diff options
Diffstat (limited to 'drivers/misc/vmw_vmci/vmci_queue_pair.c')
| -rw-r--r-- | drivers/misc/vmw_vmci/vmci_queue_pair.c | 3272 |
1 files changed, 3272 insertions, 0 deletions
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c new file mode 100644 index 000000000..db433d285 --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -0,0 +1,3272 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#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)) + + +/* + * 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()/kunmap() to dynamically map/unmap 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(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(kernel_if->u.h.page[page_index]); + return VMCI_ERROR_INVALID_ARGS; + } + bytes_copied += to_copy; + if (kernel_if->host) + kunmap(kernel_if->u.h.page[page_index]); + } + + return VMCI_SUCCESS; +} + +/* + * Copies to a given buffer or iovector from a VMCI Queue. Uses + * kmap()/kunmap() to dynamically map/unmap 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(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(kernel_if->u.h.page[page_index]); + return VMCI_ERROR_INVALID_ARGS; + } + bytes_copied += to_copy; + if (kernel_if->host) + kunmap(kernel_if->u.h.page[page_index]); + } + + 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) +{ + u32 *produce_ppns; + u32 *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++) { + unsigned long pfn; + + produce_ppns[i] = + produce_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT; + pfn = produce_ppns[i]; + + /* Fail allocation if PFN isn't supported by hypervisor. */ + if (sizeof(pfn) > sizeof(*produce_ppns) + && pfn != produce_ppns[i]) + goto ppn_error; + } + + for (i = 0; i < num_consume_pages; i++) { + unsigned long pfn; + + consume_ppns[i] = + consume_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT; + pfn = consume_ppns[i]; + + /* Fail allocation if PFN isn't supported by hypervisor. */ + if (sizeof(pfn) > sizeof(*consume_ppns) + && pfn != consume_ppns[i]) + goto ppn_error; + } + + 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; + + ppn_error: + kfree(produce_ppns); + kfree(consume_ppns); + return VMCI_ERROR_INVALID_ARGS; +} + +/* + * 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) +{ + 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)); + + 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 > 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, 1, + 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, 1, + 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; + + 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; + int result; + + if (!entry || entry->num_ppns <= 2) + return VMCI_ERROR_INVALID_ARGS; + + msg_size = sizeof(*alloc_msg) + + (size_t) entry->num_ppns * sizeof(u32); + 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_warn("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. + */ + + 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) +{ + 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; + + 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; + + 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 (produce_qsize + consume_qsize < max(produce_qsize, consume_qsize) || + produce_qsize + consume_qsize > VMCI_MAX_GUEST_QP_MEMORY) + 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, WRITE | ITER_KVEC, &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, READ | ITER_KVEC, &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, READ | ITER_KVEC, &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); |