 * (Locking not necessary because we haven't registered the
380 * interrupt handler yet, and our caller has already
381 * serialized bind operations.)
382 */
David Vrabel73cc4bb02013-07-19 15:52:00 +0100383
384 evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL);
385 if (!evtchn)
386 return -ENOMEM;
387
388 evtchn->user = u;
389 evtchn->port = port;
390 evtchn->enabled = true; /* start enabled */
391
392 rc = add_evtchn(u, evtchn);
393 if (rc < 0)
394 goto err;
Ian Campbellf7116282009-02-06 19:21:19 -0800395
David Vrabel86200152015-11-26 16:14:35 +0000396 rc = evtchn_resize_ring(u);
397 if (rc < 0)
398 goto err;
399
Juergen Grossc44b8492020-09-07 15:47:29 +0200400 rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0,
401 u->name, evtchn);
David Vrabel73cc4bb02013-07-19 15:52:00 +0100402 if (rc < 0)
403 goto err;
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800404
David Vrabel73cc4bb02013-07-19 15:52:00 +0100405 rc = evtchn_make_refcounted(port);
406 return rc;
407
408err:
409 /* bind failed, should close the port now */
410 close.port = port;
411 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
412 BUG();
413 del_evtchn(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800414 return rc;
415}
416
David Vrabel73cc4bb02013-07-19 15:52:00 +0100417static void evtchn_unbind_from_user(struct per_user_data *u,
418 struct user_evtchn *evtchn)
Ian Campbellf7116282009-02-06 19:21:19 -0800419{
David Vrabel73cc4bb02013-07-19 15:52:00 +0100420 int irq = irq_from_evtchn(evtchn->port);
Ian Campbellf7116282009-02-06 19:21:19 -0800421
Wei Liue7e44e42013-02-18 14:57:58 +0000422 BUG_ON(irq < 0);
423
David Vrabel73cc4bb02013-07-19 15:52:00 +0100424 unbind_from_irqhandler(irq, evtchn);
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800425
David Vrabel73cc4bb02013-07-19 15:52:00 +0100426 del_evtchn(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800427}
428
429static long evtchn_ioctl(struct file *file,
430 unsigned int cmd, unsigned long arg)
431{
432 int rc;
433 struct per_user_data *u = file->private_data;
434 void __user *uarg = (void __user *) arg;
435
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800436 /* Prevent bind from racing with unbind */
437 mutex_lock(&u->bind_mutex);
438
Ian Campbellf7116282009-02-06 19:21:19 -0800439 switch (cmd) {
440 case IOCTL_EVTCHN_BIND_VIRQ: {
441 struct ioctl_evtchn_bind_virq bind;
442 struct evtchn_bind_virq bind_virq;
443
David Vrabelfbc872c2016-07-11 15:45:51 +0100444 rc = -EACCES;
445 if (u->restrict_domid != UNRESTRICTED_DOMID)
446 break;
447
Ian Campbellf7116282009-02-06 19:21:19 -0800448 rc = -EFAULT;
449 if (copy_from_user(&bind, uarg, sizeof(bind)))
450 break;
451
452 bind_virq.virq = bind.virq;
Vitaly Kuznetsovcbbb4682016-06-30 17:56:42 +0200453 bind_virq.vcpu = xen_vcpu_nr(0);
Ian Campbellf7116282009-02-06 19:21:19 -0800454 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
455 &bind_virq);
456 if (rc != 0)
457 break;
458
459 rc = evtchn_bind_to_user(u, bind_virq.port);
460 if (rc == 0)
461 rc = bind_virq.port;
462 break;
463 }
464
465 case IOCTL_EVTCHN_BIND_INTERDOMAIN: {
466 struct ioctl_evtchn_bind_interdomain bind;
467 struct evtchn_bind_interdomain bind_interdomain;
468
469 rc = -EFAULT;
470 if (copy_from_user(&bind, uarg, sizeof(bind)))
471 break;
472
David Vrabelfbc872c2016-07-11 15:45:51 +0100473 rc = -EACCES;
474 if (u->restrict_domid != UNRESTRICTED_DOMID &&
475 u->restrict_domid != bind.remote_domain)
476 break;
477
Ian Campbellf7116282009-02-06 19:21:19 -0800478 bind_interdomain.remote_dom = bind.remote_domain;
479 bind_interdomain.remote_port = bind.remote_port;
480 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
481 &bind_interdomain);
482 if (rc != 0)
483 break;
484
485 rc = evtchn_bind_to_user(u, bind_interdomain.local_port);
Thomas Gleixner67473b82020-12-10 20:26:01 +0100486 if (rc == 0)
Ian Campbellf7116282009-02-06 19:21:19 -0800487 rc = bind_interdomain.local_port;
488 break;
489 }
490
491 case IOCTL_EVTCHN_BIND_UNBOUND_PORT: {
492 struct ioctl_evtchn_bind_unbound_port bind;
493 struct evtchn_alloc_unbound alloc_unbound;
494
David Vrabelfbc872c2016-07-11 15:45:51 +0100495 rc = -EACCES;
496 if (u->restrict_domid != UNRESTRICTED_DOMID)
497 break;
498
Ian Campbellf7116282009-02-06 19:21:19 -0800499 rc = -EFAULT;
500 if (copy_from_user(&bind, uarg, sizeof(bind)))
501 break;
502
503 alloc_unbound.dom = DOMID_SELF;
504 alloc_unbound.remote_dom = bind.remote_domain;
505 rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
506 &alloc_unbound);
507 if (rc != 0)
508 break;
509
510 rc = evtchn_bind_to_user(u, alloc_unbound.port);
511 if (rc == 0)
512 rc = alloc_unbound.port;
513 break;
514 }
515
516 case IOCTL_EVTCHN_UNBIND: {
517 struct ioctl_evtchn_unbind unbind;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100518 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800519
520 rc = -EFAULT;
521 if (copy_from_user(&unbind, uarg, sizeof(unbind)))
522 break;
523
524 rc = -EINVAL;
David Vrabel0dc00642013-09-23 21:03:38 +0100525 if (unbind.port >= xen_evtchn_nr_channels())
Ian Campbellf7116282009-02-06 19:21:19 -0800526 break;
527
Ian Campbellf7116282009-02-06 19:21:19 -0800528 rc = -ENOTCONN;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100529 evtchn = find_evtchn(u, unbind.port);
530 if (!evtchn)
Ian Campbellf7116282009-02-06 19:21:19 -0800531 break;
Ian Campbellf7116282009-02-06 19:21:19 -0800532
Jeremy Fitzhardinge3f5e5542010-05-28 15:28:27 -0700533 disable_irq(irq_from_evtchn(unbind.port));
David Vrabel73cc4bb02013-07-19 15:52:00 +0100534 evtchn_unbind_from_user(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800535 rc = 0;
536 break;
537 }
538
539 case IOCTL_EVTCHN_NOTIFY: {
540 struct ioctl_evtchn_notify notify;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100541 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800542
543 rc = -EFAULT;
544 if (copy_from_user(&notify, uarg, sizeof(notify)))
545 break;
546
David Vrabel73cc4bb02013-07-19 15:52:00 +0100547 rc = -ENOTCONN;
548 evtchn = find_evtchn(u, notify.port);
549 if (evtchn) {
Ian Campbellf7116282009-02-06 19:21:19 -0800550 notify_remote_via_evtchn(notify.port);
551 rc = 0;
552 }
553 break;
554 }
555
556 case IOCTL_EVTCHN_RESET: {
557 /* Initialise the ring to empty. Clear errors. */
558 mutex_lock(&u->ring_cons_mutex);
David Vrabel73cc4bb02013-07-19 15:52:00 +0100559 spin_lock_irq(&u->ring_prod_lock);
Juergen Gross6977c0b52021-02-19 16:40:30 +0100560 WRITE_ONCE(u->ring_cons, 0);
561 WRITE_ONCE(u->ring_prod, 0);
562 u->ring_overflow = 0;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100563 spin_unlock_irq(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800564 mutex_unlock(&u->ring_cons_mutex);
565 rc = 0;
566 break;
567 }
568
David Vrabelfbc872c2016-07-11 15:45:51 +0100569 case IOCTL_EVTCHN_RESTRICT_DOMID: {
570 struct ioctl_evtchn_restrict_domid ierd;
571
572 rc = -EACCES;
573 if (u->restrict_domid != UNRESTRICTED_DOMID)
574 break;
575
576 rc = -EFAULT;
577 if (copy_from_user(&ierd, uarg, sizeof(ierd)))
578 break;
579
580 rc = -EINVAL;
581 if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED)
582 break;
583
584 u->restrict_domid = ierd.domid;
585 rc = 0;
586
587 break;
588 }
589
Ian Campbellf7116282009-02-06 19:21:19 -0800590 default:
591 rc = -ENOSYS;
592 break;
593 }
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800594 mutex_unlock(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800595
596 return rc;
597}
598
Al Viroafc9a422017-07-03 06:39:46 -0400599static __poll_t evtchn_poll(struct file *file, poll_table *wait)
Ian Campbellf7116282009-02-06 19:21:19 -0800600{
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800601 __poll_t mask = EPOLLOUT | EPOLLWRNORM;
Ian Campbellf7116282009-02-06 19:21:19 -0800602 struct per_user_data *u = file->private_data;
603
604 poll_wait(file, &u->evtchn_wait, wait);
Juergen Gross6977c0b52021-02-19 16:40:30 +0100605 if (READ_ONCE(u->ring_cons) != READ_ONCE(u->ring_prod))
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800606 mask |= EPOLLIN | EPOLLRDNORM;
Ian Campbellf7116282009-02-06 19:21:19 -0800607 if (u->ring_overflow)
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800608 mask = EPOLLERR;
Ian Campbellf7116282009-02-06 19:21:19 -0800609 return mask;
610}
611
612static int evtchn_fasync(int fd, struct file *filp, int on)
613{
614 struct per_user_data *u = filp->private_data;
615 return fasync_helper(fd, filp, on, &u->evtchn_async_queue);
616}
617
618static int evtchn_open(struct inode *inode, struct file *filp)
619{
620 struct per_user_data *u;
621
622 u = kzalloc(sizeof(*u), GFP_KERNEL);
623 if (u == NULL)
624 return -ENOMEM;
625
626 u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm);
627 if (u->name == NULL) {
628 kfree(u);
629 return -ENOMEM;
630 }
631
632 init_waitqueue_head(&u->evtchn_wait);
633
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800634 mutex_init(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800635 mutex_init(&u->ring_cons_mutex);
David Vrabel73cc4bb02013-07-19 15:52:00 +0100636 spin_lock_init(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800637
David Vrabelfbc872c2016-07-11 15:45:51 +0100638 u->restrict_domid = UNRESTRICTED_DOMID;
639
Ian Campbellf7116282009-02-06 19:21:19 -0800640 filp->private_data = u;
641
Kirill Smelkovc5bf68f2019-03-26 23:51:19 +0300642 return stream_open(inode, filp);
Ian Campbellf7116282009-02-06 19:21:19 -0800643}
644
645static int evtchn_release(struct inode *inode, struct file *filp)
646{
Ian Campbellf7116282009-02-06 19:21:19 -0800647 struct per_user_data *u = filp->private_data;
David Vrabel73cc4bb02013-07-19 15:52:00 +0100648 struct rb_node *node;
Ian Campbellf7116282009-02-06 19:21:19 -0800649
David Vrabel73cc4bb02013-07-19 15:52:00 +0100650 while ((node = u->evtchns.rb_node)) {
651 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800652
David Vrabel73cc4bb02013-07-19 15:52:00 +0100653 evtchn = rb_entry(node, struct user_evtchn, node);
654 disable_irq(irq_from_evtchn(evtchn->port));
655 evtchn_unbind_from_user(u, evtchn);
Jeremy Fitzhardinge3f5e5542010-05-28 15:28:27 -0700656 }
657
David Vrabel86200152015-11-26 16:14:35 +0000658 evtchn_free_ring(u->ring);
Ian Campbellf7116282009-02-06 19:21:19 -0800659 kfree(u->name);
660 kfree(u);
661
662 return 0;
663}
664
665static const struct file_operations evtchn_fops = {
666 .owner = THIS_MODULE,
667 .read = evtchn_read,
668 .write = evtchn_write,
669 .unlocked_ioctl = evtchn_ioctl,
670 .poll = evtchn_poll,
671 .fasync = evtchn_fasync,
672 .open = evtchn_open,
673 .release = evtchn_release,
Jeremy Fitzhardingebc7fc5e2010-11-18 22:32:17 -0800674 .llseek = no_llseek,
Ian Campbellf7116282009-02-06 19:21:19 -0800675};
676
677static struct miscdevice evtchn_miscdev = {
678 .minor = MISC_DYNAMIC_MINOR,
Bastian Blank376d9082010-05-28 15:43:49 -0700679 .name = "xen/evtchn",
Ian Campbellf7116282009-02-06 19:21:19 -0800680 .fops = &evtchn_fops,
681};
682static int __init evtchn_init(void)
683{
684 int err;
685
686 if (!xen_domain())
687 return -ENODEV;
688
Wei Liu18283ea2013-02-18 14:57:59 +0000689 /* Create '/dev/xen/evtchn'. */
Ian Campbellf7116282009-02-06 19:21:19 -0800690 err = misc_register(&evtchn_miscdev);
691 if (err != 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700692 pr_err("Could not register /dev/xen/evtchn\n");
Ian Campbellf7116282009-02-06 19:21:19 -0800693 return err;
694 }
695
Joe Perches283c0972013-06-28 03:21:41 -0700696 pr_info("Event-channel device installed\n");
Ian Campbellf7116282009-02-06 19:21:19 -0800697
698 return 0;
699}
700
701static void __exit evtchn_cleanup(void)
702{
Ian Campbellf7116282009-02-06 19:21:19 -0800703 misc_deregister(&evtchn_miscdev);
704}
705
706module_init(evtchn_init);
707module_exit(evtchn_cleanup);
708
709MODULE_LICENSE("GPL");