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cos / third_party / kernel / fbb84db56cc75d8d3fcd6b22597b9d764405e297 / . / drivers / misc / vmw_vmci / vmci_queue_pair.c
blob: fe67e39d68543c49fd42731090745774084c724d [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* VMware VMCI Driver
*
* Copyright (C) 2012 VMware, Inc. All rights reserved.
*/
#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <linux/wait.h>
#include <linux/vmalloc.h>
#include <linux/skbuff.h>
#include "vmci_handle_array.h"
#include "vmci_queue_pair.h"
#include "vmci_datagram.h"
#include "vmci_resource.h"
#include "vmci_context.h"
#include "vmci_driver.h"
#include "vmci_event.h"
#include "vmci_route.h"
/*
* In the following, we will distinguish between two kinds of VMX processes -
* the ones with versions lower than VMCI_VERSION_NOVMVM that use specialized
* VMCI page files in the VMX and supporting VM to VM communication and the
* newer ones that use the guest memory directly. We will in the following
* refer to the older VMX versions as old-style VMX'en, and the newer ones as
* new-style VMX'en.
*
* The state transition datagram is as follows (the VMCIQPB_ prefix has been
* removed for readability) - see below for more details on the transtions:
*
* -------------- NEW -------------
* | |
* \_/ \_/
* CREATED_NO_MEM <-----------------> CREATED_MEM
* | | |
* | o-----------------------o |
* | | |
* \_/ \_/ \_/
* ATTACHED_NO_MEM <----------------> ATTACHED_MEM
* | | |
* | o----------------------o |
* | | |
* \_/ \_/ \_/
* SHUTDOWN_NO_MEM <----------------> SHUTDOWN_MEM
* | |
* | |
* -------------> gone <-------------
*
* In more detail. When a VMCI queue pair is first created, it will be in the
* VMCIQPB_NEW state. It will then move into one of the following states:
*
* - VMCIQPB_CREATED_NO_MEM: this state indicates that either:
*
* - the created was performed by a host endpoint, in which case there is
* no backing memory yet.
*
* - the create was initiated by an old-style VMX, that uses
* vmci_qp_broker_set_page_store to specify the UVAs of the queue pair at
* a later point in time. This state can be distinguished from the one
* above by the context ID of the creator. A host side is not allowed to
* attach until the page store has been set.
*
* - VMCIQPB_CREATED_MEM: this state is the result when the queue pair
* is created by a VMX using the queue pair device backend that
* sets the UVAs of the queue pair immediately and stores the
* information for later attachers. At this point, it is ready for
* the host side to attach to it.
*
* Once the queue pair is in one of the created states (with the exception of
* the case mentioned for older VMX'en above), it is possible to attach to the
* queue pair. Again we have two new states possible:
*
* - VMCIQPB_ATTACHED_MEM: this state can be reached through the following
* paths:
*
* - from VMCIQPB_CREATED_NO_MEM when a new-style VMX allocates a queue
* pair, and attaches to a queue pair previously created by the host side.
*
* - from VMCIQPB_CREATED_MEM when the host side attaches to a queue pair
* already created by a guest.
*
* - from VMCIQPB_ATTACHED_NO_MEM, when an old-style VMX calls
* vmci_qp_broker_set_page_store (see below).
*
* - VMCIQPB_ATTACHED_NO_MEM: If the queue pair already was in the
* VMCIQPB_CREATED_NO_MEM due to a host side create, an old-style VMX will
* bring the queue pair into this state. Once vmci_qp_broker_set_page_store
* is called to register the user memory, the VMCIQPB_ATTACH_MEM state
* will be entered.
*
* From the attached queue pair, the queue pair can enter the shutdown states
* when either side of the queue pair detaches. If the guest side detaches
* first, the queue pair will enter the VMCIQPB_SHUTDOWN_NO_MEM state, where
* the content of the queue pair will no longer be available. If the host
* side detaches first, the queue pair will either enter the
* VMCIQPB_SHUTDOWN_MEM, if the guest memory is currently mapped, or
* VMCIQPB_SHUTDOWN_NO_MEM, if the guest memory is not mapped
* (e.g., the host detaches while a guest is stunned).
*
* New-style VMX'en will also unmap guest memory, if the guest is
* quiesced, e.g., during a snapshot operation. In that case, the guest
* memory will no longer be available, and the queue pair will transition from
* *_MEM state to a *_NO_MEM state. The VMX may later map the memory once more,
* in which case the queue pair will transition from the *_NO_MEM state at that
* point back to the *_MEM state. Note that the *_NO_MEM state may have changed,
* since the peer may have either attached or detached in the meantime. The
* values are laid out such that ++ on a state will move from a *_NO_MEM to a
* *_MEM state, and vice versa.
*/
/* The Kernel specific component of the struct vmci_queue structure. */
struct vmci_queue_kern_if {
struct mutex __mutex; /* Protects the queue. */
struct mutex *mutex; /* Shared by producer and consumer queues. */
size_t num_pages; /* Number of pages incl. header. */
bool host; /* Host or guest? */
union {
struct {
dma_addr_t *pas;
void **vas;
} g; /* Used by the guest. */
struct {
struct page **page;
struct page **header_page;
} h; /* Used by the host. */
} u;
};
/*
* This structure is opaque to the clients.
*/
struct vmci_qp {
struct vmci_handle handle;
struct vmci_queue *produce_q;
struct vmci_queue *consume_q;
u64 produce_q_size;
u64 consume_q_size;
u32 peer;
u32 flags;
u32 priv_flags;
bool guest_endpoint;
unsigned int blocked;
unsigned int generation;
wait_queue_head_t event;
};
enum qp_broker_state {
VMCIQPB_NEW,
VMCIQPB_CREATED_NO_MEM,
VMCIQPB_CREATED_MEM,
VMCIQPB_ATTACHED_NO_MEM,
VMCIQPB_ATTACHED_MEM,
VMCIQPB_SHUTDOWN_NO_MEM,
VMCIQPB_SHUTDOWN_MEM,
VMCIQPB_GONE
};
#define QPBROKERSTATE_HAS_MEM(_qpb) (_qpb->state == VMCIQPB_CREATED_MEM || \
_qpb->state == VMCIQPB_ATTACHED_MEM || \
_qpb->state == VMCIQPB_SHUTDOWN_MEM)
/*
* In the queue pair broker, we always use the guest point of view for
* the produce and consume queue values and references, e.g., the
* produce queue size stored is the guests produce queue size. The
* host endpoint will need to swap these around. The only exception is
* the local queue pairs on the host, in which case the host endpoint
* that creates the queue pair will have the right orientation, and
* the attaching host endpoint will need to swap.
*/
struct qp_entry {
struct list_head list_item;
struct vmci_handle handle;
u32 peer;
u32 flags;
u64 produce_size;
u64 consume_size;
u32 ref_count;
};
struct qp_broker_entry {
struct vmci_resource resource;
struct qp_entry qp;
u32 create_id;
u32 attach_id;
enum qp_broker_state state;
bool require_trusted_attach;
bool created_by_trusted;
bool vmci_page_files; /* Created by VMX using VMCI page files */
struct vmci_queue *produce_q;
struct vmci_queue *consume_q;
struct vmci_queue_header saved_produce_q;
struct vmci_queue_header saved_consume_q;
vmci_event_release_cb wakeup_cb;
void *client_data;
void *local_mem; /* Kernel memory for local queue pair */
};
struct qp_guest_endpoint {
struct vmci_resource resource;
struct qp_entry qp;
u64 num_ppns;
void *produce_q;
void *consume_q;
struct ppn_set ppn_set;
};
struct qp_list {
struct list_head head;
struct mutex mutex; /* Protect queue list. */
};
static struct qp_list qp_broker_list = {
.head = LIST_HEAD_INIT(qp_broker_list.head),
.mutex = __MUTEX_INITIALIZER(qp_broker_list.mutex),
};
static struct qp_list qp_guest_endpoints = {
.head = LIST_HEAD_INIT(qp_guest_endpoints.head),
.mutex = __MUTEX_INITIALIZER(qp_guest_endpoints.mutex),
};
#define INVALID_VMCI_GUEST_MEM_ID 0
#define QPE_NUM_PAGES(_QPE) ((u32) \
(DIV_ROUND_UP(_QPE.produce_size, PAGE_SIZE) + \
DIV_ROUND_UP(_QPE.consume_size, PAGE_SIZE) + 2))
#define QP_SIZES_ARE_VALID(_prod_qsize, _cons_qsize) \
((_prod_qsize) + (_cons_qsize) >= max(_prod_qsize, _cons_qsize) && \
(_prod_qsize) + (_cons_qsize) <= VMCI_MAX_GUEST_QP_MEMORY)
/*
* Frees kernel VA space for a given queue and its queue header, and
* frees physical data pages.
*/
static void qp_free_queue(void *q, u64 size)
{
struct vmci_queue *queue = q;
if (queue) {
u64 i;
/* Given size does not include header, so add in a page here. */
for (i = 0; i < DIV_ROUND_UP(size, PAGE_SIZE) + 1; i++) {
dma_free_coherent(&vmci_pdev->dev, PAGE_SIZE,
queue->kernel_if->u.g.vas[i],
queue->kernel_if->u.g.pas[i]);
}
vfree(queue);
}
}
/*
* Allocates kernel queue pages of specified size with IOMMU mappings,
* plus space for the queue structure/kernel interface and the queue
* header.
*/
static void *qp_alloc_queue(u64 size, u32 flags)
{
u64 i;
struct vmci_queue *queue;
size_t pas_size;
size_t vas_size;
size_t queue_size = sizeof(*queue) + sizeof(*queue->kernel_if);
u64 num_pages;
if (size > SIZE_MAX - PAGE_SIZE)
return NULL;
num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
if (num_pages >
(SIZE_MAX - queue_size) /
(sizeof(*queue->kernel_if->u.g.pas) +
sizeof(*queue->kernel_if->u.g.vas)))
return NULL;
pas_size = num_pages * sizeof(*queue->kernel_if->u.g.pas);
vas_size = num_pages * sizeof(*queue->kernel_if->u.g.vas);
queue_size += pas_size + vas_size;
queue = vmalloc(queue_size);
if (!queue)
return NULL;
queue->q_header = NULL;
queue->saved_header = NULL;
queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1);
queue->kernel_if->mutex = NULL;
queue->kernel_if->num_pages = num_pages;
queue->kernel_if->u.g.pas = (dma_addr_t *)(queue->kernel_if + 1);
queue->kernel_if->u.g.vas =
(void **)((u8 *)queue->kernel_if->u.g.pas + pas_size);
queue->kernel_if->host = false;
for (i = 0; i < num_pages; i++) {
queue->kernel_if->u.g.vas[i] =
dma_alloc_coherent(&vmci_pdev->dev, PAGE_SIZE,
&queue->kernel_if->u.g.pas[i],
GFP_KERNEL);
if (!queue->kernel_if->u.g.vas[i]) {
/* Size excl. the header. */
qp_free_queue(queue, i * PAGE_SIZE);
return NULL;
}
}
/* Queue header is the first page. */
queue->q_header = queue->kernel_if->u.g.vas[0];
return queue;
}
/*
* Copies from a given buffer or iovector to a VMCI Queue. Uses
* kmap()/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)
{
u64 *produce_ppns;
u64 *consume_ppns;
struct vmci_queue *produce_q = prod_q;
struct vmci_queue *consume_q = cons_q;
u64 i;
if (!produce_q || !num_produce_pages || !consume_q ||
!num_consume_pages || !ppn_set)
return VMCI_ERROR_INVALID_ARGS;
if (ppn_set->initialized)
return VMCI_ERROR_ALREADY_EXISTS;
produce_ppns =
kmalloc_array(num_produce_pages, sizeof(*produce_ppns),
GFP_KERNEL);
if (!produce_ppns)
return VMCI_ERROR_NO_MEM;
consume_ppns =
kmalloc_array(num_consume_pages, sizeof(*consume_ppns),
GFP_KERNEL);
if (!consume_ppns) {
kfree(produce_ppns);
return VMCI_ERROR_NO_MEM;
}
for (i = 0; i < num_produce_pages; i++)
produce_ppns[i] =
produce_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT;
for (i = 0; i < num_consume_pages; i++)
consume_ppns[i] =
consume_q->kernel_if->u.g.pas[i] >> PAGE_SHIFT;
ppn_set->num_produce_pages = num_produce_pages;
ppn_set->num_consume_pages = num_consume_pages;
ppn_set->produce_ppns = produce_ppns;
ppn_set->consume_ppns = consume_ppns;
ppn_set->initialized = true;
return VMCI_SUCCESS;
}
/*
* Frees the two list of PPNs for a queue pair.
*/
static void qp_free_ppn_set(struct ppn_set *ppn_set)
{
if (ppn_set->initialized) {
/* Do not call these functions on NULL inputs. */
kfree(ppn_set->produce_ppns);
kfree(ppn_set->consume_ppns);
}
memset(ppn_set, 0, sizeof(*ppn_set));
}
/*
* Populates the list of PPNs in the hypercall structure with the PPNS
* of the produce queue and the consume queue.
*/
static int qp_populate_ppn_set(u8 *call_buf, const struct ppn_set *ppn_set)
{
if (vmci_use_ppn64()) {
memcpy(call_buf, ppn_set->produce_ppns,
ppn_set->num_produce_pages *
sizeof(*ppn_set->produce_ppns));
memcpy(call_buf +
ppn_set->num_produce_pages *
sizeof(*ppn_set->produce_ppns),
ppn_set->consume_ppns,
ppn_set->num_consume_pages *
sizeof(*ppn_set->consume_ppns));
} else {
int i;
u32 *ppns = (u32 *) call_buf;
for (i = 0; i < ppn_set->num_produce_pages; i++)
ppns[i] = (u32) ppn_set->produce_ppns[i];
ppns = &ppns[ppn_set->num_produce_pages];
for (i = 0; i < ppn_set->num_consume_pages; i++)
ppns[i] = (u32) ppn_set->consume_ppns[i];
}
return VMCI_SUCCESS;
}
/*
* Allocates kernel VA space of specified size plus space for the queue
* and kernel interface. This is different from the guest queue allocator,
* because we do not allocate our own queue header/data pages here but
* share those of the guest.
*/
static struct vmci_queue *qp_host_alloc_queue(u64 size)
{
struct vmci_queue *queue;
size_t queue_page_size;
u64 num_pages;
const size_t queue_size = sizeof(*queue) + sizeof(*(queue->kernel_if));
if (size > min_t(size_t, VMCI_MAX_GUEST_QP_MEMORY, SIZE_MAX - PAGE_SIZE))
return NULL;
num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
if (num_pages > (SIZE_MAX - queue_size) /
sizeof(*queue->kernel_if->u.h.page))
return NULL;
queue_page_size = num_pages * sizeof(*queue->kernel_if->u.h.page);
if (queue_size + queue_page_size > KMALLOC_MAX_SIZE)
return NULL;
queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL);
if (queue) {
queue->q_header = NULL;
queue->saved_header = NULL;
queue->kernel_if = (struct vmci_queue_kern_if *)(queue + 1);
queue->kernel_if->host = true;
queue->kernel_if->mutex = NULL;
queue->kernel_if->num_pages = num_pages;
queue->kernel_if->u.h.header_page =
(struct page **)((u8 *)queue + queue_size);
queue->kernel_if->u.h.page =
&queue->kernel_if->u.h.header_page[1];
}
return queue;
}
/*
* Frees kernel memory for a given queue (header plus translation
* structure).
*/
static void qp_host_free_queue(struct vmci_queue *queue, u64 queue_size)
{
kfree(queue);
}
/*
* Initialize the mutex for the pair of queues. This mutex is used to
* protect the q_header and the buffer from changing out from under any
* users of either queue. Of course, it's only any good if the mutexes
* are actually acquired. Queue structure must lie on non-paged memory
* or we cannot guarantee access to the mutex.
*/
static void qp_init_queue_mutex(struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
/*
* Only the host queue has shared state - the guest queues do not
* need to synchronize access using a queue mutex.
*/
if (produce_q->kernel_if->host) {
produce_q->kernel_if->mutex = &produce_q->kernel_if->__mutex;
consume_q->kernel_if->mutex = &produce_q->kernel_if->__mutex;
mutex_init(produce_q->kernel_if->mutex);
}
}
/*
* Cleans up the mutex for the pair of queues.
*/
static void qp_cleanup_queue_mutex(struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
if (produce_q->kernel_if->host) {
produce_q->kernel_if->mutex = NULL;
consume_q->kernel_if->mutex = NULL;
}
}
/*
* Acquire the mutex for the queue. Note that the produce_q and
* the consume_q share a mutex. So, only one of the two need to
* be passed in to this routine. Either will work just fine.
*/
static void qp_acquire_queue_mutex(struct vmci_queue *queue)
{
if (queue->kernel_if->host)
mutex_lock(queue->kernel_if->mutex);
}
/*
* Release the mutex for the queue. Note that the produce_q and
* the consume_q share a mutex. So, only one of the two need to
* be passed in to this routine. Either will work just fine.
*/
static void qp_release_queue_mutex(struct vmci_queue *queue)
{
if (queue->kernel_if->host)
mutex_unlock(queue->kernel_if->mutex);
}
/*
* Helper function to release pages in the PageStoreAttachInfo
* previously obtained using get_user_pages.
*/
static void qp_release_pages(struct page **pages,
u64 num_pages, bool dirty)
{
int i;
for (i = 0; i < num_pages; i++) {
if (dirty)
set_page_dirty_lock(pages[i]);
put_page(pages[i]);
pages[i] = NULL;
}
}
/*
* Lock the user pages referenced by the {produce,consume}Buffer
* struct into memory and populate the {produce,consume}Pages
* arrays in the attach structure with them.
*/
static int qp_host_get_user_memory(u64 produce_uva,
u64 consume_uva,
struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
int retval;
int err = VMCI_SUCCESS;
retval = get_user_pages_fast((uintptr_t) produce_uva,
produce_q->kernel_if->num_pages,
FOLL_WRITE,
produce_q->kernel_if->u.h.header_page);
if (retval < (int)produce_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
retval);
if (retval > 0)
qp_release_pages(produce_q->kernel_if->u.h.header_page,
retval, false);
err = VMCI_ERROR_NO_MEM;
goto out;
}
retval = get_user_pages_fast((uintptr_t) consume_uva,
consume_q->kernel_if->num_pages,
FOLL_WRITE,
consume_q->kernel_if->u.h.header_page);
if (retval < (int)consume_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
retval);
if (retval > 0)
qp_release_pages(consume_q->kernel_if->u.h.header_page,
retval, false);
qp_release_pages(produce_q->kernel_if->u.h.header_page,
produce_q->kernel_if->num_pages, false);
err = VMCI_ERROR_NO_MEM;
}
out:
return err;
}
/*
* Registers the specification of the user pages used for backing a queue
* pair. Enough information to map in pages is stored in the OS specific
* part of the struct vmci_queue structure.
*/
static int qp_host_register_user_memory(struct vmci_qp_page_store *page_store,
struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
u64 produce_uva;
u64 consume_uva;
/*
* The new style and the old style mapping only differs in
* that we either get a single or two UVAs, so we split the
* single UVA range at the appropriate spot.
*/
produce_uva = page_store->pages;
consume_uva = page_store->pages +
produce_q->kernel_if->num_pages * PAGE_SIZE;
return qp_host_get_user_memory(produce_uva, consume_uva, produce_q,
consume_q);
}
/*
* Releases and removes the references to user pages stored in the attach
* struct. Pages are released from the page cache and may become
* swappable again.
*/
static void qp_host_unregister_user_memory(struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
qp_release_pages(produce_q->kernel_if->u.h.header_page,
produce_q->kernel_if->num_pages, true);
memset(produce_q->kernel_if->u.h.header_page, 0,
sizeof(*produce_q->kernel_if->u.h.header_page) *
produce_q->kernel_if->num_pages);
qp_release_pages(consume_q->kernel_if->u.h.header_page,
consume_q->kernel_if->num_pages, true);
memset(consume_q->kernel_if->u.h.header_page, 0,
sizeof(*consume_q->kernel_if->u.h.header_page) *
consume_q->kernel_if->num_pages);
}
/*
* Once qp_host_register_user_memory has been performed on a
* queue, the queue pair headers can be mapped into the
* kernel. Once mapped, they must be unmapped with
* qp_host_unmap_queues prior to calling
* qp_host_unregister_user_memory.
* Pages are pinned.
*/
static int qp_host_map_queues(struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
int result;
if (!produce_q->q_header || !consume_q->q_header) {
struct page *headers[2];
if (produce_q->q_header != consume_q->q_header)
return VMCI_ERROR_QUEUEPAIR_MISMATCH;
if (produce_q->kernel_if->u.h.header_page == NULL ||
*produce_q->kernel_if->u.h.header_page == NULL)
return VMCI_ERROR_UNAVAILABLE;
headers[0] = *produce_q->kernel_if->u.h.header_page;
headers[1] = *consume_q->kernel_if->u.h.header_page;
produce_q->q_header = vmap(headers, 2, VM_MAP, PAGE_KERNEL);
if (produce_q->q_header != NULL) {
consume_q->q_header =
(struct vmci_queue_header *)((u8 *)
produce_q->q_header +
PAGE_SIZE);
result = VMCI_SUCCESS;
} else {
pr_warn("vmap failed\n");
result = VMCI_ERROR_NO_MEM;
}
} else {
result = VMCI_SUCCESS;
}
return result;
}
/*
* Unmaps previously mapped queue pair headers from the kernel.
* Pages are unpinned.
*/
static int qp_host_unmap_queues(u32 gid,
struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
if (produce_q->q_header) {
if (produce_q->q_header < consume_q->q_header)
vunmap(produce_q->q_header);
else
vunmap(consume_q->q_header);
produce_q->q_header = NULL;
consume_q->q_header = NULL;
}
return VMCI_SUCCESS;
}
/*
* Finds the entry in the list corresponding to a given handle. Assumes
* that the list is locked.
*/
static struct qp_entry *qp_list_find(struct qp_list *qp_list,
struct vmci_handle handle)
{
struct qp_entry *entry;
if (vmci_handle_is_invalid(handle))
return NULL;
list_for_each_entry(entry, &qp_list->head, list_item) {
if (vmci_handle_is_equal(entry->handle, handle))
return entry;
}
return NULL;
}
/*
* Finds the entry in the list corresponding to a given handle.
*/
static struct qp_guest_endpoint *
qp_guest_handle_to_entry(struct vmci_handle handle)
{
struct qp_guest_endpoint *entry;
struct qp_entry *qp = qp_list_find(&qp_guest_endpoints, handle);
entry = qp ? container_of(
qp, struct qp_guest_endpoint, qp) : NULL;
return entry;
}
/*
* Finds the entry in the list corresponding to a given handle.
*/
static struct qp_broker_entry *
qp_broker_handle_to_entry(struct vmci_handle handle)
{
struct qp_broker_entry *entry;
struct qp_entry *qp = qp_list_find(&qp_broker_list, handle);
entry = qp ? container_of(
qp, struct qp_broker_entry, qp) : NULL;
return entry;
}
/*
* Dispatches a queue pair event message directly into the local event
* queue.
*/
static int qp_notify_peer_local(bool attach, struct vmci_handle handle)
{
u32 context_id = vmci_get_context_id();
struct vmci_event_qp ev;
memset(&ev, 0, sizeof(ev));
ev.msg.hdr.dst = vmci_make_handle(context_id, VMCI_EVENT_HANDLER);
ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
VMCI_CONTEXT_RESOURCE_ID);
ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr);
ev.msg.event_data.event =
attach ? VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
ev.payload.peer_id = context_id;
ev.payload.handle = handle;
return vmci_event_dispatch(&ev.msg.hdr);
}
/*
* Allocates and initializes a qp_guest_endpoint structure.
* Allocates a queue_pair rid (and handle) iff the given entry has
* an invalid handle. 0 through VMCI_RESERVED_RESOURCE_ID_MAX
* are reserved handles. Assumes that the QP list mutex is held
* by the caller.
*/
static struct qp_guest_endpoint *
qp_guest_endpoint_create(struct vmci_handle handle,
u32 peer,
u32 flags,
u64 produce_size,
u64 consume_size,
void *produce_q,
void *consume_q)
{
int result;
struct qp_guest_endpoint *entry;
/* One page each for the queue headers. */
const u64 num_ppns = DIV_ROUND_UP(produce_size, PAGE_SIZE) +
DIV_ROUND_UP(consume_size, PAGE_SIZE) + 2;
if (vmci_handle_is_invalid(handle)) {
u32 context_id = vmci_get_context_id();
handle = vmci_make_handle(context_id, VMCI_INVALID_ID);
}
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry) {
entry->qp.peer = peer;
entry->qp.flags = flags;
entry->qp.produce_size = produce_size;
entry->qp.consume_size = consume_size;
entry->qp.ref_count = 0;
entry->num_ppns = num_ppns;
entry->produce_q = produce_q;
entry->consume_q = consume_q;
INIT_LIST_HEAD(&entry->qp.list_item);
/* Add resource obj */
result = vmci_resource_add(&entry->resource,
VMCI_RESOURCE_TYPE_QPAIR_GUEST,
handle);
entry->qp.handle = vmci_resource_handle(&entry->resource);
if ((result != VMCI_SUCCESS) ||
qp_list_find(&qp_guest_endpoints, entry->qp.handle)) {
pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d",
handle.context, handle.resource, result);
kfree(entry);
entry = NULL;
}
}
return entry;
}
/*
* Frees a qp_guest_endpoint structure.
*/
static void qp_guest_endpoint_destroy(struct qp_guest_endpoint *entry)
{
qp_free_ppn_set(&entry->ppn_set);
qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q);
qp_free_queue(entry->produce_q, entry->qp.produce_size);
qp_free_queue(entry->consume_q, entry->qp.consume_size);
/* Unlink from resource hash table and free callback */
vmci_resource_remove(&entry->resource);
kfree(entry);
}
/*
* Helper to make a queue_pairAlloc hypercall when the driver is
* supporting a guest device.
*/
static int qp_alloc_hypercall(const struct qp_guest_endpoint *entry)
{
struct vmci_qp_alloc_msg *alloc_msg;
size_t msg_size;
size_t ppn_size;
int result;
if (!entry || entry->num_ppns <= 2)
return VMCI_ERROR_INVALID_ARGS;
ppn_size = vmci_use_ppn64() ? sizeof(u64) : sizeof(u32);
msg_size = sizeof(*alloc_msg) +
(size_t) entry->num_ppns * ppn_size;
alloc_msg = kmalloc(msg_size, GFP_KERNEL);
if (!alloc_msg)
return VMCI_ERROR_NO_MEM;
alloc_msg->hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
VMCI_QUEUEPAIR_ALLOC);
alloc_msg->hdr.src = VMCI_ANON_SRC_HANDLE;
alloc_msg->hdr.payload_size = msg_size - VMCI_DG_HEADERSIZE;
alloc_msg->handle = entry->qp.handle;
alloc_msg->peer = entry->qp.peer;
alloc_msg->flags = entry->qp.flags;
alloc_msg->produce_size = entry->qp.produce_size;
alloc_msg->consume_size = entry->qp.consume_size;
alloc_msg->num_ppns = entry->num_ppns;
result = qp_populate_ppn_set((u8 *)alloc_msg + sizeof(*alloc_msg),
&entry->ppn_set);
if (result == VMCI_SUCCESS)
result = vmci_send_datagram(&alloc_msg->hdr);
kfree(alloc_msg);
return result;
}
/*
* Helper to make a queue_pairDetach hypercall when the driver is
* supporting a guest device.
*/
static int qp_detatch_hypercall(struct vmci_handle handle)
{
struct vmci_qp_detach_msg detach_msg;
detach_msg.hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
VMCI_QUEUEPAIR_DETACH);
detach_msg.hdr.src = VMCI_ANON_SRC_HANDLE;
detach_msg.hdr.payload_size = sizeof(handle);
detach_msg.handle = handle;
return vmci_send_datagram(&detach_msg.hdr);
}
/*
* Adds the given entry to the list. Assumes that the list is locked.
*/
static void qp_list_add_entry(struct qp_list *qp_list, struct qp_entry *entry)
{
if (entry)
list_add(&entry->list_item, &qp_list->head);
}
/*
* Removes the given entry from the list. Assumes that the list is locked.
*/
static void qp_list_remove_entry(struct qp_list *qp_list,
struct qp_entry *entry)
{
if (entry)
list_del(&entry->list_item);
}
/*
* Helper for VMCI queue_pair detach interface. Frees the physical
* pages for the queue pair.
*/
static int qp_detatch_guest_work(struct vmci_handle handle)
{
int result;
struct qp_guest_endpoint *entry;
u32 ref_count = ~0; /* To avoid compiler warning below */
mutex_lock(&qp_guest_endpoints.mutex);
entry = qp_guest_handle_to_entry(handle);
if (!entry) {
mutex_unlock(&qp_guest_endpoints.mutex);
return VMCI_ERROR_NOT_FOUND;
}
if (entry->qp.flags & VMCI_QPFLAG_LOCAL) {
result = VMCI_SUCCESS;
if (entry->qp.ref_count > 1) {
result = qp_notify_peer_local(false, handle);
/*
* We can fail to notify a local queuepair
* because we can't allocate. We still want
* to release the entry if that happens, so
* don't bail out yet.
*/
}
} else {
result = qp_detatch_hypercall(handle);
if (result < VMCI_SUCCESS) {
/*
* We failed to notify a non-local queuepair.
* That other queuepair might still be
* accessing the shared memory, so don't
* release the entry yet. It will get cleaned
* up by VMCIqueue_pair_Exit() if necessary
* (assuming we are going away, otherwise why
* did this fail?).
*/
mutex_unlock(&qp_guest_endpoints.mutex);
return result;
}
}
/*
* If we get here then we either failed to notify a local queuepair, or
* we succeeded in all cases. Release the entry if required.
*/
entry->qp.ref_count--;
if (entry->qp.ref_count == 0)
qp_list_remove_entry(&qp_guest_endpoints, &entry->qp);
/* If we didn't remove the entry, this could change once we unlock. */
if (entry)
ref_count = entry->qp.ref_count;
mutex_unlock(&qp_guest_endpoints.mutex);
if (ref_count == 0)
qp_guest_endpoint_destroy(entry);
return result;
}
/*
* This functions handles the actual allocation of a VMCI queue
* pair guest endpoint. Allocates physical pages for the queue
* pair. It makes OS dependent calls through generic wrappers.
*/
static int qp_alloc_guest_work(struct vmci_handle *handle,
struct vmci_queue **produce_q,
u64 produce_size,
struct vmci_queue **consume_q,
u64 consume_size,
u32 peer,
u32 flags,
u32 priv_flags)
{
const u64 num_produce_pages =
DIV_ROUND_UP(produce_size, PAGE_SIZE) + 1;
const u64 num_consume_pages =
DIV_ROUND_UP(consume_size, PAGE_SIZE) + 1;
void *my_produce_q = NULL;
void *my_consume_q = NULL;
int result;
struct qp_guest_endpoint *queue_pair_entry = NULL;
if (priv_flags != VMCI_NO_PRIVILEGE_FLAGS)
return VMCI_ERROR_NO_ACCESS;
mutex_lock(&qp_guest_endpoints.mutex);
queue_pair_entry = qp_guest_handle_to_entry(*handle);
if (queue_pair_entry) {
if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) {
/* Local attach case. */
if (queue_pair_entry->qp.ref_count > 1) {
pr_devel("Error attempting to attach more than once\n");
result = VMCI_ERROR_UNAVAILABLE;
goto error_keep_entry;
}
if (queue_pair_entry->qp.produce_size != consume_size ||
queue_pair_entry->qp.consume_size !=
produce_size ||
queue_pair_entry->qp.flags !=
(flags & ~VMCI_QPFLAG_ATTACH_ONLY)) {
pr_devel("Error mismatched queue pair in local attach\n");
result = VMCI_ERROR_QUEUEPAIR_MISMATCH;
goto error_keep_entry;
}
/*
* Do a local attach. We swap the consume and
* produce queues for the attacher and deliver
* an attach event.
*/
result = qp_notify_peer_local(true, *handle);
if (result < VMCI_SUCCESS)
goto error_keep_entry;
my_produce_q = queue_pair_entry->consume_q;
my_consume_q = queue_pair_entry->produce_q;
goto out;
}
result = VMCI_ERROR_ALREADY_EXISTS;
goto error_keep_entry;
}
my_produce_q = qp_alloc_queue(produce_size, flags);
if (!my_produce_q) {
pr_warn("Error allocating pages for produce queue\n");
result = VMCI_ERROR_NO_MEM;
goto error;
}
my_consume_q = qp_alloc_queue(consume_size, flags);
if (!my_consume_q) {
pr_warn("Error allocating pages for consume queue\n");
result = VMCI_ERROR_NO_MEM;
goto error;
}
queue_pair_entry = qp_guest_endpoint_create(*handle, peer, flags,
produce_size, consume_size,
my_produce_q, my_consume_q);
if (!queue_pair_entry) {
pr_warn("Error allocating memory in %s\n", __func__);
result = VMCI_ERROR_NO_MEM;
goto error;
}
result = qp_alloc_ppn_set(my_produce_q, num_produce_pages, my_consume_q,
num_consume_pages,
&queue_pair_entry->ppn_set);
if (result < VMCI_SUCCESS) {
pr_warn("qp_alloc_ppn_set failed\n");
goto error;
}
/*
* It's only necessary to notify the host if this queue pair will be
* attached to from another context.
*/
if (queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) {
/* Local create case. */
u32 context_id = vmci_get_context_id();
/*
* Enforce similar checks on local queue pairs as we
* do for regular ones. The handle's context must
* match the creator or attacher context id (here they
* are both the current context id) and the
* attach-only flag cannot exist during create. We
* also ensure specified peer is this context or an
* invalid one.
*/
if (queue_pair_entry->qp.handle.context != context_id ||
(queue_pair_entry->qp.peer != VMCI_INVALID_ID &&
queue_pair_entry->qp.peer != context_id)) {
result = VMCI_ERROR_NO_ACCESS;
goto error;
}
if (queue_pair_entry->qp.flags & VMCI_QPFLAG_ATTACH_ONLY) {
result = VMCI_ERROR_NOT_FOUND;
goto error;
}
} else {
result = qp_alloc_hypercall(queue_pair_entry);
if (result < VMCI_SUCCESS) {
pr_devel("qp_alloc_hypercall result = %d\n", result);
goto error;
}
}
qp_init_queue_mutex((struct vmci_queue *)my_produce_q,
(struct vmci_queue *)my_consume_q);
qp_list_add_entry(&qp_guest_endpoints, &queue_pair_entry->qp);
out:
queue_pair_entry->qp.ref_count++;
*handle = queue_pair_entry->qp.handle;
*produce_q = (struct vmci_queue *)my_produce_q;
*consume_q = (struct vmci_queue *)my_consume_q;
/*
* We should initialize the queue pair header pages on a local
* queue pair create. For non-local queue pairs, the
* hypervisor initializes the header pages in the create step.
*/
if ((queue_pair_entry->qp.flags & VMCI_QPFLAG_LOCAL) &&
queue_pair_entry->qp.ref_count == 1) {
vmci_q_header_init((*produce_q)->q_header, *handle);
vmci_q_header_init((*consume_q)->q_header, *handle);
}
mutex_unlock(&qp_guest_endpoints.mutex);
return VMCI_SUCCESS;
error:
mutex_unlock(&qp_guest_endpoints.mutex);
if (queue_pair_entry) {
/* The queues will be freed inside the destroy routine. */
qp_guest_endpoint_destroy(queue_pair_entry);
} else {
qp_free_queue(my_produce_q, produce_size);
qp_free_queue(my_consume_q, consume_size);
}
return result;
error_keep_entry:
/* This path should only be used when an existing entry was found. */
mutex_unlock(&qp_guest_endpoints.mutex);
return result;
}
/*
* The first endpoint issuing a queue pair allocation will create the state
* of the queue pair in the queue pair broker.
*
* If the creator is a guest, it will associate a VMX virtual address range
* with the queue pair as specified by the page_store. For compatibility with
* older VMX'en, that would use a separate step to set the VMX virtual
* address range, the virtual address range can be registered later using
* vmci_qp_broker_set_page_store. In that case, a page_store of NULL should be
* used.
*
* If the creator is the host, a page_store of NULL should be used as well,
* since the host is not able to supply a page store for the queue pair.
*
* For older VMX and host callers, the queue pair will be created in the
* VMCIQPB_CREATED_NO_MEM state, and for current VMX callers, it will be
* created in VMCOQPB_CREATED_MEM state.
*/
static int qp_broker_create(struct vmci_handle handle,
u32 peer,
u32 flags,
u32 priv_flags,
u64 produce_size,
u64 consume_size,
struct vmci_qp_page_store *page_store,
struct vmci_ctx *context,
vmci_event_release_cb wakeup_cb,
void *client_data, struct qp_broker_entry **ent)
{
struct qp_broker_entry *entry = NULL;
const u32 context_id = vmci_ctx_get_id(context);
bool is_local = flags & VMCI_QPFLAG_LOCAL;
int result;
u64 guest_produce_size;
u64 guest_consume_size;
/* Do not create if the caller asked not to. */
if (flags & VMCI_QPFLAG_ATTACH_ONLY)
return VMCI_ERROR_NOT_FOUND;
/*
* Creator's context ID should match handle's context ID or the creator
* must allow the context in handle's context ID as the "peer".
*/
if (handle.context != context_id && handle.context != peer)
return VMCI_ERROR_NO_ACCESS;
if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(peer))
return VMCI_ERROR_DST_UNREACHABLE;
/*
* Creator's context ID for local queue pairs should match the
* peer, if a peer is specified.
*/
if (is_local && peer != VMCI_INVALID_ID && context_id != peer)
return VMCI_ERROR_NO_ACCESS;
entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return VMCI_ERROR_NO_MEM;
if (vmci_ctx_get_id(context) == VMCI_HOST_CONTEXT_ID && !is_local) {
/*
* The queue pair broker entry stores values from the guest
* point of view, so a creating host side endpoint should swap
* produce and consume values -- unless it is a local queue
* pair, in which case no swapping is necessary, since the local
* attacher will swap queues.
*/
guest_produce_size = consume_size;
guest_consume_size = produce_size;
} else {
guest_produce_size = produce_size;
guest_consume_size = consume_size;
}
entry->qp.handle = handle;
entry->qp.peer = peer;
entry->qp.flags = flags;
entry->qp.produce_size = guest_produce_size;
entry->qp.consume_size = guest_consume_size;
entry->qp.ref_count = 1;
entry->create_id = context_id;
entry->attach_id = VMCI_INVALID_ID;
entry->state = VMCIQPB_NEW;
entry->require_trusted_attach =
!!(context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED);
entry->created_by_trusted =
!!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED);
entry->vmci_page_files = false;
entry->wakeup_cb = wakeup_cb;
entry->client_data = client_data;
entry->produce_q = qp_host_alloc_queue(guest_produce_size);
if (entry->produce_q == NULL) {
result = VMCI_ERROR_NO_MEM;
goto error;
}
entry->consume_q = qp_host_alloc_queue(guest_consume_size);
if (entry->consume_q == NULL) {
result = VMCI_ERROR_NO_MEM;
goto error;
}
qp_init_queue_mutex(entry->produce_q, entry->consume_q);
INIT_LIST_HEAD(&entry->qp.list_item);
if (is_local) {
u8 *tmp;
entry->local_mem = kcalloc(QPE_NUM_PAGES(entry->qp),
PAGE_SIZE, GFP_KERNEL);
if (entry->local_mem == NULL) {
result = VMCI_ERROR_NO_MEM;
goto error;
}
entry->state = VMCIQPB_CREATED_MEM;
entry->produce_q->q_header = entry->local_mem;
tmp = (u8 *)entry->local_mem + PAGE_SIZE *
(DIV_ROUND_UP(entry->qp.produce_size, PAGE_SIZE) + 1);
entry->consume_q->q_header = (struct vmci_queue_header *)tmp;
} else if (page_store) {
/*
* The VMX already initialized the queue pair headers, so no
* need for the kernel side to do that.
*/
result = qp_host_register_user_memory(page_store,
entry->produce_q,
entry->consume_q);
if (result < VMCI_SUCCESS)
goto error;
entry->state = VMCIQPB_CREATED_MEM;
} else {
/*
* A create without a page_store may be either a host
* side create (in which case we are waiting for the
* guest side to supply the memory) or an old style
* queue pair create (in which case we will expect a
* set page store call as the next step).
*/
entry->state = VMCIQPB_CREATED_NO_MEM;
}
qp_list_add_entry(&qp_broker_list, &entry->qp);
if (ent != NULL)
*ent = entry;
/* Add to resource obj */
result = vmci_resource_add(&entry->resource,
VMCI_RESOURCE_TYPE_QPAIR_HOST,
handle);
if (result != VMCI_SUCCESS) {
pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d",
handle.context, handle.resource, result);
goto error;
}
entry->qp.handle = vmci_resource_handle(&entry->resource);
if (is_local) {
vmci_q_header_init(entry->produce_q->q_header,
entry->qp.handle);
vmci_q_header_init(entry->consume_q->q_header,
entry->qp.handle);
}
vmci_ctx_qp_create(context, entry->qp.handle);
return VMCI_SUCCESS;
error:
if (entry != NULL) {
qp_host_free_queue(entry->produce_q, guest_produce_size);
qp_host_free_queue(entry->consume_q, guest_consume_size);
kfree(entry);
}
return result;
}
/*
* Enqueues an event datagram to notify the peer VM attached to
* the given queue pair handle about attach/detach event by the
* given VM. Returns Payload size of datagram enqueued on
* success, error code otherwise.
*/
static int qp_notify_peer(bool attach,
struct vmci_handle handle,
u32 my_id,
u32 peer_id)
{
int rv;
struct vmci_event_qp ev;
if (vmci_handle_is_invalid(handle) || my_id == VMCI_INVALID_ID ||
peer_id == VMCI_INVALID_ID)
return VMCI_ERROR_INVALID_ARGS;
/*
* In vmci_ctx_enqueue_datagram() we enforce the upper limit on
* number of pending events from the hypervisor to a given VM
* otherwise a rogue VM could do an arbitrary number of attach
* and detach operations causing memory pressure in the host
* kernel.
*/
memset(&ev, 0, sizeof(ev));
ev.msg.hdr.dst = vmci_make_handle(peer_id, VMCI_EVENT_HANDLER);
ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
VMCI_CONTEXT_RESOURCE_ID);
ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr);
ev.msg.event_data.event = attach ?
VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
ev.payload.handle = handle;
ev.payload.peer_id = my_id;
rv = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID,
&ev.msg.hdr, false);
if (rv < VMCI_SUCCESS)
pr_warn("Failed to enqueue queue_pair %s event datagram for context (ID=0x%x)\n",
attach ? "ATTACH" : "DETACH", peer_id);
return rv;
}
/*
* The second endpoint issuing a queue pair allocation will attach to
* the queue pair registered with the queue pair broker.
*
* If the attacher is a guest, it will associate a VMX virtual address
* range with the queue pair as specified by the page_store. At this
* point, the already attach host endpoint may start using the queue
* pair, and an attach event is sent to it. For compatibility with
* older VMX'en, that used a separate step to set the VMX virtual
* address range, the virtual address range can be registered later
* using vmci_qp_broker_set_page_store. In that case, a page_store of
* NULL should be used, and the attach event will be generated once
* the actual page store has been set.
*
* If the attacher is the host, a page_store of NULL should be used as
* well, since the page store information is already set by the guest.
*
* For new VMX and host callers, the queue pair will be moved to the
* VMCIQPB_ATTACHED_MEM state, and for older VMX callers, it will be
* moved to the VMCOQPB_ATTACHED_NO_MEM state.
*/
static int qp_broker_attach(struct qp_broker_entry *entry,
u32 peer,
u32 flags,
u32 priv_flags,
u64 produce_size,
u64 consume_size,
struct vmci_qp_page_store *page_store,
struct vmci_ctx *context,
vmci_event_release_cb wakeup_cb,
void *client_data,
struct qp_broker_entry **ent)
{
const u32 context_id = vmci_ctx_get_id(context);
bool is_local = flags & VMCI_QPFLAG_LOCAL;
int result;
if (entry->state != VMCIQPB_CREATED_NO_MEM &&
entry->state != VMCIQPB_CREATED_MEM)
return VMCI_ERROR_UNAVAILABLE;
if (is_local) {
if (!(entry->qp.flags & VMCI_QPFLAG_LOCAL) ||
context_id != entry->create_id) {
return VMCI_ERROR_INVALID_ARGS;
}
} else if (context_id == entry->create_id ||
context_id == entry->attach_id) {
return VMCI_ERROR_ALREADY_EXISTS;
}
if (VMCI_CONTEXT_IS_VM(context_id) &&
VMCI_CONTEXT_IS_VM(entry->create_id))
return VMCI_ERROR_DST_UNREACHABLE;
/*
* If we are attaching from a restricted context then the queuepair
* must have been created by a trusted endpoint.
*/
if ((context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) &&
!entry->created_by_trusted)
return VMCI_ERROR_NO_ACCESS;
/*
* If we are attaching to a queuepair that was created by a restricted
* context then we must be trusted.
*/
if (entry->require_trusted_attach &&
(!(priv_flags & VMCI_PRIVILEGE_FLAG_TRUSTED)))
return VMCI_ERROR_NO_ACCESS;
/*
* If the creator specifies VMCI_INVALID_ID in "peer" field, access
* control check is not performed.
*/
if (entry->qp.peer != VMCI_INVALID_ID && entry->qp.peer != context_id)
return VMCI_ERROR_NO_ACCESS;
if (entry->create_id == VMCI_HOST_CONTEXT_ID) {
/*
* Do not attach if the caller doesn't support Host Queue Pairs
* and a host created this queue pair.
*/
if (!vmci_ctx_supports_host_qp(context))
return VMCI_ERROR_INVALID_RESOURCE;
} else if (context_id == VMCI_HOST_CONTEXT_ID) {
struct vmci_ctx *create_context;
bool supports_host_qp;
/*
* Do not attach a host to a user created queue pair if that
* user doesn't support host queue pair end points.
*/
create_context = vmci_ctx_get(entry->create_id);
supports_host_qp = vmci_ctx_supports_host_qp(create_context);
vmci_ctx_put(create_context);
if (!supports_host_qp)
return VMCI_ERROR_INVALID_RESOURCE;
}
if ((entry->qp.flags & ~VMCI_QP_ASYMM) != (flags & ~VMCI_QP_ASYMM_PEER))
return VMCI_ERROR_QUEUEPAIR_MISMATCH;
if (context_id != VMCI_HOST_CONTEXT_ID) {
/*
* The queue pair broker entry stores values from the guest
* point of view, so an attaching guest should match the values
* stored in the entry.
*/
if (entry->qp.produce_size != produce_size ||
entry->qp.consume_size != consume_size) {
return VMCI_ERROR_QUEUEPAIR_MISMATCH;
}
} else if (entry->qp.produce_size != consume_size ||
entry->qp.consume_size != produce_size) {
return VMCI_ERROR_QUEUEPAIR_MISMATCH;
}
if (context_id != VMCI_HOST_CONTEXT_ID) {
/*
* If a guest attached to a queue pair, it will supply
* the backing memory. If this is a pre NOVMVM vmx,
* the backing memory will be supplied by calling
* vmci_qp_broker_set_page_store() following the
* return of the vmci_qp_broker_alloc() call. If it is
* a vmx of version NOVMVM or later, the page store
* must be supplied as part of the
* vmci_qp_broker_alloc call. Under all circumstances
* must the initially created queue pair not have any
* memory associated with it already.
*/
if (entry->state != VMCIQPB_CREATED_NO_MEM)
return VMCI_ERROR_INVALID_ARGS;
if (page_store != NULL) {
/*
* Patch up host state to point to guest
* supplied memory. The VMX already
* initialized the queue pair headers, so no
* need for the kernel side to do that.
*/
result = qp_host_register_user_memory(page_store,
entry->produce_q,
entry->consume_q);
if (result < VMCI_SUCCESS)
return result;
entry->state = VMCIQPB_ATTACHED_MEM;
} else {
entry->state = VMCIQPB_ATTACHED_NO_MEM;
}
} else if (entry->state == VMCIQPB_CREATED_NO_MEM) {
/*
* The host side is attempting to attach to a queue
* pair that doesn't have any memory associated with
* it. This must be a pre NOVMVM vmx that hasn't set
* the page store information yet, or a quiesced VM.
*/
return VMCI_ERROR_UNAVAILABLE;
} else {
/* The host side has successfully attached to a queue pair. */
entry->state = VMCIQPB_ATTACHED_MEM;
}
if (entry->state == VMCIQPB_ATTACHED_MEM) {
result =
qp_notify_peer(true, entry->qp.handle, context_id,
entry->create_id);
if (result < VMCI_SUCCESS)
pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n",
entry->create_id, entry->qp.handle.context,
entry->qp.handle.resource);
}
entry->attach_id = context_id;
entry->qp.ref_count++;
if (wakeup_cb) {
entry->wakeup_cb = wakeup_cb;
entry->client_data = client_data;
}
/*
* When attaching to local queue pairs, the context already has
* an entry tracking the queue pair, so don't add another one.
*/
if (!is_local)
vmci_ctx_qp_create(context, entry->qp.handle);
if (ent != NULL)
*ent = entry;
return VMCI_SUCCESS;
}
/*
* queue_pair_Alloc for use when setting up queue pair endpoints
* on the host.
*/
static int qp_broker_alloc(struct vmci_handle handle,
u32 peer,
u32 flags,
u32 priv_flags,
u64 produce_size,
u64 consume_size,
struct vmci_qp_page_store *page_store,
struct vmci_ctx *context,
vmci_event_release_cb wakeup_cb,
void *client_data,
struct qp_broker_entry **ent,
bool *swap)
{
const u32 context_id = vmci_ctx_get_id(context);
bool create;
struct qp_broker_entry *entry = NULL;
bool is_local = flags & VMCI_QPFLAG_LOCAL;
int result;
if (vmci_handle_is_invalid(handle) ||
(flags & ~VMCI_QP_ALL_FLAGS) || is_local ||
!(produce_size || consume_size) ||
!context || context_id == VMCI_INVALID_ID ||
handle.context == VMCI_INVALID_ID) {
return VMCI_ERROR_INVALID_ARGS;
}
if (page_store && !VMCI_QP_PAGESTORE_IS_WELLFORMED(page_store))
return VMCI_ERROR_INVALID_ARGS;
/*
* In the initial argument check, we ensure that non-vmkernel hosts
* are not allowed to create local queue pairs.
*/
mutex_lock(&qp_broker_list.mutex);
if (!is_local && vmci_ctx_qp_exists(context, handle)) {
pr_devel("Context (ID=0x%x) already attached to queue pair (handle=0x%x:0x%x)\n",
context_id, handle.context, handle.resource);
mutex_unlock(&qp_broker_list.mutex);
return VMCI_ERROR_ALREADY_EXISTS;
}
if (handle.resource != VMCI_INVALID_ID)
entry = qp_broker_handle_to_entry(handle);
if (!entry) {
create = true;
result =
qp_broker_create(handle, peer, flags, priv_flags,
produce_size, consume_size, page_store,
context, wakeup_cb, client_data, ent);
} else {
create = false;
result =
qp_broker_attach(entry, peer, flags, priv_flags,
produce_size, consume_size, page_store,
context, wakeup_cb, client_data, ent);
}
mutex_unlock(&qp_broker_list.mutex);
if (swap)
*swap = (context_id == VMCI_HOST_CONTEXT_ID) &&
!(create && is_local);
return result;
}
/*
* This function implements the kernel API for allocating a queue
* pair.
*/
static int qp_alloc_host_work(struct vmci_handle *handle,
struct vmci_queue **produce_q,
u64 produce_size,
struct vmci_queue **consume_q,
u64 consume_size,
u32 peer,
u32 flags,
u32 priv_flags,
vmci_event_release_cb wakeup_cb,
void *client_data)
{
struct vmci_handle new_handle;
struct vmci_ctx *context;
struct qp_broker_entry *entry;
int result;
bool swap;
if (vmci_handle_is_invalid(*handle)) {
new_handle = vmci_make_handle(
VMCI_HOST_CONTEXT_ID, VMCI_INVALID_ID);
} else
new_handle = *handle;
context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID);
entry = NULL;
result =
qp_broker_alloc(new_handle, peer, flags, priv_flags,
produce_size, consume_size, NULL, context,
wakeup_cb, client_data, &entry, &swap);
if (result == VMCI_SUCCESS) {
if (swap) {
/*
* If this is a local queue pair, the attacher
* will swap around produce and consume
* queues.
*/
*produce_q = entry->consume_q;
*consume_q = entry->produce_q;
} else {
*produce_q = entry->produce_q;
*consume_q = entry->consume_q;
}
*handle = vmci_resource_handle(&entry->resource);
} else {
*handle = VMCI_INVALID_HANDLE;
pr_devel("queue pair broker failed to alloc (result=%d)\n",
result);
}
vmci_ctx_put(context);
return result;
}
/*
* Allocates a VMCI queue_pair. Only checks validity of input
* arguments. The real work is done in the host or guest
* specific function.
*/
int vmci_qp_alloc(struct vmci_handle *handle,
struct vmci_queue **produce_q,
u64 produce_size,
struct vmci_queue **consume_q,
u64 consume_size,
u32 peer,
u32 flags,
u32 priv_flags,
bool guest_endpoint,
vmci_event_release_cb wakeup_cb,
void *client_data)
{
if (!handle || !produce_q || !consume_q ||
(!produce_size && !consume_size) || (flags & ~VMCI_QP_ALL_FLAGS))
return VMCI_ERROR_INVALID_ARGS;
if (guest_endpoint) {
return qp_alloc_guest_work(handle, produce_q,
produce_size, consume_q,
consume_size, peer,
flags, priv_flags);
} else {
return qp_alloc_host_work(handle, produce_q,
produce_size, consume_q,
consume_size, peer, flags,
priv_flags, wakeup_cb, client_data);
}
}
/*
* This function implements the host kernel API for detaching from
* a queue pair.
*/
static int qp_detatch_host_work(struct vmci_handle handle)
{
int result;
struct vmci_ctx *context;
context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID);
result = vmci_qp_broker_detach(handle, context);
vmci_ctx_put(context);
return result;
}
/*
* Detaches from a VMCI queue_pair. Only checks validity of input argument.
* Real work is done in the host or guest specific function.
*/
static int qp_detatch(struct vmci_handle handle, bool guest_endpoint)
{
if (vmci_handle_is_invalid(handle))
return VMCI_ERROR_INVALID_ARGS;
if (guest_endpoint)
return qp_detatch_guest_work(handle);
else
return qp_detatch_host_work(handle);
}
/*
* Returns the entry from the head of the list. Assumes that the list is
* locked.
*/
static struct qp_entry *qp_list_get_head(struct qp_list *qp_list)
{
if (!list_empty(&qp_list->head)) {
struct qp_entry *entry =
list_first_entry(&qp_list->head, struct qp_entry,
list_item);
return entry;
}
return NULL;
}
void vmci_qp_broker_exit(void)
{
struct qp_entry *entry;
struct qp_broker_entry *be;
mutex_lock(&qp_broker_list.mutex);
while ((entry = qp_list_get_head(&qp_broker_list))) {
be = (struct qp_broker_entry *)entry;
qp_list_remove_entry(&qp_broker_list, entry);
kfree(be);
}
mutex_unlock(&qp_broker_list.mutex);
}
/*
* Requests that a queue pair be allocated with the VMCI queue
* pair broker. Allocates a queue pair entry if one does not
* exist. Attaches to one if it exists, and retrieves the page
* files backing that queue_pair. Assumes that the queue pair
* broker lock is held.
*/
int vmci_qp_broker_alloc(struct vmci_handle handle,
u32 peer,
u32 flags,
u32 priv_flags,
u64 produce_size,
u64 consume_size,
struct vmci_qp_page_store *page_store,
struct vmci_ctx *context)
{
if (!QP_SIZES_ARE_VALID(produce_size, consume_size))
return VMCI_ERROR_NO_RESOURCES;
return qp_broker_alloc(handle, peer, flags, priv_flags,
produce_size, consume_size,
page_store, context, NULL, NULL, NULL, NULL);
}
/*
* VMX'en with versions lower than VMCI_VERSION_NOVMVM use a separate
* step to add the UVAs of the VMX mapping of the queue pair. This function
* provides backwards compatibility with such VMX'en, and takes care of
* registering the page store for a queue pair previously allocated by the
* VMX during create or attach. This function will move the queue pair state
* to either from VMCIQBP_CREATED_NO_MEM to VMCIQBP_CREATED_MEM or
* VMCIQBP_ATTACHED_NO_MEM to VMCIQBP_ATTACHED_MEM. If moving to the
* attached state with memory, the queue pair is ready to be used by the
* host peer, and an attached event will be generated.
*
* Assumes that the queue pair broker lock is held.
*
* This function is only used by the hosted platform, since there is no
* issue with backwards compatibility for vmkernel.
*/
int vmci_qp_broker_set_page_store(struct vmci_handle handle,
u64 produce_uva,
u64 consume_uva,
struct vmci_ctx *context)
{
struct qp_broker_entry *entry;
int result;
const u32 context_id = vmci_ctx_get_id(context);
if (vmci_handle_is_invalid(handle) || !context ||
context_id == VMCI_INVALID_ID)
return VMCI_ERROR_INVALID_ARGS;
/*
* We only support guest to host queue pairs, so the VMX must
* supply UVAs for the mapped page files.
*/
if (produce_uva == 0 || consume_uva == 0)
return VMCI_ERROR_INVALID_ARGS;
mutex_lock(&qp_broker_list.mutex);
if (!vmci_ctx_qp_exists(context, handle)) {
pr_warn("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
entry = qp_broker_handle_to_entry(handle);
if (!entry) {
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
/*
* If I'm the owner then I can set the page store.
*
* Or, if a host created the queue_pair and I'm the attached peer
* then I can set the page store.
*/
if (entry->create_id != context_id &&
(entry->create_id != VMCI_HOST_CONTEXT_ID ||
entry->attach_id != context_id)) {
result = VMCI_ERROR_QUEUEPAIR_NOTOWNER;
goto out;
}
if (entry->state != VMCIQPB_CREATED_NO_MEM &&
entry->state != VMCIQPB_ATTACHED_NO_MEM) {
result = VMCI_ERROR_UNAVAILABLE;
goto out;
}
result = qp_host_get_user_memory(produce_uva, consume_uva,
entry->produce_q, entry->consume_q);
if (result < VMCI_SUCCESS)
goto out;
result = qp_host_map_queues(entry->produce_q, entry->consume_q);
if (result < VMCI_SUCCESS) {
qp_host_unregister_user_memory(entry->produce_q,
entry->consume_q);
goto out;
}
if (entry->state == VMCIQPB_CREATED_NO_MEM)
entry->state = VMCIQPB_CREATED_MEM;
else
entry->state = VMCIQPB_ATTACHED_MEM;
entry->vmci_page_files = true;
if (entry->state == VMCIQPB_ATTACHED_MEM) {
result =
qp_notify_peer(true, handle, context_id, entry->create_id);
if (result < VMCI_SUCCESS) {
pr_warn("Failed to notify peer (ID=0x%x) of attach to queue pair (handle=0x%x:0x%x)\n",
entry->create_id, entry->qp.handle.context,
entry->qp.handle.resource);
}
}
result = VMCI_SUCCESS;
out:
mutex_unlock(&qp_broker_list.mutex);
return result;
}
/*
* Resets saved queue headers for the given QP broker
* entry. Should be used when guest memory becomes available
* again, or the guest detaches.
*/
static void qp_reset_saved_headers(struct qp_broker_entry *entry)
{
entry->produce_q->saved_header = NULL;
entry->consume_q->saved_header = NULL;
}
/*
* The main entry point for detaching from a queue pair registered with the
* queue pair broker. If more than one endpoint is attached to the queue
* pair, the first endpoint will mainly decrement a reference count and
* generate a notification to its peer. The last endpoint will clean up
* the queue pair state registered with the broker.
*
* When a guest endpoint detaches, it will unmap and unregister the guest
* memory backing the queue pair. If the host is still attached, it will
* no longer be able to access the queue pair content.
*
* If the queue pair is already in a state where there is no memory
* registered for the queue pair (any *_NO_MEM state), it will transition to
* the VMCIQPB_SHUTDOWN_NO_MEM state. This will also happen, if a guest
* endpoint is the first of two endpoints to detach. If the host endpoint is
* the first out of two to detach, the queue pair will move to the
* VMCIQPB_SHUTDOWN_MEM state.
*/
int vmci_qp_broker_detach(struct vmci_handle handle, struct vmci_ctx *context)
{
struct qp_broker_entry *entry;
const u32 context_id = vmci_ctx_get_id(context);
u32 peer_id;
bool is_local = false;
int result;
if (vmci_handle_is_invalid(handle) || !context ||
context_id == VMCI_INVALID_ID) {
return VMCI_ERROR_INVALID_ARGS;
}
mutex_lock(&qp_broker_list.mutex);
if (!vmci_ctx_qp_exists(context, handle)) {
pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
entry = qp_broker_handle_to_entry(handle);
if (!entry) {
pr_devel("Context (ID=0x%x) reports being attached to queue pair(handle=0x%x:0x%x) that isn't present in broker\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
if (context_id != entry->create_id && context_id != entry->attach_id) {
result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
goto out;
}
if (context_id == entry->create_id) {
peer_id = entry->attach_id;
entry->create_id = VMCI_INVALID_ID;
} else {
peer_id = entry->create_id;
entry->attach_id = VMCI_INVALID_ID;
}
entry->qp.ref_count--;
is_local = entry->qp.flags & VMCI_QPFLAG_LOCAL;
if (context_id != VMCI_HOST_CONTEXT_ID) {
bool headers_mapped;
/*
* Pre NOVMVM vmx'en may detach from a queue pair
* before setting the page store, and in that case
* there is no user memory to detach from. Also, more
* recent VMX'en may detach from a queue pair in the
* quiesced state.
*/
qp_acquire_queue_mutex(entry->produce_q);
headers_mapped = entry->produce_q->q_header ||
entry->consume_q->q_header;
if (QPBROKERSTATE_HAS_MEM(entry)) {
result =
qp_host_unmap_queues(INVALID_VMCI_GUEST_MEM_ID,
entry->produce_q,
entry->consume_q);
if (result < VMCI_SUCCESS)
pr_warn("Failed to unmap queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n",
handle.context, handle.resource,
result);
qp_host_unregister_user_memory(entry->produce_q,
entry->consume_q);
}
if (!headers_mapped)
qp_reset_saved_headers(entry);
qp_release_queue_mutex(entry->produce_q);
if (!headers_mapped && entry->wakeup_cb)
entry->wakeup_cb(entry->client_data);
} else {
if (entry->wakeup_cb) {
entry->wakeup_cb = NULL;
entry->client_data = NULL;
}
}
if (entry->qp.ref_count == 0) {
qp_list_remove_entry(&qp_broker_list, &entry->qp);
if (is_local)
kfree(entry->local_mem);
qp_cleanup_queue_mutex(entry->produce_q, entry->consume_q);
qp_host_free_queue(entry->produce_q, entry->qp.produce_size);
qp_host_free_queue(entry->consume_q, entry->qp.consume_size);
/* Unlink from resource hash table and free callback */
vmci_resource_remove(&entry->resource);
kfree(entry);
vmci_ctx_qp_destroy(context, handle);
} else {
qp_notify_peer(false, handle, context_id, peer_id);
if (context_id == VMCI_HOST_CONTEXT_ID &&
QPBROKERSTATE_HAS_MEM(entry)) {
entry->state = VMCIQPB_SHUTDOWN_MEM;
} else {
entry->state = VMCIQPB_SHUTDOWN_NO_MEM;
}
if (!is_local)
vmci_ctx_qp_destroy(context, handle);
}
result = VMCI_SUCCESS;
out:
mutex_unlock(&qp_broker_list.mutex);
return result;
}
/*
* Establishes the necessary mappings for a queue pair given a
* reference to the queue pair guest memory. This is usually
* called when a guest is unquiesced and the VMX is allowed to
* map guest memory once again.
*/
int vmci_qp_broker_map(struct vmci_handle handle,
struct vmci_ctx *context,
u64 guest_mem)
{
struct qp_broker_entry *entry;
const u32 context_id = vmci_ctx_get_id(context);
int result;
if (vmci_handle_is_invalid(handle) || !context ||
context_id == VMCI_INVALID_ID)
return VMCI_ERROR_INVALID_ARGS;
mutex_lock(&qp_broker_list.mutex);
if (!vmci_ctx_qp_exists(context, handle)) {
pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
entry = qp_broker_handle_to_entry(handle);
if (!entry) {
pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
if (context_id != entry->create_id && context_id != entry->attach_id) {
result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
goto out;
}
result = VMCI_SUCCESS;
if (context_id != VMCI_HOST_CONTEXT_ID &&
!QPBROKERSTATE_HAS_MEM(entry)) {
struct vmci_qp_page_store page_store;
page_store.pages = guest_mem;
page_store.len = QPE_NUM_PAGES(entry->qp);
qp_acquire_queue_mutex(entry->produce_q);
qp_reset_saved_headers(entry);
result =
qp_host_register_user_memory(&page_store,
entry->produce_q,
entry->consume_q);
qp_release_queue_mutex(entry->produce_q);
if (result == VMCI_SUCCESS) {
/* Move state from *_NO_MEM to *_MEM */
entry->state++;
if (entry->wakeup_cb)
entry->wakeup_cb(entry->client_data);
}
}
out:
mutex_unlock(&qp_broker_list.mutex);
return result;
}
/*
* Saves a snapshot of the queue headers for the given QP broker
* entry. Should be used when guest memory is unmapped.
* Results:
* VMCI_SUCCESS on success, appropriate error code if guest memory
* can't be accessed..
*/
static int qp_save_headers(struct qp_broker_entry *entry)
{
int result;
if (entry->produce_q->saved_header != NULL &&
entry->consume_q->saved_header != NULL) {
/*
* If the headers have already been saved, we don't need to do
* it again, and we don't want to map in the headers
* unnecessarily.
*/
return VMCI_SUCCESS;
}
if (NULL == entry->produce_q->q_header ||
NULL == entry->consume_q->q_header) {
result = qp_host_map_queues(entry->produce_q, entry->consume_q);
if (result < VMCI_SUCCESS)
return result;
}
memcpy(&entry->saved_produce_q, entry->produce_q->q_header,
sizeof(entry->saved_produce_q));
entry->produce_q->saved_header = &entry->saved_produce_q;
memcpy(&entry->saved_consume_q, entry->consume_q->q_header,
sizeof(entry->saved_consume_q));
entry->consume_q->saved_header = &entry->saved_consume_q;
return VMCI_SUCCESS;
}
/*
* Removes all references to the guest memory of a given queue pair, and
* will move the queue pair from state *_MEM to *_NO_MEM. It is usually
* called when a VM is being quiesced where access to guest memory should
* avoided.
*/
int vmci_qp_broker_unmap(struct vmci_handle handle,
struct vmci_ctx *context,
u32 gid)
{
struct qp_broker_entry *entry;
const u32 context_id = vmci_ctx_get_id(context);
int result;
if (vmci_handle_is_invalid(handle) || !context ||
context_id == VMCI_INVALID_ID)
return VMCI_ERROR_INVALID_ARGS;
mutex_lock(&qp_broker_list.mutex);
if (!vmci_ctx_qp_exists(context, handle)) {
pr_devel("Context (ID=0x%x) not attached to queue pair (handle=0x%x:0x%x)\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
entry = qp_broker_handle_to_entry(handle);
if (!entry) {
pr_devel("Context (ID=0x%x) reports being attached to queue pair (handle=0x%x:0x%x) that isn't present in broker\n",
context_id, handle.context, handle.resource);
result = VMCI_ERROR_NOT_FOUND;
goto out;
}
if (context_id != entry->create_id && context_id != entry->attach_id) {
result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
goto out;
}
if (context_id != VMCI_HOST_CONTEXT_ID &&
QPBROKERSTATE_HAS_MEM(entry)) {
qp_acquire_queue_mutex(entry->produce_q);
result = qp_save_headers(entry);
if (result < VMCI_SUCCESS)
pr_warn("Failed to save queue headers for queue pair (handle=0x%x:0x%x,result=%d)\n",
handle.context, handle.resource, result);
qp_host_unmap_queues(gid, entry->produce_q, entry->consume_q);
/*
* On hosted, when we unmap queue pairs, the VMX will also
* unmap the guest memory, so we invalidate the previously
* registered memory. If the queue pair is mapped again at a
* later point in time, we will need to reregister the user
* memory with a possibly new user VA.
*/
qp_host_unregister_user_memory(entry->produce_q,
entry->consume_q);
/*
* Move state from *_MEM to *_NO_MEM.
*/
entry->state--;
qp_release_queue_mutex(entry->produce_q);
}
result = VMCI_SUCCESS;
out:
mutex_unlock(&qp_broker_list.mutex);
return result;
}
/*
* Destroys all guest queue pair endpoints. If active guest queue
* pairs still exist, hypercalls to attempt detach from these
* queue pairs will be made. Any failure to detach is silently
* ignored.
*/
void vmci_qp_guest_endpoints_exit(void)
{
struct qp_entry *entry;
struct qp_guest_endpoint *ep;
mutex_lock(&qp_guest_endpoints.mutex);
while ((entry = qp_list_get_head(&qp_guest_endpoints))) {
ep = (struct qp_guest_endpoint *)entry;
/* Don't make a hypercall for local queue_pairs. */
if (!(entry->flags & VMCI_QPFLAG_LOCAL))
qp_detatch_hypercall(entry->handle);
/* We cannot fail the exit, so let's reset ref_count. */
entry->ref_count = 0;
qp_list_remove_entry(&qp_guest_endpoints, entry);
qp_guest_endpoint_destroy(ep);
}
mutex_unlock(&qp_guest_endpoints.mutex);
}
/*
* Helper routine that will lock the queue pair before subsequent
* operations.
* Note: Non-blocking on the host side is currently only implemented in ESX.
* Since non-blocking isn't yet implemented on the host personality we
* have no reason to acquire a spin lock. So to avoid the use of an
* unnecessary lock only acquire the mutex if we can block.
*/
static void qp_lock(const struct vmci_qp *qpair)
{
qp_acquire_queue_mutex(qpair->produce_q);
}
/*
* Helper routine that unlocks the queue pair after calling
* qp_lock.
*/
static void qp_unlock(const struct vmci_qp *qpair)
{
qp_release_queue_mutex(qpair->produce_q);
}
/*
* The queue headers may not be mapped at all times. If a queue is
* currently not mapped, it will be attempted to do so.
*/
static int qp_map_queue_headers(struct vmci_queue *produce_q,
struct vmci_queue *consume_q)
{
int result;
if (NULL == produce_q->q_header || NULL == consume_q->q_header) {
result = qp_host_map_queues(produce_q, consume_q);
if (result < VMCI_SUCCESS)
return (produce_q->saved_header &&
consume_q->saved_header) ?
VMCI_ERROR_QUEUEPAIR_NOT_READY :
VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
}
return VMCI_SUCCESS;
}
/*
* Helper routine that will retrieve the produce and consume
* headers of a given queue pair. If the guest memory of the
* queue pair is currently not available, the saved queue headers
* will be returned, if these are available.
*/
static int qp_get_queue_headers(const struct vmci_qp *qpair,
struct vmci_queue_header **produce_q_header,
struct vmci_queue_header **consume_q_header)
{
int result;
result = qp_map_queue_headers(qpair->produce_q, qpair->consume_q);
if (result == VMCI_SUCCESS) {
*produce_q_header = qpair->produce_q->q_header;
*consume_q_header = qpair->consume_q->q_header;
} else if (qpair->produce_q->saved_header &&
qpair->consume_q->saved_header) {
*produce_q_header = qpair->produce_q->saved_header;
*consume_q_header = qpair->consume_q->saved_header;
result = VMCI_SUCCESS;
}
return result;
}
/*
* Callback from VMCI queue pair broker indicating that a queue
* pair that was previously not ready, now either is ready or
* gone forever.
*/
static int qp_wakeup_cb(void *client_data)
{
struct vmci_qp *qpair = (struct vmci_qp *)client_data;
qp_lock(qpair);
while (qpair->blocked > 0) {
qpair->blocked--;
qpair->generation++;
wake_up(&qpair->event);
}
qp_unlock(qpair);
return VMCI_SUCCESS;
}
/*
* Makes the calling thread wait for the queue pair to become
* ready for host side access. Returns true when thread is
* woken up after queue pair state change, false otherwise.
*/
static bool qp_wait_for_ready_queue(struct vmci_qp *qpair)
{
unsigned int generation;
qpair->blocked++;
generation = qpair->generation;
qp_unlock(qpair);
wait_event(qpair->event, generation != qpair->generation);
qp_lock(qpair);
return true;
}
/*
* Enqueues a given buffer to the produce queue using the provided
* function. As many bytes as possible (space available in the queue)
* are enqueued. Assumes the queue->mutex has been acquired. Returns
* VMCI_ERROR_QUEUEPAIR_NOSPACE if no space was available to enqueue
* data, VMCI_ERROR_INVALID_SIZE, if any queue pointer is outside the
* queue (as defined by the queue size), VMCI_ERROR_INVALID_ARGS, if
* an error occured when accessing the buffer,
* VMCI_ERROR_QUEUEPAIR_NOTATTACHED, if the queue pair pages aren't
* available. Otherwise, the number of bytes written to the queue is
* returned. Updates the tail pointer of the produce queue.
*/
static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
struct vmci_queue *consume_q,
const u64 produce_q_size,
struct iov_iter *from)
{
s64 free_space;
u64 tail;
size_t buf_size = iov_iter_count(from);
size_t written;
ssize_t result;
result = qp_map_queue_headers(produce_q, consume_q);
if (unlikely(result != VMCI_SUCCESS))
return result;
free_space = vmci_q_header_free_space(produce_q->q_header,
consume_q->q_header,
produce_q_size);
if (free_space == 0)
return VMCI_ERROR_QUEUEPAIR_NOSPACE;
if (free_space < VMCI_SUCCESS)
return (ssize_t) free_space;
written = (size_t) (free_space > buf_size ? buf_size : free_space);
tail = vmci_q_header_producer_tail(produce_q->q_header);
if (likely(tail + written < produce_q_size)) {
result = qp_memcpy_to_queue_iter(produce_q, tail, from, written);
} else {
/* Tail pointer wraps around. */
const size_t tmp = (size_t) (produce_q_size - tail);
result = qp_memcpy_to_queue_iter(produce_q, tail, from, tmp);
if (result >= VMCI_SUCCESS)
result = qp_memcpy_to_queue_iter(produce_q, 0, from,
written - tmp);
}
if (result < VMCI_SUCCESS)
return result;
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 (!QP_SIZES_ARE_VALID(produce_qsize, consume_qsize))
return VMCI_ERROR_NO_RESOURCES;
retval = vmci_route(&src, &dst, false, &route);
if (retval < VMCI_SUCCESS)
route = vmci_guest_code_active() ?
VMCI_ROUTE_AS_GUEST : VMCI_ROUTE_AS_HOST;
if (flags & (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED)) {
pr_devel("NONBLOCK OR PINNED set");
return VMCI_ERROR_INVALID_ARGS;
}
my_qpair = kzalloc(sizeof(*my_qpair), GFP_KERNEL);
if (!my_qpair)
return VMCI_ERROR_NO_MEM;
my_qpair->produce_q_size = produce_qsize;
my_qpair->consume_q_size = consume_qsize;
my_qpair->peer = peer;
my_qpair->flags = flags;
my_qpair->priv_flags = priv_flags;
wakeup_cb = NULL;
client_data = NULL;
if (VMCI_ROUTE_AS_HOST == route) {
my_qpair->guest_endpoint = false;
if (!(flags & VMCI_QPFLAG_LOCAL)) {
my_qpair->blocked = 0;
my_qpair->generation = 0;
init_waitqueue_head(&my_qpair->event);
wakeup_cb = qp_wakeup_cb;
client_data = (void *)my_qpair;
}
} else {
my_qpair->guest_endpoint = true;
}
retval = vmci_qp_alloc(handle,
&my_qpair->produce_q,
my_qpair->produce_q_size,
&my_qpair->consume_q,
my_qpair->consume_q_size,
my_qpair->peer,
my_qpair->flags,
my_qpair->priv_flags,
my_qpair->guest_endpoint,
wakeup_cb, client_data);
if (retval < VMCI_SUCCESS) {
kfree(my_qpair);
return retval;
}
*qpair = my_qpair;
my_qpair->handle = *handle;
return retval;
}
EXPORT_SYMBOL_GPL(vmci_qpair_alloc);
/*
* vmci_qpair_detach() - Detatches the client from a queue pair.
* @qpair: Reference of a pointer to the qpair struct.
*
* This is the client interface for detaching from a VMCIQPair.
* Note that this routine will free the memory allocated for the
* vmci_qp structure too.
*/
int vmci_qpair_detach(struct vmci_qp **qpair)
{
int result;
struct vmci_qp *old_qpair;
if (!qpair || !(*qpair))
return VMCI_ERROR_INVALID_ARGS;
old_qpair = *qpair;
result = qp_detatch(old_qpair->handle, old_qpair->guest_endpoint);
/*
* The guest can fail to detach for a number of reasons, and
* if it does so, it will cleanup the entry (if there is one).
* The host can fail too, but it won't cleanup the entry
* immediately, it will do that later when the context is
* freed. Either way, we need to release the qpair struct
* here; there isn't much the caller can do, and we don't want
* to leak.
*/
memset(old_qpair, 0, sizeof(*old_qpair));
old_qpair->handle = VMCI_INVALID_HANDLE;
old_qpair->peer = VMCI_INVALID_ID;
kfree(old_qpair);
*qpair = NULL;
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_detach);
/*
* vmci_qpair_get_produce_indexes() - Retrieves the indexes of the producer.
* @qpair: Pointer to the queue pair struct.
* @producer_tail: Reference used for storing producer tail index.
* @consumer_head: Reference used for storing the consumer head index.
*
* This is the client interface for getting the current indexes of the
* QPair from the point of the view of the caller as the producer.
*/
int vmci_qpair_get_produce_indexes(const struct vmci_qp *qpair,
u64 *producer_tail,
u64 *consumer_head)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
int result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
vmci_q_header_get_pointers(produce_q_header, consume_q_header,
producer_tail, consumer_head);
qp_unlock(qpair);
if (result == VMCI_SUCCESS &&
((producer_tail && *producer_tail >= qpair->produce_q_size) ||
(consumer_head && *consumer_head >= qpair->produce_q_size)))
return VMCI_ERROR_INVALID_SIZE;
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_get_produce_indexes);
/*
* vmci_qpair_get_consume_indexes() - Retrieves the indexes of the consumer.
* @qpair: Pointer to the queue pair struct.
* @consumer_tail: Reference used for storing consumer tail index.
* @producer_head: Reference used for storing the producer head index.
*
* This is the client interface for getting the current indexes of the
* QPair from the point of the view of the caller as the consumer.
*/
int vmci_qpair_get_consume_indexes(const struct vmci_qp *qpair,
u64 *consumer_tail,
u64 *producer_head)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
int result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
vmci_q_header_get_pointers(consume_q_header, produce_q_header,
consumer_tail, producer_head);
qp_unlock(qpair);
if (result == VMCI_SUCCESS &&
((consumer_tail && *consumer_tail >= qpair->consume_q_size) ||
(producer_head && *producer_head >= qpair->consume_q_size)))
return VMCI_ERROR_INVALID_SIZE;
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_get_consume_indexes);
/*
* vmci_qpair_produce_free_space() - Retrieves free space in producer queue.
* @qpair: Pointer to the queue pair struct.
*
* This is the client interface for getting the amount of free
* space in the QPair from the point of the view of the caller as
* the producer which is the common case. Returns < 0 if err, else
* available bytes into which data can be enqueued if > 0.
*/
s64 vmci_qpair_produce_free_space(const struct vmci_qp *qpair)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
s64 result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
result = vmci_q_header_free_space(produce_q_header,
consume_q_header,
qpair->produce_q_size);
else
result = 0;
qp_unlock(qpair);
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_produce_free_space);
/*
* vmci_qpair_consume_free_space() - Retrieves free space in consumer queue.
* @qpair: Pointer to the queue pair struct.
*
* This is the client interface for getting the amount of free
* space in the QPair from the point of the view of the caller as
* the consumer which is not the common case. Returns < 0 if err, else
* available bytes into which data can be enqueued if > 0.
*/
s64 vmci_qpair_consume_free_space(const struct vmci_qp *qpair)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
s64 result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
result = vmci_q_header_free_space(consume_q_header,
produce_q_header,
qpair->consume_q_size);
else
result = 0;
qp_unlock(qpair);
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_consume_free_space);
/*
* vmci_qpair_produce_buf_ready() - Gets bytes ready to read from
* producer queue.
* @qpair: Pointer to the queue pair struct.
*
* This is the client interface for getting the amount of
* enqueued data in the QPair from the point of the view of the
* caller as the producer which is not the common case. Returns < 0 if err,
* else available bytes that may be read.
*/
s64 vmci_qpair_produce_buf_ready(const struct vmci_qp *qpair)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
s64 result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
result = vmci_q_header_buf_ready(produce_q_header,
consume_q_header,
qpair->produce_q_size);
else
result = 0;
qp_unlock(qpair);
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_produce_buf_ready);
/*
* vmci_qpair_consume_buf_ready() - Gets bytes ready to read from
* consumer queue.
* @qpair: Pointer to the queue pair struct.
*
* This is the client interface for getting the amount of
* enqueued data in the QPair from the point of the view of the
* caller as the consumer which is the normal case. Returns < 0 if err,
* else available bytes that may be read.
*/
s64 vmci_qpair_consume_buf_ready(const struct vmci_qp *qpair)
{
struct vmci_queue_header *produce_q_header;
struct vmci_queue_header *consume_q_header;
s64 result;
if (!qpair)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
result =
qp_get_queue_headers(qpair, &produce_q_header, &consume_q_header);
if (result == VMCI_SUCCESS)
result = vmci_q_header_buf_ready(consume_q_header,
produce_q_header,
qpair->consume_q_size);
else
result = 0;
qp_unlock(qpair);
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_consume_buf_ready);
/*
* vmci_qpair_enqueue() - Throw data on the queue.
* @qpair: Pointer to the queue pair struct.
* @buf: Pointer to buffer containing data
* @buf_size: Length of buffer.
* @buf_type: Buffer type (Unused).
*
* This is the client interface for enqueueing data into the queue.
* Returns number of bytes enqueued or < 0 on error.
*/
ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
const void *buf,
size_t buf_size,
int buf_type)
{
ssize_t result;
struct iov_iter from;
struct kvec v = {.iov_base = (void *)buf, .iov_len = buf_size};
if (!qpair || !buf)
return VMCI_ERROR_INVALID_ARGS;
iov_iter_kvec(&from, WRITE, &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, &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, &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);