1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 2012 VMware, Inc. All rights reserved.
8 #include <linux/vmw_vmci_defs.h>
9 #include <linux/vmw_vmci_api.h>
10 #include <linux/highmem.h>
11 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/pagemap.h>
16 #include <linux/pci.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/uio.h>
20 #include <linux/wait.h>
21 #include <linux/vmalloc.h>
22 #include <linux/skbuff.h>
24 #include "vmci_handle_array.h"
25 #include "vmci_queue_pair.h"
26 #include "vmci_datagram.h"
27 #include "vmci_resource.h"
28 #include "vmci_context.h"
29 #include "vmci_driver.h"
30 #include "vmci_event.h"
31 #include "vmci_route.h"
34 * In the following, we will distinguish between two kinds of VMX processes -
35 * the ones with versions lower than VMCI_VERSION_NOVMVM that use specialized
36 * VMCI page files in the VMX and supporting VM to VM communication and the
37 * newer ones that use the guest memory directly. We will in the following
38 * refer to the older VMX versions as old-style VMX'en, and the newer ones as
41 * The state transition datagram is as follows (the VMCIQPB_ prefix has been
42 * removed for readability) - see below for more details on the transtions:
44 * -------------- NEW -------------
47 * CREATED_NO_MEM <-----------------> CREATED_MEM
49 * | o-----------------------o |
52 * ATTACHED_NO_MEM <----------------> ATTACHED_MEM
54 * | o----------------------o |
57 * SHUTDOWN_NO_MEM <----------------> SHUTDOWN_MEM
60 * -------------> gone <-------------
62 * In more detail. When a VMCI queue pair is first created, it will be in the
63 * VMCIQPB_NEW state. It will then move into one of the following states:
65 * - VMCIQPB_CREATED_NO_MEM: this state indicates that either:
67 * - the created was performed by a host endpoint, in which case there is
68 * no backing memory yet.
70 * - the create was initiated by an old-style VMX, that uses
71 * vmci_qp_broker_set_page_store to specify the UVAs of the queue pair at
72 * a later point in time. This state can be distinguished from the one
73 * above by the context ID of the creator. A host side is not allowed to
74 * attach until the page store has been set.
76 * - VMCIQPB_CREATED_MEM: this state is the result when the queue pair
77 * is created by a VMX using the queue pair device backend that
78 * sets the UVAs of the queue pair immediately and stores the
79 * information for later attachers. At this point, it is ready for
80 * the host side to attach to it.
82 * Once the queue pair is in one of the created states (with the exception of
83 * the case mentioned for older VMX'en above), it is possible to attach to the
84 * queue pair. Again we have two new states possible:
86 * - VMCIQPB_ATTACHED_MEM: this state can be reached through the following
89 * - from VMCIQPB_CREATED_NO_MEM when a new-style VMX allocates a queue
90 * pair, and attaches to a queue pair previously created by the host side.
92 * - from VMCIQPB_CREATED_MEM when the host side attaches to a queue pair
93 * already created by a guest.
95 * - from VMCIQPB_ATTACHED_NO_MEM, when an old-style VMX calls
96 * vmci_qp_broker_set_page_store (see below).
98 * - VMCIQPB_ATTACHED_NO_MEM: If the queue pair already was in the
99 * VMCIQPB_CREATED_NO_MEM due to a host side create, an old-style VMX will
100 * bring the queue pair into this state. Once vmci_qp_broker_set_page_store
101 * is called to register the user memory, the VMCIQPB_ATTACH_MEM state
104 * From the attached queue pair, the queue pair can enter the shutdown states
105 * when either side of the queue pair detaches. If the guest side detaches
106 * first, the queue pair will enter the VMCIQPB_SHUTDOWN_NO_MEM state, where
107 * the content of the queue pair will no longer be available. If the host
108 * side detaches first, the queue pair will either enter the
109 * VMCIQPB_SHUTDOWN_MEM, if the guest memory is currently mapped, or
110 * VMCIQPB_SHUTDOWN_NO_MEM, if the guest memory is not mapped
111 * (e.g., the host detaches while a guest is stunned).
113 * New-style VMX'en will also unmap guest memory, if the guest is
114 * quiesced, e.g., during a snapshot operation. In that case, the guest
115 * memory will no longer be available, and the queue pair will transition from
116 * *_MEM state to a *_NO_MEM state. The VMX may later map the memory once more,
117 * in which case the queue pair will transition from the *_NO_MEM state at that
118 * point back to the *_MEM state. Note that the *_NO_MEM state may have changed,
119 * since the peer may have either attached or detached in the meantime. The
120 * values are laid out such that ++ on a state will move from a *_NO_MEM to a
121 * *_MEM state, and vice versa.
124 /* The Kernel specific component of the struct vmci_queue structure. */
125 struct vmci_queue_kern_if {
126 struct mutex __mutex; /* Protects the queue. */
127 struct mutex *mutex; /* Shared by producer and consumer queues. */
128 size_t num_pages; /* Number of pages incl. header. */
129 bool host; /* Host or guest? */
134 } g; /* Used by the guest. */
137 struct page **header_page;
138 } h; /* Used by the host. */
143 * This structure is opaque to the clients.
146 struct vmci_handle handle;
147 struct vmci_queue *produce_q;
148 struct vmci_queue *consume_q;
155 unsigned int blocked;
156 unsigned int generation;
157 wait_queue_head_t event;
160 enum qp_broker_state {
162 VMCIQPB_CREATED_NO_MEM,
164 VMCIQPB_ATTACHED_NO_MEM,
165 VMCIQPB_ATTACHED_MEM,
166 VMCIQPB_SHUTDOWN_NO_MEM,
167 VMCIQPB_SHUTDOWN_MEM,
171 #define QPBROKERSTATE_HAS_MEM(_qpb) (_qpb->state == VMCIQPB_CREATED_MEM || \
172 _qpb->state == VMCIQPB_ATTACHED_MEM || \
173 _qpb->state == VMCIQPB_SHUTDOWN_MEM)
176 * In the queue pair broker, we always use the guest point of view for
177 * the produce and consume queue values and references, e.g., the
178 * produce queue size stored is the guests produce queue size. The
179 * host endpoint will need to swap these around. The only exception is
180 * the local queue pairs on the host, in which case the host endpoint
181 * that creates the queue pair will have the right orientation, and
182 * the attaching host endpoint will need to swap.
185 struct list_head list_item;
186 struct vmci_handle handle;
194 struct qp_broker_entry {
195 struct vmci_resource resource;
199 enum qp_broker_state state;
200 bool require_trusted_attach;
201 bool created_by_trusted;
202 bool vmci_page_files; /* Created by VMX using VMCI page files */
203 struct vmci_queue *produce_q;
204 struct vmci_queue *consume_q;
205 struct vmci_queue_header saved_produce_q;
206 struct vmci_queue_header saved_consume_q;
207 vmci_event_release_cb wakeup_cb;
209 void *local_mem; /* Kernel memory for local queue pair */
212 struct qp_guest_endpoint {
213 struct vmci_resource resource;
218 struct ppn_set ppn_set;
222 struct list_head head;
223 struct mutex mutex; /* Protect queue list. */
226 static struct qp_list qp_broker_list = {
227 .head = LIST_HEAD_INIT(qp_broker_list.head),
228 .mutex = __MUTEX_INITIALIZER(qp_broker_list.mutex),
231 static struct qp_list qp_guest_endpoints = {
232 .head = LIST_HEAD_INIT(qp_guest_endpoints.head),
233 .mutex = __MUTEX_INITIALIZER(qp_guest_endpoints.mutex),
236 #define INVALID_VMCI_GUEST_MEM_ID 0
237 #define QPE_NUM_PAGES(_QPE) ((u32) \
238 (DIV_ROUND_UP(_QPE.produce_size, PAGE_SIZE) + \
239 DIV_ROUND_UP(_QPE.consume_size, PAGE_SIZE) + 2))
243 * Frees kernel VA space for a given queue and its queue header, and
244 * frees physical data pages.
246 static void qp_free_queue(void *q, u64 size)
248 struct vmci_queue *queue = q;
253 /* Given size does not include header, so add in a page here. */
254 for (i = 0; i < DIV_ROUND_UP(size, PAGE_SIZE) + 1; i++) {
255 dma_free_coherent(&vmci_pdev->dev, PAGE_SIZE,
256 queue->kernel_if->u.g.vas[i],
257 queue->kernel_if->u.g.pas[i]);
265 * Allocates kernel queue pages of specified size with IOMMU mappings,
266 * plus space for the queue structure/kernel interface and the queue
269 static void *qp_alloc_queue(u64 size, u32 flags)
272 struct vmci_queue *queue;
275 size_t queue_size = sizeof(*queue) + sizeof(*queue->kernel_if);
278 if (size > SIZE_MAX - PAGE_SIZE)
280 num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
282 (SIZE_MAX - queue_size) /
283 (sizeof(*queue->kernel_if->u.g.pas) +
284 sizeof(*queue->kernel_if->u.g.vas)))
287 pas_size = num_pages * sizeof(*queue->kernel_if->u.g.pas);
288 vas_size = num_pages * sizeof(*queue->kernel_if->u.g.vas);
289 queue_size += pas_size + vas_size;
291 queue = vmalloc(queue_size);
295 queue->q_header = NULL;
296 queue->saved_header = NULL;
297 queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1);
298 queue->kernel_if->mutex = NULL;
299 queue->kernel_if->num_pages = num_pages;
300 queue->kernel_if->u.g.pas = (dma_addr_t *)(queue->kernel_if + 1);
301 queue->kernel_if->u.g.vas =
302 (void **)((u8 *)queue->kernel_if->u.g.pas + pas_size);
303 queue->kernel_if->host = false;
305 for (i = 0; i < num_pages; i++) {
306 queue->kernel_if->u.g.vas[i] =
307 dma_alloc_coherent(&vmci_pdev->dev, PAGE_SIZE,
308 &queue->kernel_if->u.g.pas[i],
310 if (!queue->kernel_if->u.g.vas[i]) {
311 /* Size excl. the header. */
312 qp_free_queue(queue, i * PAGE_SIZE);
317 /* Queue header is the first page. */
318 queue->q_header = queue->kernel_if->u.g.vas[0];
324 * Copies from a given buffer or iovector to a VMCI Queue. Uses
325 * kmap()/kunmap() to dynamically map/unmap required portions of the queue
326 * by traversing the offset -> page translation structure for the queue.
327 * Assumes that offset + size does not wrap around in the queue.
329 static int qp_memcpy_to_queue_iter(struct vmci_queue *queue,
331 struct iov_iter *from,
334 struct vmci_queue_kern_if *kernel_if = queue->kernel_if;
335 size_t bytes_copied = 0;
337 while (bytes_copied < size) {
338 const u64 page_index =
339 (queue_offset + bytes_copied) / PAGE_SIZE;
340 const size_t page_offset =
341 (queue_offset + bytes_copied) & (PAGE_SIZE - 1);
346 va = kmap(kernel_if->u.h.page[page_index]);
348 va = kernel_if->u.g.vas[page_index + 1];
351 if (size - bytes_copied > PAGE_SIZE - page_offset)
352 /* Enough payload to fill up from this page. */
353 to_copy = PAGE_SIZE - page_offset;
355 to_copy = size - bytes_copied;
357 if (!copy_from_iter_full((u8 *)va + page_offset, to_copy,
360 kunmap(kernel_if->u.h.page[page_index]);
361 return VMCI_ERROR_INVALID_ARGS;
363 bytes_copied += to_copy;
365 kunmap(kernel_if->u.h.page[page_index]);
372 * Copies to a given buffer or iovector from a VMCI Queue. Uses
373 * kmap()/kunmap() to dynamically map/unmap required portions of the queue
374 * by traversing the offset -> page translation structure for the queue.
375 * Assumes that offset + size does not wrap around in the queue.
377 static int qp_memcpy_from_queue_iter(struct iov_iter *to,
378 const struct vmci_queue *queue,
379 u64 queue_offset, size_t size)
381 struct vmci_queue_kern_if *kernel_if = queue->kernel_if;
382 size_t bytes_copied = 0;
384 while (bytes_copied < size) {
385 const u64 page_index =
386 (queue_offset + bytes_copied) / PAGE_SIZE;
387 const size_t page_offset =
388 (queue_offset + bytes_copied) & (PAGE_SIZE - 1);
394 va = kmap(kernel_if->u.h.page[page_index]);
396 va = kernel_if->u.g.vas[page_index + 1];
399 if (size - bytes_copied > PAGE_SIZE - page_offset)
400 /* Enough payload to fill up this page. */
401 to_copy = PAGE_SIZE - page_offset;
403 to_copy = size - bytes_copied;
405 err = copy_to_iter((u8 *)va + page_offset, to_copy, to);
406 if (err != to_copy) {
408 kunmap(kernel_if->u.h.page[page_index]);
409 return VMCI_ERROR_INVALID_ARGS;
411 bytes_copied += to_copy;
413 kunmap(kernel_if->u.h.page[page_index]);
420 * Allocates two list of PPNs --- one for the pages in the produce queue,
421 * and the other for the pages in the consume queue. Intializes the list
422 * of PPNs with the page frame numbers of the KVA for the two queues (and
423 * the queue headers).
425 static int qp_alloc_ppn_set(void *prod_q,
426 u64 num_produce_pages,
428 u64 num_consume_pages, struct ppn_set *ppn_set)
432 struct vmci_queue *produce_q = prod_q;
433 struct vmci_queue *consume_q = cons_q;
436 if (!produce_q || !num_produce_pages || !consume_q ||
437 !num_consume_pages || !ppn_set)
438 return VMCI_ERROR_INVALID_ARGS;
440 if (ppn_set->initialized)
441 return VMCI_ERROR_ALREADY_EXISTS;
444 kmalloc_array(num_produce_pages, sizeof(*produce_ppns),
447 return VMCI_ERROR_NO_MEM;
450 kmalloc_array(num_consume_pages, sizeof(*consume_ppns),
454 return VMCI_ERROR_NO_MEM;
457 for (i = 0; i < num_produce_pages; i++)
459 produce_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT;
461 for (i = 0; i < num_consume_pages; i++)
463 consume_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT;
465 ppn_set->num_produce_pages = num_produce_pages;
466 ppn_set->num_consume_pages = num_consume_pages;
467 ppn_set->produce_ppns = produce_ppns;
468 ppn_set->consume_ppns = consume_ppns;
469 ppn_set->initialized = true;
474 * Frees the two list of PPNs for a queue pair.
476 static void qp_free_ppn_set(struct ppn_set *ppn_set)
478 if (ppn_set->initialized) {
479 /* Do not call these functions on NULL inputs. */
480 kfree(ppn_set->produce_ppns);
481 kfree(ppn_set->consume_ppns);
483 memset(ppn_set, 0, sizeof(*ppn_set));
487 * Populates the list of PPNs in the hypercall structure with the PPNS
488 * of the produce queue and the consume queue.
490 static int qp_populate_ppn_set(u8 *call_buf, const struct ppn_set *ppn_set)
492 if (vmci_use_ppn64()) {
493 memcpy(call_buf, ppn_set->produce_ppns,
494 ppn_set->num_produce_pages *
495 sizeof(*ppn_set->produce_ppns));
497 ppn_set->num_produce_pages *
498 sizeof(*ppn_set->produce_ppns),
499 ppn_set->consume_ppns,
500 ppn_set->num_consume_pages *
501 sizeof(*ppn_set->consume_ppns));
504 u32 *ppns = (u32 *) call_buf;
506 for (i = 0; i < ppn_set->num_produce_pages; i++)
507 ppns[i] = (u32) ppn_set->produce_ppns[i];
509 ppns = &ppns[ppn_set->num_produce_pages];
511 for (i = 0; i < ppn_set->num_consume_pages; i++)
512 ppns[i] = (u32) ppn_set->consume_ppns[i];
519 * Allocates kernel VA space of specified size plus space for the queue
520 * and kernel interface. This is different from the guest queue allocator,
521 * because we do not allocate our own queue header/data pages here but
522 * share those of the guest.
524 static struct vmci_queue *qp_host_alloc_queue(u64 size)
526 struct vmci_queue *queue;
527 size_t queue_page_size;
529 const size_t queue_size = sizeof(*queue) + sizeof(*(queue->kernel_if));
531 if (size > SIZE_MAX - PAGE_SIZE)
533 num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
534 if (num_pages > (SIZE_MAX - queue_size) /
535 sizeof(*queue->kernel_if->u.h.page))
538 queue_page_size = num_pages * sizeof(*queue->kernel_if->u.h.page);
540 if (queue_size + queue_page_size > KMALLOC_MAX_SIZE)
543 queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL);
545 queue->q_header = NULL;
546 queue->saved_header = NULL;
547 queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1);
548 queue->kernel_if->host = true;
549 queue->kernel_if->mutex = NULL;
550 queue->kernel_if->num_pages = num_pages;
551 queue->kernel_if->u.h.header_page =
552 (struct page **)((u8 *)queue + queue_size);
553 queue->kernel_if->u.h.page =
554 &queue->kernel_if->u.h.header_page[1];
561 * Frees kernel memory for a given queue (header plus translation
564 static void qp_host_free_queue(struct vmci_queue *queue, u64 queue_size)
570 * Initialize the mutex for the pair of queues. This mutex is used to
571 * protect the q_header and the buffer from changing out from under any
572 * users of either queue. Of course, it's only any good if the mutexes
573 * are actually acquired. Queue structure must lie on non-paged memory
574 * or we cannot guarantee access to the mutex.
576 static void qp_init_queue_mutex(struct vmci_queue *produce_q,
577 struct vmci_queue *consume_q)
580 * Only the host queue has shared state - the guest queues do not
581 * need to synchronize access using a queue mutex.
584 if (produce_q->kernel_if->host) {
585 produce_q->kernel_if->mutex = &produce_q->kernel_if->__mutex;
586 consume_q->kernel_if->mutex = &produce_q->kernel_if->__mutex;
587 mutex_init(produce_q->kernel_if->mutex);
592 * Cleans up the mutex for the pair of queues.
594 static void qp_cleanup_queue_mutex(struct vmci_queue *produce_q,
595 struct vmci_queue *consume_q)
597 if (produce_q->kernel_if->host) {
598 produce_q->kernel_if->mutex = NULL;
599 consume_q->kernel_if->mutex = NULL;
604 * Acquire the mutex for the queue. Note that the produce_q and
605 * the consume_q share a mutex. So, only one of the two need to
606 * be passed in to this routine. Either will work just fine.
608 static void qp_acquire_queue_mutex(struct vmci_queue *queue)
610 if (queue->kernel_if->host)
611 mutex_lock(queue->kernel_if->mutex);
615 * Release the mutex for the queue. Note that the produce_q and
616 * the consume_q share a mutex. So, only one of the two need to
617 * be passed in to this routine. Either will work just fine.
619 static void qp_release_queue_mutex(struct vmci_queue *queue)
621 if (queue->kernel_if->host)
622 mutex_unlock(queue->kernel_if->mutex);
626 * Helper function to release pages in the PageStoreAttachInfo
627 * previously obtained using get_user_pages.
629 static void qp_release_pages(struct page **pages,
630 u64 num_pages, bool dirty)
634 for (i = 0; i < num_pages; i++) {
636 set_page_dirty_lock(pages[i]);
644 * Lock the user pages referenced by the {produce,consume}Buffer
645 * struct into memory and populate the {produce,consume}Pages
646 * arrays in the attach structure with them.
648 static int qp_host_get_user_memory(u64 produce_uva,
650 struct vmci_queue *produce_q,
651 struct vmci_queue *consume_q)
654 int err = VMCI_SUCCESS;
656 retval = get_user_pages_fast((uintptr_t) produce_uva,
657 produce_q->kernel_if->num_pages,
659 produce_q->kernel_if->u.h.header_page);
660 if (retval < (int)produce_q->kernel_if->num_pages) {
661 pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
664 qp_release_pages(produce_q->kernel_if->u.h.header_page,
666 err = VMCI_ERROR_NO_MEM;
670 retval = get_user_pages_fast((uintptr_t) consume_uva,
671 consume_q->kernel_if->num_pages,
673 consume_q->kernel_if->u.h.header_page);
674 if (retval < (int)consume_q->kernel_if->num_pages) {
675 pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
678 qp_release_pages(consume_q->kernel_if->u.h.header_page,
680 qp_release_pages(produce_q->kernel_if->u.h.header_page,
681 produce_q->kernel_if->num_pages, false);
682 err = VMCI_ERROR_NO_MEM;
690 * Registers the specification of the user pages used for backing a queue
691 * pair. Enough information to map in pages is stored in the OS specific
692 * part of the struct vmci_queue structure.
694 static int qp_host_register_user_memory(struct vmci_qp_page_store *page_store,
695 struct vmci_queue *produce_q,
696 struct vmci_queue *consume_q)
702 * The new style and the old style mapping only differs in
703 * that we either get a single or two UVAs, so we split the
704 * single UVA range at the appropriate spot.
706 produce_uva = page_store->pages;
707 consume_uva = page_store->pages +
708 produce_q->kernel_if->num_pages * PAGE_SIZE;
709 return qp_host_get_user_memory(produce_uva, consume_uva, produce_q,
714 * Releases and removes the references to user pages stored in the attach
715 * struct. Pages are released from the page cache and may become
718 static void qp_host_unregister_user_memory(struct vmci_queue *produce_q,
719 struct vmci_queue *consume_q)
721 qp_release_pages(produce_q->kernel_if->u.h.header_page,
722 produce_q->kernel_if->num_pages, true);
723 memset(produce_q->kernel_if->u.h.header_page, 0,
724 sizeof(*produce_q->kernel_if->u.h.header_page) *
725 produce_q->kernel_if->num_pages);
726 qp_release_pages(consume_q->kernel_if->u.h.header_page,
727 consume_q->kernel_if->num_pages, true);
728 memset(consume_q->kernel_if->u.h.header_page, 0,
729 sizeof(*consume_q->kernel_if->u.h.header_page) *
730 consume_q->kernel_if->num_pages);
734 * Once qp_host_register_user_memory has been performed on a
735 * queue, the queue pair headers can be mapped into the
736 * kernel. Once mapped, they must be unmapped with
737 * qp_host_unmap_queues prior to calling
738 * qp_host_unregister_user_memory.
741 static int qp_host_map_queues(struct vmci_queue *produce_q,
742 struct vmci_queue *consume_q)
746 if (!produce_q->q_header || !consume_q->q_header) {
747 struct page *headers[2];
749 if (produce_q->q_header != consume_q->q_header)
750 return VMCI_ERROR_QUEUEPAIR_MISMATCH;
752 if (produce_q->kernel_if->u.h.header_page == NULL ||
753 *produce_q->kernel_if->u.h.header_page == NULL)
754 return VMCI_ERROR_UNAVAILABLE;
756 headers[0] = *produce_q->kernel_if->u.h.header_page;
757 headers[1] = *consume_q->kernel_if->u.h.header_page;
759 produce_q->q_header = vmap(headers, 2, VM_MAP, PAGE_KERNEL);
760 if (produce_q->q_header != NULL) {
761 consume_q->q_header =
762 (struct vmci_queue_header *)((u8 *)
763 produce_q->q_header +
765 result = VMCI_SUCCESS;
767 pr_warn("vmap failed\n");
768 result = VMCI_ERROR_NO_MEM;
771 result = VMCI_SUCCESS;
778 * Unmaps previously mapped queue pair headers from the kernel.
779 * Pages are unpinned.
781 static int qp_host_unmap_queues(u32 gid,
782 struct vmci_queue *produce_q,
783 struct vmci_queue *consume_q)
785 if (produce_q->q_header) {
786 if (produce_q->q_header < consume_q->q_header)
787 vunmap(produce_q->q_header);
789 vunmap(consume_q->q_header);
791 produce_q->q_header = NULL;
792 consume_q->q_header = NULL;
799 * Finds the entry in the list corresponding to a given handle. Assumes
800 * that the list is locked.
802 static struct qp_entry *qp_list_find(struct qp_list *qp_list,
803 struct vmci_handle handle)
805 struct qp_entry *entry;
807 if (vmci_handle_is_invalid(handle))
810 list_for_each_entry(entry, &qp_list->head, list_item) {
811 if (vmci_handle_is_equal(entry->handle, handle))
819 * Finds the entry in the list corresponding to a given handle.
821 static struct qp_guest_endpoint *
822 qp_guest_handle_to_entry(struct vmci_handle handle)
824 struct qp_guest_endpoint *entry;
825 struct qp_entry *qp = qp_list_find(&qp_guest_endpoints, handle);
827 entry = qp ? container_of(
828 qp, struct qp_guest_endpoint, qp) : NULL;
833 * Finds the entry in the list corresponding to a given handle.
835 static struct qp_broker_entry *
836 qp_broker_handle_to_entry(struct vmci_handle handle)
838 struct qp_broker_entry *entry;
839 struct qp_entry *qp = qp_list_find(&qp_broker_list, handle);
841 entry = qp ? container_of(
842 qp, struct qp_broker_entry, qp) : NULL;
847 * Dispatches a queue pair event message directly into the local event
850 static int qp_notify_peer_local(bool attach, struct vmci_handle handle)
852 u32 context_id = vmci_get_context_id();
853 struct vmci_event_qp ev;
855 ev.msg.hdr.dst = vmci_make_handle(context_id, VMCI_EVENT_HANDLER);
856 ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
857 VMCI_CONTEXT_RESOURCE_ID);
858 ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr);
859 ev.msg.event_data.event =
860 attach ? VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
861 ev.payload.peer_id = context_id;
862 ev.payload.handle = handle;
864 return vmci_event_dispatch(&ev.msg.hdr);
868 * Allocates and initializes a qp_guest_endpoint structure.
869 * Allocates a queue_pair rid (and handle) iff the given entry has
870 * an invalid handle. 0 through VMCI_RESERVED_RESOURCE_ID_MAX
871 * are reserved handles. Assumes that the QP list mutex is held
874 static struct qp_guest_endpoint *
875 qp_guest_endpoint_create(struct vmci_handle handle,
884 struct qp_guest_endpoint *entry;
885 /* One page each for the queue headers. */
886 const u64 num_ppns = DIV_ROUND_UP(produce_size, PAGE_SIZE) +
887 DIV_ROUND_UP(consume_size, PAGE_SIZE) + 2;
889 if (vmci_handle_is_invalid(handle)) {
890 u32 context_id = vmci_get_context_id();
892 handle = vmci_make_handle(context_id, VMCI_INVALID_ID);
895 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
897 entry->qp.peer = peer;
898 entry->qp.flags = flags;
899 entry->qp.produce_size = produce_size;
900 entry->qp.consume_size = consume_size;
901 entry->qp.ref_count = 0;
902 entry->num_ppns = num_ppns;
903 entry->produce_q = produce_q;
904 entry->consume_q = consume_q;
905 INIT_LIST_HEAD(&entry->qp.list_item);
907 /* Add resource obj */
908 result = vmci_resource_add(&entry->resource,
909 VMCI_RESOURCE_TYPE_QPAIR_GUEST,
911 entry->qp.handle = vmci_resource_handle(&entry->resource);
912 if ((result != VMCI_SUCCESS) ||
913 qp_list_find(&qp_guest_endpoints, entry->qp.handle)) {
914 pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d",
915 handle.context, handle.resource, result);
924 * Frees a qp_guest_endpoint structure.
926 static void qp_guest_endpoint_destroy(struct qp_guest_endpoint *entry)
928 qp_free_ppn_set(&entry->ppn_set);
929 qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q);
930 qp_free_queue(entry->produce_q, entry->qp.produce_size);
931 qp_free_queue(entry->consume_q, entry->qp.consume_size);
932 /* Unlink from resource hash table and free callback */
933 vmci_resource_remove(&entry->resource);
939 * Helper to make a queue_pairAlloc hypercall when the driver is
940 * supporting a guest device.
942 static int qp_alloc_hypercall(const struct qp_guest_endpoint *entry)
944 struct vmci_qp_alloc_msg *alloc_msg;
949 if (!entry || entry->num_ppns <= 2)
950 return VMCI_ERROR_INVALID_ARGS;
952 ppn_size = vmci_use_ppn64() ? sizeof(u64) : sizeof(u32);
953 msg_size = sizeof(*alloc_msg) +
954 (size_t) entry->num_ppns * ppn_size;
955 alloc_msg = kmalloc(msg_size, GFP_KERNEL);
957 return VMCI_ERROR_NO_MEM;
959 alloc_msg->hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
960 VMCI_QUEUEPAIR_ALLOC);
961 alloc_msg->hdr.src = VMCI_ANON_SRC_HANDLE;
962 alloc_msg->hdr.payload_size = msg_size - VMCI_DG_HEADERSIZE;
963 alloc_msg->handle = entry->qp.handle;
964 alloc_msg->peer = entry->qp.peer;
965 alloc_msg->flags = entry->qp.flags;
966 alloc_msg->produce_size = entry->qp.produce_size;
967 alloc_msg->consume_size = entry->qp.consume_size;
968 alloc_msg->num_ppns = entry->num_ppns;
970 result = qp_populate_ppn_set((u8 *)alloc_msg + sizeof(*alloc_msg),
972 if (result == VMCI_SUCCESS)
973 result = vmci_send_datagram(&alloc_msg->hdr);
981 * Helper to make a queue_pairDetach hypercall when the driver is
982 * supporting a guest device.
984 static int qp_detatch_hypercall(struct vmci_handle handle)
986 struct vmci_qp_detach_msg detach_msg;
988 detach_msg.hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
989 VMCI_QUEUEPAIR_DETACH);
990 detach_msg.hdr.src = VMCI_ANON_SRC_HANDLE;
991 detach_msg.hdr.payload_size = sizeof(handle);
992 detach_msg.handle = handle;
994 return vmci_send_datagram(&detach_msg.hdr);
998 * Adds the given entry to the list. Assumes that the list is locked.
1000 static void qp_list_add_entry(struct qp_list *qp_list, struct qp_entry *entry)
1003 list_add(&entry->list_item, &qp_list->head);
1007 * Removes the given entry from the list. Assumes that the list is locked.
1009 static void qp_list_remove_entry(struct qp_list *qp_list,
1010 struct qp_entry *entry)
1013 list_del(&entry->list_item);
1017 * Helper for VMCI queue_pair detach interface. Frees the physical
1018 * pages for the queue pair.
1020 static int qp_detatch_guest_work(struct vmci_handle handle)
1023 struct qp_guest_endpoint *entry;
1024 u32 ref_count = ~0; /* To avoid compiler warning below */
1026 mutex_lock(&qp_guest_endpoints.mutex);
1028 entry = qp_guest_handle_to_entry(handle);
1030 mutex_unlock(&qp_guest_endpoints.mutex);
1031 return VMCI_ERROR_NOT_FOUND;
1034 if (entry->qp.flags & VMCI_QPFLAG_LOCAL) {
1035 result = VMCI_SUCCESS;
1037 if (entry->qp.ref_count > 1) {
1038 result = qp_notify_peer_local(false, handle);
1040 * We can fail to notify a local queuepair
1041 * because we can't allocate. We still want
1042 * to release the entry if that happens, so
1043 * don't bail out yet.
1047 result = qp_detatch_hypercall(handle);
1048 if (result < VMCI_SUCCESS) {
1050 * We failed to notify a non-local queuepair.
1051 * That other queuepair might still be
1052 * accessing the shared memory, so don't
1053 * release the entry yet. It will get cleaned
1054 * up by VMCIqueue_pair_Exit() if necessary
1055 * (assuming we are going away, otherwise why
1059 mutex_unlock(&qp_guest_endpoints.mutex);
1065 * If we get here then we either failed to notify a local queuepair, or
1066 * we succeeded in all cases. Release the entry if required.
1069 entry->qp.ref_count--;
1070 if (entry->qp.ref_count == 0)
1071 qp_list_remove_entry(&qp_guest_endpoints, &entry->qp);
1073 /* If we didn't remove the entry, this could change once we unlock. */
1075 ref_count = entry->qp.ref_count;
1077 mutex_unlock(&qp_guest_endpoints.mutex);
1080 qp_guest_endpoint_destroy(entry);
1086 * This functions handles the actual allocation of a VMCI queue
1087 * pair guest endpoint. Allocates physical pages for the queue
1088 * pair. It makes OS dependent calls through generic wrappers.
1090 static int qp_alloc_guest_work(struct vmci_handle *handle,
1091 struct vmci_queue **produce_q,
1093 struct vmci_queue **consume_q,
1099 const u64 num_produce_pages =
1100 DIV_ROUND_UP(produce_size, PAGE_SIZE) + 1;
1101 const u64 num_consume_pages =
1102 DIV_ROUND_UP(consume_size, PAGE_SIZE) + 1;
1103 void *my_produce_q = NULL;
1104 void *my_consume_q = NULL;
1106 struct qp_guest_endpoint *queue_pair_entry = NULL;
1108 if (priv_flags != VMCI_NO_PRIVILEGE_FLAGS)
1109 return VMCI_ERROR_NO_ACCESS;
1111 mutex_lock(&qp_guest_endpoints.mutex);
1113 queue_pair_entry = qp_guest_handle_to_entry(*handle);
1114 if (queue_pair_entry) {
1115 if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) {
1116 /* Local attach case. */
1117 if (queue_pair_entry->qp.ref_count > 1) {
1118 pr_devel("Error attempting to attach more than once\n");
1119 result = VMCI_ERROR_UNAVAILABLE;
1120 goto error_keep_entry;
1123 if (queue_pair_entry->qp.produce_size != consume_size ||
1124 queue_pair_entry->qp.consume_size !=
1126 queue_pair_entry->qp.flags !=
1127 (flags & ~VMCI_QPFLAG_ATTACH_ONLY)) {
1128 pr_devel("Error mismatched queue pair in local attach\n");
1129 result = VMCI_ERROR_QUEUEPAIR_MISMATCH;
1130 goto error_keep_entry;
1134 * Do a local attach. We swap the consume and
1135 * produce queues for the attacher and deliver
1138 result = qp_notify_peer_local(true, *handle);
1139 if (result < VMCI_SUCCESS)
1140 goto error_keep_entry;
1142 my_produce_q = queue_pair_entry->consume_q;
1143 my_consume_q = queue_pair_entry->produce_q;
1147 result = VMCI_ERROR_ALREADY_EXISTS;
1148 goto error_keep_entry;
1151 my_produce_q = qp_alloc_queue(produce_size, flags);
1152 if (!my_produce_q) {
1153 pr_warn("Error allocating pages for produce queue\n");
1154 result = VMCI_ERROR_NO_MEM;
1158 my_consume_q = qp_alloc_queue(consume_size, flags);
1159 if (!my_consume_q) {
1160 pr_warn("Error allocating pages for consume queue\n");
1161 result = VMCI_ERROR_NO_MEM;
1165 queue_pair_entry = qp_guest_endpoint_create(*handle, peer, flags,
1166 produce_size, consume_size,
1167 my_produce_q, my_consume_q);
1168 if (!queue_pair_entry) {
1169 pr_warn("Error allocating memory in %s\n", __func__);
1170 result = VMCI_ERROR_NO_MEM;
1174 result = qp_alloc_ppn_set(my_produce_q, num_produce_pages, my_consume_q,
1176 &queue_pair_entry->ppn_set);
1177 if (result < VMCI_SUCCESS) {
1178 pr_warn("qp_alloc_ppn_set failed\n");
1183 * It's only necessary to notify the host if this queue pair will be
1184 * attached to from another context.
1186 if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) {
1187 /* Local create case. */
1188 u32 context_id = vmci_get_context_id();
1191 * Enforce similar checks on local queue pairs as we
1192 * do for regular ones. The handle's context must
1193 * match the creator or attacher context id (here they
1194 * are both the current context id) and the
1195 * attach-only flag cannot exist during create. We
1196 * also ensure specified peer is this context or an
1199 if (queue_pair_entry->qp.handle.context != context_id ||
1200 (queue_pair_entry->qp.peer != VMCI_INVALID_ID &&
1201 queue_pair_entry->qp.peer != context_id)) {
1202 result = VMCI_ERROR_NO_ACCESS;
1206 if (queue_pair_entry->qp.flags & VMCI_QPFLAG_ATTACH_ONLY) {
1207 result = VMCI_ERROR_NOT_FOUND;
1211 result = qp_alloc_hypercall(queue_pair_entry);
1212 if (result < VMCI_SUCCESS) {
1213 pr_warn("qp_alloc_hypercall result = %d\n", result);
1218 qp_init_queue_mutex((struct vmci_queue *)my_produce_q,
1219 (struct vmci_queue *)my_consume_q);
1221 qp_list_add_entry(&qp_guest_endpoints, &queue_pair_entry->qp);
1224 queue_pair_entry->qp.ref_count++;
1225 *handle = queue_pair_entry->qp.handle;
1226 *produce_q = (struct vmci_queue *)my_produce_q;
1227 *consume_q = (struct vmci_queue *)my_consume_q;
1230 * We should initialize the queue pair header pages on a local
1231 * queue pair create. For non-local queue pairs, the
1232 * hypervisor initializes the header pages in the create step.
1234 if ((queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) &&
1235 queue_pair_entry->qp.ref_count == 1) {
1236 vmci_q_header_init((*produce_q)->q_header, *handle);
1237 vmci_q_header_init((*consume_q)->q_header, *handle);
1240 mutex_unlock(&qp_guest_endpoints.mutex);
1242 return VMCI_SUCCESS;
1245 mutex_unlock(&qp_guest_endpoints.mutex);
1246 if (queue_pair_entry) {
1247 /* The queues will be freed inside the destroy routine. */
1248 qp_guest_endpoint_destroy(queue_pair_entry);
1250 qp_free_queue(my_produce_q, produce_size);
1251 qp_free_queue(my_consume_q, consume_size);
1256 /* This path should only be used when an existing entry was found. */
1257 mutex_unlock(&qp_guest_endpoints.mutex);
1262 * The first endpoint issuing a queue pair allocation will create the state
1263 * of the queue pair in the queue pair broker.
1265 * If the creator is a guest, it will associate a VMX virtual address range
1266 * with the queue pair as specified by the page_store. For compatibility with
1267 * older VMX'en, that would use a separate step to set the VMX virtual
1268 * address range, the virtual address range can be registered later using
1269 * vmci_qp_broker_set_page_store. In that case, a page_store of NULL should be
1272 * If the creator is the host, a page_store of NULL should be used as well,
1273 * since the host is not able to supply a page store for the queue pair.
1275 * For older VMX and host callers, the queue pair will be created in the
1276 * VMCIQPB_CREATED_NO_MEM state, and for current VMX callers, it will be
1277 * created in VMCOQPB_CREATED_MEM state.
1279 static int qp_broker_create(struct vmci_handle handle,
1285 struct vmci_qp_page_store *page_store,
1286 struct vmci_ctx *context,
1287 vmci_event_release_cb wakeup_cb,
1288 void *client_data, struct qp_broker_entry **ent)
1290 struct qp_broker_entry *entry = NULL;
1291 const u32 context_id = vmci_ctx_get_id(context);
1292 bool is_local = flags & VMCI_QPFLAG_LOCAL;
1294 u64 guest_produce_size;
1295 u64 guest_consume_size;
1297 /* Do not create if the caller asked not to. */
1298 if (flags & VMCI_QPFLAG_ATTACH_ONLY)
1299 return VMCI_ERROR_NOT_FOUND;
1302 * Creator's context ID should match handle's context ID or the creator
1303 * must allow the context in handle's context ID as the "peer".
1305 if (handle.context != context_id && handle.context != peer)
1306 return VMCI_ERROR_NO_ACCESS;
1308 if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(peer))
1309 return VMCI_ERROR_DST_UNREACHABLE;
1312 * Creator's context ID for local queue pairs should match the
1313 * peer, if a peer is specified.
1315 if (is_local && peer != VMCI_INVALID_ID && context_id != peer)
1316 return VMCI_ERROR_NO_ACCESS;
1318 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
1320 return VMCI_ERROR_NO_MEM;
1322 if (vmci_ctx_get_id(context) == VMCI_HOST_CONTEXT_ID && !is_local) {
1324 * The queue pair broker entry stores values from the guest
1325 * point of view, so a creating host side endpoint should swap
1326 * produce and consume values -- unless it is a local queue
1327 * pair, in which case no swapping is necessary, since the local
1328 * attacher will swap queues.
1331 guest_produce_size = consume_size;
1332 guest_consume_size = produce_size;
1334 guest_produce_size = produce_size;
1335 guest_consume_size = consume_size;
1338 entry->qp.handle = handle;
1339 entry->qp.peer = peer;
1340 entry->qp.flags = flags;
1341 entry->qp.produce_size = guest_produce_size;
1342 entry->qp.consume_size = guest_consume_size;
1343 entry->qp.ref_count = 1;
1344 entry->create_id = context_id;
1345 entry->attach_id = VMCI_INVALID_ID;
1346 entry->state = VMCIQPB_NEW;
1347 entry->require_trusted_attach =
1348 !!(context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED);
1349 entry->created_by_trusted =
1350 !!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED);
1351 entry->vmci_page_files = false;
1352 entry->wakeup_cb = wakeup_cb;
1353 entry->client_data = client_data;
1354 entry->produce_q = qp_host_alloc_queue(guest_produce_size);
1355 if (entry->produce_q == NULL) {
1356 result = VMCI_ERROR_NO_MEM;
1359 entry->consume_q = qp_host_alloc_queue(guest_consume_size);
1360 if (entry->consume_q == NULL) {
1361 result = VMCI_ERROR_NO_MEM;
1365 qp_init_queue_mutex(entry->produce_q, entry->consume_q);
1367 INIT_LIST_HEAD(&entry->qp.list_item);
1372 entry->local_mem = kcalloc(QPE_NUM_PAGES(entry->qp),
1373 PAGE_SIZE, GFP_KERNEL);
1374 if (entry->local_mem == NULL) {
1375 result = VMCI_ERROR_NO_MEM;
1378 entry->state = VMCIQPB_CREATED_MEM;
1379 entry->produce_q->q_header = entry->local_mem;
1380 tmp = (u8 *)entry->local_mem + PAGE_SIZE *
1381 (DIV_ROUND_UP(entry->qp.produce_size, PAGE_SIZE) + 1);
1382 entry->consume_q->q_header = (struct vmci_queue_header *)tmp;
1383 } else if (page_store) {
1385 * The VMX already initialized the queue pair headers, so no
1386 * need for the kernel side to do that.
1388 result = qp_host_register_user_memory(page_store,
1391 if (result < VMCI_SUCCESS)
1394 entry->state = VMCIQPB_CREATED_MEM;
1397 * A create without a page_store may be either a host
1398 * side create (in which case we are waiting for the
1399 * guest side to supply the memory) or an old style
1400 * queue pair create (in which case we will expect a
1401 * set page store call as the next step).
1403 entry->state = VMCIQPB_CREATED_NO_MEM;
1406 qp_list_add_entry(&qp_broker_list, &entry->qp);
1410 /* Add to resource obj */
1411 result = vmci_resource_add(&entry->resource,
1412 VMCI_RESOURCE_TYPE_QPAIR_HOST,
1414 if (result != VMCI_SUCCESS) {
1415 pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d",
1416 handle.context, handle.resource, result);
1420 entry->qp.handle = vmci_resource_handle(&entry->resource);
1422 vmci_q_header_init(entry->produce_q->q_header,
1424 vmci_q_header_init(entry->consume_q->q_header,
1428 vmci_ctx_qp_create(context, entry->qp.handle);
1430 return VMCI_SUCCESS;
1433 if (entry != NULL) {
1434 qp_host_free_queue(entry->produce_q, guest_produce_size);
1435 qp_host_free_queue(entry->consume_q, guest_consume_size);
1443 * Enqueues an event datagram to notify the peer VM attached to
1444 * the given queue pair handle about attach/detach event by the
1445 * given VM. Returns Payload size of datagram enqueued on
1446 * success, error code otherwise.
1448 static int qp_notify_peer(bool attach,
1449 struct vmci_handle handle,
1454 struct vmci_event_qp ev;
1456 if (vmci_handle_is_invalid(handle) || my_id == VMCI_INVALID_ID ||
1457 peer_id == VMCI_INVALID_ID)
1458 return VMCI_ERROR_INVALID_ARGS;
1461 * In vmci_ctx_enqueue_datagram() we enforce the upper limit on
1462 * number of pending events from the hypervisor to a given VM
1463 * otherwise a rogue VM could do an arbitrary number of attach
1464 * and detach operations causing memory pressure in the host
1468 ev.msg.hdr.dst = vmci_make_handle(peer_id, VMCI_EVENT_HANDLER);
1469 ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
1470 VMCI_CONTEXT_RESOURCE_ID);
1471 ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr);
1472 ev.msg.event_data.event = attach ?
1473 VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
1474 ev.payload.handle = handle;
1475 ev.payload.peer_id = my_id;
1477 rv = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID,
1478 &ev.msg.hdr, false);
1479 if (rv < VMCI_SUCCESS)
1480 pr_warn("Failed to enqueue queue_pair %s event datagram for context (ID=0x%x)\n",
1481 attach ? "ATTACH" : "DETACH", peer_id);
1487 * The second endpoint issuing a queue pair allocation will attach to
1488 * the queue pair registered with the queue pair broker.
1490 * If the attacher is a guest, it will associate a VMX virtual address
1491 * range with the queue pair as specified by the page_store. At this
1492 * point, the already attach host endpoint may start using the queue
1493 * pair, and an attach event is sent to it. For compatibility with
1494 * older VMX'en, that used a separate step to set the VMX virtual
1495 * address range, the virtual address range can be registered later
1496 * using vmci_qp_broker_set_page_store. In that case, a page_store of
1497 * NULL should be used, and the attach event will be generated once
1498 * the actual page store has been set.
1500 * If the attacher is the host, a page_store of NULL should be used as
1501 * well, since the page store information is already set by the guest.
1503 * For new VMX and host callers, the queue pair will be moved to the
1504 * VMCIQPB_ATTACHED_MEM state, and for older VMX callers, it will be
1505 * moved to the VMCOQPB_ATTACHED_NO_MEM state.
1507 static int qp_broker_attach(struct qp_broker_entry *entry,
1513 struct vmci_qp_page_store *page_store,
1514 struct vmci_ctx *context,
1515 vmci_event_release_cb wakeup_cb,
1517 struct qp_broker_entry **ent)
1519 const u32 context_id = vmci_ctx_get_id(context);
1520 bool is_local = flags & VMCI_QPFLAG_LOCAL;
1523 if (entry->state != VMCIQPB_CREATED_NO_MEM &&
1524 entry->state != VMCIQPB_CREATED_MEM)
1525 return VMCI_ERROR_UNAVAILABLE;
1528 if (!(entry->qp.flags & VMCI_QPFLAG_LOCAL) ||
1529 context_id != entry->create_id) {
1530 return VMCI_ERROR_INVALID_ARGS;
1532 } else if (context_id == entry->create_id ||
1533 context_id == entry->attach_id) {
1534 return VMCI_ERROR_ALREADY_EXISTS;
1537 if (VMCI_CONTEXT_IS_VM(context_id) &&
1538 VMCI_CONTEXT_IS_VM(entry->create_id))
1539 return VMCI_ERROR_DST_UNREACHABLE;
1542 * If we are attaching from a restricted context then the queuepair
1543 * must have been created by a trusted endpoint.
1545 if ((context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) &&
1546 !entry->created_by_trusted)
1547 return VMCI_ERROR_NO_ACCESS;
1550 * If we are attaching to a queuepair that was created by a restricted
1551 * context then we must be trusted.
1553 if (entry->require_trusted_attach &&
1554 (!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED)))
1555 return VMCI_ERROR_NO_ACCESS;
1558 * If the creator specifies VMCI_INVALID_ID in "peer" field, access
1559 * control check is not performed.
1561 if (entry->qp.peer != VMCI_INVALID_ID && entry->qp.peer != context_id)
1562 return VMCI_ERROR_NO_ACCESS;
1564 if (entry->create_id == VMCI_HOST_CONTEXT_ID) {
1566 * Do not attach if the caller doesn't support Host Queue Pairs
1567 * and a host created this queue pair.
1570 if (!vmci_ctx_supports_host_qp(context))
1571 return VMCI_ERROR_INVALID_RESOURCE;
1573 } else if (context_id == VMCI_HOST_CONTEXT_ID) {
1574 struct vmci_ctx *create_context;
1575 bool supports_host_qp;
1578 * Do not attach a host to a user created queue pair if that
1579 * user doesn't support host queue pair end points.
1582 create_context = vmci_ctx_get(entry->create_id);
1583 supports_host_qp = vmci_ctx_supports_host_qp(create_context);
1584 vmci_ctx_put(create_context);
1586 if (!supports_host_qp)
1587 return VMCI_ERROR_INVALID_RESOURCE;
1590 if ((entry->qp.flags & ~VMCI_QP_ASYMM) != (flags & ~VMCI_QP_ASYMM_PEER))
1591 return VMCI_ERROR_QUEUEPAIR_MISMATCH;
1593 if (context_id != VMCI_HOST_CONTEXT_ID) {
1595 * The queue pair broker entry stores values from the guest
1596 * point of view, so an attaching guest should match the values
1597 * stored in the entry.
1600 if (entry->qp.produce_size != produce_size ||
1601 entry->qp.consume_size != consume_size) {
1602 return VMCI_ERROR_QUEUEPAIR_MISMATCH;
1604 } else if (entry->qp.produce_size != consume_size ||
1605 entry->qp.consume_size != produce_size) {
1606 return VMCI_ERROR_QUEUEPAIR_MISMATCH;
1609 if (context_id != VMCI_HOST_CONTEXT_ID) {
1611 * If a guest attached to a queue pair, it will supply
1612 * the backing memory. If this is a pre NOVMVM vmx,
1613 * the backing memory will be supplied by calling
1614 * vmci_qp_broker_set_page_store() following the
1615 * return of the vmci_qp_broker_alloc() call. If it is
1616 * a vmx of version NOVMVM or later, the page store
1617 * must be supplied as part of the
1618 * vmci_qp_broker_alloc call. Under all circumstances
1619 * must the initially created queue pair not have any
1620 * memory associated with it already.
1623 if (entry->state != VMCIQPB_CREATED_NO_MEM)
1624 return VMCI_ERROR_INVALID_ARGS;
1626 if (page_store != NULL) {
1628 * Patch up host state to point to guest
1629 * supplied memory. The VMX already
1630 * initialized the queue pair headers, so no
1631 * need for the kernel side to do that.
1634 result = qp_host_register_user_memory(page_store,
1637 if (result < VMCI_SUCCESS)
1640 entry->state = VMCIQPB_ATTACHED_MEM;
1642 entry->state = VMCIQPB_ATTACHED_NO_MEM;
1644 } else if (entry->state == VMCIQPB_CREATED_NO_MEM) {
1646 * The host side is attempting to attach to a queue
1647 * pair that doesn't have any memory associated with
1648 * it. This must be a pre NOVMVM vmx that hasn't set
1649 * the page store information yet, or a quiesced VM.
1652 return VMCI_ERROR_UNAVAILABLE;
1654 /* The host side has successfully attached to a queue pair. */
1655 entry->state = VMCIQPB_ATTACHED_MEM;
1658 if (entry->state == VMCIQPB_ATTACHED_MEM) {
1660 qp_notify_peer(true, entry->qp.handle, context_id,
1662 if (result < VMCI_SUCCESS)
1663 pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n",
1664 entry->create_id, entry->qp.handle.context,
1665 entry->qp.handle.resource);
1668 entry->attach_id = context_id;
1669 entry->qp.ref_count++;
1671 entry->wakeup_cb = wakeup_cb;
1672 entry->client_data = client_data;
1676 * When attaching to local queue pairs, the context already has
1677 * an entry tracking the queue pair, so don't add another one.
1680 vmci_ctx_qp_create(context, entry->qp.handle);
1685 return VMCI_SUCCESS;
1689 * queue_pair_Alloc for use when setting up queue pair endpoints
1692 static int qp_broker_alloc(struct vmci_handle handle,
1698 struct vmci_qp_page_store *page_store,
1699 struct vmci_ctx *context,
1700 vmci_event_release_cb wakeup_cb,
1702 struct qp_broker_entry **ent,
1705 const u32 context_id = vmci_ctx_get_id(context);
1707 struct qp_broker_entry *entry = NULL;
1708 bool is_local = flags & VMCI_QPFLAG_LOCAL;
1711 if (vmci_handle_is_invalid(handle) ||
1712 (flags & ~VMCI_QP_ALL_FLAGS) || is_local ||
1713 !(produce_size || consume_size) ||
1714 !context || context_id == VMCI_INVALID_ID ||
1715 handle.context == VMCI_INVALID_ID) {
1716 return VMCI_ERROR_INVALID_ARGS;
1719 if (page_store && !VMCI_QP_PAGESTORE_IS_WELLFORMED(page_store))
1720 return VMCI_ERROR_INVALID_ARGS;
1723 * In the initial argument check, we ensure that non-vmkernel hosts
1724 * are not allowed to create local queue pairs.
1727 mutex_lock(&qp_broker_list.mutex);
1729 if (!is_local && vmci_ctx_qp_exists(context, handle)) {
1730 pr_devel("Context (ID=0x%x) already attached to queue pair (handle=0x%x:0x%x)\n",
1731 context_id, handle.context, handle.resource);
1732 mutex_unlock(&qp_broker_list.mutex);
1733 return VMCI_ERROR_ALREADY_EXISTS;
1736 if (handle.resource != VMCI_INVALID_ID)
1737 entry = qp_broker_handle_to_entry(handle);
1742 qp_broker_create(handle, peer, flags, priv_flags,
1743 produce_size, consume_size, page_store,
1744 context, wakeup_cb, client_data, ent);
1748 qp_broker_attach(entry, peer, flags, priv_flags,
1749 produce_size, consume_size, page_store,
1750 context, wakeup_cb, client_data, ent);
1753 mutex_unlock(&qp_broker_list.mutex);
1756 *swap = (context_id == VMCI_HOST_CONTEXT_ID) &&
1757 !(create && is_local);
1763 * This function implements the kernel API for allocating a queue
1766 static int qp_alloc_host_work(struct vmci_handle *handle,
1767 struct vmci_queue **produce_q,
1769 struct vmci_queue **consume_q,
1774 vmci_event_release_cb wakeup_cb,
1777 struct vmci_handle new_handle;
1778 struct vmci_ctx *context;
1779 struct qp_broker_entry *entry;
1783 if (vmci_handle_is_invalid(*handle)) {
1784 new_handle = vmci_make_handle(
1785 VMCI_HOST_CONTEXT_ID, VMCI_INVALID_ID);
1787 new_handle = *handle;
1789 context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID);
1792 qp_broker_alloc(new_handle, peer, flags, priv_flags,
1793 produce_size, consume_size, NULL, context,
1794 wakeup_cb, client_data, &entry, &swap);
1795 if (result == VMCI_SUCCESS) {
1798 * If this is a local queue pair, the attacher
1799 * will swap around produce and consume
1803 *produce_q = entry->consume_q;
1804 *consume_q = entry->produce_q;
1806 *produce_q = entry->produce_q;
1807 *consume_q = entry->consume_q;
1810 *handle = vmci_resource_handle(&entry->resource);
1812 *handle = VMCI_INVALID_HANDLE;
1813 pr_devel("queue pair broker failed to alloc (result=%d)\n",
1816 vmci_ctx_put(context);
1821 * Allocates a VMCI queue_pair. Only checks validity of input
1822 * arguments. The real work is done in the host or guest
1823 * specific function.
1825 int vmci_qp_alloc(struct vmci_handle *handle,
1826 struct vmci_queue **produce_q,
1828 struct vmci_queue **consume_q,
1833 bool guest_endpoint,
1834 vmci_event_release_cb wakeup_cb,
1837 if (!handle || !produce_q || !consume_q ||
1838 (!produce_size && !consume_size) || (flags & ~VMCI_QP_ALL_FLAGS))
1839 return VMCI_ERROR_INVALID_ARGS;
1841 if (guest_endpoint) {
1842 return qp_alloc_guest_work(handle, produce_q,
1843 produce_size, consume_q,
1847 return qp_alloc_host_work(handle, produce_q,
1848 produce_size, consume_q,
1849 consume_size, peer, flags,
1850 priv_flags, wakeup_cb, client_data);
1855 * This function implements the host kernel API for detaching from
1858 static int qp_detatch_host_work(struct vmci_handle handle)
1861 struct vmci_ctx *context;
1863 context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID);
1865 result = vmci_qp_broker_detach(handle, context);
1867 vmci_ctx_put(context);
1872 * Detaches from a VMCI queue_pair. Only checks validity of input argument.
1873 * Real work is done in the host or guest specific function.
1875 static int qp_detatch(struct vmci_handle handle, bool guest_endpoint)
1877 if (vmci_handle_is_invalid(handle))
1878 return VMCI_ERROR_INVALID_ARGS;
1881 return qp_detatch_guest_work(handle);
1883 return qp_detatch_host_work(handle);
1887 * Returns the entry from the head of the list. Assumes that the list is
1890 static struct qp_entry *qp_list_get_head(struct qp_list *qp_list)
1892 if (!list_empty(&qp_list->head)) {
1893 struct qp_entry *entry =
1894 list_first_entry(&qp_list->head, struct qp_entry,
1902 void vmci_qp_broker_exit(void)
1904 struct qp_entry *entry;
1905 struct qp_broker_entry *be;
1907 mutex_lock(&qp_broker_list.mutex);
1909 while ((entry = qp_list_get_head(&qp_broker_list))) {
1910 be = (struct qp_broker_entry *)entry;
1912 qp_list_remove_entry(&qp_broker_list, entry);
1916 mutex_unlock(&qp_broker_list.mutex);
1920 * Requests that a queue pair be allocated with the VMCI queue
1921 * pair broker. Allocates a queue pair entry if one does not
1922 * exist. Attaches to one if it exists, and retrieves the page
1923 * files backing that queue_pair. Assumes that the queue pair
1924 * broker lock is held.
1926 int vmci_qp_broker_alloc(struct vmci_handle handle,
1932 struct vmci_qp_page_store *page_store,
1933 struct vmci_ctx *context)
1935 return qp_broker_alloc(handle, peer, flags, priv_flags,
1936 produce_size, consume_size,
1937 page_store, context, NULL, NULL, NULL, NULL);
1941 * VMX'en with versions lower than VMCI_VERSION_NOVMVM use a separate
1942 * step to add the UVAs of the VMX mapping of the queue pair. This function
1943 * provides backwards compatibility with such VMX'en, and takes care of
1944 * registering the page store for a queue pair previously allocated by the
1945 * VMX during create or attach. This function will move the queue pair state
1946 * to either from VMCIQBP_CREATED_NO_MEM to VMCIQBP_CREATED_MEM or
1947 * VMCIQBP_ATTACHED_NO_MEM to VMCIQBP_ATTACHED_MEM. If moving to the
1948 * attached state with memory, the queue pair is ready to be used by the
1949 * host peer, and an attached event will be generated.
1951 * Assumes that the queue pair broker lock is held.
1953 * This function is only used by the hosted platform, since there is no
1954 * issue with backwards compatibility for vmkernel.
1956 int vmci_qp_broker_set_page_store(struct vmci_handle handle,
1959 struct vmci_ctx *context)
1961 struct qp_broker_entry *entry;
1963 const u32 context_id = vmci_ctx_get_id(context);
1965 if (vmci_handle_is_invalid(handle) || !context ||
1966 context_id == VMCI_INVALID_ID)
1967 return VMCI_ERROR_INVALID_ARGS;
1970 * We only support guest to host queue pairs, so the VMX must
1971 * supply UVAs for the mapped page files.
1974 if (produce_uva == 0 || consume_uva == 0)
1975 return VMCI_ERROR_INVALID_ARGS;
1977 mutex_lock(&qp_broker_list.mutex);
1979 if (!vmci_ctx_qp_exists(context, handle)) {
1980 pr_warn("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
1981 context_id, handle.context, handle.resource);
1982 result = VMCI_ERROR_NOT_FOUND;
1986 entry = qp_broker_handle_to_entry(handle);
1988 result = VMCI_ERROR_NOT_FOUND;
1993 * If I'm the owner then I can set the page store.
1995 * Or, if a host created the queue_pair and I'm the attached peer
1996 * then I can set the page store.
1998 if (entry->create_id != context_id &&
1999 (entry->create_id != VMCI_HOST_CONTEXT_ID ||
2000 entry->attach_id != context_id)) {
2001 result = VMCI_ERROR_QUEUEPAIR_NOTOWNER;
2005 if (entry->state != VMCIQPB_CREATED_NO_MEM &&
2006 entry->state != VMCIQPB_ATTACHED_NO_MEM) {
2007 result = VMCI_ERROR_UNAVAILABLE;
2011 result = qp_host_get_user_memory(produce_uva, consume_uva,
2012 entry->produce_q, entry->consume_q);
2013 if (result < VMCI_SUCCESS)
2016 result = qp_host_map_queues(entry->produce_q, entry->consume_q);
2017 if (result < VMCI_SUCCESS) {
2018 qp_host_unregister_user_memory(entry->produce_q,
2023 if (entry->state == VMCIQPB_CREATED_NO_MEM)
2024 entry->state = VMCIQPB_CREATED_MEM;
2026 entry->state = VMCIQPB_ATTACHED_MEM;
2028 entry->vmci_page_files = true;
2030 if (entry->state == VMCIQPB_ATTACHED_MEM) {
2032 qp_notify_peer(true, handle, context_id, entry->create_id);
2033 if (result < VMCI_SUCCESS) {
2034 pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n",
2035 entry->create_id, entry->qp.handle.context,
2036 entry->qp.handle.resource);
2040 result = VMCI_SUCCESS;
2042 mutex_unlock(&qp_broker_list.mutex);
2047 * Resets saved queue headers for the given QP broker
2048 * entry. Should be used when guest memory becomes available
2049 * again, or the guest detaches.
2051 static void qp_reset_saved_headers(struct qp_broker_entry *entry)
2053 entry->produce_q->saved_header = NULL;
2054 entry->consume_q->saved_header = NULL;
2058 * The main entry point for detaching from a queue pair registered with the
2059 * queue pair broker. If more than one endpoint is attached to the queue
2060 * pair, the first endpoint will mainly decrement a reference count and
2061 * generate a notification to its peer. The last endpoint will clean up
2062 * the queue pair state registered with the broker.
2064 * When a guest endpoint detaches, it will unmap and unregister the guest
2065 * memory backing the queue pair. If the host is still attached, it will
2066 * no longer be able to access the queue pair content.
2068 * If the queue pair is already in a state where there is no memory
2069 * registered for the queue pair (any *_NO_MEM state), it will transition to
2070 * the VMCIQPB_SHUTDOWN_NO_MEM state. This will also happen, if a guest
2071 * endpoint is the first of two endpoints to detach. If the host endpoint is
2072 * the first out of two to detach, the queue pair will move to the
2073 * VMCIQPB_SHUTDOWN_MEM state.
2075 int vmci_qp_broker_detach(struct vmci_handle handle, struct vmci_ctx *context)
2077 struct qp_broker_entry *entry;
2078 const u32 context_id = vmci_ctx_get_id(context);
2080 bool is_local = false;
2083 if (vmci_handle_is_invalid(handle) || !context ||
2084 context_id == VMCI_INVALID_ID) {
2085 return VMCI_ERROR_INVALID_ARGS;
2088 mutex_lock(&qp_broker_list.mutex);
2090 if (!vmci_ctx_qp_exists(context, handle)) {
2091 pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
2092 context_id, handle.context, handle.resource);
2093 result = VMCI_ERROR_NOT_FOUND;
2097 entry = qp_broker_handle_to_entry(handle);
2099 pr_devel("Context (ID=0x%x) reports being attached to queue pair(handle=0x%x:0x%x) that isn't present in broker\n",
2100 context_id, handle.context, handle.resource);
2101 result = VMCI_ERROR_NOT_FOUND;
2105 if (context_id != entry->create_id && context_id != entry->attach_id) {
2106 result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
2110 if (context_id == entry->create_id) {
2111 peer_id = entry->attach_id;
2112 entry->create_id = VMCI_INVALID_ID;
2114 peer_id = entry->create_id;
2115 entry->attach_id = VMCI_INVALID_ID;
2117 entry->qp.ref_count--;
2119 is_local = entry->qp.flags & VMCI_QPFLAG_LOCAL;
2121 if (context_id != VMCI_HOST_CONTEXT_ID) {
2122 bool headers_mapped;
2125 * Pre NOVMVM vmx'en may detach from a queue pair
2126 * before setting the page store, and in that case
2127 * there is no user memory to detach from. Also, more
2128 * recent VMX'en may detach from a queue pair in the
2132 qp_acquire_queue_mutex(entry->produce_q);
2133 headers_mapped = entry->produce_q->q_header ||
2134 entry->consume_q->q_header;
2135 if (QPBROKERSTATE_HAS_MEM(entry)) {
2137 qp_host_unmap_queues(INVALID_VMCI_GUEST_MEM_ID,
2140 if (result < VMCI_SUCCESS)
2141 pr_warn("Failed to unmap queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n",
2142 handle.context, handle.resource,
2145 qp_host_unregister_user_memory(entry->produce_q,
2150 if (!headers_mapped)
2151 qp_reset_saved_headers(entry);
2153 qp_release_queue_mutex(entry->produce_q);
2155 if (!headers_mapped && entry->wakeup_cb)
2156 entry->wakeup_cb(entry->client_data);
2159 if (entry->wakeup_cb) {
2160 entry->wakeup_cb = NULL;
2161 entry->client_data = NULL;
2165 if (entry->qp.ref_count == 0) {
2166 qp_list_remove_entry(&qp_broker_list, &entry->qp);
2169 kfree(entry->local_mem);
2171 qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q);
2172 qp_host_free_queue(entry->produce_q, entry->qp.produce_size);
2173 qp_host_free_queue(entry->consume_q, entry->qp.consume_size);
2174 /* Unlink from resource hash table and free callback */
2175 vmci_resource_remove(&entry->resource);
2179 vmci_ctx_qp_destroy(context, handle);
2181 qp_notify_peer(false, handle, context_id, peer_id);
2182 if (context_id == VMCI_HOST_CONTEXT_ID &&
2183 QPBROKERSTATE_HAS_MEM(entry)) {
2184 entry->state = VMCIQPB_SHUTDOWN_MEM;
2186 entry->state = VMCIQPB_SHUTDOWN_NO_MEM;
2190 vmci_ctx_qp_destroy(context, handle);
2193 result = VMCI_SUCCESS;
2195 mutex_unlock(&qp_broker_list.mutex);
2200 * Establishes the necessary mappings for a queue pair given a
2201 * reference to the queue pair guest memory. This is usually
2202 * called when a guest is unquiesced and the VMX is allowed to
2203 * map guest memory once again.
2205 int vmci_qp_broker_map(struct vmci_handle handle,
2206 struct vmci_ctx *context,
2209 struct qp_broker_entry *entry;
2210 const u32 context_id = vmci_ctx_get_id(context);
2213 if (vmci_handle_is_invalid(handle) || !context ||
2214 context_id == VMCI_INVALID_ID)
2215 return VMCI_ERROR_INVALID_ARGS;
2217 mutex_lock(&qp_broker_list.mutex);
2219 if (!vmci_ctx_qp_exists(context, handle)) {
2220 pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
2221 context_id, handle.context, handle.resource);
2222 result = VMCI_ERROR_NOT_FOUND;
2226 entry = qp_broker_handle_to_entry(handle);
2228 pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n",
2229 context_id, handle.context, handle.resource);
2230 result = VMCI_ERROR_NOT_FOUND;
2234 if (context_id != entry->create_id && context_id != entry->attach_id) {
2235 result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
2239 result = VMCI_SUCCESS;
2241 if (context_id != VMCI_HOST_CONTEXT_ID &&
2242 !QPBROKERSTATE_HAS_MEM(entry)) {
2243 struct vmci_qp_page_store page_store;
2245 page_store.pages = guest_mem;
2246 page_store.len = QPE_NUM_PAGES(entry->qp);
2248 qp_acquire_queue_mutex(entry->produce_q);
2249 qp_reset_saved_headers(entry);
2251 qp_host_register_user_memory(&page_store,
2254 qp_release_queue_mutex(entry->produce_q);
2255 if (result == VMCI_SUCCESS) {
2256 /* Move state from *_NO_MEM to *_MEM */
2260 if (entry->wakeup_cb)
2261 entry->wakeup_cb(entry->client_data);
2266 mutex_unlock(&qp_broker_list.mutex);
2271 * Saves a snapshot of the queue headers for the given QP broker
2272 * entry. Should be used when guest memory is unmapped.
2274 * VMCI_SUCCESS on success, appropriate error code if guest memory
2275 * can't be accessed..
2277 static int qp_save_headers(struct qp_broker_entry *entry)
2281 if (entry->produce_q->saved_header != NULL &&
2282 entry->consume_q->saved_header != NULL) {
2284 * If the headers have already been saved, we don't need to do
2285 * it again, and we don't want to map in the headers
2289 return VMCI_SUCCESS;
2292 if (NULL == entry->produce_q->q_header ||
2293 NULL == entry->consume_q->q_header) {
2294 result = qp_host_map_queues(entry->produce_q, entry->consume_q);
2295 if (result < VMCI_SUCCESS)
2299 memcpy(&entry->saved_produce_q, entry->produce_q->q_header,
2300 sizeof(entry->saved_produce_q));
2301 entry->produce_q->saved_header = &entry->saved_produce_q;
2302 memcpy(&entry->saved_consume_q, entry->consume_q->q_header,
2303 sizeof(entry->saved_consume_q));
2304 entry->consume_q->saved_header = &entry->saved_consume_q;
2306 return VMCI_SUCCESS;
2310 * Removes all references to the guest memory of a given queue pair, and
2311 * will move the queue pair from state *_MEM to *_NO_MEM. It is usually
2312 * called when a VM is being quiesced where access to guest memory should
2315 int vmci_qp_broker_unmap(struct vmci_handle handle,
2316 struct vmci_ctx *context,
2319 struct qp_broker_entry *entry;
2320 const u32 context_id = vmci_ctx_get_id(context);
2323 if (vmci_handle_is_invalid(handle) || !context ||
2324 context_id == VMCI_INVALID_ID)
2325 return VMCI_ERROR_INVALID_ARGS;
2327 mutex_lock(&qp_broker_list.mutex);
2329 if (!vmci_ctx_qp_exists(context, handle)) {
2330 pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
2331 context_id, handle.context, handle.resource);
2332 result = VMCI_ERROR_NOT_FOUND;
2336 entry = qp_broker_handle_to_entry(handle);
2338 pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n",
2339 context_id, handle.context, handle.resource);
2340 result = VMCI_ERROR_NOT_FOUND;
2344 if (context_id != entry->create_id && context_id != entry->attach_id) {
2345 result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
2349 if (context_id != VMCI_HOST_CONTEXT_ID &&
2350 QPBROKERSTATE_HAS_MEM(entry)) {
2351 qp_acquire_queue_mutex(entry->produce_q);
2352 result = qp_save_headers(entry);
2353 if (result < VMCI_SUCCESS)
2354 pr_warn("Failed to save queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n",
2355 handle.context, handle.resource, result);
2357 qp_host_unmap_queues(gid, entry->produce_q, entry->consume_q);
2360 * On hosted, when we unmap queue pairs, the VMX will also
2361 * unmap the guest memory, so we invalidate the previously
2362 * registered memory. If the queue pair is mapped again at a
2363 * later point in time, we will need to reregister the user
2364 * memory with a possibly new user VA.
2366 qp_host_unregister_user_memory(entry->produce_q,
2370 * Move state from *_MEM to *_NO_MEM.
2374 qp_release_queue_mutex(entry->produce_q);
2377 result = VMCI_SUCCESS;
2380 mutex_unlock(&qp_broker_list.mutex);
2385 * Destroys all guest queue pair endpoints. If active guest queue
2386 * pairs still exist, hypercalls to attempt detach from these
2387 * queue pairs will be made. Any failure to detach is silently
2390 void vmci_qp_guest_endpoints_exit(void)
2392 struct qp_entry *entry;
2393 struct qp_guest_endpoint *ep;
2395 mutex_lock(&qp_guest_endpoints.mutex);
2397 while ((entry = qp_list_get_head(&qp_guest_endpoints))) {
2398 ep = (struct qp_guest_endpoint *)entry;
2400 /* Don't make a hypercall for local queue_pairs. */
2401 if (!(entry->flags & VMCI_QPFLAG_LOCAL))
2402 qp_detatch_hypercall(entry->handle);
2404 /* We cannot fail the exit, so let's reset ref_count. */
2405 entry->ref_count = 0;
2406 qp_list_remove_entry(&qp_guest_endpoints, entry);
2408 qp_guest_endpoint_destroy(ep);
2411 mutex_unlock(&qp_guest_endpoints.mutex);
2415 * Helper routine that will lock the queue pair before subsequent
2417 * Note: Non-blocking on the host side is currently only implemented in ESX.
2418 * Since non-blocking isn't yet implemented on the host personality we
2419 * have no reason to acquire a spin lock. So to avoid the use of an
2420 * unnecessary lock only acquire the mutex if we can block.
2422 static void qp_lock(const struct vmci_qp *qpair)
2424 qp_acquire_queue_mutex(qpair->produce_q);
2428 * Helper routine that unlocks the queue pair after calling
2431 static void qp_unlock(const struct vmci_qp *qpair)
2433 qp_release_queue_mutex(qpair->produce_q);
2437 * The queue headers may not be mapped at all times. If a queue is
2438 * currently not mapped, it will be attempted to do so.
2440 static int qp_map_queue_headers(struct vmci_queue *produce_q,
2441 struct vmci_queue *consume_q)
2445 if (NULL == produce_q->q_header || NULL == consume_q->q_header) {
2446 result = qp_host_map_queues(produce_q, consume_q);
2447 if (result < VMCI_SUCCESS)
2448 return (produce_q->saved_header &&
2449 consume_q->saved_header) ?
2450 VMCI_ERROR_QUEUEPAIR_NOT_READY :
2451 VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
2454 return VMCI_SUCCESS;
2458 * Helper routine that will retrieve the produce and consume
2459 * headers of a given queue pair. If the guest memory of the
2460 * queue pair is currently not available, the saved queue headers
2461 * will be returned, if these are available.
2463 static int qp_get_queue_headers(const struct vmci_qp *qpair,
2464 struct vmci_queue_header **produce_q_header,
2465 struct vmci_queue_header **consume_q_header)
2469 result = qp_map_queue_headers(qpair->produce_q, qpair->consume_q);
2470 if (result == VMCI_SUCCESS) {
2471 *produce_q_header = qpair->produce_q->q_header;
2472 *consume_q_header = qpair->consume_q->q_header;
2473 } else if (qpair->produce_q->saved_header &&
2474 qpair->consume_q->saved_header) {
2475 *produce_q_header = qpair->produce_q->saved_header;
2476 *consume_q_header = qpair->consume_q->saved_header;
2477 result = VMCI_SUCCESS;
2484 * Callback from VMCI queue pair broker indicating that a queue
2485 * pair that was previously not ready, now either is ready or
2488 static int qp_wakeup_cb(void *client_data)
2490 struct vmci_qp *qpair = (struct vmci_qp *)client_data;
2493 while (qpair->blocked > 0) {
2495 qpair->generation++;
2496 wake_up(&qpair->event);
2500 return VMCI_SUCCESS;
2504 * Makes the calling thread wait for the queue pair to become
2505 * ready for host side access. Returns true when thread is
2506 * woken up after queue pair state change, false otherwise.
2508 static bool qp_wait_for_ready_queue(struct vmci_qp *qpair)
2510 unsigned int generation;
2513 generation = qpair->generation;
2515 wait_event(qpair->event, generation != qpair->generation);
2522 * Enqueues a given buffer to the produce queue using the provided
2523 * function. As many bytes as possible (space available in the queue)
2524 * are enqueued. Assumes the queue->mutex has been acquired. Returns
2525 * VMCI_ERROR_QUEUEPAIR_NOSPACE if no space was available to enqueue
2526 * data, VMCI_ERROR_INVALID_SIZE, if any queue pointer is outside the
2527 * queue (as defined by the queue size), VMCI_ERROR_INVALID_ARGS, if
2528 * an error occured when accessing the buffer,
2529 * VMCI_ERROR_QUEUEPAIR_NOTATTACHED, if the queue pair pages aren't
2530 * available. Otherwise, the number of bytes written to the queue is
2531 * returned. Updates the tail pointer of the produce queue.
2533 static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
2534 struct vmci_queue *consume_q,
2535 const u64 produce_q_size,
2536 struct iov_iter *from)
2540 size_t buf_size = iov_iter_count(from);
2544 result = qp_map_queue_headers(produce_q, consume_q);
2545 if (unlikely(result != VMCI_SUCCESS))
2548 free_space = vmci_q_header_free_space(produce_q->q_header,
2549 consume_q->q_header,
2551 if (free_space == 0)
2552 return VMCI_ERROR_QUEUEPAIR_NOSPACE;
2554 if (free_space < VMCI_SUCCESS)
2555 return (ssize_t) free_space;
2557 written = (size_t) (free_space > buf_size ? buf_size : free_space);
2558 tail = vmci_q_header_producer_tail(produce_q->q_header);
2559 if (likely(tail + written < produce_q_size)) {
2560 result = qp_memcpy_to_queue_iter(produce_q, tail, from, written);
2562 /* Tail pointer wraps around. */
2564 const size_t tmp = (size_t) (produce_q_size - tail);
2566 result = qp_memcpy_to_queue_iter(produce_q, tail, from, tmp);
2567 if (result >= VMCI_SUCCESS)
2568 result = qp_memcpy_to_queue_iter(produce_q, 0, from,
2572 if (result < VMCI_SUCCESS)
2575 vmci_q_header_add_producer_tail(produce_q->q_header, written,
2581 * Dequeues data (if available) from the given consume queue. Writes data
2582 * to the user provided buffer using the provided function.
2583 * Assumes the queue->mutex has been acquired.
2585 * VMCI_ERROR_QUEUEPAIR_NODATA if no data was available to dequeue.
2586 * VMCI_ERROR_INVALID_SIZE, if any queue pointer is outside the queue
2587 * (as defined by the queue size).
2588 * VMCI_ERROR_INVALID_ARGS, if an error occured when accessing the buffer.
2589 * Otherwise the number of bytes dequeued is returned.
2591 * Updates the head pointer of the consume queue.
2593 static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
2594 struct vmci_queue *consume_q,
2595 const u64 consume_q_size,
2596 struct iov_iter *to,
2597 bool update_consumer)
2599 size_t buf_size = iov_iter_count(to);
2605 result = qp_map_queue_headers(produce_q, consume_q);
2606 if (unlikely(result != VMCI_SUCCESS))
2609 buf_ready = vmci_q_header_buf_ready(consume_q->q_header,
2610 produce_q->q_header,
2613 return VMCI_ERROR_QUEUEPAIR_NODATA;
2615 if (buf_ready < VMCI_SUCCESS)
2616 return (ssize_t) buf_ready;
2618 read = (size_t) (buf_ready > buf_size ? buf_size : buf_ready);
2619 head = vmci_q_header_consumer_head(produce_q->q_header);
2620 if (likely(head + read < consume_q_size)) {
2621 result = qp_memcpy_from_queue_iter(to, consume_q, head, read);
2623 /* Head pointer wraps around. */
2625 const size_t tmp = (size_t) (consume_q_size - head);
2627 result = qp_memcpy_from_queue_iter(to, consume_q, head, tmp);
2628 if (result >= VMCI_SUCCESS)
2629 result = qp_memcpy_from_queue_iter(to, consume_q, 0,
2634 if (result < VMCI_SUCCESS)
2637 if (update_consumer)
2638 vmci_q_header_add_consumer_head(produce_q->q_header,
2639 read, consume_q_size);
2645 * vmci_qpair_alloc() - Allocates a queue pair.
2646 * @qpair: Pointer for the new vmci_qp struct.
2647 * @handle: Handle to track the resource.
2648 * @produce_qsize: Desired size of the producer queue.
2649 * @consume_qsize: Desired size of the consumer queue.
2650 * @peer: ContextID of the peer.
2651 * @flags: VMCI flags.
2652 * @priv_flags: VMCI priviledge flags.
2654 * This is the client interface for allocating the memory for a
2655 * vmci_qp structure and then attaching to the underlying
2656 * queue. If an error occurs allocating the memory for the
2657 * vmci_qp structure no attempt is made to attach. If an
2658 * error occurs attaching, then the structure is freed.
2660 int vmci_qpair_alloc(struct vmci_qp **qpair,
2661 struct vmci_handle *handle,
2668 struct vmci_qp *my_qpair;
2670 struct vmci_handle src = VMCI_INVALID_HANDLE;
2671 struct vmci_handle dst = vmci_make_handle(peer, VMCI_INVALID_ID);
2672 enum vmci_route route;
2673 vmci_event_release_cb wakeup_cb;
2677 * Restrict the size of a queuepair. The device already
2678 * enforces a limit on the total amount of memory that can be
2679 * allocated to queuepairs for a guest. However, we try to
2680 * allocate this memory before we make the queuepair
2681 * allocation hypercall. On Linux, we allocate each page
2682 * separately, which means rather than fail, the guest will
2683 * thrash while it tries to allocate, and will become
2684 * increasingly unresponsive to the point where it appears to
2685 * be hung. So we place a limit on the size of an individual
2686 * queuepair here, and leave the device to enforce the
2687 * restriction on total queuepair memory. (Note that this
2688 * doesn't prevent all cases; a user with only this much
2689 * physical memory could still get into trouble.) The error
2690 * used by the device is NO_RESOURCES, so use that here too.
2693 if (produce_qsize + consume_qsize < max(produce_qsize, consume_qsize) ||
2694 produce_qsize + consume_qsize > VMCI_MAX_GUEST_QP_MEMORY)
2695 return VMCI_ERROR_NO_RESOURCES;
2697 retval = vmci_route(&src, &dst, false, &route);
2698 if (retval < VMCI_SUCCESS)
2699 route = vmci_guest_code_active() ?
2700 VMCI_ROUTE_AS_GUEST : VMCI_ROUTE_AS_HOST;
2702 if (flags & (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED)) {
2703 pr_devel("NONBLOCK OR PINNED set");
2704 return VMCI_ERROR_INVALID_ARGS;
2707 my_qpair = kzalloc(sizeof(*my_qpair), GFP_KERNEL);
2709 return VMCI_ERROR_NO_MEM;
2711 my_qpair->produce_q_size = produce_qsize;
2712 my_qpair->consume_q_size = consume_qsize;
2713 my_qpair->peer = peer;
2714 my_qpair->flags = flags;
2715 my_qpair->priv_flags = priv_flags;
2720 if (VMCI_ROUTE_AS_HOST == route) {
2721 my_qpair->guest_endpoint = false;
2722 if (!(flags & VMCI_QPFLAG_LOCAL)) {
2723 my_qpair->blocked = 0;
2724 my_qpair->generation = 0;
2725 init_waitqueue_head(&my_qpair->event);
2726 wakeup_cb = qp_wakeup_cb;
2727 client_data = (void *)my_qpair;
2730 my_qpair->guest_endpoint = true;
2733 retval = vmci_qp_alloc(handle,
2734 &my_qpair->produce_q,
2735 my_qpair->produce_q_size,
2736 &my_qpair->consume_q,
2737 my_qpair->consume_q_size,
2740 my_qpair->priv_flags,
2741 my_qpair->guest_endpoint,
2742 wakeup_cb, client_data);
2744 if (retval < VMCI_SUCCESS) {
2750 my_qpair->handle = *handle;
2754 EXPORT_SYMBOL_GPL(vmci_qpair_alloc);
2757 * vmci_qpair_detach() - Detatches the client from a queue pair.
2758 * @qpair: Reference of a pointer to the qpair struct.
2760 * This is the client interface for detaching from a VMCIQPair.
2761 * Note that this routine will free the memory allocated for the
2762 * vmci_qp structure too.
2764 int vmci_qpair_detach(struct vmci_qp **qpair)
2767 struct vmci_qp *old_qpair;
2769 if (!qpair || !(*qpair))
2770 return VMCI_ERROR_INVALID_ARGS;
2773 result = qp_detatch(old_qpair->handle, old_qpair->guest_endpoint);
2776 * The guest can fail to detach for a number of reasons, and
2777 * if it does so, it will cleanup the entry (if there is one).
2778 * The host can fail too, but it won't cleanup the entry
2779 * immediately, it will do that later when the context is
2780 * freed. Either way, we need to release the qpair struct
2781 * here; there isn't much the caller can do, and we don't want
2785 memset(old_qpair, 0, sizeof(*old_qpair));
2786 old_qpair->handle = VMCI_INVALID_HANDLE;
2787 old_qpair->peer = VMCI_INVALID_ID;
2793 EXPORT_SYMBOL_GPL(vmci_qpair_detach);
2796 * vmci_qpair_get_produce_indexes() - Retrieves the indexes of the producer.
2797 * @qpair: Pointer to the queue pair struct.
2798 * @producer_tail: Reference used for storing producer tail index.
2799 * @consumer_head: Reference used for storing the consumer head index.
2801 * This is the client interface for getting the current indexes of the
2802 * QPair from the point of the view of the caller as the producer.
2804 int vmci_qpair_get_produce_indexes(const struct vmci_qp *qpair,
2808 struct vmci_queue_header *produce_q_header;
2809 struct vmci_queue_header *consume_q_header;
2813 return VMCI_ERROR_INVALID_ARGS;
2817 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2818 if (result == VMCI_SUCCESS)
2819 vmci_q_header_get_pointers(produce_q_header, consume_q_header,
2820 producer_tail, consumer_head);
2823 if (result == VMCI_SUCCESS &&
2824 ((producer_tail && *producer_tail >= qpair->produce_q_size) ||
2825 (consumer_head && *consumer_head >= qpair->produce_q_size)))
2826 return VMCI_ERROR_INVALID_SIZE;
2830 EXPORT_SYMBOL_GPL(vmci_qpair_get_produce_indexes);
2833 * vmci_qpair_get_consume_indexes() - Retrieves the indexes of the consumer.
2834 * @qpair: Pointer to the queue pair struct.
2835 * @consumer_tail: Reference used for storing consumer tail index.
2836 * @producer_head: Reference used for storing the producer head index.
2838 * This is the client interface for getting the current indexes of the
2839 * QPair from the point of the view of the caller as the consumer.
2841 int vmci_qpair_get_consume_indexes(const struct vmci_qp *qpair,
2845 struct vmci_queue_header *produce_q_header;
2846 struct vmci_queue_header *consume_q_header;
2850 return VMCI_ERROR_INVALID_ARGS;
2854 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2855 if (result == VMCI_SUCCESS)
2856 vmci_q_header_get_pointers(consume_q_header, produce_q_header,
2857 consumer_tail, producer_head);
2860 if (result == VMCI_SUCCESS &&
2861 ((consumer_tail && *consumer_tail >= qpair->consume_q_size) ||
2862 (producer_head && *producer_head >= qpair->consume_q_size)))
2863 return VMCI_ERROR_INVALID_SIZE;
2867 EXPORT_SYMBOL_GPL(vmci_qpair_get_consume_indexes);
2870 * vmci_qpair_produce_free_space() - Retrieves free space in producer queue.
2871 * @qpair: Pointer to the queue pair struct.
2873 * This is the client interface for getting the amount of free
2874 * space in the QPair from the point of the view of the caller as
2875 * the producer which is the common case. Returns < 0 if err, else
2876 * available bytes into which data can be enqueued if > 0.
2878 s64 vmci_qpair_produce_free_space(const struct vmci_qp *qpair)
2880 struct vmci_queue_header *produce_q_header;
2881 struct vmci_queue_header *consume_q_header;
2885 return VMCI_ERROR_INVALID_ARGS;
2889 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2890 if (result == VMCI_SUCCESS)
2891 result = vmci_q_header_free_space(produce_q_header,
2893 qpair->produce_q_size);
2901 EXPORT_SYMBOL_GPL(vmci_qpair_produce_free_space);
2904 * vmci_qpair_consume_free_space() - Retrieves free space in consumer queue.
2905 * @qpair: Pointer to the queue pair struct.
2907 * This is the client interface for getting the amount of free
2908 * space in the QPair from the point of the view of the caller as
2909 * the consumer which is not the common case. Returns < 0 if err, else
2910 * available bytes into which data can be enqueued if > 0.
2912 s64 vmci_qpair_consume_free_space(const struct vmci_qp *qpair)
2914 struct vmci_queue_header *produce_q_header;
2915 struct vmci_queue_header *consume_q_header;
2919 return VMCI_ERROR_INVALID_ARGS;
2923 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2924 if (result == VMCI_SUCCESS)
2925 result = vmci_q_header_free_space(consume_q_header,
2927 qpair->consume_q_size);
2935 EXPORT_SYMBOL_GPL(vmci_qpair_consume_free_space);
2938 * vmci_qpair_produce_buf_ready() - Gets bytes ready to read from
2940 * @qpair: Pointer to the queue pair struct.
2942 * This is the client interface for getting the amount of
2943 * enqueued data in the QPair from the point of the view of the
2944 * caller as the producer which is not the common case. Returns < 0 if err,
2945 * else available bytes that may be read.
2947 s64 vmci_qpair_produce_buf_ready(const struct vmci_qp *qpair)
2949 struct vmci_queue_header *produce_q_header;
2950 struct vmci_queue_header *consume_q_header;
2954 return VMCI_ERROR_INVALID_ARGS;
2958 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2959 if (result == VMCI_SUCCESS)
2960 result = vmci_q_header_buf_ready(produce_q_header,
2962 qpair->produce_q_size);
2970 EXPORT_SYMBOL_GPL(vmci_qpair_produce_buf_ready);
2973 * vmci_qpair_consume_buf_ready() - Gets bytes ready to read from
2975 * @qpair: Pointer to the queue pair struct.
2977 * This is the client interface for getting the amount of
2978 * enqueued data in the QPair from the point of the view of the
2979 * caller as the consumer which is the normal case. Returns < 0 if err,
2980 * else available bytes that may be read.
2982 s64 vmci_qpair_consume_buf_ready(const struct vmci_qp *qpair)
2984 struct vmci_queue_header *produce_q_header;
2985 struct vmci_queue_header *consume_q_header;
2989 return VMCI_ERROR_INVALID_ARGS;
2993 qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
2994 if (result == VMCI_SUCCESS)
2995 result = vmci_q_header_buf_ready(consume_q_header,
2997 qpair->consume_q_size);
3005 EXPORT_SYMBOL_GPL(vmci_qpair_consume_buf_ready);
3008 * vmci_qpair_enqueue() - Throw data on the queue.
3009 * @qpair: Pointer to the queue pair struct.
3010 * @buf: Pointer to buffer containing data
3011 * @buf_size: Length of buffer.
3012 * @buf_type: Buffer type (Unused).
3014 * This is the client interface for enqueueing data into the queue.
3015 * Returns number of bytes enqueued or < 0 on error.
3017 ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
3023 struct iov_iter from;
3024 struct kvec v = {.iov_base = (void *)buf, .iov_len = buf_size};
3027 return VMCI_ERROR_INVALID_ARGS;
3029 iov_iter_kvec(&from, WRITE, &v, 1, buf_size);
3034 result = qp_enqueue_locked(qpair->produce_q,
3036 qpair->produce_q_size,
3039 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3040 !qp_wait_for_ready_queue(qpair))
3041 result = VMCI_ERROR_WOULD_BLOCK;
3043 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3049 EXPORT_SYMBOL_GPL(vmci_qpair_enqueue);
3052 * vmci_qpair_dequeue() - Get data from the queue.
3053 * @qpair: Pointer to the queue pair struct.
3054 * @buf: Pointer to buffer for the data
3055 * @buf_size: Length of buffer.
3056 * @buf_type: Buffer type (Unused).
3058 * This is the client interface for dequeueing data from the queue.
3059 * Returns number of bytes dequeued or < 0 on error.
3061 ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
3068 struct kvec v = {.iov_base = buf, .iov_len = buf_size};
3071 return VMCI_ERROR_INVALID_ARGS;
3073 iov_iter_kvec(&to, READ, &v, 1, buf_size);
3078 result = qp_dequeue_locked(qpair->produce_q,
3080 qpair->consume_q_size,
3083 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3084 !qp_wait_for_ready_queue(qpair))
3085 result = VMCI_ERROR_WOULD_BLOCK;
3087 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3093 EXPORT_SYMBOL_GPL(vmci_qpair_dequeue);
3096 * vmci_qpair_peek() - Peek at the data in the queue.
3097 * @qpair: Pointer to the queue pair struct.
3098 * @buf: Pointer to buffer for the data
3099 * @buf_size: Length of buffer.
3100 * @buf_type: Buffer type (Unused on Linux).
3102 * This is the client interface for peeking into a queue. (I.e.,
3103 * copy data from the queue without updating the head pointer.)
3104 * Returns number of bytes dequeued or < 0 on error.
3106 ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
3112 struct kvec v = {.iov_base = buf, .iov_len = buf_size};
3116 return VMCI_ERROR_INVALID_ARGS;
3118 iov_iter_kvec(&to, READ, &v, 1, buf_size);
3123 result = qp_dequeue_locked(qpair->produce_q,
3125 qpair->consume_q_size,
3128 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3129 !qp_wait_for_ready_queue(qpair))
3130 result = VMCI_ERROR_WOULD_BLOCK;
3132 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3138 EXPORT_SYMBOL_GPL(vmci_qpair_peek);
3141 * vmci_qpair_enquev() - Throw data on the queue using iov.
3142 * @qpair: Pointer to the queue pair struct.
3143 * @iov: Pointer to buffer containing data
3144 * @iov_size: Length of buffer.
3145 * @buf_type: Buffer type (Unused).
3147 * This is the client interface for enqueueing data into the queue.
3148 * This function uses IO vectors to handle the work. Returns number
3149 * of bytes enqueued or < 0 on error.
3151 ssize_t vmci_qpair_enquev(struct vmci_qp *qpair,
3159 return VMCI_ERROR_INVALID_ARGS;
3164 result = qp_enqueue_locked(qpair->produce_q,
3166 qpair->produce_q_size,
3169 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3170 !qp_wait_for_ready_queue(qpair))
3171 result = VMCI_ERROR_WOULD_BLOCK;
3173 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3179 EXPORT_SYMBOL_GPL(vmci_qpair_enquev);
3182 * vmci_qpair_dequev() - Get data from the queue using iov.
3183 * @qpair: Pointer to the queue pair struct.
3184 * @iov: Pointer to buffer for the data
3185 * @iov_size: Length of buffer.
3186 * @buf_type: Buffer type (Unused).
3188 * This is the client interface for dequeueing data from the queue.
3189 * This function uses IO vectors to handle the work. Returns number
3190 * of bytes dequeued or < 0 on error.
3192 ssize_t vmci_qpair_dequev(struct vmci_qp *qpair,
3200 return VMCI_ERROR_INVALID_ARGS;
3205 result = qp_dequeue_locked(qpair->produce_q,
3207 qpair->consume_q_size,
3208 &msg->msg_iter, true);
3210 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3211 !qp_wait_for_ready_queue(qpair))
3212 result = VMCI_ERROR_WOULD_BLOCK;
3214 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3220 EXPORT_SYMBOL_GPL(vmci_qpair_dequev);
3223 * vmci_qpair_peekv() - Peek at the data in the queue using iov.
3224 * @qpair: Pointer to the queue pair struct.
3225 * @iov: Pointer to buffer for the data
3226 * @iov_size: Length of buffer.
3227 * @buf_type: Buffer type (Unused on Linux).
3229 * This is the client interface for peeking into a queue. (I.e.,
3230 * copy data from the queue without updating the head pointer.)
3231 * This function uses IO vectors to handle the work. Returns number
3232 * of bytes peeked or < 0 on error.
3234 ssize_t vmci_qpair_peekv(struct vmci_qp *qpair,
3242 return VMCI_ERROR_INVALID_ARGS;
3247 result = qp_dequeue_locked(qpair->produce_q,
3249 qpair->consume_q_size,
3250 &msg->msg_iter, false);
3252 if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
3253 !qp_wait_for_ready_queue(qpair))
3254 result = VMCI_ERROR_WOULD_BLOCK;
3256 } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
3261 EXPORT_SYMBOL_GPL(vmci_qpair_peekv);