2 * (c) 2017 Stefano Stabellini <stefano@aporeto.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/inet.h>
16 #include <linux/kthread.h>
17 #include <linux/list.h>
18 #include <linux/radix-tree.h>
19 #include <linux/module.h>
20 #include <linux/semaphore.h>
21 #include <linux/wait.h>
23 #include <net/inet_common.h>
24 #include <net/inet_connection_sock.h>
25 #include <net/request_sock.h>
27 #include <xen/events.h>
28 #include <xen/grant_table.h>
30 #include <xen/xenbus.h>
31 #include <xen/interface/io/pvcalls.h>
33 #define PVCALLS_VERSIONS "1"
34 #define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER
36 struct pvcalls_back_global {
37 struct list_head frontends;
38 struct semaphore frontends_lock;
39 } pvcalls_back_global;
42 * Per-frontend data structure. It contains pointers to the command
43 * ring, its event channel, a list of active sockets and a tree of
46 struct pvcalls_fedata {
47 struct list_head list;
48 struct xenbus_device *dev;
49 struct xen_pvcalls_sring *sring;
50 struct xen_pvcalls_back_ring ring;
52 struct list_head socket_mappings;
53 struct radix_tree_root socketpass_mappings;
54 struct semaphore socket_lock;
57 struct pvcalls_ioworker {
58 struct work_struct register_work;
59 struct workqueue_struct *wq;
63 struct list_head list;
64 struct pvcalls_fedata *fedata;
65 struct sockpass_mapping *sockpass;
69 struct pvcalls_data_intf *ring;
71 struct pvcalls_data data;
78 void (*saved_data_ready)(struct sock *sk);
79 struct pvcalls_ioworker ioworker;
82 struct sockpass_mapping {
83 struct list_head list;
84 struct pvcalls_fedata *fedata;
87 struct xen_pvcalls_request reqcopy;
89 struct workqueue_struct *wq;
90 struct work_struct register_work;
91 void (*saved_data_ready)(struct sock *sk);
94 static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map);
95 static int pvcalls_back_release_active(struct xenbus_device *dev,
96 struct pvcalls_fedata *fedata,
97 struct sock_mapping *map);
99 static void pvcalls_conn_back_read(void *opaque)
101 struct sock_mapping *map = (struct sock_mapping *)opaque;
104 RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons;
106 struct pvcalls_data_intf *intf = map->ring;
107 struct pvcalls_data *data = &map->data;
111 array_size = XEN_FLEX_RING_SIZE(map->ring_order);
112 cons = intf->in_cons;
113 prod = intf->in_prod;
114 error = intf->in_error;
115 /* read the indexes first, then deal with the data */
121 size = pvcalls_queued(prod, cons, array_size);
122 if (size >= array_size)
124 spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
125 if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) {
126 atomic_set(&map->read, 0);
127 spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock,
131 spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
132 wanted = array_size - size;
133 masked_prod = pvcalls_mask(prod, array_size);
134 masked_cons = pvcalls_mask(cons, array_size);
136 memset(&msg, 0, sizeof(msg));
137 if (masked_prod < masked_cons) {
138 vec[0].iov_base = data->in + masked_prod;
139 vec[0].iov_len = wanted;
140 iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted);
142 vec[0].iov_base = data->in + masked_prod;
143 vec[0].iov_len = array_size - masked_prod;
144 vec[1].iov_base = data->in;
145 vec[1].iov_len = wanted - vec[0].iov_len;
146 iov_iter_kvec(&msg.msg_iter, WRITE, vec, 2, wanted);
149 atomic_set(&map->read, 0);
150 ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT);
151 WARN_ON(ret > wanted);
152 if (ret == -EAGAIN) /* shouldn't happen */
156 spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
157 if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue))
158 atomic_inc(&map->read);
159 spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
161 /* write the data, then modify the indexes */
164 atomic_set(&map->read, 0);
165 intf->in_error = ret;
167 intf->in_prod = prod + ret;
168 /* update the indexes, then notify the other end */
170 notify_remote_via_irq(map->irq);
175 static void pvcalls_conn_back_write(struct sock_mapping *map)
177 struct pvcalls_data_intf *intf = map->ring;
178 struct pvcalls_data *data = &map->data;
181 RING_IDX cons, prod, size, array_size;
184 cons = intf->out_cons;
185 prod = intf->out_prod;
186 /* read the indexes before dealing with the data */
189 array_size = XEN_FLEX_RING_SIZE(map->ring_order);
190 size = pvcalls_queued(prod, cons, array_size);
194 memset(&msg, 0, sizeof(msg));
195 msg.msg_flags |= MSG_DONTWAIT;
196 if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) {
197 vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
198 vec[0].iov_len = size;
199 iov_iter_kvec(&msg.msg_iter, READ, vec, 1, size);
201 vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
202 vec[0].iov_len = array_size - pvcalls_mask(cons, array_size);
203 vec[1].iov_base = data->out;
204 vec[1].iov_len = size - vec[0].iov_len;
205 iov_iter_kvec(&msg.msg_iter, READ, vec, 2, size);
208 atomic_set(&map->write, 0);
209 ret = inet_sendmsg(map->sock, &msg, size);
210 if (ret == -EAGAIN || (ret >= 0 && ret < size)) {
211 atomic_inc(&map->write);
212 atomic_inc(&map->io);
217 /* write the data, then update the indexes */
220 intf->out_error = ret;
223 intf->out_cons = cons + ret;
224 prod = intf->out_prod;
226 /* update the indexes, then notify the other end */
228 if (prod != cons + ret)
229 atomic_inc(&map->write);
230 notify_remote_via_irq(map->irq);
233 static void pvcalls_back_ioworker(struct work_struct *work)
235 struct pvcalls_ioworker *ioworker = container_of(work,
236 struct pvcalls_ioworker, register_work);
237 struct sock_mapping *map = container_of(ioworker, struct sock_mapping,
240 while (atomic_read(&map->io) > 0) {
241 if (atomic_read(&map->release) > 0) {
242 atomic_set(&map->release, 0);
246 if (atomic_read(&map->read) > 0)
247 pvcalls_conn_back_read(map);
248 if (atomic_read(&map->write) > 0)
249 pvcalls_conn_back_write(map);
251 atomic_dec(&map->io);
255 static int pvcalls_back_socket(struct xenbus_device *dev,
256 struct xen_pvcalls_request *req)
258 struct pvcalls_fedata *fedata;
260 struct xen_pvcalls_response *rsp;
262 fedata = dev_get_drvdata(&dev->dev);
264 if (req->u.socket.domain != AF_INET ||
265 req->u.socket.type != SOCK_STREAM ||
266 (req->u.socket.protocol != IPPROTO_IP &&
267 req->u.socket.protocol != AF_INET))
272 /* leave the actual socket allocation for later */
274 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
275 rsp->req_id = req->req_id;
277 rsp->u.socket.id = req->u.socket.id;
283 static void pvcalls_sk_state_change(struct sock *sock)
285 struct sock_mapping *map = sock->sk_user_data;
290 atomic_inc(&map->read);
291 notify_remote_via_irq(map->irq);
294 static void pvcalls_sk_data_ready(struct sock *sock)
296 struct sock_mapping *map = sock->sk_user_data;
297 struct pvcalls_ioworker *iow;
302 iow = &map->ioworker;
303 atomic_inc(&map->read);
304 atomic_inc(&map->io);
305 queue_work(iow->wq, &iow->register_work);
308 static struct sock_mapping *pvcalls_new_active_socket(
309 struct pvcalls_fedata *fedata,
316 struct sock_mapping *map;
319 map = kzalloc(sizeof(*map), GFP_KERNEL);
323 map->fedata = fedata;
328 ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page);
332 map->ring_order = map->ring->ring_order;
333 /* first read the order, then map the data ring */
335 if (map->ring_order > MAX_RING_ORDER) {
336 pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n",
337 __func__, map->ring_order, MAX_RING_ORDER);
340 ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref,
341 (1 << map->ring_order), &page);
346 ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id,
348 pvcalls_back_conn_event,
356 map->data.in = map->bytes;
357 map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order);
359 map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1);
360 if (!map->ioworker.wq)
362 atomic_set(&map->io, 1);
363 INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker);
365 down(&fedata->socket_lock);
366 list_add_tail(&map->list, &fedata->socket_mappings);
367 up(&fedata->socket_lock);
369 write_lock_bh(&map->sock->sk->sk_callback_lock);
370 map->saved_data_ready = map->sock->sk->sk_data_ready;
371 map->sock->sk->sk_user_data = map;
372 map->sock->sk->sk_data_ready = pvcalls_sk_data_ready;
373 map->sock->sk->sk_state_change = pvcalls_sk_state_change;
374 write_unlock_bh(&map->sock->sk->sk_callback_lock);
378 down(&fedata->socket_lock);
379 list_del(&map->list);
380 pvcalls_back_release_active(fedata->dev, fedata, map);
381 up(&fedata->socket_lock);
385 static int pvcalls_back_connect(struct xenbus_device *dev,
386 struct xen_pvcalls_request *req)
388 struct pvcalls_fedata *fedata;
391 struct sock_mapping *map;
392 struct xen_pvcalls_response *rsp;
393 struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr;
395 fedata = dev_get_drvdata(&dev->dev);
397 if (req->u.connect.len < sizeof(sa->sa_family) ||
398 req->u.connect.len > sizeof(req->u.connect.addr) ||
399 sa->sa_family != AF_INET)
402 ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
405 ret = inet_stream_connect(sock, sa, req->u.connect.len, 0);
411 map = pvcalls_new_active_socket(fedata,
414 req->u.connect.evtchn,
422 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
423 rsp->req_id = req->req_id;
425 rsp->u.connect.id = req->u.connect.id;
431 static int pvcalls_back_release_active(struct xenbus_device *dev,
432 struct pvcalls_fedata *fedata,
433 struct sock_mapping *map)
435 disable_irq(map->irq);
436 if (map->sock->sk != NULL) {
437 write_lock_bh(&map->sock->sk->sk_callback_lock);
438 map->sock->sk->sk_user_data = NULL;
439 map->sock->sk->sk_data_ready = map->saved_data_ready;
440 write_unlock_bh(&map->sock->sk->sk_callback_lock);
443 atomic_set(&map->release, 1);
444 flush_work(&map->ioworker.register_work);
446 xenbus_unmap_ring_vfree(dev, map->bytes);
447 xenbus_unmap_ring_vfree(dev, (void *)map->ring);
448 unbind_from_irqhandler(map->irq, map);
450 sock_release(map->sock);
456 static int pvcalls_back_release_passive(struct xenbus_device *dev,
457 struct pvcalls_fedata *fedata,
458 struct sockpass_mapping *mappass)
460 if (mappass->sock->sk != NULL) {
461 write_lock_bh(&mappass->sock->sk->sk_callback_lock);
462 mappass->sock->sk->sk_user_data = NULL;
463 mappass->sock->sk->sk_data_ready = mappass->saved_data_ready;
464 write_unlock_bh(&mappass->sock->sk->sk_callback_lock);
466 sock_release(mappass->sock);
467 flush_workqueue(mappass->wq);
468 destroy_workqueue(mappass->wq);
474 static int pvcalls_back_release(struct xenbus_device *dev,
475 struct xen_pvcalls_request *req)
477 struct pvcalls_fedata *fedata;
478 struct sock_mapping *map, *n;
479 struct sockpass_mapping *mappass;
481 struct xen_pvcalls_response *rsp;
483 fedata = dev_get_drvdata(&dev->dev);
485 down(&fedata->socket_lock);
486 list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) {
487 if (map->id == req->u.release.id) {
488 list_del(&map->list);
489 up(&fedata->socket_lock);
490 ret = pvcalls_back_release_active(dev, fedata, map);
494 mappass = radix_tree_lookup(&fedata->socketpass_mappings,
496 if (mappass != NULL) {
497 radix_tree_delete(&fedata->socketpass_mappings, mappass->id);
498 up(&fedata->socket_lock);
499 ret = pvcalls_back_release_passive(dev, fedata, mappass);
501 up(&fedata->socket_lock);
504 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
505 rsp->req_id = req->req_id;
506 rsp->u.release.id = req->u.release.id;
512 static void __pvcalls_back_accept(struct work_struct *work)
514 struct sockpass_mapping *mappass = container_of(
515 work, struct sockpass_mapping, register_work);
516 struct sock_mapping *map;
517 struct pvcalls_ioworker *iow;
518 struct pvcalls_fedata *fedata;
520 struct xen_pvcalls_response *rsp;
521 struct xen_pvcalls_request *req;
526 fedata = mappass->fedata;
528 * __pvcalls_back_accept can race against pvcalls_back_accept.
529 * We only need to check the value of "cmd" on read. It could be
530 * done atomically, but to simplify the code on the write side, we
533 spin_lock_irqsave(&mappass->copy_lock, flags);
534 req = &mappass->reqcopy;
535 if (req->cmd != PVCALLS_ACCEPT) {
536 spin_unlock_irqrestore(&mappass->copy_lock, flags);
539 spin_unlock_irqrestore(&mappass->copy_lock, flags);
544 sock->type = mappass->sock->type;
545 sock->ops = mappass->sock->ops;
547 ret = inet_accept(mappass->sock, sock, O_NONBLOCK, true);
548 if (ret == -EAGAIN) {
553 map = pvcalls_new_active_socket(fedata,
554 req->u.accept.id_new,
556 req->u.accept.evtchn,
564 map->sockpass = mappass;
565 iow = &map->ioworker;
566 atomic_inc(&map->read);
567 atomic_inc(&map->io);
568 queue_work(iow->wq, &iow->register_work);
571 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
572 rsp->req_id = req->req_id;
574 rsp->u.accept.id = req->u.accept.id;
576 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify);
578 notify_remote_via_irq(fedata->irq);
580 mappass->reqcopy.cmd = 0;
583 static void pvcalls_pass_sk_data_ready(struct sock *sock)
585 struct sockpass_mapping *mappass = sock->sk_user_data;
586 struct pvcalls_fedata *fedata;
587 struct xen_pvcalls_response *rsp;
594 fedata = mappass->fedata;
595 spin_lock_irqsave(&mappass->copy_lock, flags);
596 if (mappass->reqcopy.cmd == PVCALLS_POLL) {
597 rsp = RING_GET_RESPONSE(&fedata->ring,
598 fedata->ring.rsp_prod_pvt++);
599 rsp->req_id = mappass->reqcopy.req_id;
600 rsp->u.poll.id = mappass->reqcopy.u.poll.id;
601 rsp->cmd = mappass->reqcopy.cmd;
604 mappass->reqcopy.cmd = 0;
605 spin_unlock_irqrestore(&mappass->copy_lock, flags);
607 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify);
609 notify_remote_via_irq(mappass->fedata->irq);
611 spin_unlock_irqrestore(&mappass->copy_lock, flags);
612 queue_work(mappass->wq, &mappass->register_work);
616 static int pvcalls_back_bind(struct xenbus_device *dev,
617 struct xen_pvcalls_request *req)
619 struct pvcalls_fedata *fedata;
621 struct sockpass_mapping *map;
622 struct xen_pvcalls_response *rsp;
624 fedata = dev_get_drvdata(&dev->dev);
626 map = kzalloc(sizeof(*map), GFP_KERNEL);
632 INIT_WORK(&map->register_work, __pvcalls_back_accept);
633 spin_lock_init(&map->copy_lock);
634 map->wq = alloc_workqueue("pvcalls_wq", WQ_UNBOUND, 1);
640 ret = sock_create(AF_INET, SOCK_STREAM, 0, &map->sock);
644 ret = inet_bind(map->sock, (struct sockaddr *)&req->u.bind.addr,
649 map->fedata = fedata;
650 map->id = req->u.bind.id;
652 down(&fedata->socket_lock);
653 ret = radix_tree_insert(&fedata->socketpass_mappings, map->id,
655 up(&fedata->socket_lock);
659 write_lock_bh(&map->sock->sk->sk_callback_lock);
660 map->saved_data_ready = map->sock->sk->sk_data_ready;
661 map->sock->sk->sk_user_data = map;
662 map->sock->sk->sk_data_ready = pvcalls_pass_sk_data_ready;
663 write_unlock_bh(&map->sock->sk->sk_callback_lock);
667 if (map && map->sock)
668 sock_release(map->sock);
670 destroy_workqueue(map->wq);
673 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
674 rsp->req_id = req->req_id;
676 rsp->u.bind.id = req->u.bind.id;
681 static int pvcalls_back_listen(struct xenbus_device *dev,
682 struct xen_pvcalls_request *req)
684 struct pvcalls_fedata *fedata;
686 struct sockpass_mapping *map;
687 struct xen_pvcalls_response *rsp;
689 fedata = dev_get_drvdata(&dev->dev);
691 down(&fedata->socket_lock);
692 map = radix_tree_lookup(&fedata->socketpass_mappings, req->u.listen.id);
693 up(&fedata->socket_lock);
697 ret = inet_listen(map->sock, req->u.listen.backlog);
700 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
701 rsp->req_id = req->req_id;
703 rsp->u.listen.id = req->u.listen.id;
708 static int pvcalls_back_accept(struct xenbus_device *dev,
709 struct xen_pvcalls_request *req)
711 struct pvcalls_fedata *fedata;
712 struct sockpass_mapping *mappass;
714 struct xen_pvcalls_response *rsp;
717 fedata = dev_get_drvdata(&dev->dev);
719 down(&fedata->socket_lock);
720 mappass = radix_tree_lookup(&fedata->socketpass_mappings,
722 up(&fedata->socket_lock);
727 * Limitation of the current implementation: only support one
728 * concurrent accept or poll call on one socket.
730 spin_lock_irqsave(&mappass->copy_lock, flags);
731 if (mappass->reqcopy.cmd != 0) {
732 spin_unlock_irqrestore(&mappass->copy_lock, flags);
737 mappass->reqcopy = *req;
738 spin_unlock_irqrestore(&mappass->copy_lock, flags);
739 queue_work(mappass->wq, &mappass->register_work);
741 /* Tell the caller we don't need to send back a notification yet */
745 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
746 rsp->req_id = req->req_id;
748 rsp->u.accept.id = req->u.accept.id;
753 static int pvcalls_back_poll(struct xenbus_device *dev,
754 struct xen_pvcalls_request *req)
756 struct pvcalls_fedata *fedata;
757 struct sockpass_mapping *mappass;
758 struct xen_pvcalls_response *rsp;
759 struct inet_connection_sock *icsk;
760 struct request_sock_queue *queue;
765 fedata = dev_get_drvdata(&dev->dev);
767 down(&fedata->socket_lock);
768 mappass = radix_tree_lookup(&fedata->socketpass_mappings,
770 up(&fedata->socket_lock);
775 * Limitation of the current implementation: only support one
776 * concurrent accept or poll call on one socket.
778 spin_lock_irqsave(&mappass->copy_lock, flags);
779 if (mappass->reqcopy.cmd != 0) {
784 mappass->reqcopy = *req;
785 icsk = inet_csk(mappass->sock->sk);
786 queue = &icsk->icsk_accept_queue;
787 data = queue->rskq_accept_head != NULL;
789 mappass->reqcopy.cmd = 0;
793 spin_unlock_irqrestore(&mappass->copy_lock, flags);
795 /* Tell the caller we don't need to send back a notification yet */
799 spin_unlock_irqrestore(&mappass->copy_lock, flags);
801 rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);
802 rsp->req_id = req->req_id;
804 rsp->u.poll.id = req->u.poll.id;
809 static int pvcalls_back_handle_cmd(struct xenbus_device *dev,
810 struct xen_pvcalls_request *req)
816 ret = pvcalls_back_socket(dev, req);
818 case PVCALLS_CONNECT:
819 ret = pvcalls_back_connect(dev, req);
821 case PVCALLS_RELEASE:
822 ret = pvcalls_back_release(dev, req);
825 ret = pvcalls_back_bind(dev, req);
828 ret = pvcalls_back_listen(dev, req);
831 ret = pvcalls_back_accept(dev, req);
834 ret = pvcalls_back_poll(dev, req);
838 struct pvcalls_fedata *fedata;
839 struct xen_pvcalls_response *rsp;
841 fedata = dev_get_drvdata(&dev->dev);
842 rsp = RING_GET_RESPONSE(
843 &fedata->ring, fedata->ring.rsp_prod_pvt++);
844 rsp->req_id = req->req_id;
846 rsp->ret = -ENOTSUPP;
853 static void pvcalls_back_work(struct pvcalls_fedata *fedata)
855 int notify, notify_all = 0, more = 1;
856 struct xen_pvcalls_request req;
857 struct xenbus_device *dev = fedata->dev;
860 while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) {
861 RING_COPY_REQUEST(&fedata->ring,
862 fedata->ring.req_cons++,
865 if (!pvcalls_back_handle_cmd(dev, &req)) {
866 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(
867 &fedata->ring, notify);
868 notify_all += notify;
873 notify_remote_via_irq(fedata->irq);
877 RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more);
881 static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
883 struct xenbus_device *dev = dev_id;
884 struct pvcalls_fedata *fedata = NULL;
889 fedata = dev_get_drvdata(&dev->dev);
893 pvcalls_back_work(fedata);
897 static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
899 struct sock_mapping *map = sock_map;
900 struct pvcalls_ioworker *iow;
902 if (map == NULL || map->sock == NULL || map->sock->sk == NULL ||
903 map->sock->sk->sk_user_data != map)
906 iow = &map->ioworker;
908 atomic_inc(&map->write);
909 atomic_inc(&map->io);
910 queue_work(iow->wq, &iow->register_work);
915 static int backend_connect(struct xenbus_device *dev)
918 grant_ref_t ring_ref;
919 struct pvcalls_fedata *fedata = NULL;
921 fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL);
926 err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u",
930 xenbus_dev_fatal(dev, err, "reading %s/event-channel",
935 err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref);
938 xenbus_dev_fatal(dev, err, "reading %s/ring-ref",
943 err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn);
948 err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event,
949 IRQF_ONESHOT, "pvcalls-back", dev);
953 err = xenbus_map_ring_valloc(dev, &ring_ref, 1,
954 (void **)&fedata->sring);
958 BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1);
961 INIT_LIST_HEAD(&fedata->socket_mappings);
962 INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL);
963 sema_init(&fedata->socket_lock, 1);
964 dev_set_drvdata(&dev->dev, fedata);
966 down(&pvcalls_back_global.frontends_lock);
967 list_add_tail(&fedata->list, &pvcalls_back_global.frontends);
968 up(&pvcalls_back_global.frontends_lock);
973 if (fedata->irq >= 0)
974 unbind_from_irqhandler(fedata->irq, dev);
975 if (fedata->sring != NULL)
976 xenbus_unmap_ring_vfree(dev, fedata->sring);
981 static int backend_disconnect(struct xenbus_device *dev)
983 struct pvcalls_fedata *fedata;
984 struct sock_mapping *map, *n;
985 struct sockpass_mapping *mappass;
986 struct radix_tree_iter iter;
990 fedata = dev_get_drvdata(&dev->dev);
992 down(&fedata->socket_lock);
993 list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) {
994 list_del(&map->list);
995 pvcalls_back_release_active(dev, fedata, map);
998 radix_tree_for_each_slot(slot, &fedata->socketpass_mappings, &iter, 0) {
999 mappass = radix_tree_deref_slot(slot);
1002 if (radix_tree_exception(mappass)) {
1003 if (radix_tree_deref_retry(mappass))
1004 slot = radix_tree_iter_retry(&iter);
1006 radix_tree_delete(&fedata->socketpass_mappings,
1008 pvcalls_back_release_passive(dev, fedata, mappass);
1011 up(&fedata->socket_lock);
1013 unbind_from_irqhandler(fedata->irq, dev);
1014 xenbus_unmap_ring_vfree(dev, fedata->sring);
1016 list_del(&fedata->list);
1018 dev_set_drvdata(&dev->dev, NULL);
1023 static int pvcalls_back_probe(struct xenbus_device *dev,
1024 const struct xenbus_device_id *id)
1027 struct xenbus_transaction xbt;
1032 err = xenbus_transaction_start(&xbt);
1034 pr_warn("%s cannot create xenstore transaction\n", __func__);
1038 err = xenbus_printf(xbt, dev->nodename, "versions", "%s",
1041 pr_warn("%s write out 'versions' failed\n", __func__);
1045 err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u",
1048 pr_warn("%s write out 'max-page-order' failed\n", __func__);
1052 err = xenbus_printf(xbt, dev->nodename, "function-calls",
1053 XENBUS_FUNCTIONS_CALLS);
1055 pr_warn("%s write out 'function-calls' failed\n", __func__);
1061 err = xenbus_transaction_end(xbt, abort);
1063 if (err == -EAGAIN && !abort)
1065 pr_warn("%s cannot complete xenstore transaction\n", __func__);
1072 xenbus_switch_state(dev, XenbusStateInitWait);
1077 static void set_backend_state(struct xenbus_device *dev,
1078 enum xenbus_state state)
1080 while (dev->state != state) {
1081 switch (dev->state) {
1082 case XenbusStateClosed:
1084 case XenbusStateInitWait:
1085 case XenbusStateConnected:
1086 xenbus_switch_state(dev, XenbusStateInitWait);
1088 case XenbusStateClosing:
1089 xenbus_switch_state(dev, XenbusStateClosing);
1095 case XenbusStateInitWait:
1096 case XenbusStateInitialised:
1098 case XenbusStateConnected:
1099 backend_connect(dev);
1100 xenbus_switch_state(dev, XenbusStateConnected);
1102 case XenbusStateClosing:
1103 case XenbusStateClosed:
1104 xenbus_switch_state(dev, XenbusStateClosing);
1110 case XenbusStateConnected:
1112 case XenbusStateInitWait:
1113 case XenbusStateClosing:
1114 case XenbusStateClosed:
1115 down(&pvcalls_back_global.frontends_lock);
1116 backend_disconnect(dev);
1117 up(&pvcalls_back_global.frontends_lock);
1118 xenbus_switch_state(dev, XenbusStateClosing);
1124 case XenbusStateClosing:
1126 case XenbusStateInitWait:
1127 case XenbusStateConnected:
1128 case XenbusStateClosed:
1129 xenbus_switch_state(dev, XenbusStateClosed);
1141 static void pvcalls_back_changed(struct xenbus_device *dev,
1142 enum xenbus_state frontend_state)
1144 switch (frontend_state) {
1145 case XenbusStateInitialising:
1146 set_backend_state(dev, XenbusStateInitWait);
1149 case XenbusStateInitialised:
1150 case XenbusStateConnected:
1151 set_backend_state(dev, XenbusStateConnected);
1154 case XenbusStateClosing:
1155 set_backend_state(dev, XenbusStateClosing);
1158 case XenbusStateClosed:
1159 set_backend_state(dev, XenbusStateClosed);
1160 if (xenbus_dev_is_online(dev))
1162 device_unregister(&dev->dev);
1164 case XenbusStateUnknown:
1165 set_backend_state(dev, XenbusStateClosed);
1166 device_unregister(&dev->dev);
1170 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1176 static int pvcalls_back_remove(struct xenbus_device *dev)
1181 static int pvcalls_back_uevent(struct xenbus_device *xdev,
1182 struct kobj_uevent_env *env)
1187 static const struct xenbus_device_id pvcalls_back_ids[] = {
1192 static struct xenbus_driver pvcalls_back_driver = {
1193 .ids = pvcalls_back_ids,
1194 .probe = pvcalls_back_probe,
1195 .remove = pvcalls_back_remove,
1196 .uevent = pvcalls_back_uevent,
1197 .otherend_changed = pvcalls_back_changed,
1200 static int __init pvcalls_back_init(void)
1207 ret = xenbus_register_backend(&pvcalls_back_driver);
1211 sema_init(&pvcalls_back_global.frontends_lock, 1);
1212 INIT_LIST_HEAD(&pvcalls_back_global.frontends);
1215 module_init(pvcalls_back_init);
1217 static void __exit pvcalls_back_fin(void)
1219 struct pvcalls_fedata *fedata, *nfedata;
1221 down(&pvcalls_back_global.frontends_lock);
1222 list_for_each_entry_safe(fedata, nfedata,
1223 &pvcalls_back_global.frontends, list) {
1224 backend_disconnect(fedata->dev);
1226 up(&pvcalls_back_global.frontends_lock);
1228 xenbus_unregister_driver(&pvcalls_back_driver);
1231 module_exit(pvcalls_back_fin);
1233 MODULE_DESCRIPTION("Xen PV Calls backend driver");
1234 MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>");
1235 MODULE_LICENSE("GPL");