| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| George Zhang | 10351 | 91.62% | 2 | 5.71% |
| Andy King | 409 | 3.62% | 4 | 11.43% |
| Al Viro | 189 | 1.67% | 6 | 17.14% |
| Jorgen Hansen | 105 | 0.93% | 4 | 11.43% |
| Vishnu DASA | 105 | 0.93% | 2 | 5.71% |
| Dan Carpenter | 43 | 0.38% | 2 | 5.71% |
| Alexander Potapenko | 26 | 0.23% | 1 | 2.86% |
| Alex Dewar | 12 | 0.11% | 1 | 2.86% |
| Fabio M. De Francesco | 12 | 0.11% | 1 | 2.86% |
| Wang Hai | 11 | 0.10% | 1 | 2.86% |
| Sabyrzhan Tasbolatov | 11 | 0.10% | 1 | 2.86% |
| Kees Cook | 4 | 0.04% | 1 | 2.86% |
| Davidlohr Bueso A | 4 | 0.04% | 1 | 2.86% |
| Dmitry Torokhov | 4 | 0.04% | 1 | 2.86% |
| David Rientjes | 3 | 0.03% | 1 | 2.86% |
| Jan Kara | 2 | 0.02% | 1 | 2.86% |
| Ira Weiny | 2 | 0.02% | 1 | 2.86% |
| Thomas Gleixner | 2 | 0.02% | 1 | 2.86% |
| Masahiro Yamada | 1 | 0.01% | 1 | 2.86% |
| Kirill A. Shutemov | 1 | 0.01% | 1 | 2.86% |
| Rusty Russell | 1 | 0.01% | 1 | 2.86% |
| Total | 11298 | 35 |
// SPDX-License-Identifier: GPL-2.0-only /* * VMware VMCI Driver * * Copyright (C) 2012 VMware, Inc. All rights reserved. */ #include <linux/vmw_vmci_defs.h> #include <linux/vmw_vmci_api.h> #include <linux/highmem.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/pagemap.h> #include <linux/pci.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/uio.h> #include <linux/wait.h> #include <linux/vmalloc.h> #include <linux/skbuff.h> #include "vmci_handle_array.h" #include "vmci_queue_pair.h" #include "vmci_datagram.h" #include "vmci_resource.h" #include "vmci_context.h" #include "vmci_driver.h" #include "vmci_event.h" #include "vmci_route.h" /* * In the following, we will distinguish between two kinds of VMX processes - * the ones with versions lower than VMCI_VERSION_NOVMVM that use specialized * VMCI page files in the VMX and supporting VM to VM communication and the * newer ones that use the guest memory directly. We will in the following * refer to the older VMX versions as old-style VMX'en, and the newer ones as * new-style VMX'en. * * The state transition datagram is as follows (the VMCIQPB_ prefix has been * removed for readability) - see below for more details on the transtions: * * -------------- NEW ------------- * | | * \_/ \_/ * CREATED_NO_MEM <-----------------> CREATED_MEM * | | | * | o-----------------------o | * | | | * \_/ \_/ \_/ * ATTACHED_NO_MEM <----------------> ATTACHED_MEM * | | | * | o----------------------o | * | | | * \_/ \_/ \_/ * SHUTDOWN_NO_MEM <----------------> SHUTDOWN_MEM * | | * | | * -------------> gone <------------- * * In more detail. When a VMCI queue pair is first created, it will be in the * VMCIQPB_NEW state. It will then move into one of the following states: * * - VMCIQPB_CREATED_NO_MEM: this state indicates that either: * * - the created was performed by a host endpoint, in which case there is * no backing memory yet. * * - the create was initiated by an old-style VMX, that uses * vmci_qp_broker_set_page_store to specify the UVAs of the queue pair at * a later point in time. This state can be distinguished from the one * above by the context ID of the creator. A host side is not allowed to * attach until the page store has been set. * * - VMCIQPB_CREATED_MEM: this state is the result when the queue pair * is created by a VMX using the queue pair device backend that * sets the UVAs of the queue pair immediately and stores the * information for later attachers. At this point, it is ready for * the host side to attach to it. * * Once the queue pair is in one of the created states (with the exception of * the case mentioned for older VMX'en above), it is possible to attach to the * queue pair. Again we have two new states possible: * * - VMCIQPB_ATTACHED_MEM: this state can be reached through the following * paths: * * - from VMCIQPB_CREATED_NO_MEM when a new-style VMX allocates a queue * pair, and attaches to a queue pair previously created by the host side. * * - from VMCIQPB_CREATED_MEM when the host side attaches to a queue pair * already created by a guest. * * - from VMCIQPB_ATTACHED_NO_MEM, when an old-style VMX calls * vmci_qp_broker_set_page_store (see below). * * - VMCIQPB_ATTACHED_NO_MEM: If the queue pair already was in the * VMCIQPB_CREATED_NO_MEM due to a host side create, an old-style VMX will * bring the queue pair into this state. Once vmci_qp_broker_set_page_store * is called to register the user memory, the VMCIQPB_ATTACH_MEM state * will be entered. * * From the attached queue pair, the queue pair can enter the shutdown states * when either side of the queue pair detaches. If the guest side detaches * first, the queue pair will enter the VMCIQPB_SHUTDOWN_NO_MEM state, where * the content of the queue pair will no longer be available. If the host * side detaches first, the queue pair will either enter the * VMCIQPB_SHUTDOWN_MEM, if the guest memory is currently mapped, or * VMCIQPB_SHUTDOWN_NO_MEM, if the guest memory is not mapped * (e.g., the host detaches while a guest is stunned). * * New-style VMX'en will also unmap guest memory, if the guest is * quiesced, e.g., during a snapshot operation. In that case, the guest * memory will no longer be available, and the queue pair will transition from * *_MEM state to a *_NO_MEM state. The VMX may later map the memory once more, * in which case the queue pair will transition from the *_NO_MEM state at that * point back to the *_MEM state. Note that the *_NO_MEM state may have changed, * since the peer may have either attached or detached in the meantime. The * values are laid out such that ++ on a state will move from a *_NO_MEM to a * *_MEM state, and vice versa. */ /* The Kernel specific component of the struct vmci_queue structure. */ struct vmci_queue_kern_if { struct mutex __mutex; /* Protects the queue. */ struct mutex *mutex; /* Shared by producer and consumer queues. */ size_t num_pages; /* Number of pages incl. header. */ bool host; /* Host or guest? */ union { struct { dma_addr_t *pas; void **vas; } g; /* Used by the guest. */ struct { struct page **page; struct page **header_page; } h; /* Used by the host. */ } u; }; /* * This structure is opaque to the clients. */ struct vmci_qp { struct vmci_handle handle; struct vmci_queue *produce_q; struct vmci_queue *consume_q; u64 produce_q_size; u64 consume_q_size; u32 peer; u32 flags; u32 priv_flags; bool guest_endpoint; unsigned int blocked; unsigned int generation; wait_queue_head_t event; }; enum qp_broker_state { VMCIQPB_NEW, VMCIQPB_CREATED_NO_MEM, VMCIQPB_CREATED_MEM, VMCIQPB_ATTACHED_NO_MEM, VMCIQPB_ATTACHED_MEM, VMCIQPB_SHUTDOWN_NO_MEM, VMCIQPB_SHUTDOWN_MEM, VMCIQPB_GONE }; #define QPBROKERSTATE_HAS_MEM(_qpb) (_qpb->state == VMCIQPB_CREATED_MEM || \ _qpb->state == VMCIQPB_ATTACHED_MEM || \ _qpb->state == VMCIQPB_SHUTDOWN_MEM) /* * In the queue pair broker, we always use the guest point of view for * the produce and consume queue values and references, e.g., the * produce queue size stored is the guests produce queue size. The * host endpoint will need to swap these around. The only exception is * the local queue pairs on the host, in which case the host endpoint * that creates the queue pair will have the right orientation, and * the attaching host endpoint will need to swap. */ struct qp_entry { struct list_head list_item; struct vmci_handle handle; u32 peer; u32 flags; u64 produce_size; u64 consume_size; u32 ref_count; }; struct qp_broker_entry { struct vmci_resource resource; struct qp_entry qp; u32 create_id; u32 attach_id; enum qp_broker_state state; bool require_trusted_attach; bool created_by_trusted; bool vmci_page_files; /* Created by VMX using VMCI page files */ struct vmci_queue *produce_q; struct vmci_queue *consume_q; struct vmci_queue_header saved_produce_q; struct vmci_queue_header saved_consume_q; vmci_event_release_cb wakeup_cb; void *client_data; void *local_mem; /* Kernel memory for local queue pair */ }; struct qp_guest_endpoint { struct vmci_resource resource; struct qp_entry qp; u64 num_ppns; void *produce_q; void *consume_q; struct ppn_set ppn_set; }; struct qp_list { struct list_head head; struct mutex mutex; /* Protect queue list. */ }; static struct qp_list qp_broker_list = { .head = LIST_HEAD_INIT(qp_broker_list.head), .mutex = __MUTEX_INITIALIZER(qp_broker_list.mutex), }; static struct qp_list qp_guest_endpoints = { .head = LIST_HEAD_INIT(qp_guest_endpoints.head), .mutex = __MUTEX_INITIALIZER(qp_guest_endpoints.mutex), }; #define INVALID_VMCI_GUEST_MEM_ID 0 #define QPE_NUM_PAGES(_QPE) ((u32) \ (DIV_ROUND_UP(_QPE.produce_size, PAGE_SIZE) + \ DIV_ROUND_UP(_QPE.consume_size, PAGE_SIZE) + 2)) #define QP_SIZES_ARE_VALID(_prod_qsize, _cons_qsize) \ ((_prod_qsize) + (_cons_qsize) >= max(_prod_qsize, _cons_qsize) && \ (_prod_qsize) + (_cons_qsize) <= VMCI_MAX_GUEST_QP_MEMORY) /* * Frees kernel VA space for a given queue and its queue header, and * frees physical data pages. */ static void qp_free_queue(void *q, u64 size) { struct vmci_queue *queue = q; if (queue) { u64 i; /* Given size does not include header, so add in a page here. */ for (i = 0; i < DIV_ROUND_UP(size, PAGE_SIZE) + 1; i++) { dma_free_coherent(&vmci_pdev->dev, PAGE_SIZE, queue->kernel_if->u.g.vas[i], queue->kernel_if->u.g.pas[i]); } vfree(queue); } } /* * Allocates kernel queue pages of specified size with IOMMU mappings, * plus space for the queue structure/kernel interface and the queue * header. */ static void *qp_alloc_queue(u64 size, u32 flags) { u64 i; struct vmci_queue *queue; size_t pas_size; size_t vas_size; size_t queue_size = sizeof(*queue) + sizeof(*queue->kernel_if); u64 num_pages; if (size > SIZE_MAX - PAGE_SIZE) return NULL; num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1; if (num_pages > (SIZE_MAX - queue_size) / (sizeof(*queue->kernel_if->u.g.pas) + sizeof(*queue->kernel_if->u.g.vas))) return NULL; pas_size = num_pages * sizeof(*queue->kernel_if->u.g.pas); vas_size = num_pages * sizeof(*queue->kernel_if->u.g.vas); queue_size += pas_size + vas_size; queue = vmalloc(queue_size); if (!queue) return NULL; queue->q_header = NULL; queue->saved_header = NULL; queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1); queue->kernel_if->mutex = NULL; queue->kernel_if->num_pages = num_pages; queue->kernel_if->u.g.pas = (dma_addr_t *)(queue->kernel_if + 1); queue->kernel_if->u.g.vas = (void **)((u8 *)queue->kernel_if->u.g.pas + pas_size); queue->kernel_if->host = false; for (i = 0; i < num_pages; i++) { queue->kernel_if->u.g.vas[i] = dma_alloc_coherent(&vmci_pdev->dev, PAGE_SIZE, &queue->kernel_if->u.g.pas[i], GFP_KERNEL); if (!queue->kernel_if->u.g.vas[i]) { /* Size excl. the header. */ qp_free_queue(queue, i * PAGE_SIZE); return NULL; } } /* Queue header is the first page. */ queue->q_header = queue->kernel_if->u.g.vas[0]; return queue; } /* * Copies from a given buffer or iovector to a VMCI Queue. Uses * kmap_local_page() to dynamically map required portions of the queue * by traversing the offset -> page translation structure for the queue. * Assumes that offset + size does not wrap around in the queue. */ static int qp_memcpy_to_queue_iter(struct vmci_queue *queue, u64 queue_offset, struct iov_iter *from, size_t size) { struct vmci_queue_kern_if *kernel_if = queue->kernel_if; size_t bytes_copied = 0; while (bytes_copied < size) { const u64 page_index = (queue_offset + bytes_copied) / PAGE_SIZE; const size_t page_offset = (queue_offset + bytes_copied) & (PAGE_SIZE - 1); void *va; size_t to_copy; if (kernel_if->host) va = kmap_local_page(kernel_if->u.h.page[page_index]); else va = kernel_if->u.g.vas[page_index + 1]; /* Skip header. */ if (size - bytes_copied > PAGE_SIZE - page_offset) /* Enough payload to fill up from this page. */ to_copy = PAGE_SIZE - page_offset; else to_copy = size - bytes_copied; if (!copy_from_iter_full((u8 *)va + page_offset, to_copy, from)) { if (kernel_if->host) kunmap_local(va); return VMCI_ERROR_INVALID_ARGS; } bytes_copied += to_copy; if (kernel_if->host) kunmap_local(va); } return VMCI_SUCCESS; } /* * Copies to a given buffer or iovector from a VMCI Queue. Uses * kmap_local_page() to dynamically map required portions of the queue * by traversing the offset -> page translation structure for the queue. * Assumes that offset + size does not wrap around in the queue. */ static int qp_memcpy_from_queue_iter(struct iov_iter *to, const struct vmci_queue *queue, u64 queue_offset, size_t size) { struct vmci_queue_kern_if *kernel_if = queue->kernel_if; size_t bytes_copied = 0; while (bytes_copied < size) { const u64 page_index = (queue_offset + bytes_copied) / PAGE_SIZE; const size_t page_offset = (queue_offset + bytes_copied) & (PAGE_SIZE - 1); void *va; size_t to_copy; int err; if (kernel_if->host) va = kmap_local_page(kernel_if->u.h.page[page_index]); else va = kernel_if->u.g.vas[page_index + 1]; /* Skip header. */ if (size - bytes_copied > PAGE_SIZE - page_offset) /* Enough payload to fill up this page. */ to_copy = PAGE_SIZE - page_offset; else to_copy = size - bytes_copied; err = copy_to_iter((u8 *)va + page_offset, to_copy, to); if (err != to_copy) { if (kernel_if->host) kunmap_local(va); return VMCI_ERROR_INVALID_ARGS; } bytes_copied += to_copy; if (kernel_if->host) kunmap_local(va); } return VMCI_SUCCESS; } /* * Allocates two list of PPNs --- one for the pages in the produce queue, * and the other for the pages in the consume queue. Intializes the list * of PPNs with the page frame numbers of the KVA for the two queues (and * the queue headers). */ static int qp_alloc_ppn_set(void *prod_q, u64 num_produce_pages, void *cons_q, u64 num_consume_pages, struct ppn_set *ppn_set) { u64 *produce_ppns; u64 *consume_ppns; struct vmci_queue *produce_q = prod_q; struct vmci_queue *consume_q = cons_q; u64 i; if (!produce_q || !num_produce_pages || !consume_q || !num_consume_pages || !ppn_set) return VMCI_ERROR_INVALID_ARGS; if (ppn_set->initialized) return VMCI_ERROR_ALREADY_EXISTS; produce_ppns = kmalloc_array(num_produce_pages, sizeof(*produce_ppns), GFP_KERNEL); if (!produce_ppns) return VMCI_ERROR_NO_MEM; consume_ppns = kmalloc_array(num_consume_pages, sizeof(*consume_ppns), GFP_KERNEL); if (!consume_ppns) { kfree(produce_ppns); return VMCI_ERROR_NO_MEM; } for (i = 0; i < num_produce_pages; i++) produce_ppns[i] = produce_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT; for (i = 0; i < num_consume_pages; i++) consume_ppns[i] = consume_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT; ppn_set->num_produce_pages = num_produce_pages; ppn_set->num_consume_pages = num_consume_pages; ppn_set->produce_ppns = produce_ppns; ppn_set->consume_ppns = consume_ppns; ppn_set->initialized = true; return VMCI_SUCCESS; } /* * Frees the two list of PPNs for a queue pair. */ static void qp_free_ppn_set(struct ppn_set *ppn_set) { if (ppn_set->initialized) { /* Do not call these functions on NULL inputs. */ kfree(ppn_set->produce_ppns); kfree(ppn_set->consume_ppns); } memset(ppn_set, 0, sizeof(*ppn_set)); } /* * Populates the list of PPNs in the hypercall structure with the PPNS * of the produce queue and the consume queue. */ static int qp_populate_ppn_set(u8 *call_buf, const struct ppn_set *ppn_set) { if (vmci_use_ppn64()) { memcpy(call_buf, ppn_set->produce_ppns, ppn_set->num_produce_pages * sizeof(*ppn_set->produce_ppns)); memcpy(call_buf + ppn_set->num_produce_pages * sizeof(*ppn_set->produce_ppns), ppn_set->consume_ppns, ppn_set->num_consume_pages * sizeof(*ppn_set->consume_ppns)); } else { int i; u32 *ppns = (u32 *) call_buf; for (i = 0; i < ppn_set->num_produce_pages; i++) ppns[i] = (u32) ppn_set->produce_ppns[i]; ppns = &ppns[ppn_set->num_produce_pages]; for (i = 0; i < ppn_set->num_consume_pages; i++) ppns[i] = (u32) ppn_set->consume_ppns[i]; } return VMCI_SUCCESS; } /* * Allocates kernel VA space of specified size plus space for the queue * and kernel interface. This is different from the guest queue allocator, * because we do not allocate our own queue header/data pages here but * share those of the guest. */ static struct vmci_queue *qp_host_alloc_queue(u64 size) { struct vmci_queue *queue; size_t queue_page_size; u64 num_pages; const size_t queue_size = sizeof(*queue) + sizeof(*(queue->kernel_if)); if (size > min_t(size_t, VMCI_MAX_GUEST_QP_MEMORY, SIZE_MAX - PAGE_SIZE)) return NULL; num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1; if (num_pages > (SIZE_MAX - queue_size) / sizeof(*queue->kernel_if->u.h.page)) return NULL; queue_page_size = num_pages * sizeof(*queue->kernel_if->u.h.page); if (queue_size + queue_page_size > KMALLOC_MAX_SIZE) return NULL; queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL); if (queue) { queue->q_header = NULL; queue->saved_header = NULL; queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1); queue->kernel_if->host = true; queue->kernel_if->mutex = NULL; queue->kernel_if->num_pages = num_pages; queue->kernel_if->u.h.header_page = (struct page **)((u8 *)queue + queue_size); queue->kernel_if->u.h.page = &queue->kernel_if->u.h.header_page[1]; } return queue; } /* * Frees kernel memory for a given queue (header plus translation * structure). */ static void qp_host_free_queue(struct vmci_queue *queue, u64 queue_size) { kfree(queue); } /* * Initialize the mutex for the pair of queues. This mutex is used to * protect the q_header and the buffer from changing out from under any * users of either queue. Of course, it's only any good if the mutexes * are actually acquired. Queue structure must lie on non-paged memory * or we cannot guarantee access to the mutex. */ static void qp_init_queue_mutex(struct vmci_queue *produce_q, struct vmci_queue *consume_q) { /* * Only the host queue has shared state - the guest queues do not * need to synchronize access using a queue mutex. */ if (produce_q->kernel_if->host) { produce_q->kernel_if->mutex = &produce_q->kernel_if->__mutex; consume_q->kernel_if->mutex = &produce_q->kernel_if->__mutex; mutex_init(produce_q->kernel_if->mutex); } } /* * Cleans up the mutex for the pair of queues. */ static void qp_cleanup_queue_mutex(struct vmci_queue *produce_q, struct vmci_queue *consume_q) { if (produce_q->kernel_if->host) { produce_q->kernel_if->mutex = NULL; consume_q->kernel_if->mutex = NULL; } } /* * Acquire the mutex for the queue. Note that the produce_q and * the consume_q share a mutex. So, only one of the two need to * be passed in to this routine. Either will work just fine. */ static void qp_acquire_queue_mutex(struct vmci_queue *queue) { if (queue->kernel_if->host) mutex_lock(queue->kernel_if->mutex); } /* * Release the mutex for the queue. Note that the produce_q and * the consume_q share a mutex. So, only one of the two need to * be passed in to this routine. Either will work just fine. */ static void qp_release_queue_mutex(struct vmci_queue *queue) { if (queue->kernel_if->host) mutex_unlock(queue->kernel_if->mutex); } /* * Helper function to release pages in the PageStoreAttachInfo * previously obtained using get_user_pages. */ static void qp_release_pages(struct page **pages, u64 num_pages, bool dirty) { int i; for (i = 0; i < num_pages; i++) { if (dirty) set_page_dirty_lock(pages[i]); put_page(pages[i]); pages[i] = NULL; } } /* * Lock the user pages referenced by the {produce,consume}Buffer * struct into memory and populate the {produce,consume}Pages * arrays in the attach structure with them. */ static int qp_host_get_user_memory(u64 produce_uva, u64 consume_uva, struct vmci_queue *produce_q, struct vmci_queue *consume_q) { int retval; int err = VMCI_SUCCESS; retval = get_user_pages_fast((uintptr_t) produce_uva, produce_q->kernel_if->num_pages, FOLL_WRITE, produce_q->kernel_if->u.h.header_page); if (retval < (int)produce_q->kernel_if->num_pages) { pr_debug("get_user_pages_fast(produce) failed (retval=%d)", retval); if (retval > 0) qp_release_pages(produce_q->kernel_if->u.h.header_page, retval, false); err = VMCI_ERROR_NO_MEM; goto out; } retval = get_user_pages_fast((uintptr_t) consume_uva, consume_q->kernel_if->num_pages, FOLL_WRITE, consume_q->kernel_if->u.h.header_page); if (retval < (int)consume_q->kernel_if->num_pages) { pr_debug("get_user_pages_fast(consume) failed (retval=%d)", retval); if (retval > 0) qp_release_pages(consume_q->kernel_if->u.h.header_page, retval, false); qp_release_pages(produce_q->kernel_if->u.h.header_page, produce_q->kernel_if->num_pages, false); err = VMCI_ERROR_NO_MEM; } out: return err; } /* * Registers the specification of the user pages used for backing a queue * pair. Enough information to map in pages is stored in the OS specific * part of the struct vmci_queue structure. */ static int qp_host_register_user_memory(struct vmci_qp_page_store *page_store, struct vmci_queue *produce_q, struct vmci_queue *consume_q) { u64 produce_uva; u64 consume_uva; /* * The new style and the old style mapping only differs in * that we either get a single or two UVAs, so we split the * single UVA range at the appropriate spot. */ produce_uva = page_store->pages; consume_uva = page_store->pages + produce_q->kernel_if->num_pages * PAGE_SIZE; return qp_host_get_user_memory(produce_uva, consume_uva, produce_q, consume_q); } /* * Releases and removes the references to user pages stored in the attach * struct. Pages are released from the page cache and may become * swappable again. */ static void qp_host_unregister_user_memory(struct vmci_queue *produce_q, struct vmci_queue *consume_q) { qp_release_pages(produce_q->kernel_if->u.h.header_page, produce_q->kernel_if->num_pages, true); memset(produce_q->kernel_if->u.h.header_page, 0, sizeof(*produce_q->kernel_if->u.h.header_page) * produce_q->kernel_if->num_pages); qp_release_pages(consume_q->kernel_if->u.h.header_page, consume_q->kernel_if->num_pages, true); memset(consume_q->kernel_if->u.h.header_page, 0, sizeof(*consume_q->kernel_if->u.h.header_page) * consume_q->kernel_if->num_pages); } /* * Once qp_host_register_user_memory has been performed on a * queue, the queue pair headers can be mapped into the * kernel. Once mapped, they must be unmapped with * qp_host_unmap_queues prior to calling * qp_host_unregister_user_memory. * Pages are pinned. */ static int qp_host_map_queues(struct vmci_queue *produce_q, struct vmci_queue *consume_q) { int result; if (!produce_q->q_header || !consume_q->q_header) { struct page *headers[2]; if (produce_q->q_header != consume_q->q_header) return VMCI_ERROR_QUEUEPAIR_MISMATCH; if (produce_q->kernel_if->u.h.header_page == NULL || *produce_q->kernel_if->u.h.header_page == NULL) return VMCI_ERROR_UNAVAILABLE; headers[0] = *produce_q->kernel_if->u.h.header_page; headers[1] = *consume_q->kernel_if->u.h.header_page; produce_q->q_header = vmap(headers, 2, VM_MAP, PAGE_KERNEL); if (produce_q->q_header != NULL) { consume_q->q_header = (struct vmci_queue_header *)((u8 *) produce_q->q_header + PAGE_SIZE); result = VMCI_SUCCESS; } else { pr_warn("vmap failed\n"); result = VMCI_ERROR_NO_MEM; } } else { result = VMCI_SUCCESS; } return result; } /* * Unmaps previously mapped queue pair headers from the kernel. * Pages are unpinned. */ static int qp_host_unmap_queues(u32 gid, struct vmci_queue *produce_q, struct vmci_queue *consume_q) { if (produce_q->q_header) { if (produce_q->q_header < consume_q->q_header) vunmap(produce_q->q_header); else vunmap(consume_q->q_header); produce_q->q_header = NULL; consume_q->q_header = NULL; } return VMCI_SUCCESS; } /* * Finds the entry in the list corresponding to a given handle. Assumes * that the list is locked. */ static struct qp_entry *qp_list_find(struct qp_list *qp_list, struct vmci_handle handle) { struct qp_entry *entry; if (vmci_handle_is_invalid(handle)) return NULL; list_for_each_entry(entry, &qp_list->head, list_item) { if (vmci_handle_is_equal(entry->handle, handle)) return entry; } return NULL; } /* * Finds the entry in the list corresponding to a given handle. */ static struct qp_guest_endpoint * qp_guest_handle_to_entry(struct vmci_handle handle) { struct qp_guest_endpoint *entry; struct qp_entry *qp = qp_list_find(&qp_guest_endpoints, handle); entry = qp ? container_of( qp, struct qp_guest_endpoint, qp) : NULL; return entry; } /* * Finds the entry in the list corresponding to a given handle. */ static struct qp_broker_entry * qp_broker_handle_to_entry(struct vmci_handle handle) { struct qp_broker_entry *entry; struct qp_entry *qp = qp_list_find(&qp_broker_list, handle); entry = qp ? container_of( qp, struct qp_broker_entry, qp) : NULL; return entry; } /* * Dispatches a queue pair event message directly into the local event * queue. */ static int qp_notify_peer_local(bool attach, struct vmci_handle handle) { u32 context_id = vmci_get_context_id(); struct vmci_event_qp ev; memset(&ev, 0, sizeof(ev)); ev.msg.hdr.dst = vmci_make_handle(context_id, VMCI_EVENT_HANDLER); ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); ev.msg.event_data.event = attach ? VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH; ev.payload.peer_id = context_id; ev.payload.handle = handle; return vmci_event_dispatch(&ev.msg.hdr); } /* * Allocates and initializes a qp_guest_endpoint structure. * Allocates a queue_pair rid (and handle) iff the given entry has * an invalid handle. 0 through VMCI_RESERVED_RESOURCE_ID_MAX * are reserved handles. Assumes that the QP list mutex is held * by the caller. */ static struct qp_guest_endpoint * qp_guest_endpoint_create(struct vmci_handle handle, u32 peer, u32 flags, u64 produce_size, u64 consume_size, void *produce_q, void *consume_q) { int result; struct qp_guest_endpoint *entry; /* One page each for the queue headers. */ const u64 num_ppns = DIV_ROUND_UP(produce_size, PAGE_SIZE) + DIV_ROUND_UP(consume_size, PAGE_SIZE) + 2; if (vmci_handle_is_invalid(handle)) { u32 context_id = vmci_get_context_id(); handle = vmci_make_handle(context_id, VMCI_INVALID_ID); } entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (entry) { entry->qp.peer = peer; entry->qp.flags = flags; entry->qp.produce_size = produce_size; entry->qp.consume_size = consume_size; entry->qp.ref_count = 0; entry->num_ppns = num_ppns; entry->produce_q = produce_q; entry->consume_q = consume_q; INIT_LIST_HEAD(&entry->qp.list_item); /* Add resource obj */ result = vmci_resource_add(&entry->resource, VMCI_RESOURCE_TYPE_QPAIR_GUEST, handle); entry->qp.handle = vmci_resource_handle(&entry->resource); if ((result != VMCI_SUCCESS) || qp_list_find(&qp_guest_endpoints, entry->qp.handle)) { pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d", handle.context, handle.resource, result); kfree(entry); entry = NULL; } } return entry; } /* * Frees a qp_guest_endpoint structure. */ static void qp_guest_endpoint_destroy(struct qp_guest_endpoint *entry) { qp_free_ppn_set(&entry->ppn_set); qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q); qp_free_queue(entry->produce_q, entry->qp.produce_size); qp_free_queue(entry->consume_q, entry->qp.consume_size); /* Unlink from resource hash table and free callback */ vmci_resource_remove(&entry->resource); kfree(entry); } /* * Helper to make a queue_pairAlloc hypercall when the driver is * supporting a guest device. */ static int qp_alloc_hypercall(const struct qp_guest_endpoint *entry) { struct vmci_qp_alloc_msg *alloc_msg; size_t msg_size; size_t ppn_size; int result; if (!entry || entry->num_ppns <= 2) return VMCI_ERROR_INVALID_ARGS; ppn_size = vmci_use_ppn64() ? sizeof(u64) : sizeof(u32); msg_size = sizeof(*alloc_msg) + (size_t) entry->num_ppns * ppn_size; alloc_msg = kmalloc(msg_size, GFP_KERNEL); if (!alloc_msg) return VMCI_ERROR_NO_MEM; alloc_msg->hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_QUEUEPAIR_ALLOC); alloc_msg->hdr.src = VMCI_ANON_SRC_HANDLE; alloc_msg->hdr.payload_size = msg_size - VMCI_DG_HEADERSIZE; alloc_msg->handle = entry->qp.handle; alloc_msg->peer = entry->qp.peer; alloc_msg->flags = entry->qp.flags; alloc_msg->produce_size = entry->qp.produce_size; alloc_msg->consume_size = entry->qp.consume_size; alloc_msg->num_ppns = entry->num_ppns; result = qp_populate_ppn_set((u8 *)alloc_msg + sizeof(*alloc_msg), &entry->ppn_set); if (result == VMCI_SUCCESS) result = vmci_send_datagram(&alloc_msg->hdr); kfree(alloc_msg); return result; } /* * Helper to make a queue_pairDetach hypercall when the driver is * supporting a guest device. */ static int qp_detatch_hypercall(struct vmci_handle handle) { struct vmci_qp_detach_msg detach_msg; detach_msg.hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_QUEUEPAIR_DETACH); detach_msg.hdr.src = VMCI_ANON_SRC_HANDLE; detach_msg.hdr.payload_size = sizeof(handle); detach_msg.handle = handle; return vmci_send_datagram(&detach_msg.hdr); } /* * Adds the given entry to the list. Assumes that the list is locked. */ static void qp_list_add_entry(struct qp_list *qp_list, struct qp_entry *entry) { if (entry) list_add(&entry->list_item, &qp_list->head); } /* * Removes the given entry from the list. Assumes that the list is locked. */ static void qp_list_remove_entry(struct qp_list *qp_list, struct qp_entry *entry) { if (entry) list_del(&entry->list_item); } /* * Helper for VMCI queue_pair detach interface. Frees the physical * pages for the queue pair. */ static int qp_detatch_guest_work(struct vmci_handle handle) { int result; struct qp_guest_endpoint *entry; u32 ref_count = ~0; /* To avoid compiler warning below */ mutex_lock(&qp_guest_endpoints.mutex); entry = qp_guest_handle_to_entry(handle); if (!entry) { mutex_unlock(&qp_guest_endpoints.mutex); return VMCI_ERROR_NOT_FOUND; } if (entry->qp.flags & VMCI_QPFLAG_LOCAL) { result = VMCI_SUCCESS; if (entry->qp.ref_count > 1) { result = qp_notify_peer_local(false, handle); /* * We can fail to notify a local queuepair * because we can't allocate. We still want * to release the entry if that happens, so * don't bail out yet. */ } } else { result = qp_detatch_hypercall(handle); if (result < VMCI_SUCCESS) { /* * We failed to notify a non-local queuepair. * That other queuepair might still be * accessing the shared memory, so don't * release the entry yet. It will get cleaned * up by VMCIqueue_pair_Exit() if necessary * (assuming we are going away, otherwise why * did this fail?). */ mutex_unlock(&qp_guest_endpoints.mutex); return result; } } /* * If we get here then we either failed to notify a local queuepair, or * we succeeded in all cases. Release the entry if required. */ entry->qp.ref_count--; if (entry->qp.ref_count == 0) qp_list_remove_entry(&qp_guest_endpoints, &entry->qp); /* If we didn't remove the entry, this could change once we unlock. */ if (entry) ref_count = entry->qp.ref_count; mutex_unlock(&qp_guest_endpoints.mutex); if (ref_count == 0) qp_guest_endpoint_destroy(entry); return result; } /* * This functions handles the actual allocation of a VMCI queue * pair guest endpoint. Allocates physical pages for the queue * pair. It makes OS dependent calls through generic wrappers. */ static int qp_alloc_guest_work(struct vmci_handle *handle, struct vmci_queue **produce_q, u64 produce_size, struct vmci_queue **consume_q, u64 consume_size, u32 peer, u32 flags, u32 priv_flags) { const u64 num_produce_pages = DIV_ROUND_UP(produce_size, PAGE_SIZE) + 1; const u64 num_consume_pages = DIV_ROUND_UP(consume_size, PAGE_SIZE) + 1; void *my_produce_q = NULL; void *my_consume_q = NULL; int result; struct qp_guest_endpoint *queue_pair_entry = NULL; if (priv_flags != VMCI_NO_PRIVILEGE_FLAGS) return VMCI_ERROR_NO_ACCESS; mutex_lock(&qp_guest_endpoints.mutex); queue_pair_entry = qp_guest_handle_to_entry(*handle); if (queue_pair_entry) { if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) { /* Local attach case. */ if (queue_pair_entry->qp.ref_count > 1) { pr_devel("Error attempting to attach more than once\n"); result = VMCI_ERROR_UNAVAILABLE; goto error_keep_entry; } if (queue_pair_entry->qp.produce_size != consume_size || queue_pair_entry->qp.consume_size != produce_size || queue_pair_entry->qp.flags != (flags & ~VMCI_QPFLAG_ATTACH_ONLY)) { pr_devel("Error mismatched queue pair in local attach\n"); result = VMCI_ERROR_QUEUEPAIR_MISMATCH; goto error_keep_entry; } /* * Do a local attach. We swap the consume and * produce queues for the attacher and deliver * an attach event. */ result = qp_notify_peer_local(true, *handle); if (result < VMCI_SUCCESS) goto error_keep_entry; my_produce_q = queue_pair_entry->consume_q; my_consume_q = queue_pair_entry->produce_q; goto out; } result = VMCI_ERROR_ALREADY_EXISTS; goto error_keep_entry; } my_produce_q = qp_alloc_queue(produce_size, flags); if (!my_produce_q) { pr_warn("Error allocating pages for produce queue\n"); result = VMCI_ERROR_NO_MEM; goto error; } my_consume_q = qp_alloc_queue(consume_size, flags); if (!my_consume_q) { pr_warn("Error allocating pages for consume queue\n"); result = VMCI_ERROR_NO_MEM; goto error; } queue_pair_entry = qp_guest_endpoint_create(*handle, peer, flags, produce_size, consume_size, my_produce_q, my_consume_q); if (!queue_pair_entry) { pr_warn("Error allocating memory in %s\n", __func__); result = VMCI_ERROR_NO_MEM; goto error; } result = qp_alloc_ppn_set(my_produce_q, num_produce_pages, my_consume_q, num_consume_pages, &queue_pair_entry->ppn_set); if (result < VMCI_SUCCESS) { pr_warn("qp_alloc_ppn_set failed\n"); goto error; } /* * It's only necessary to notify the host if this queue pair will be * attached to from another context. */ if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) { /* Local create case. */ u32 context_id = vmci_get_context_id(); /* * Enforce similar checks on local queue pairs as we * do for regular ones. The handle's context must * match the creator or attacher context id (here they * are both the current context id) and the * attach-only flag cannot exist during create. We * also ensure specified peer is this context or an * invalid one. */ if (queue_pair_entry->qp.handle.context != context_id || (queue_pair_entry->qp.peer != VMCI_INVALID_ID && queue_pair_entry->qp.peer != context_id)) { result = VMCI_ERROR_NO_ACCESS; goto error; } if (queue_pair_entry->qp.flags & VMCI_QPFLAG_ATTACH_ONLY) { result = VMCI_ERROR_NOT_FOUND; goto error; } } else { result = qp_alloc_hypercall(queue_pair_entry); if (result < VMCI_SUCCESS) { pr_devel("qp_alloc_hypercall result = %d\n", result); goto error; } } qp_init_queue_mutex((struct vmci_queue *)my_produce_q, (struct vmci_queue *)my_consume_q); qp_list_add_entry(&qp_guest_endpoints, &queue_pair_entry->qp); out: queue_pair_entry->qp.ref_count++; *handle = queue_pair_entry->qp.handle; *produce_q = (struct vmci_queue *)my_produce_q; *consume_q = (struct vmci_queue *)my_consume_q; /* * We should initialize the queue pair header pages on a local * queue pair create. For non-local queue pairs, the * hypervisor initializes the header pages in the create step. */ if ((queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) && queue_pair_entry->qp.ref_count == 1) { vmci_q_header_init((*produce_q)->q_header, *handle); vmci_q_header_init((*consume_q)->q_header, *handle); } mutex_unlock(&qp_guest_endpoints.mutex); return VMCI_SUCCESS; error: mutex_unlock(&qp_guest_endpoints.mutex); if (queue_pair_entry) { /* The queues will be freed inside the destroy routine. */ qp_guest_endpoint_destroy(queue_pair_entry); } else { qp_free_queue(my_produce_q, produce_size); qp_free_queue(my_consume_q, consume_size); } return result; error_keep_entry: /* This path should only be used when an existing entry was found. */ mutex_unlock(&qp_guest_endpoints.mutex); return result; } /* * The first endpoint issuing a queue pair allocation will create the state * of the queue pair in the queue pair broker. * * If the creator is a guest, it will associate a VMX virtual address range * with the queue pair as specified by the page_store. For compatibility with * older VMX'en, that would use a separate step to set the VMX virtual * address range, the virtual address range can be registered later using * vmci_qp_broker_set_page_store. In that case, a page_store of NULL should be * used. * * If the creator is the host, a page_store of NULL should be used as well, * since the host is not able to supply a page store for the queue pair. * * For older VMX and host callers, the queue pair will be created in the * VMCIQPB_CREATED_NO_MEM state, and for current VMX callers, it will be * created in VMCOQPB_CREATED_MEM state. */ static int qp_broker_create(struct vmci_handle handle, u32 peer, u32 flags, u32 priv_flags, u64 produce_size, u64 consume_size, struct vmci_qp_page_store *page_store, struct vmci_ctx *context, vmci_event_release_cb wakeup_cb, void *client_data, struct qp_broker_entry **ent) { struct qp_broker_entry *entry = NULL; const u32 context_id = vmci_ctx_get_id(context); bool is_local = flags & VMCI_QPFLAG_LOCAL; int result; u64 guest_produce_size; u64 guest_consume_size; /* Do not create if the caller asked not to. */ if (flags & VMCI_QPFLAG_ATTACH_ONLY) return VMCI_ERROR_NOT_FOUND; /* * Creator's context ID should match handle's context ID or the creator * must allow the context in handle's context ID as the "peer". */ if (handle.context != context_id && handle.context != peer) return VMCI_ERROR_NO_ACCESS; if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(peer)) return VMCI_ERROR_DST_UNREACHABLE; /* * Creator's context ID for local queue pairs should match the * peer, if a peer is specified. */ if (is_local && peer != VMCI_INVALID_ID && context_id != peer) return VMCI_ERROR_NO_ACCESS; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) return VMCI_ERROR_NO_MEM; if (vmci_ctx_get_id(context) == VMCI_HOST_CONTEXT_ID && !is_local) { /* * The queue pair broker entry stores values from the guest * point of view, so a creating host side endpoint should swap * produce and consume values -- unless it is a local queue * pair, in which case no swapping is necessary, since the local * attacher will swap queues. */ guest_produce_size = consume_size; guest_consume_size = produce_size; } else { guest_produce_size = produce_size; guest_consume_size = consume_size; } entry->qp.handle = handle; entry->qp.peer = peer; entry->qp.flags = flags; entry->qp.produce_size = guest_produce_size; entry->qp.consume_size = guest_consume_size; entry->qp.ref_count = 1; entry->create_id = context_id; entry->attach_id = VMCI_INVALID_ID; entry->state = VMCIQPB_NEW; entry->require_trusted_attach = !!(context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED); entry->created_by_trusted = !!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED); entry->vmci_page_files = false; entry->wakeup_cb = wakeup_cb; entry->client_data = client_data; entry->produce_q = qp_host_alloc_queue(guest_produce_size); if (entry->produce_q == NULL) { result = VMCI_ERROR_NO_MEM; goto error; } entry->consume_q = qp_host_alloc_queue(guest_consume_size); if (entry->consume_q == NULL) { result = VMCI_ERROR_NO_MEM; goto error; } qp_init_queue_mutex(entry->produce_q, entry->consume_q); INIT_LIST_HEAD(&entry->qp.list_item); if (is_local) { u8 *tmp; entry->local_mem = kcalloc(QPE_NUM_PAGES(entry->qp), PAGE_SIZE, GFP_KERNEL); if (entry->local_mem == NULL) { result = VMCI_ERROR_NO_MEM; goto error; } entry->state = VMCIQPB_CREATED_MEM; entry->produce_q->q_header = entry->local_mem; tmp = (u8 *)entry->local_mem + PAGE_SIZE * (DIV_ROUND_UP(entry->qp.produce_size, PAGE_SIZE) + 1); entry->consume_q->q_header = (struct vmci_queue_header *)tmp; } else if (page_store) { /* * The VMX already initialized the queue pair headers, so no * need for the kernel side to do that. */ result = qp_host_register_user_memory(page_store, entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) goto error; entry->state = VMCIQPB_CREATED_MEM; } else { /* * A create without a page_store may be either a host * side create (in which case we are waiting for the * guest side to supply the memory) or an old style * queue pair create (in which case we will expect a * set page store call as the next step). */ entry->state = VMCIQPB_CREATED_NO_MEM; } qp_list_add_entry(&qp_broker_list, &entry->qp); if (ent != NULL) *ent = entry; /* Add to resource obj */ result = vmci_resource_add(&entry->resource, VMCI_RESOURCE_TYPE_QPAIR_HOST, handle); if (result != VMCI_SUCCESS) { pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d", handle.context, handle.resource, result); goto error; } entry->qp.handle = vmci_resource_handle(&entry->resource); if (is_local) { vmci_q_header_init(entry->produce_q->q_header, entry->qp.handle); vmci_q_header_init(entry->consume_q->q_header, entry->qp.handle); } vmci_ctx_qp_create(context, entry->qp.handle); return VMCI_SUCCESS; error: if (entry != NULL) { qp_host_free_queue(entry->produce_q, guest_produce_size); qp_host_free_queue(entry->consume_q, guest_consume_size); kfree(entry); } return result; } /* * Enqueues an event datagram to notify the peer VM attached to * the given queue pair handle about attach/detach event by the * given VM. Returns Payload size of datagram enqueued on * success, error code otherwise. */ static int qp_notify_peer(bool attach, struct vmci_handle handle, u32 my_id, u32 peer_id) { int rv; struct vmci_event_qp ev; if (vmci_handle_is_invalid(handle) || my_id == VMCI_INVALID_ID || peer_id == VMCI_INVALID_ID) return VMCI_ERROR_INVALID_ARGS; /* * In vmci_ctx_enqueue_datagram() we enforce the upper limit on * number of pending events from the hypervisor to a given VM * otherwise a rogue VM could do an arbitrary number of attach * and detach operations causing memory pressure in the host * kernel. */ memset(&ev, 0, sizeof(ev)); ev.msg.hdr.dst = vmci_make_handle(peer_id, VMCI_EVENT_HANDLER); ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); ev.msg.event_data.event = attach ? VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH; ev.payload.handle = handle; ev.payload.peer_id = my_id; rv = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID, &ev.msg.hdr, false); if (rv < VMCI_SUCCESS) pr_warn("Failed to enqueue queue_pair %s event datagram for context (ID=0x%x)\n", attach ? "ATTACH" : "DETACH", peer_id); return rv; } /* * The second endpoint issuing a queue pair allocation will attach to * the queue pair registered with the queue pair broker. * * If the attacher is a guest, it will associate a VMX virtual address * range with the queue pair as specified by the page_store. At this * point, the already attach host endpoint may start using the queue * pair, and an attach event is sent to it. For compatibility with * older VMX'en, that used a separate step to set the VMX virtual * address range, the virtual address range can be registered later * using vmci_qp_broker_set_page_store. In that case, a page_store of * NULL should be used, and the attach event will be generated once * the actual page store has been set. * * If the attacher is the host, a page_store of NULL should be used as * well, since the page store information is already set by the guest. * * For new VMX and host callers, the queue pair will be moved to the * VMCIQPB_ATTACHED_MEM state, and for older VMX callers, it will be * moved to the VMCOQPB_ATTACHED_NO_MEM state. */ static int qp_broker_attach(struct qp_broker_entry *entry, u32 peer, u32 flags, u32 priv_flags, u64 produce_size, u64 consume_size, struct vmci_qp_page_store *page_store, struct vmci_ctx *context, vmci_event_release_cb wakeup_cb, void *client_data, struct qp_broker_entry **ent) { const u32 context_id = vmci_ctx_get_id(context); bool is_local = flags & VMCI_QPFLAG_LOCAL; int result; if (entry->state != VMCIQPB_CREATED_NO_MEM && entry->state != VMCIQPB_CREATED_MEM) return VMCI_ERROR_UNAVAILABLE; if (is_local) { if (!(entry->qp.flags & VMCI_QPFLAG_LOCAL) || context_id != entry->create_id) { return VMCI_ERROR_INVALID_ARGS; } } else if (context_id == entry->create_id || context_id == entry->attach_id) { return VMCI_ERROR_ALREADY_EXISTS; } if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(entry->create_id)) return VMCI_ERROR_DST_UNREACHABLE; /* * If we are attaching from a restricted context then the queuepair * must have been created by a trusted endpoint. */ if ((context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) && !entry->created_by_trusted) return VMCI_ERROR_NO_ACCESS; /* * If we are attaching to a queuepair that was created by a restricted * context then we must be trusted. */ if (entry->require_trusted_attach && (!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED))) return VMCI_ERROR_NO_ACCESS; /* * If the creator specifies VMCI_INVALID_ID in "peer" field, access * control check is not performed. */ if (entry->qp.peer != VMCI_INVALID_ID && entry->qp.peer != context_id) return VMCI_ERROR_NO_ACCESS; if (entry->create_id == VMCI_HOST_CONTEXT_ID) { /* * Do not attach if the caller doesn't support Host Queue Pairs * and a host created this queue pair. */ if (!vmci_ctx_supports_host_qp(context)) return VMCI_ERROR_INVALID_RESOURCE; } else if (context_id == VMCI_HOST_CONTEXT_ID) { struct vmci_ctx *create_context; bool supports_host_qp; /* * Do not attach a host to a user created queue pair if that * user doesn't support host queue pair end points. */ create_context = vmci_ctx_get(entry->create_id); supports_host_qp = vmci_ctx_supports_host_qp(create_context); vmci_ctx_put(create_context); if (!supports_host_qp) return VMCI_ERROR_INVALID_RESOURCE; } if ((entry->qp.flags & ~VMCI_QP_ASYMM) != (flags & ~VMCI_QP_ASYMM_PEER)) return VMCI_ERROR_QUEUEPAIR_MISMATCH; if (context_id != VMCI_HOST_CONTEXT_ID) { /* * The queue pair broker entry stores values from the guest * point of view, so an attaching guest should match the values * stored in the entry. */ if (entry->qp.produce_size != produce_size || entry->qp.consume_size != consume_size) { return VMCI_ERROR_QUEUEPAIR_MISMATCH; } } else if (entry->qp.produce_size != consume_size || entry->qp.consume_size != produce_size) { return VMCI_ERROR_QUEUEPAIR_MISMATCH; } if (context_id != VMCI_HOST_CONTEXT_ID) { /* * If a guest attached to a queue pair, it will supply * the backing memory. If this is a pre NOVMVM vmx, * the backing memory will be supplied by calling * vmci_qp_broker_set_page_store() following the * return of the vmci_qp_broker_alloc() call. If it is * a vmx of version NOVMVM or later, the page store * must be supplied as part of the * vmci_qp_broker_alloc call. Under all circumstances * must the initially created queue pair not have any * memory associated with it already. */ if (entry->state != VMCIQPB_CREATED_NO_MEM) return VMCI_ERROR_INVALID_ARGS; if (page_store != NULL) { /* * Patch up host state to point to guest * supplied memory. The VMX already * initialized the queue pair headers, so no * need for the kernel side to do that. */ result = qp_host_register_user_memory(page_store, entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) return result; entry->state = VMCIQPB_ATTACHED_MEM; } else { entry->state = VMCIQPB_ATTACHED_NO_MEM; } } else if (entry->state == VMCIQPB_CREATED_NO_MEM) { /* * The host side is attempting to attach to a queue * pair that doesn't have any memory associated with * it. This must be a pre NOVMVM vmx that hasn't set * the page store information yet, or a quiesced VM. */ return VMCI_ERROR_UNAVAILABLE; } else { /* The host side has successfully attached to a queue pair. */ entry->state = VMCIQPB_ATTACHED_MEM; } if (entry->state == VMCIQPB_ATTACHED_MEM) { result = qp_notify_peer(true, entry->qp.handle, context_id, entry->create_id); if (result < VMCI_SUCCESS) pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n", entry->create_id, entry->qp.handle.context, entry->qp.handle.resource); } entry->attach_id = context_id; entry->qp.ref_count++; if (wakeup_cb) { entry->wakeup_cb = wakeup_cb; entry->client_data = client_data; } /* * When attaching to local queue pairs, the context already has * an entry tracking the queue pair, so don't add another one. */ if (!is_local) vmci_ctx_qp_create(context, entry->qp.handle); if (ent != NULL) *ent = entry; return VMCI_SUCCESS; } /* * queue_pair_Alloc for use when setting up queue pair endpoints * on the host. */ static int qp_broker_alloc(struct vmci_handle handle, u32 peer, u32 flags, u32 priv_flags, u64 produce_size, u64 consume_size, struct vmci_qp_page_store *page_store, struct vmci_ctx *context, vmci_event_release_cb wakeup_cb, void *client_data, struct qp_broker_entry **ent, bool *swap) { const u32 context_id = vmci_ctx_get_id(context); bool create; struct qp_broker_entry *entry = NULL; bool is_local = flags & VMCI_QPFLAG_LOCAL; int result; if (vmci_handle_is_invalid(handle) || (flags & ~VMCI_QP_ALL_FLAGS) || is_local || !(produce_size || consume_size) || !context || context_id == VMCI_INVALID_ID || handle.context == VMCI_INVALID_ID) { return VMCI_ERROR_INVALID_ARGS; } if (page_store && !VMCI_QP_PAGESTORE_IS_WELLFORMED(page_store)) return VMCI_ERROR_INVALID_ARGS; /* * In the initial argument check, we ensure that non-vmkernel hosts * are not allowed to create local queue pairs. */ mutex_lock(&qp_broker_list.mutex); if (!is_local && vmci_ctx_qp_exists(context, handle)) { pr_devel("Context (ID=0x%x) already attached to queue pair (handle=0x%x:0x%x)\n", context_id, handle.context, handle.resource); mutex_unlock(&qp_broker_list.mutex); return VMCI_ERROR_ALREADY_EXISTS; } if (handle.resource != VMCI_INVALID_ID) entry = qp_broker_handle_to_entry(handle); if (!entry) { create = true; result = qp_broker_create(handle, peer, flags, priv_flags, produce_size, consume_size, page_store, context, wakeup_cb, client_data, ent); } else { create = false; result = qp_broker_attach(entry, peer, flags, priv_flags, produce_size, consume_size, page_store, context, wakeup_cb, client_data, ent); } mutex_unlock(&qp_broker_list.mutex); if (swap) *swap = (context_id == VMCI_HOST_CONTEXT_ID) && !(create && is_local); return result; } /* * This function implements the kernel API for allocating a queue * pair. */ static int qp_alloc_host_work(struct vmci_handle *handle, struct vmci_queue **produce_q, u64 produce_size, struct vmci_queue **consume_q, u64 consume_size, u32 peer, u32 flags, u32 priv_flags, vmci_event_release_cb wakeup_cb, void *client_data) { struct vmci_handle new_handle; struct vmci_ctx *context; struct qp_broker_entry *entry; int result; bool swap; if (vmci_handle_is_invalid(*handle)) { new_handle = vmci_make_handle( VMCI_HOST_CONTEXT_ID, VMCI_INVALID_ID); } else new_handle = *handle; context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID); entry = NULL; result = qp_broker_alloc(new_handle, peer, flags, priv_flags, produce_size, consume_size, NULL, context, wakeup_cb, client_data, &entry, &swap); if (result == VMCI_SUCCESS) { if (swap) { /* * If this is a local queue pair, the attacher * will swap around produce and consume * queues. */ *produce_q = entry->consume_q; *consume_q = entry->produce_q; } else { *produce_q = entry->produce_q; *consume_q = entry->consume_q; } *handle = vmci_resource_handle(&entry->resource); } else { *handle = VMCI_INVALID_HANDLE; pr_devel("queue pair broker failed to alloc (result=%d)\n", result); } vmci_ctx_put(context); return result; } /* * Allocates a VMCI queue_pair. Only checks validity of input * arguments. The real work is done in the host or guest * specific function. */ int vmci_qp_alloc(struct vmci_handle *handle, struct vmci_queue **produce_q, u64 produce_size, struct vmci_queue **consume_q, u64 consume_size, u32 peer, u32 flags, u32 priv_flags, bool guest_endpoint, vmci_event_release_cb wakeup_cb, void *client_data) { if (!handle || !produce_q || !consume_q || (!produce_size && !consume_size) || (flags & ~VMCI_QP_ALL_FLAGS)) return VMCI_ERROR_INVALID_ARGS; if (guest_endpoint) { return qp_alloc_guest_work(handle, produce_q, produce_size, consume_q, consume_size, peer, flags, priv_flags); } else { return qp_alloc_host_work(handle, produce_q, produce_size, consume_q, consume_size, peer, flags, priv_flags, wakeup_cb, client_data); } } /* * This function implements the host kernel API for detaching from * a queue pair. */ static int qp_detatch_host_work(struct vmci_handle handle) { int result; struct vmci_ctx *context; context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID); result = vmci_qp_broker_detach(handle, context); vmci_ctx_put(context); return result; } /* * Detaches from a VMCI queue_pair. Only checks validity of input argument. * Real work is done in the host or guest specific function. */ static int qp_detatch(struct vmci_handle handle, bool guest_endpoint) { if (vmci_handle_is_invalid(handle)) return VMCI_ERROR_INVALID_ARGS; if (guest_endpoint) return qp_detatch_guest_work(handle); else return qp_detatch_host_work(handle); } /* * Returns the entry from the head of the list. Assumes that the list is * locked. */ static struct qp_entry *qp_list_get_head(struct qp_list *qp_list) { if (!list_empty(&qp_list->head)) { struct qp_entry *entry = list_first_entry(&qp_list->head, struct qp_entry, list_item); return entry; } return NULL; } void vmci_qp_broker_exit(void) { struct qp_entry *entry; struct qp_broker_entry *be; mutex_lock(&qp_broker_list.mutex); while ((entry = qp_list_get_head(&qp_broker_list))) { be = (struct qp_broker_entry *)entry; qp_list_remove_entry(&qp_broker_list, entry); kfree(be); } mutex_unlock(&qp_broker_list.mutex); } /* * Requests that a queue pair be allocated with the VMCI queue * pair broker. Allocates a queue pair entry if one does not * exist. Attaches to one if it exists, and retrieves the page * files backing that queue_pair. Assumes that the queue pair * broker lock is held. */ int vmci_qp_broker_alloc(struct vmci_handle handle, u32 peer, u32 flags, u32 priv_flags, u64 produce_size, u64 consume_size, struct vmci_qp_page_store *page_store, struct vmci_ctx *context) { if (!QP_SIZES_ARE_VALID(produce_size, consume_size)) return VMCI_ERROR_NO_RESOURCES; return qp_broker_alloc(handle, peer, flags, priv_flags, produce_size, consume_size, page_store, context, NULL, NULL, NULL, NULL); } /* * VMX'en with versions lower than VMCI_VERSION_NOVMVM use a separate * step to add the UVAs of the VMX mapping of the queue pair. This function * provides backwards compatibility with such VMX'en, and takes care of * registering the page store for a queue pair previously allocated by the * VMX during create or attach. This function will move the queue pair state * to either from VMCIQBP_CREATED_NO_MEM to VMCIQBP_CREATED_MEM or * VMCIQBP_ATTACHED_NO_MEM to VMCIQBP_ATTACHED_MEM. If moving to the * attached state with memory, the queue pair is ready to be used by the * host peer, and an attached event will be generated. * * Assumes that the queue pair broker lock is held. * * This function is only used by the hosted platform, since there is no * issue with backwards compatibility for vmkernel. */ int vmci_qp_broker_set_page_store(struct vmci_handle handle, u64 produce_uva, u64 consume_uva, struct vmci_ctx *context) { struct qp_broker_entry *entry; int result; const u32 context_id = vmci_ctx_get_id(context); if (vmci_handle_is_invalid(handle) || !context || context_id == VMCI_INVALID_ID) return VMCI_ERROR_INVALID_ARGS; /* * We only support guest to host queue pairs, so the VMX must * supply UVAs for the mapped page files. */ if (produce_uva == 0 || consume_uva == 0) return VMCI_ERROR_INVALID_ARGS; mutex_lock(&qp_broker_list.mutex); if (!vmci_ctx_qp_exists(context, handle)) { pr_warn("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } entry = qp_broker_handle_to_entry(handle); if (!entry) { result = VMCI_ERROR_NOT_FOUND; goto out; } /* * If I'm the owner then I can set the page store. * * Or, if a host created the queue_pair and I'm the attached peer * then I can set the page store. */ if (entry->create_id != context_id && (entry->create_id != VMCI_HOST_CONTEXT_ID || entry->attach_id != context_id)) { result = VMCI_ERROR_QUEUEPAIR_NOTOWNER; goto out; } if (entry->state != VMCIQPB_CREATED_NO_MEM && entry->state != VMCIQPB_ATTACHED_NO_MEM) { result = VMCI_ERROR_UNAVAILABLE; goto out; } result = qp_host_get_user_memory(produce_uva, consume_uva, entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) goto out; result = qp_host_map_queues(entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) { qp_host_unregister_user_memory(entry->produce_q, entry->consume_q); goto out; } if (entry->state == VMCIQPB_CREATED_NO_MEM) entry->state = VMCIQPB_CREATED_MEM; else entry->state = VMCIQPB_ATTACHED_MEM; entry->vmci_page_files = true; if (entry->state == VMCIQPB_ATTACHED_MEM) { result = qp_notify_peer(true, handle, context_id, entry->create_id); if (result < VMCI_SUCCESS) { pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n", entry->create_id, entry->qp.handle.context, entry->qp.handle.resource); } } result = VMCI_SUCCESS; out: mutex_unlock(&qp_broker_list.mutex); return result; } /* * Resets saved queue headers for the given QP broker * entry. Should be used when guest memory becomes available * again, or the guest detaches. */ static void qp_reset_saved_headers(struct qp_broker_entry *entry) { entry->produce_q->saved_header = NULL; entry->consume_q->saved_header = NULL; } /* * The main entry point for detaching from a queue pair registered with the * queue pair broker. If more than one endpoint is attached to the queue * pair, the first endpoint will mainly decrement a reference count and * generate a notification to its peer. The last endpoint will clean up * the queue pair state registered with the broker. * * When a guest endpoint detaches, it will unmap and unregister the guest * memory backing the queue pair. If the host is still attached, it will * no longer be able to access the queue pair content. * * If the queue pair is already in a state where there is no memory * registered for the queue pair (any *_NO_MEM state), it will transition to * the VMCIQPB_SHUTDOWN_NO_MEM state. This will also happen, if a guest * endpoint is the first of two endpoints to detach. If the host endpoint is * the first out of two to detach, the queue pair will move to the * VMCIQPB_SHUTDOWN_MEM state. */ int vmci_qp_broker_detach(struct vmci_handle handle, struct vmci_ctx *context) { struct qp_broker_entry *entry; const u32 context_id = vmci_ctx_get_id(context); u32 peer_id; bool is_local = false; int result; if (vmci_handle_is_invalid(handle) || !context || context_id == VMCI_INVALID_ID) { return VMCI_ERROR_INVALID_ARGS; } mutex_lock(&qp_broker_list.mutex); if (!vmci_ctx_qp_exists(context, handle)) { pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } entry = qp_broker_handle_to_entry(handle); if (!entry) { pr_devel("Context (ID=0x%x) reports being attached to queue pair(handle=0x%x:0x%x) that isn't present in broker\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } if (context_id != entry->create_id && context_id != entry->attach_id) { result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED; goto out; } if (context_id == entry->create_id) { peer_id = entry->attach_id; entry->create_id = VMCI_INVALID_ID; } else { peer_id = entry->create_id; entry->attach_id = VMCI_INVALID_ID; } entry->qp.ref_count--; is_local = entry->qp.flags & VMCI_QPFLAG_LOCAL; if (context_id != VMCI_HOST_CONTEXT_ID) { bool headers_mapped; /* * Pre NOVMVM vmx'en may detach from a queue pair * before setting the page store, and in that case * there is no user memory to detach from. Also, more * recent VMX'en may detach from a queue pair in the * quiesced state. */ qp_acquire_queue_mutex(entry->produce_q); headers_mapped = entry->produce_q->q_header || entry->consume_q->q_header; if (QPBROKERSTATE_HAS_MEM(entry)) { result = qp_host_unmap_queues(INVALID_VMCI_GUEST_MEM_ID, entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) pr_warn("Failed to unmap queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n", handle.context, handle.resource, result); qp_host_unregister_user_memory(entry->produce_q, entry->consume_q); } if (!headers_mapped) qp_reset_saved_headers(entry); qp_release_queue_mutex(entry->produce_q); if (!headers_mapped && entry->wakeup_cb) entry->wakeup_cb(entry->client_data); } else { if (entry->wakeup_cb) { entry->wakeup_cb = NULL; entry->client_data = NULL; } } if (entry->qp.ref_count == 0) { qp_list_remove_entry(&qp_broker_list, &entry->qp); if (is_local) kfree(entry->local_mem); qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q); qp_host_free_queue(entry->produce_q, entry->qp.produce_size); qp_host_free_queue(entry->consume_q, entry->qp.consume_size); /* Unlink from resource hash table and free callback */ vmci_resource_remove(&entry->resource); kfree(entry); vmci_ctx_qp_destroy(context, handle); } else { qp_notify_peer(false, handle, context_id, peer_id); if (context_id == VMCI_HOST_CONTEXT_ID && QPBROKERSTATE_HAS_MEM(entry)) { entry->state = VMCIQPB_SHUTDOWN_MEM; } else { entry->state = VMCIQPB_SHUTDOWN_NO_MEM; } if (!is_local) vmci_ctx_qp_destroy(context, handle); } result = VMCI_SUCCESS; out: mutex_unlock(&qp_broker_list.mutex); return result; } /* * Establishes the necessary mappings for a queue pair given a * reference to the queue pair guest memory. This is usually * called when a guest is unquiesced and the VMX is allowed to * map guest memory once again. */ int vmci_qp_broker_map(struct vmci_handle handle, struct vmci_ctx *context, u64 guest_mem) { struct qp_broker_entry *entry; const u32 context_id = vmci_ctx_get_id(context); int result; if (vmci_handle_is_invalid(handle) || !context || context_id == VMCI_INVALID_ID) return VMCI_ERROR_INVALID_ARGS; mutex_lock(&qp_broker_list.mutex); if (!vmci_ctx_qp_exists(context, handle)) { pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } entry = qp_broker_handle_to_entry(handle); if (!entry) { pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } if (context_id != entry->create_id && context_id != entry->attach_id) { result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED; goto out; } result = VMCI_SUCCESS; if (context_id != VMCI_HOST_CONTEXT_ID && !QPBROKERSTATE_HAS_MEM(entry)) { struct vmci_qp_page_store page_store; page_store.pages = guest_mem; page_store.len = QPE_NUM_PAGES(entry->qp); qp_acquire_queue_mutex(entry->produce_q); qp_reset_saved_headers(entry); result = qp_host_register_user_memory(&page_store, entry->produce_q, entry->consume_q); qp_release_queue_mutex(entry->produce_q); if (result == VMCI_SUCCESS) { /* Move state from *_NO_MEM to *_MEM */ entry->state++; if (entry->wakeup_cb) entry->wakeup_cb(entry->client_data); } } out: mutex_unlock(&qp_broker_list.mutex); return result; } /* * Saves a snapshot of the queue headers for the given QP broker * entry. Should be used when guest memory is unmapped. * Results: * VMCI_SUCCESS on success, appropriate error code if guest memory * can't be accessed.. */ static int qp_save_headers(struct qp_broker_entry *entry) { int result; if (entry->produce_q->saved_header != NULL && entry->consume_q->saved_header != NULL) { /* * If the headers have already been saved, we don't need to do * it again, and we don't want to map in the headers * unnecessarily. */ return VMCI_SUCCESS; } if (NULL == entry->produce_q->q_header || NULL == entry->consume_q->q_header) { result = qp_host_map_queues(entry->produce_q, entry->consume_q); if (result < VMCI_SUCCESS) return result; } memcpy(&entry->saved_produce_q, entry->produce_q->q_header, sizeof(entry->saved_produce_q)); entry->produce_q->saved_header = &entry->saved_produce_q; memcpy(&entry->saved_consume_q, entry->consume_q->q_header, sizeof(entry->saved_consume_q)); entry->consume_q->saved_header = &entry->saved_consume_q; return VMCI_SUCCESS; } /* * Removes all references to the guest memory of a given queue pair, and * will move the queue pair from state *_MEM to *_NO_MEM. It is usually * called when a VM is being quiesced where access to guest memory should * avoided. */ int vmci_qp_broker_unmap(struct vmci_handle handle, struct vmci_ctx *context, u32 gid) { struct qp_broker_entry *entry; const u32 context_id = vmci_ctx_get_id(context); int result; if (vmci_handle_is_invalid(handle) || !context || context_id == VMCI_INVALID_ID) return VMCI_ERROR_INVALID_ARGS; mutex_lock(&qp_broker_list.mutex); if (!vmci_ctx_qp_exists(context, handle)) { pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } entry = qp_broker_handle_to_entry(handle); if (!entry) { pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n", context_id, handle.context, handle.resource); result = VMCI_ERROR_NOT_FOUND; goto out; } if (context_id != entry->create_id && context_id != entry->attach_id) { result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED; goto out; } if (context_id != VMCI_HOST_CONTEXT_ID && QPBROKERSTATE_HAS_MEM(entry)) { qp_acquire_queue_mutex(entry->produce_q); result = qp_save_headers(entry); if (result < VMCI_SUCCESS) pr_warn("Failed to save queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n", handle.context, handle.resource, result); qp_host_unmap_queues(gid, entry->produce_q, entry->consume_q); /* * On hosted, when we unmap queue pairs, the VMX will also * unmap the guest memory, so we invalidate the previously * registered memory. If the queue pair is mapped again at a * later point in time, we will need to reregister the user * memory with a possibly new user VA. */ qp_host_unregister_user_memory(entry->produce_q, entry->consume_q); /* * Move state from *_MEM to *_NO_MEM. */ entry->state--; qp_release_queue_mutex(entry->produce_q); } result = VMCI_SUCCESS; out: mutex_unlock(&qp_broker_list.mutex); return result; } /* * Destroys all guest queue pair endpoints. If active guest queue * pairs still exist, hypercalls to attempt detach from these * queue pairs will be made. Any failure to detach is silently * ignored. */ void vmci_qp_guest_endpoints_exit(void) { struct qp_entry *entry; struct qp_guest_endpoint *ep; mutex_lock(&qp_guest_endpoints.mutex); while ((entry = qp_list_get_head(&qp_guest_endpoints))) { ep = (struct qp_guest_endpoint *)entry; /* Don't make a hypercall for local queue_pairs. */ if (!(entry->flags & VMCI_QPFLAG_LOCAL)) qp_detatch_hypercall(entry->handle); /* We cannot fail the exit, so let's reset ref_count. */ entry->ref_count = 0; qp_list_remove_entry(&qp_guest_endpoints, entry); qp_guest_endpoint_destroy(ep); } mutex_unlock(&qp_guest_endpoints.mutex); } /* * Helper routine that will lock the queue pair before subsequent * operations. * Note: Non-blocking on the host side is currently only implemented in ESX. * Since non-blocking isn't yet implemented on the host personality we * have no reason to acquire a spin lock. So to avoid the use of an * unnecessary lock only acquire the mutex if we can block. */ static void qp_lock(const struct vmci_qp *qpair) { qp_acquire_queue_mutex(qpair->produce_q); } /* * Helper routine that unlocks the queue pair after calling * qp_lock. */ static void qp_unlock(const struct vmci_qp *qpair) { qp_release_queue_mutex(qpair->produce_q); } /* * The queue headers may not be mapped at all times. If a queue is * currently not mapped, it will be attempted to do so. */ static int qp_map_queue_headers(struct vmci_queue *produce_q, struct vmci_queue *consume_q) { int result; if (NULL == produce_q->q_header || NULL == consume_q->q_header) { result = qp_host_map_queues(produce_q, consume_q); if (result < VMCI_SUCCESS) return (produce_q->saved_header && consume_q->saved_header) ? VMCI_ERROR_QUEUEPAIR_NOT_READY : VMCI_ERROR_QUEUEPAIR_NOTATTACHED; } return VMCI_SUCCESS; } /* * Helper routine that will retrieve the produce and consume * headers of a given queue pair. If the guest memory of the * queue pair is currently not available, the saved queue headers * will be returned, if these are available. */ static int qp_get_queue_headers(const struct vmci_qp *qpair, struct vmci_queue_header **produce_q_header, struct vmci_queue_header **consume_q_header) { int result; result = qp_map_queue_headers(qpair->produce_q, qpair->consume_q); if (result == VMCI_SUCCESS) { *produce_q_header = qpair->produce_q->q_header; *consume_q_header = qpair->consume_q->q_header; } else if (qpair->produce_q->saved_header && qpair->consume_q->saved_header) { *produce_q_header = qpair->produce_q->saved_header; *consume_q_header = qpair->consume_q->saved_header; result = VMCI_SUCCESS; } return result; } /* * Callback from VMCI queue pair broker indicating that a queue * pair that was previously not ready, now either is ready or * gone forever. */ static int qp_wakeup_cb(void *client_data) { struct vmci_qp *qpair = (struct vmci_qp *)client_data; qp_lock(qpair); while (qpair->blocked > 0) { qpair->blocked--; qpair->generation++; wake_up(&qpair->event); } qp_unlock(qpair); return VMCI_SUCCESS; } /* * Makes the calling thread wait for the queue pair to become * ready for host side access. Returns true when thread is * woken up after queue pair state change, false otherwise. */ static bool qp_wait_for_ready_queue(struct vmci_qp *qpair) { unsigned int generation; qpair->blocked++; generation = qpair->generation; qp_unlock(qpair); wait_event(qpair->event, generation != qpair->generation); qp_lock(qpair); return true; } /* * Enqueues a given buffer to the produce queue using the provided * function. As many bytes as possible (space available in the queue) * are enqueued. Assumes the queue->mutex has been acquired. Returns * VMCI_ERROR_QUEUEPAIR_NOSPACE if no space was available to enqueue * data, VMCI_ERROR_INVALID_SIZE, if any queue pointer is outside the * queue (as defined by the queue size), VMCI_ERROR_INVALID_ARGS, if * an error occured when accessing the buffer, * VMCI_ERROR_QUEUEPAIR_NOTATTACHED, if the queue pair pages aren't * available. Otherwise, the number of bytes written to the queue is * returned. Updates the tail pointer of the produce queue. */ static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q, struct vmci_queue *consume_q, const u64 produce_q_size, struct iov_iter *from) { s64 free_space; u64 tail; size_t buf_size = iov_iter_count(from); size_t written; ssize_t result; result = qp_map_queue_headers(produce_q, consume_q); if (unlikely(result != VMCI_SUCCESS)) return result; free_space = vmci_q_header_free_space(produce_q->q_header, consume_q->q_header, produce_q_size); if (free_space == 0) return VMCI_ERROR_QUEUEPAIR_NOSPACE; if (free_space < VMCI_SUCCESS) return (ssize_t) free_space; written = (size_t) (free_space > buf_size ? buf_size : free_space); tail = vmci_q_header_producer_tail(produce_q->q_header); if (likely(tail + written < produce_q_size)) { result = qp_memcpy_to_queue_iter(produce_q, tail, from, written); } else { /* Tail pointer wraps around. */ const size_t tmp = (size_t) (produce_q_size - tail); result = qp_memcpy_to_queue_iter(produce_q, tail, from, tmp); if (result >= VMCI_SUCCESS) result = qp_memcpy_to_queue_iter(produce_q, 0, from, written - tmp); } if (result < VMCI_SUCCESS) return result; /* * This virt_wmb() ensures that data written to the queue * is observable before the new producer_tail is. */ virt_wmb(); vmci_q_header_add_producer_tail(produce_q->q_header, written, produce_q_size); return written; } /* * Dequeues data (if available) from the given consume queue. Writes data * to the user provided buffer using the provided function. * Assumes the queue->mutex has been acquired. * Results: * VMCI_ERROR_QUEUEPAIR_NODATA if no data was available to dequeue. * VMCI_ERROR_INVALID_SIZE, if any queue pointer is outside the queue * (as defined by the queue size). * VMCI_ERROR_INVALID_ARGS, if an error occured when accessing the buffer. * Otherwise the number of bytes dequeued is returned. * Side effects: * Updates the head pointer of the consume queue. */ static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q, struct vmci_queue *consume_q, const u64 consume_q_size, struct iov_iter *to, bool update_consumer) { size_t buf_size = iov_iter_count(to); s64 buf_ready; u64 head; size_t read; ssize_t result; result = qp_map_queue_headers(produce_q, consume_q); if (unlikely(result != VMCI_SUCCESS)) return result; buf_ready = vmci_q_header_buf_ready(consume_q->q_header, produce_q->q_header, consume_q_size); if (buf_ready == 0) return VMCI_ERROR_QUEUEPAIR_NODATA; if (buf_ready < VMCI_SUCCESS) return (ssize_t) buf_ready; /* * This virt_rmb() ensures that data from the queue will be read * after we have determined how much is ready to be consumed. */ virt_rmb(); read = (size_t) (buf_ready > buf_size ? buf_size : buf_ready); head = vmci_q_header_consumer_head(produce_q->q_header); if (likely(head + read < consume_q_size)) { result = qp_memcpy_from_queue_iter(to, consume_q, head, read); } else { /* Head pointer wraps around. */ const size_t tmp = (size_t) (consume_q_size - head); result = qp_memcpy_from_queue_iter(to, consume_q, head, tmp); if (result >= VMCI_SUCCESS) result = qp_memcpy_from_queue_iter(to, consume_q, 0, read - tmp); } if (result < VMCI_SUCCESS) return result; if (update_consumer) vmci_q_header_add_consumer_head(produce_q->q_header, read, consume_q_size); return read; } /* * vmci_qpair_alloc() - Allocates a queue pair. * @qpair: Pointer for the new vmci_qp struct. * @handle: Handle to track the resource. * @produce_qsize: Desired size of the producer queue. * @consume_qsize: Desired size of the consumer queue. * @peer: ContextID of the peer. * @flags: VMCI flags. * @priv_flags: VMCI priviledge flags. * * This is the client interface for allocating the memory for a * vmci_qp structure and then attaching to the underlying * queue. If an error occurs allocating the memory for the * vmci_qp structure no attempt is made to attach. If an * error occurs attaching, then the structure is freed. */ int vmci_qpair_alloc(struct vmci_qp **qpair, struct vmci_handle *handle, u64 produce_qsize, u64 consume_qsize, u32 peer, u32 flags, u32 priv_flags) { struct vmci_qp *my_qpair; int retval; struct vmci_handle src = VMCI_INVALID_HANDLE; struct vmci_handle dst = vmci_make_handle(peer, VMCI_INVALID_ID); enum vmci_route route; vmci_event_release_cb wakeup_cb; void *client_data; /* * Restrict the size of a queuepair. The device already * enforces a limit on the total amount of memory that can be * allocated to queuepairs for a guest. However, we try to * allocate this memory before we make the queuepair * allocation hypercall. On Linux, we allocate each page * separately, which means rather than fail, the guest will * thrash while it tries to allocate, and will become * increasingly unresponsive to the point where it appears to * be hung. So we place a limit on the size of an individual * queuepair here, and leave the device to enforce the * restriction on total queuepair memory. (Note that this * doesn't prevent all cases; a user with only this much * physical memory could still get into trouble.) The error * used by the device is NO_RESOURCES, so use that here too. */ if (!QP_SIZES_ARE_VALID(produce_qsize, consume_qsize)) return VMCI_ERROR_NO_RESOURCES; retval = vmci_route(&src, &dst, false, &route); if (retval < VMCI_SUCCESS) route = vmci_guest_code_active() ? VMCI_ROUTE_AS_GUEST : VMCI_ROUTE_AS_HOST; if (flags & (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED)) { pr_devel("NONBLOCK OR PINNED set"); return VMCI_ERROR_INVALID_ARGS; } my_qpair = kzalloc(sizeof(*my_qpair), GFP_KERNEL); if (!my_qpair) return VMCI_ERROR_NO_MEM; my_qpair->produce_q_size = produce_qsize; my_qpair->consume_q_size = consume_qsize; my_qpair->peer = peer; my_qpair->flags = flags; my_qpair->priv_flags = priv_flags; wakeup_cb = NULL; client_data = NULL; if (VMCI_ROUTE_AS_HOST == route) { my_qpair->guest_endpoint = false; if (!(flags & VMCI_QPFLAG_LOCAL)) { my_qpair->blocked = 0; my_qpair->generation = 0; init_waitqueue_head(&my_qpair->event); wakeup_cb = qp_wakeup_cb; client_data = (void *)my_qpair; } } else { my_qpair->guest_endpoint = true; } retval = vmci_qp_alloc(handle, &my_qpair->produce_q, my_qpair->produce_q_size, &my_qpair->consume_q, my_qpair->consume_q_size, my_qpair->peer, my_qpair->flags, my_qpair->priv_flags, my_qpair->guest_endpoint, wakeup_cb, client_data); if (retval < VMCI_SUCCESS) { kfree(my_qpair); return retval; } *qpair = my_qpair; my_qpair->handle = *handle; return retval; } EXPORT_SYMBOL_GPL(vmci_qpair_alloc); /* * vmci_qpair_detach() - Detatches the client from a queue pair. * @qpair: Reference of a pointer to the qpair struct. * * This is the client interface for detaching from a VMCIQPair. * Note that this routine will free the memory allocated for the * vmci_qp structure too. */ int vmci_qpair_detach(struct vmci_qp **qpair) { int result; struct vmci_qp *old_qpair; if (!qpair || !(*qpair)) return VMCI_ERROR_INVALID_ARGS; old_qpair = *qpair; result = qp_detatch(old_qpair->handle, old_qpair->guest_endpoint); /* * The guest can fail to detach for a number of reasons, and * if it does so, it will cleanup the entry (if there is one). * The host can fail too, but it won't cleanup the entry * immediately, it will do that later when the context is * freed. Either way, we need to release the qpair struct * here; there isn't much the caller can do, and we don't want * to leak. */ memset(old_qpair, 0, sizeof(*old_qpair)); old_qpair->handle = VMCI_INVALID_HANDLE; old_qpair->peer = VMCI_INVALID_ID; kfree(old_qpair); *qpair = NULL; return result; } EXPORT_SYMBOL_GPL(vmci_qpair_detach); /* * vmci_qpair_get_produce_indexes() - Retrieves the indexes of the producer. * @qpair: Pointer to the queue pair struct. * @producer_tail: Reference used for storing producer tail index. * @consumer_head: Reference used for storing the consumer head index. * * This is the client interface for getting the current indexes of the * QPair from the point of the view of the caller as the producer. */ int vmci_qpair_get_produce_indexes(const struct vmci_qp *qpair, u64 *producer_tail, u64 *consumer_head) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; int result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) vmci_q_header_get_pointers(produce_q_header, consume_q_header, producer_tail, consumer_head); qp_unlock(qpair); if (result == VMCI_SUCCESS && ((producer_tail && *producer_tail >= qpair->produce_q_size) || (consumer_head && *consumer_head >= qpair->produce_q_size))) return VMCI_ERROR_INVALID_SIZE; return result; } EXPORT_SYMBOL_GPL(vmci_qpair_get_produce_indexes); /* * vmci_qpair_get_consume_indexes() - Retrieves the indexes of the consumer. * @qpair: Pointer to the queue pair struct. * @consumer_tail: Reference used for storing consumer tail index. * @producer_head: Reference used for storing the producer head index. * * This is the client interface for getting the current indexes of the * QPair from the point of the view of the caller as the consumer. */ int vmci_qpair_get_consume_indexes(const struct vmci_qp *qpair, u64 *consumer_tail, u64 *producer_head) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; int result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) vmci_q_header_get_pointers(consume_q_header, produce_q_header, consumer_tail, producer_head); qp_unlock(qpair); if (result == VMCI_SUCCESS && ((consumer_tail && *consumer_tail >= qpair->consume_q_size) || (producer_head && *producer_head >= qpair->consume_q_size))) return VMCI_ERROR_INVALID_SIZE; return result; } EXPORT_SYMBOL_GPL(vmci_qpair_get_consume_indexes); /* * vmci_qpair_produce_free_space() - Retrieves free space in producer queue. * @qpair: Pointer to the queue pair struct. * * This is the client interface for getting the amount of free * space in the QPair from the point of the view of the caller as * the producer which is the common case. Returns < 0 if err, else * available bytes into which data can be enqueued if > 0. */ s64 vmci_qpair_produce_free_space(const struct vmci_qp *qpair) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; s64 result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) result = vmci_q_header_free_space(produce_q_header, consume_q_header, qpair->produce_q_size); else result = 0; qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_produce_free_space); /* * vmci_qpair_consume_free_space() - Retrieves free space in consumer queue. * @qpair: Pointer to the queue pair struct. * * This is the client interface for getting the amount of free * space in the QPair from the point of the view of the caller as * the consumer which is not the common case. Returns < 0 if err, else * available bytes into which data can be enqueued if > 0. */ s64 vmci_qpair_consume_free_space(const struct vmci_qp *qpair) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; s64 result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) result = vmci_q_header_free_space(consume_q_header, produce_q_header, qpair->consume_q_size); else result = 0; qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_consume_free_space); /* * vmci_qpair_produce_buf_ready() - Gets bytes ready to read from * producer queue. * @qpair: Pointer to the queue pair struct. * * This is the client interface for getting the amount of * enqueued data in the QPair from the point of the view of the * caller as the producer which is not the common case. Returns < 0 if err, * else available bytes that may be read. */ s64 vmci_qpair_produce_buf_ready(const struct vmci_qp *qpair) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; s64 result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) result = vmci_q_header_buf_ready(produce_q_header, consume_q_header, qpair->produce_q_size); else result = 0; qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_produce_buf_ready); /* * vmci_qpair_consume_buf_ready() - Gets bytes ready to read from * consumer queue. * @qpair: Pointer to the queue pair struct. * * This is the client interface for getting the amount of * enqueued data in the QPair from the point of the view of the * caller as the consumer which is the normal case. Returns < 0 if err, * else available bytes that may be read. */ s64 vmci_qpair_consume_buf_ready(const struct vmci_qp *qpair) { struct vmci_queue_header *produce_q_header; struct vmci_queue_header *consume_q_header; s64 result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); result = qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header); if (result == VMCI_SUCCESS) result = vmci_q_header_buf_ready(consume_q_header, produce_q_header, qpair->consume_q_size); else result = 0; qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_consume_buf_ready); /* * vmci_qpair_enqueue() - Throw data on the queue. * @qpair: Pointer to the queue pair struct. * @buf: Pointer to buffer containing data * @buf_size: Length of buffer. * @buf_type: Buffer type (Unused). * * This is the client interface for enqueueing data into the queue. * Returns number of bytes enqueued or < 0 on error. */ ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair, const void *buf, size_t buf_size, int buf_type) { ssize_t result; struct iov_iter from; struct kvec v = {.iov_base = (void *)buf, .iov_len = buf_size}; if (!qpair || !buf) return VMCI_ERROR_INVALID_ARGS; iov_iter_kvec(&from, ITER_SOURCE, &v, 1, buf_size); qp_lock(qpair); do { result = qp_enqueue_locked(qpair->produce_q, qpair->consume_q, qpair->produce_q_size, &from); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_enqueue); /* * vmci_qpair_dequeue() - Get data from the queue. * @qpair: Pointer to the queue pair struct. * @buf: Pointer to buffer for the data * @buf_size: Length of buffer. * @buf_type: Buffer type (Unused). * * This is the client interface for dequeueing data from the queue. * Returns number of bytes dequeued or < 0 on error. */ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair, void *buf, size_t buf_size, int buf_type) { ssize_t result; struct iov_iter to; struct kvec v = {.iov_base = buf, .iov_len = buf_size}; if (!qpair || !buf) return VMCI_ERROR_INVALID_ARGS; iov_iter_kvec(&to, ITER_DEST, &v, 1, buf_size); qp_lock(qpair); do { result = qp_dequeue_locked(qpair->produce_q, qpair->consume_q, qpair->consume_q_size, &to, true); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_dequeue); /* * vmci_qpair_peek() - Peek at the data in the queue. * @qpair: Pointer to the queue pair struct. * @buf: Pointer to buffer for the data * @buf_size: Length of buffer. * @buf_type: Buffer type (Unused on Linux). * * This is the client interface for peeking into a queue. (I.e., * copy data from the queue without updating the head pointer.) * Returns number of bytes dequeued or < 0 on error. */ ssize_t vmci_qpair_peek(struct vmci_qp *qpair, void *buf, size_t buf_size, int buf_type) { struct iov_iter to; struct kvec v = {.iov_base = buf, .iov_len = buf_size}; ssize_t result; if (!qpair || !buf) return VMCI_ERROR_INVALID_ARGS; iov_iter_kvec(&to, ITER_DEST, &v, 1, buf_size); qp_lock(qpair); do { result = qp_dequeue_locked(qpair->produce_q, qpair->consume_q, qpair->consume_q_size, &to, false); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_peek); /* * vmci_qpair_enquev() - Throw data on the queue using iov. * @qpair: Pointer to the queue pair struct. * @iov: Pointer to buffer containing data * @iov_size: Length of buffer. * @buf_type: Buffer type (Unused). * * This is the client interface for enqueueing data into the queue. * This function uses IO vectors to handle the work. Returns number * of bytes enqueued or < 0 on error. */ ssize_t vmci_qpair_enquev(struct vmci_qp *qpair, struct msghdr *msg, size_t iov_size, int buf_type) { ssize_t result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); do { result = qp_enqueue_locked(qpair->produce_q, qpair->consume_q, qpair->produce_q_size, &msg->msg_iter); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_enquev); /* * vmci_qpair_dequev() - Get data from the queue using iov. * @qpair: Pointer to the queue pair struct. * @iov: Pointer to buffer for the data * @iov_size: Length of buffer. * @buf_type: Buffer type (Unused). * * This is the client interface for dequeueing data from the queue. * This function uses IO vectors to handle the work. Returns number * of bytes dequeued or < 0 on error. */ ssize_t vmci_qpair_dequev(struct vmci_qp *qpair, struct msghdr *msg, size_t iov_size, int buf_type) { ssize_t result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); do { result = qp_dequeue_locked(qpair->produce_q, qpair->consume_q, qpair->consume_q_size, &msg->msg_iter, true); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_dequev); /* * vmci_qpair_peekv() - Peek at the data in the queue using iov. * @qpair: Pointer to the queue pair struct. * @iov: Pointer to buffer for the data * @iov_size: Length of buffer. * @buf_type: Buffer type (Unused on Linux). * * This is the client interface for peeking into a queue. (I.e., * copy data from the queue without updating the head pointer.) * This function uses IO vectors to handle the work. Returns number * of bytes peeked or < 0 on error. */ ssize_t vmci_qpair_peekv(struct vmci_qp *qpair, struct msghdr *msg, size_t iov_size, int buf_type) { ssize_t result; if (!qpair) return VMCI_ERROR_INVALID_ARGS; qp_lock(qpair); do { result = qp_dequeue_locked(qpair->produce_q, qpair->consume_q, qpair->consume_q_size, &msg->msg_iter, false); if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY && !qp_wait_for_ready_queue(qpair)) result = VMCI_ERROR_WOULD_BLOCK; } while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY); qp_unlock(qpair); return result; } EXPORT_SYMBOL_GPL(vmci_qpair_peekv);
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