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);
290 kfree(printf_buffer);
296 * @dev: xenbus device
297 * @err: error to report
298 * @fmt: error message format
300 * Report the given negative errno into the store, along with the given
303 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...)
308 xenbus_va_dev_error(dev, err, fmt, ap);
311 EXPORT_SYMBOL_GPL(xenbus_dev_error);
315 * @dev: xenbus device
316 * @err: error to report
317 * @fmt: error message format
319 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
320 * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
321 * closedown of this driver and its peer.
324 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...)
329 xenbus_va_dev_error(dev, err, fmt, ap);
332 xenbus_switch_state(dev, XenbusStateClosing);
334 EXPORT_SYMBOL_GPL(xenbus_dev_fatal);
337 * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps
338 * avoiding recursion within xenbus_switch_state.
340 static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err,
341 const char *fmt, ...)
346 xenbus_va_dev_error(dev, err, fmt, ap);
350 __xenbus_switch_state(dev, XenbusStateClosing, 1);
355 * @dev: xenbus device
356 * @vaddr: starting virtual address of the ring
357 * @nr_pages: number of pages to be granted
358 * @grefs: grant reference array to be filled in
360 * Grant access to the given @vaddr to the peer of the given device.
361 * Then fill in @grefs with grant references. Return 0 on success, or
362 * -errno on error. On error, the device will switch to
363 * XenbusStateClosing, and the error will be saved in the store.
365 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
366 unsigned int nr_pages, grant_ref_t *grefs)
370 grant_ref_t gref_head;
372 err = gnttab_alloc_grant_references(nr_pages, &gref_head);
374 xenbus_dev_fatal(dev, err, "granting access to ring page");
378 for (i = 0; i < nr_pages; i++) {
381 if (is_vmalloc_addr(vaddr))
382 gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr));
384 gfn = virt_to_gfn(vaddr);
386 grefs[i] = gnttab_claim_grant_reference(&gref_head);
387 gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id,
390 vaddr = vaddr + XEN_PAGE_SIZE;
395 EXPORT_SYMBOL_GPL(xenbus_grant_ring);
399 * Allocate an event channel for the given xenbus_device, assigning the newly
400 * created local port to *port. Return 0 on success, or -errno on error. On
401 * error, the device will switch to XenbusStateClosing, and the error will be
402 * saved in the store.
404 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
406 struct evtchn_alloc_unbound alloc_unbound;
409 alloc_unbound.dom = DOMID_SELF;
410 alloc_unbound.remote_dom = dev->otherend_id;
412 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
415 xenbus_dev_fatal(dev, err, "allocating event channel");
417 *port = alloc_unbound.port;
421 EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
425 * Free an existing event channel. Returns 0 on success or -errno on error.
427 int xenbus_free_evtchn(struct xenbus_device *dev, int port)
429 struct evtchn_close close;
434 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
436 xenbus_dev_error(dev, err, "freeing event channel %d", port);
440 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
444 * xenbus_map_ring_valloc
445 * @dev: xenbus device
446 * @gnt_refs: grant reference array
447 * @nr_grefs: number of grant references
448 * @vaddr: pointer to address to be filled out by mapping
450 * Map @nr_grefs pages of memory into this domain from another
451 * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
452 * pages of virtual address space, maps the pages to that address, and
453 * sets *vaddr to that address. Returns 0 on success, and GNTST_*
454 * (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on
455 * error. If an error is returned, device will switch to
456 * XenbusStateClosing and the error message will be saved in XenStore.
458 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
459 unsigned int nr_grefs, void **vaddr)
463 err = ring_ops->map(dev, gnt_refs, nr_grefs, vaddr);
464 /* Some hypervisors are buggy and can return 1. */
466 err = GNTST_general_error;
470 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
472 /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
473 * long), e.g. 32-on-64. Caller is responsible for preparing the
474 * right array to feed into this function */
475 static int __xenbus_map_ring(struct xenbus_device *dev,
476 grant_ref_t *gnt_refs,
477 unsigned int nr_grefs,
478 grant_handle_t *handles,
483 struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS];
484 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
486 int err = GNTST_okay;
488 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
491 for (i = 0; i < nr_grefs; i++) {
492 memset(&map[i], 0, sizeof(map[i]));
493 gnttab_set_map_op(&map[i], addrs[i], flags, gnt_refs[i],
495 handles[i] = INVALID_GRANT_HANDLE;
498 gnttab_batch_map(map, i);
500 for (i = 0; i < nr_grefs; i++) {
501 if (map[i].status != GNTST_okay) {
503 xenbus_dev_fatal(dev, map[i].status,
504 "mapping in shared page %d from domain %d",
505 gnt_refs[i], dev->otherend_id);
508 handles[i] = map[i].handle;
514 for (i = j = 0; i < nr_grefs; i++) {
515 if (handles[i] != INVALID_GRANT_HANDLE) {
516 memset(&unmap[j], 0, sizeof(unmap[j]));
517 gnttab_set_unmap_op(&unmap[j], (phys_addr_t)addrs[i],
518 GNTMAP_host_map, handles[i]);
523 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, j))
527 for (i = 0; i < j; i++) {
528 if (unmap[i].status != GNTST_okay) {
537 struct map_ring_valloc_hvm
541 /* Why do we need two arrays? See comment of __xenbus_map_ring */
542 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
543 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
546 static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn,
547 unsigned int goffset,
551 struct map_ring_valloc_hvm *info = data;
552 unsigned long vaddr = (unsigned long)gfn_to_virt(gfn);
554 info->phys_addrs[info->idx] = vaddr;
555 info->addrs[info->idx] = vaddr;
560 static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
561 grant_ref_t *gnt_ref,
562 unsigned int nr_grefs,
565 struct xenbus_map_node *node;
569 struct map_ring_valloc_hvm info = {
572 unsigned int nr_pages = XENBUS_PAGES(nr_grefs);
574 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
579 node = kzalloc(sizeof(*node), GFP_KERNEL);
583 err = alloc_xenballooned_pages(nr_pages, node->hvm.pages);
587 gnttab_foreach_grant(node->hvm.pages, nr_grefs,
588 xenbus_map_ring_setup_grant_hvm,
591 err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
592 info.phys_addrs, GNTMAP_host_map, &leaked);
593 node->nr_handles = nr_grefs;
596 goto out_free_ballooned_pages;
598 addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP,
602 goto out_xenbus_unmap_ring;
605 node->hvm.addr = addr;
607 spin_lock(&xenbus_valloc_lock);
608 list_add(&node->next, &xenbus_valloc_pages);
609 spin_unlock(&xenbus_valloc_lock);
614 out_xenbus_unmap_ring:
616 xenbus_unmap_ring(dev, node->handles, nr_grefs, info.addrs);
618 pr_alert("leaking %p size %u page(s)",
620 out_free_ballooned_pages:
622 free_xenballooned_pages(nr_pages, node->hvm.pages);
631 * @dev: xenbus device
632 * @gnt_refs: grant reference array
633 * @nr_grefs: number of grant reference
634 * @handles: pointer to grant handle to be filled
635 * @vaddrs: addresses to be mapped to
636 * @leaked: fail to clean up a failed map, caller should not free vaddr
638 * Map pages of memory into this domain from another domain's grant table.
639 * xenbus_map_ring does not allocate the virtual address space (you must do
640 * this yourself!). It only maps in the pages to the specified address.
641 * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
642 * or -ENOMEM / -EINVAL on error. If an error is returned, device will switch to
643 * XenbusStateClosing and the first error message will be saved in XenStore.
644 * Further more if we fail to map the ring, caller should check @leaked.
645 * If @leaked is not zero it means xenbus_map_ring fails to clean up, caller
646 * should not free the address space of @vaddr.
648 int xenbus_map_ring(struct xenbus_device *dev, grant_ref_t *gnt_refs,
649 unsigned int nr_grefs, grant_handle_t *handles,
650 unsigned long *vaddrs, bool *leaked)
652 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
655 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
658 for (i = 0; i < nr_grefs; i++)
659 phys_addrs[i] = (unsigned long)vaddrs[i];
661 return __xenbus_map_ring(dev, gnt_refs, nr_grefs, handles,
662 phys_addrs, GNTMAP_host_map, leaked);
664 EXPORT_SYMBOL_GPL(xenbus_map_ring);
668 * xenbus_unmap_ring_vfree
669 * @dev: xenbus device
670 * @vaddr: addr to unmap
672 * Based on Rusty Russell's skeleton driver's unmap_page.
673 * Unmap a page of memory in this domain that was imported from another domain.
674 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
675 * xenbus_map_ring_valloc (it will free the virtual address space).
676 * Returns 0 on success and returns GNTST_* on error
677 * (see xen/include/interface/grant_table.h).
679 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
681 return ring_ops->unmap(dev, vaddr);
683 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
686 static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
687 grant_ref_t *gnt_refs,
688 unsigned int nr_grefs,
691 struct xenbus_map_node *node;
692 struct vm_struct *area;
693 pte_t *ptes[XENBUS_MAX_RING_GRANTS];
694 phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
695 int err = GNTST_okay;
701 if (nr_grefs > XENBUS_MAX_RING_GRANTS)
704 node = kzalloc(sizeof(*node), GFP_KERNEL);
708 area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, ptes);
714 for (i = 0; i < nr_grefs; i++)
715 phys_addrs[i] = arbitrary_virt_to_machine(ptes[i]).maddr;
717 err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
719 GNTMAP_host_map | GNTMAP_contains_pte,
724 node->nr_handles = nr_grefs;
725 node->pv.area = area;
727 spin_lock(&xenbus_valloc_lock);
728 list_add(&node->next, &xenbus_valloc_pages);
729 spin_unlock(&xenbus_valloc_lock);
738 pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
744 static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
746 struct xenbus_map_node *node;
747 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
753 spin_lock(&xenbus_valloc_lock);
754 list_for_each_entry(node, &xenbus_valloc_pages, next) {
755 if (node->pv.area->addr == vaddr) {
756 list_del(&node->next);
762 spin_unlock(&xenbus_valloc_lock);
765 xenbus_dev_error(dev, -ENOENT,
766 "can't find mapped virtual address %p", vaddr);
767 return GNTST_bad_virt_addr;
770 for (i = 0; i < node->nr_handles; i++) {
773 memset(&unmap[i], 0, sizeof(unmap[i]));
774 addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i);
775 unmap[i].host_addr = arbitrary_virt_to_machine(
776 lookup_address(addr, &level)).maddr;
777 unmap[i].dev_bus_addr = 0;
778 unmap[i].handle = node->handles[i];
781 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
786 for (i = 0; i < node->nr_handles; i++) {
787 if (unmap[i].status != GNTST_okay) {
789 xenbus_dev_error(dev, unmap[i].status,
790 "unmapping page at handle %d error %d",
791 node->handles[i], unmap[i].status);
792 err = unmap[i].status;
798 free_vm_area(node->pv.area);
800 pr_alert("leaking VM area %p size %u page(s)",
801 node->pv.area, node->nr_handles);
807 static const struct xenbus_ring_ops ring_ops_pv = {
808 .map = xenbus_map_ring_valloc_pv,
809 .unmap = xenbus_unmap_ring_vfree_pv,
813 struct unmap_ring_vfree_hvm
816 unsigned long addrs[XENBUS_MAX_RING_GRANTS];
819 static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn,
820 unsigned int goffset,
824 struct unmap_ring_vfree_hvm *info = data;
826 info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn);
831 static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
834 struct xenbus_map_node *node;
836 struct unmap_ring_vfree_hvm info = {
839 unsigned int nr_pages;
841 spin_lock(&xenbus_valloc_lock);
842 list_for_each_entry(node, &xenbus_valloc_pages, next) {
843 addr = node->hvm.addr;
845 list_del(&node->next);
851 spin_unlock(&xenbus_valloc_lock);
854 xenbus_dev_error(dev, -ENOENT,
855 "can't find mapped virtual address %p", vaddr);
856 return GNTST_bad_virt_addr;
859 nr_pages = XENBUS_PAGES(node->nr_handles);
861 gnttab_foreach_grant(node->hvm.pages, node->nr_handles,
862 xenbus_unmap_ring_setup_grant_hvm,
865 rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
869 free_xenballooned_pages(nr_pages, node->hvm.pages);
872 WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages);
880 * @dev: xenbus device
881 * @handles: grant handle array
882 * @nr_handles: number of handles in the array
883 * @vaddrs: addresses to unmap
885 * Unmap memory in this domain that was imported from another domain.
886 * Returns 0 on success and returns GNTST_* on error
887 * (see xen/include/interface/grant_table.h).
889 int xenbus_unmap_ring(struct xenbus_device *dev,
890 grant_handle_t *handles, unsigned int nr_handles,
891 unsigned long *vaddrs)
893 struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
897 if (nr_handles > XENBUS_MAX_RING_GRANTS)
900 for (i = 0; i < nr_handles; i++)
901 gnttab_set_unmap_op(&unmap[i], vaddrs[i],
902 GNTMAP_host_map, handles[i]);
904 if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
908 for (i = 0; i < nr_handles; i++) {
909 if (unmap[i].status != GNTST_okay) {
910 xenbus_dev_error(dev, unmap[i].status,
911 "unmapping page at handle %d error %d",
912 handles[i], unmap[i].status);
913 err = unmap[i].status;
920 EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
924 * xenbus_read_driver_state
925 * @path: path for driver
927 * Return the state of the driver rooted at the given store path, or
928 * XenbusStateUnknown if no state can be read.
930 enum xenbus_state xenbus_read_driver_state(const char *path)
932 enum xenbus_state result;
933 int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
935 result = XenbusStateUnknown;
939 EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
941 static const struct xenbus_ring_ops ring_ops_hvm = {
942 .map = xenbus_map_ring_valloc_hvm,
943 .unmap = xenbus_unmap_ring_vfree_hvm,
946 void __init xenbus_ring_ops_init(void)
949 if (!xen_feature(XENFEAT_auto_translated_physmap))
950 ring_ops = &ring_ops_pv;
953 ring_ops = &ring_ops_hvm;