1 /******************************************************************************
2 * Client-facing interface for the Xenbus driver. In other words, the
3 * interface between the Xenbus and the device-specific code, be it the
4 * frontend or the backend of that driver.
6 * Copyright (C) 2005 XenSource Ltd
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version 2
10 * as published by the Free Software Foundation; or, when distributed
11 * separately from the Linux kernel or incorporated into other
12 * software packages, subject to the following license:
14 * Permission is hereby granted, free of charge, to any person obtaining a copy
15 * of this source file (the "Software"), to deal in the Software without
16 * restriction, including without limitation the rights to use, copy, modify,
17 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18 * and to permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
21 * The above copyright notice and this permission notice shall be included in
22 * all copies or substantial portions of the Software.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
34 #include <linux/slab.h>
35 #include <linux/types.h>
36 #include <linux/spinlock.h>
37 #include <linux/vmalloc.h>
38 #include <linux/export.h>
39 #include <asm/xen/hypervisor.h>
41 #include <xen/interface/xen.h>
42 #include <xen/interface/event_channel.h>
43 #include <xen/balloon.h>
44 #include <xen/events.h>
45 #include <xen/grant_table.h>
46 #include <xen/xenbus.h>
48 #include <xen/features.h>
52 #define XENBUS_PAGES(_grants) (DIV_ROUND_UP(_grants, XEN_PFN_PER_PAGE))
54 #define XENBUS_MAX_RING_PAGES (XENBUS_PAGES(XENBUS_MAX_RING_GRANTS))
56 struct xenbus_map_node {
57 struct list_head next;
60 struct vm_struct *area;
63 struct page *pages[XENBUS_MAX_RING_PAGES];
64 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
68 grant_handle_t handles[XENBUS_MAX_RING_GRANTS];
69 unsigned int nr_handles;
72 static DEFINE_SPINLOCK(xenbus_valloc_lock);
73 static LIST_HEAD(xenbus_valloc_pages);
75 struct xenbus_ring_ops {
76 int (*map)(struct xenbus_device *dev,
77 grant_ref_t *gnt_refs, unsigned int nr_grefs,
79 int (*unmap)(struct xenbus_device *dev, void *vaddr);
82 static const struct xenbus_ring_ops *ring_ops __read_mostly;
84 const char *xenbus_strstate(enum xenbus_state state)
86 static const char *const name[] = {
87 [ XenbusStateUnknown ] = "Unknown",
88 [ XenbusStateInitialising ] = "Initialising",
89 [ XenbusStateInitWait ] = "InitWait",
90 [ XenbusStateInitialised ] = "Initialised",
91 [ XenbusStateConnected ] = "Connected",
92 [ XenbusStateClosing ] = "Closing",
93 [ XenbusStateClosed ] = "Closed",
94 [XenbusStateReconfiguring] = "Reconfiguring",
95 [XenbusStateReconfigured] = "Reconfigured",
97 return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
99 EXPORT_SYMBOL_GPL(xenbus_strstate);
102 * xenbus_watch_path - register a watch
103 * @dev: xenbus device
104 * @path: path to watch
105 * @watch: watch to register
106 * @callback: callback to register
108 * Register a @watch on the given path, using the given xenbus_watch structure
109 * for storage, and the given @callback function as the callback. Return 0 on
110 * success, or -errno on error. On success, the given @path will be saved as
111 * @watch->node, and remains the caller's to free. On error, @watch->node will
112 * be NULL, the device will switch to %XenbusStateClosing, and the error will
113 * be saved in the store.
115 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
116 struct xenbus_watch *watch,
117 bool (*will_handle)(struct xenbus_watch *,
118 const char *, const char *),
119 void (*callback)(struct xenbus_watch *,
120 const char *, const char *))
125 watch->will_handle = will_handle;
126 watch->callback = callback;
128 err = register_xenbus_watch(watch);
132 watch->will_handle = NULL;
133 watch->callback = NULL;
134 xenbus_dev_fatal(dev, err, "adding watch on %s", path);
139 EXPORT_SYMBOL_GPL(xenbus_watch_path);
143 * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path
144 * @dev: xenbus device
145 * @watch: watch to register
146 * @callback: callback to register
147 * @pathfmt: format of path to watch
149 * Register a watch on the given @path, using the given xenbus_watch
150 * structure for storage, and the given @callback function as the callback.
151 * Return 0 on success, or -errno on error. On success, the watched path
152 * (@path/@path2) will be saved as @watch->node, and becomes the caller's to
153 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
154 * free, the device will switch to %XenbusStateClosing, and the error will be
155 * saved in the store.
157 int xenbus_watch_pathfmt(struct xenbus_device *dev,
158 struct xenbus_watch *watch,
159 bool (*will_handle)(struct xenbus_watch *,
160 const char *, const char *),
161 void (*callback)(struct xenbus_watch *,
162 const char *, const char *),
163 const char *pathfmt, ...)
169 va_start(ap, pathfmt);
170 path = kvasprintf(GFP_NOIO | __GFP_HIGH, pathfmt, ap);
174 xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
177 err = xenbus_watch_path(dev, path, watch, will_handle, callback);
183 EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
185 static void xenbus_switch_fatal(struct xenbus_device *, int, int,
189 __xenbus_switch_state(struct xenbus_device *dev,
190 enum xenbus_state state, int depth)
192 /* We check whether the state is currently set to the given value, and
193 if not, then the state is set. We don't want to unconditionally
194 write the given state, because we don't want to fire watches
195 unnecessarily. Furthermore, if the node has gone, we don't write
196 to it, as the device will be tearing down, and we don't want to
197 resurrect that directory.
199 Note that, because of this cached value of our state, this
200 function will not take a caller's Xenstore transaction
201 (something it was trying to in the past) because dev->state
202 would not get reset if the transaction was aborted.
205 struct xenbus_transaction xbt;
209 if (state == dev->state)
215 err = xenbus_transaction_start(&xbt);
217 xenbus_switch_fatal(dev, depth, err, "starting transaction");
221 err = xenbus_scanf(xbt, dev->nodename, "state", "%d", ¤t_state);
225 err = xenbus_printf(xbt, dev->nodename, "state", "%d", state);
227 xenbus_switch_fatal(dev, depth, err, "writing new state");
233 err = xenbus_transaction_end(xbt, abort);
235 if (err == -EAGAIN && !abort)
237 xenbus_switch_fatal(dev, depth, err, "ending transaction");
245 * xenbus_switch_state
246 * @dev: xenbus device
249 * Advertise in the store a change of the given driver to the given new_state.
250 * Return 0 on success, or -errno on error. On error, the device will switch
251 * to XenbusStateClosing, and the error will be saved in the store.
253 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state)
255 return __xenbus_switch_state(dev, state, 0);
258 EXPORT_SYMBOL_GPL(xenbus_switch_state);
260 int xenbus_frontend_closed(struct xenbus_device *dev)
262 xenbus_switch_state(dev, XenbusStateClosed);
263 complete(&dev->down);
266 EXPORT_SYMBOL_GPL(xenbus_frontend_closed);
268 static void xenbus_va_dev_error(struct xenbus_device *dev, int err,
269 const char *fmt, va_list ap)
275 #define PRINTF_BUFFER_SIZE 4096
277 printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL);
281 len = sprintf(printf_buffer, "%i ", -err);
282 vsnprintf(printf_buffer + len, PRINTF_BUFFER_SIZE - len, fmt, ap);
284 dev_err(&dev->dev, "%s\n", printf_buffer);
286 path_buffer = kasprintf(GFP_KERNEL, "error/%s", dev->nodename);
288 xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer))
289 dev_err(&dev->dev, "failed to write error node for %s (%s)\n",
290 dev->nodename, printf_buffer);
292 kfree(printf_buffer);
298 * @dev: xenbus device
299 * @err: error to report
300 * @fmt: error message format
302 * Report the given negative errno into the store, along with the given
305 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...)
310 xenbus_va_dev_error(dev, err, fmt, ap);
313 EXPORT_SYMBOL_GPL(xenbus_dev_error);
317 * @dev: xenbus device
318 * @err: error to report
319 * @fmt: error message format
321 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
322 * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
323 * closedown of this driver and its peer.
326 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...)
331 xenbus_va_dev_error(dev, err, fmt, ap);
334 xenbus_switch_state(dev, XenbusStateClosing);
336 EXPORT_SYMBOL_GPL(xenbus_dev_fatal);
339 * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps
340 * avoiding recursion within xenbus_switch_state.
342 static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err,
343 const char *fmt, ...)
348 xenbus_va_dev_error(dev, err, fmt, ap);
352 __xenbus_switch_state(dev, XenbusStateClosing, 1);
357 * @dev: xenbus device
358 * @vaddr: starting virtual address of the ring
359 * @nr_pages: number of pages to be granted
360 * @grefs: grant reference array to be filled in
362 * Grant access to the given @vaddr to the peer of the given device.
363 * Then fill in @grefs with grant references. Return 0 on success, or
364 * -errno on error. On error, the device will switch to
365 * XenbusStateClosing, and the error will be saved in the store.
367 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
368 unsigned int nr_pages, grant_ref_t *grefs)
372 grant_ref_t gref_head;
374 err = gnttab_alloc_grant_references(nr_pages, &gref_head);
376 xenbus_dev_fatal(dev, err, "granting access to ring page");
380 for (i = 0; i < nr_pages; i++) {
383 if (is_vmalloc_addr(vaddr))
384 gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr));
386 gfn = virt_to_gfn(vaddr);
388 grefs[i] = gnttab_claim_grant_reference(&gref_head);
389 gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
392 vaddr = vaddr + XEN_PAGE_SIZE;
397 EXPORT_SYMBOL_GPL(xenbus_grant_ring);
401 * Allocate an event channel for the given xenbus_device, assigning the newly
402 * created local port to *port. Return 0 on success, or -errno on error. On
403 * error, the device will switch to XenbusStateClosing, and the error will be
404 * saved in the store.
406 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
408 struct evtchn_alloc_unbound alloc_unbound;
411 alloc_unbound.dom = DOMID_SELF;
412 alloc_unbound.remote_dom = dev->otherend_id;
414 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
417 xenbus_dev_fatal(dev, err, "allocating event channel");
419 *port = alloc_unbound.port;
423 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
427 * Free an existing event channel. Returns 0 on success or -errno on error.
429 int xenbus_free_evtchn(struct xenbus_device *dev, int port)
431 struct evtchn_close close;
436 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
438 xenbus_dev_error(dev, err, "freeing event channel %d", port);
442 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
446 * xenbus_map_ring_valloc
447 * @dev: xenbus device
448 * @gnt_refs: grant reference array
449 * @nr_grefs: number of grant references
450 * @vaddr: pointer to address to be filled out by mapping
452 * Map @nr_grefs pages of memory into this domain from another
453 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
454 * pages of virtual address space, maps the pages to that address, and
455 * sets *vaddr to that address. Returns 0 on success, and GNTST_*
456 * (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on
457 * error. If an error is returned, device will switch to
458 * XenbusStateClosing and the error message will be saved in XenStore.
460 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
461 unsigned int nr_grefs, void **vaddr)
465 err = ring_ops->map(dev, gnt_refs, nr_grefs, vaddr);
466 /* Some hypervisors are buggy and can return 1. */
468 err = GNTST_general_error;
472 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
474 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
475 * long), e.g. 32-on-64. Caller is responsible for preparing the
476 * right array to feed into this function */
477 static int __xenbus_map_ring(struct xenbus_device *dev,
478 grant_ref_t *gnt_refs,
479 unsigned int nr_grefs,
480 grant_handle_t *handles,
485 struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS];
486 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
488 int err = GNTST_okay;
490 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
493 for (i = 0; i < nr_grefs; i++) {
494 memset(&map[i], 0, sizeof(map[i]));
495 gnttab_set_map_op(&map[i], addrs[i], flags, gnt_refs[i],
497 handles[i] = INVALID_GRANT_HANDLE;
500 gnttab_batch_map(map, i);
502 for (i = 0; i < nr_grefs; i++) {
503 if (map[i].status != GNTST_okay) {
505 xenbus_dev_fatal(dev, map[i].status,
506 "mapping in shared page %d from domain %d",
507 gnt_refs[i], dev->otherend_id);
510 handles[i] = map[i].handle;
516 for (i = j = 0; i < nr_grefs; i++) {
517 if (handles[i] != INVALID_GRANT_HANDLE) {
518 memset(&unmap[j], 0, sizeof(unmap[j]));
519 gnttab_set_unmap_op(&unmap[j], (phys_addr_t)addrs[i],
520 GNTMAP_host_map, handles[i]);
525 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, j))
529 for (i = 0; i < j; i++) {
530 if (unmap[i].status != GNTST_okay) {
539 struct map_ring_valloc_hvm
543 /* Why do we need two arrays? See comment of __xenbus_map_ring */
544 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
545 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
548 static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn,
549 unsigned int goffset,
553 struct map_ring_valloc_hvm *info = data;
554 unsigned long vaddr = (unsigned long)gfn_to_virt(gfn);
556 info->phys_addrs[info->idx] = vaddr;
557 info->addrs[info->idx] = vaddr;
562 static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
563 grant_ref_t *gnt_ref,
564 unsigned int nr_grefs,
567 struct xenbus_map_node *node;
571 struct map_ring_valloc_hvm info = {
574 unsigned int nr_pages = XENBUS_PAGES(nr_grefs);
576 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
581 node = kzalloc(sizeof(*node), GFP_KERNEL);
585 err = alloc_xenballooned_pages(nr_pages, node->hvm.pages);
589 gnttab_foreach_grant(node->hvm.pages, nr_grefs,
590 xenbus_map_ring_setup_grant_hvm,
593 err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
594 info.phys_addrs, GNTMAP_host_map, &leaked);
595 node->nr_handles = nr_grefs;
598 goto out_free_ballooned_pages;
600 addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP,
604 goto out_xenbus_unmap_ring;
607 node->hvm.addr = addr;
609 spin_lock(&xenbus_valloc_lock);
610 list_add(&node->next, &xenbus_valloc_pages);
611 spin_unlock(&xenbus_valloc_lock);
616 out_xenbus_unmap_ring:
618 xenbus_unmap_ring(dev, node->handles, nr_grefs, info.addrs);
620 pr_alert("leaking %p size %u page(s)",
622 out_free_ballooned_pages:
624 free_xenballooned_pages(nr_pages, node->hvm.pages);
633 * @dev: xenbus device
634 * @gnt_refs: grant reference array
635 * @nr_grefs: number of grant reference
636 * @handles: pointer to grant handle to be filled
637 * @vaddrs: addresses to be mapped to
638 * @leaked: fail to clean up a failed map, caller should not free vaddr
640 * Map pages of memory into this domain from another domain's grant table.
641 * xenbus_map_ring does not allocate the virtual address space (you must do
642 * this yourself!). It only maps in the pages to the specified address.
643 * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
644 * or -ENOMEM / -EINVAL on error. If an error is returned, device will switch to
645 * XenbusStateClosing and the first error message will be saved in XenStore.
646 * Further more if we fail to map the ring, caller should check @leaked.
647 * If @leaked is not zero it means xenbus_map_ring fails to clean up, caller
648 * should not free the address space of @vaddr.
650 int xenbus_map_ring(struct xenbus_device *dev, grant_ref_t *gnt_refs,
651 unsigned int nr_grefs, grant_handle_t *handles,
652 unsigned long *vaddrs, bool *leaked)
654 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
657 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
660 for (i = 0; i < nr_grefs; i++)
661 phys_addrs[i] = (unsigned long)vaddrs[i];
663 return __xenbus_map_ring(dev, gnt_refs, nr_grefs, handles,
664 phys_addrs, GNTMAP_host_map, leaked);
666 EXPORT_SYMBOL_GPL(xenbus_map_ring);
670 * xenbus_unmap_ring_vfree
671 * @dev: xenbus device
672 * @vaddr: addr to unmap
674 * Based on Rusty Russell's skeleton driver's unmap_page.
675 * Unmap a page of memory in this domain that was imported from another domain.
676 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
677 * xenbus_map_ring_valloc (it will free the virtual address space).
678 * Returns 0 on success and returns GNTST_* on error
679 * (see xen/include/interface/grant_table.h).
681 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
683 return ring_ops->unmap(dev, vaddr);
685 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
688 static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
689 grant_ref_t *gnt_refs,
690 unsigned int nr_grefs,
693 struct xenbus_map_node *node;
694 struct vm_struct *area;
695 pte_t *ptes[XENBUS_MAX_RING_GRANTS];
696 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
697 int err = GNTST_okay;
703 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
706 node = kzalloc(sizeof(*node), GFP_KERNEL);
710 area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, ptes);
716 for (i = 0; i < nr_grefs; i++)
717 phys_addrs[i] = arbitrary_virt_to_machine(ptes[i]).maddr;
719 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
721 GNTMAP_host_map | GNTMAP_contains_pte,
726 node->nr_handles = nr_grefs;
727 node->pv.area = area;
729 spin_lock(&xenbus_valloc_lock);
730 list_add(&node->next, &xenbus_valloc_pages);
731 spin_unlock(&xenbus_valloc_lock);
740 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
746 static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
748 struct xenbus_map_node *node;
749 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
755 spin_lock(&xenbus_valloc_lock);
756 list_for_each_entry(node, &xenbus_valloc_pages, next) {
757 if (node->pv.area->addr == vaddr) {
758 list_del(&node->next);
764 spin_unlock(&xenbus_valloc_lock);
767 xenbus_dev_error(dev, -ENOENT,
768 "can't find mapped virtual address %p", vaddr);
769 return GNTST_bad_virt_addr;
772 for (i = 0; i < node->nr_handles; i++) {
775 memset(&unmap[i], 0, sizeof(unmap[i]));
776 addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i);
777 unmap[i].host_addr = arbitrary_virt_to_machine(
778 lookup_address(addr, &level)).maddr;
779 unmap[i].dev_bus_addr = 0;
780 unmap[i].handle = node->handles[i];
783 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
788 for (i = 0; i < node->nr_handles; i++) {
789 if (unmap[i].status != GNTST_okay) {
791 xenbus_dev_error(dev, unmap[i].status,
792 "unmapping page at handle %d error %d",
793 node->handles[i], unmap[i].status);
794 err = unmap[i].status;
800 free_vm_area(node->pv.area);
802 pr_alert("leaking VM area %p size %u page(s)",
803 node->pv.area, node->nr_handles);
809 static const struct xenbus_ring_ops ring_ops_pv = {
810 .map = xenbus_map_ring_valloc_pv,
811 .unmap = xenbus_unmap_ring_vfree_pv,
815 struct unmap_ring_vfree_hvm
818 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
821 static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn,
822 unsigned int goffset,
826 struct unmap_ring_vfree_hvm *info = data;
828 info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn);
833 static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
836 struct xenbus_map_node *node;
838 struct unmap_ring_vfree_hvm info = {
841 unsigned int nr_pages;
843 spin_lock(&xenbus_valloc_lock);
844 list_for_each_entry(node, &xenbus_valloc_pages, next) {
845 addr = node->hvm.addr;
847 list_del(&node->next);
853 spin_unlock(&xenbus_valloc_lock);
856 xenbus_dev_error(dev, -ENOENT,
857 "can't find mapped virtual address %p", vaddr);
858 return GNTST_bad_virt_addr;
861 nr_pages = XENBUS_PAGES(node->nr_handles);
863 gnttab_foreach_grant(node->hvm.pages, node->nr_handles,
864 xenbus_unmap_ring_setup_grant_hvm,
867 rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
871 free_xenballooned_pages(nr_pages, node->hvm.pages);
874 WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages);
882 * @dev: xenbus device
883 * @handles: grant handle array
884 * @nr_handles: number of handles in the array
885 * @vaddrs: addresses to unmap
887 * Unmap memory in this domain that was imported from another domain.
888 * Returns 0 on success and returns GNTST_* on error
889 * (see xen/include/interface/grant_table.h).
891 int xenbus_unmap_ring(struct xenbus_device *dev,
892 grant_handle_t *handles, unsigned int nr_handles,
893 unsigned long *vaddrs)
895 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
899 if (nr_handles > XENBUS_MAX_RING_GRANTS)
902 for (i = 0; i < nr_handles; i++)
903 gnttab_set_unmap_op(&unmap[i], vaddrs[i],
904 GNTMAP_host_map, handles[i]);
906 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
910 for (i = 0; i < nr_handles; i++) {
911 if (unmap[i].status != GNTST_okay) {
912 xenbus_dev_error(dev, unmap[i].status,
913 "unmapping page at handle %d error %d",
914 handles[i], unmap[i].status);
915 err = unmap[i].status;
922 EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
926 * xenbus_read_driver_state
927 * @path: path for driver
929 * Return the state of the driver rooted at the given store path, or
930 * XenbusStateUnknown if no state can be read.
932 enum xenbus_state xenbus_read_driver_state(const char *path)
934 enum xenbus_state result;
935 int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
937 result = XenbusStateUnknown;
941 EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
943 static const struct xenbus_ring_ops ring_ops_hvm = {
944 .map = xenbus_map_ring_valloc_hvm,
945 .unmap = xenbus_unmap_ring_vfree_hvm,
948 void __init xenbus_ring_ops_init(void)
951 if (!xen_feature(XENFEAT_auto_translated_physmap))
952 ring_ops = &ring_ops_pv;
955 ring_ops = &ring_ops_hvm;