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linux/drivers/misc/vmw_vmci/vmci_queue_pair.c
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00

3356 lines
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/*
* 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.
*/
/*
* VMCIMemcpy{To,From}QueueFunc() prototypes. Functions of these
* types are passed around to enqueue and dequeue routines. Note that
* often the functions passed are simply wrappers around memcpy
* itself.
*
* Note: In order for the memcpy typedefs to be compatible with the VMKernel,
* there's an unused last parameter for the hosted side. In
* ESX, that parameter holds a buffer type.
*/
typedef int vmci_memcpy_to_queue_func(struct vmci_queue *queue,
u64 queue_offset, const void *src,
size_t src_offset, size_t size);
typedef int vmci_memcpy_from_queue_func(void *dest, size_t dest_offset,
const struct vmci_queue *queue,
u64 queue_offset, size_t size);
/* 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);
const u64 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(struct vmci_queue *queue,
u64 queue_offset,
const void *src,
size_t size,
bool is_iovec)
{
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 (is_iovec) {
struct msghdr *msg = (struct msghdr *)src;
int err;
/* The iovec will track bytes_copied internally. */
err = memcpy_from_msg((u8 *)va + page_offset,
msg, to_copy);
if (err != 0) {
if (kernel_if->host)
kunmap(kernel_if->u.h.page[page_index]);
return VMCI_ERROR_INVALID_ARGS;
}
} else {
memcpy((u8 *)va + page_offset,
(u8 *)src + bytes_copied, to_copy);
}
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(void *dest,
const struct vmci_queue *queue,
u64 queue_offset,
size_t size,
bool is_iovec)
{
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 this page. */
to_copy = PAGE_SIZE - page_offset;
else
to_copy = size - bytes_copied;
if (is_iovec) {
struct msghdr *msg = dest;
int err;
/* The iovec will track bytes_copied internally. */
err = memcpy_to_msg(msg, (u8 *)va + page_offset,
to_copy);
if (err != 0) {
if (kernel_if->host)
kunmap(kernel_if->u.h.page[page_index]);
return VMCI_ERROR_INVALID_ARGS;
}
} else {
memcpy((u8 *)dest + bytes_copied,
(u8 *)va + page_offset, to_copy);
}
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(num_produce_pages * sizeof(*produce_ppns), GFP_KERNEL);
if (!produce_ppns)
return VMCI_ERROR_NO_MEM;
consume_ppns =
kmalloc(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;
}
static int qp_memcpy_to_queue(struct vmci_queue *queue,
u64 queue_offset,
const void *src, size_t src_offset, size_t size)
{
return __qp_memcpy_to_queue(queue, queue_offset,
(u8 *)src + src_offset, size, false);
}
static int qp_memcpy_from_queue(void *dest,
size_t dest_offset,
const struct vmci_queue *queue,
u64 queue_offset, size_t size)
{
return __qp_memcpy_from_queue((u8 *)dest + dest_offset,
queue, queue_offset, size, false);
}
/*
* Copies from a given iovec from a VMCI Queue.
*/
static int qp_memcpy_to_queue_iov(struct vmci_queue *queue,
u64 queue_offset,
const void *msg,
size_t src_offset, size_t size)
{
/*
* We ignore src_offset because src is really a struct iovec * and will
* maintain offset internally.
*/
return __qp_memcpy_to_queue(queue, queue_offset, msg, size, true);
}
/*
* Copies to a given iovec from a VMCI Queue.
*/
static int qp_memcpy_from_queue_iov(void *dest,
size_t dest_offset,
const struct vmci_queue *queue,
u64 queue_offset, size_t size)
{
/*
* We ignore dest_offset because dest is really a struct iovec * and
* will maintain offset internally.
*/
return __qp_memcpy_from_queue(dest, queue, queue_offset, size, true);
}
/*
* 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;
const u64 num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1;
const size_t queue_size = sizeof(*queue) + sizeof(*(queue->kernel_if));
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);
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(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 < produce_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
retval);
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 < consume_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
retval);
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);
if (entry->vmci_page_files)
qp_host_unregister_user_memory(entry->produce_q,
entry->
consume_q);
else
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);
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;
}
is_local = entry->qp.flags & VMCI_QPFLAG_LOCAL;
result = VMCI_SUCCESS;
if (context_id != VMCI_HOST_CONTEXT_ID) {
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);
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;
}
is_local = entry->qp.flags & VMCI_QPFLAG_LOCAL;
if (context_id != VMCI_HOST_CONTEXT_ID) {
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,
const void *buf,
size_t buf_size,
vmci_memcpy_to_queue_func memcpy_to_queue)
{
s64 free_space;
u64 tail;
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 = memcpy_to_queue(produce_q, tail, buf, 0, written);
} else {
/* Tail pointer wraps around. */
const size_t tmp = (size_t) (produce_q_size - tail);
result = memcpy_to_queue(produce_q, tail, buf, 0, tmp);
if (result >= VMCI_SUCCESS)
result = memcpy_to_queue(produce_q, 0, buf, tmp,
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,
void *buf,
size_t buf_size,
vmci_memcpy_from_queue_func memcpy_from_queue,
bool update_consumer)
{
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 = memcpy_from_queue(buf, 0, consume_q, head, read);
} else {
/* Head pointer wraps around. */
const size_t tmp = (size_t) (consume_q_size - head);
result = memcpy_from_queue(buf, 0, consume_q, head, tmp);
if (result >= VMCI_SUCCESS)
result = memcpy_from_queue(buf, tmp, 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 comsumer.
* @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;
if (!qpair || !buf)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
do {
result = qp_enqueue_locked(qpair->produce_q,
qpair->consume_q,
qpair->produce_q_size,
buf, buf_size,
qp_memcpy_to_queue);
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;
if (!qpair || !buf)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
do {
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
buf, buf_size,
qp_memcpy_from_queue, 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)
{
ssize_t result;
if (!qpair || !buf)
return VMCI_ERROR_INVALID_ARGS;
qp_lock(qpair);
do {
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
buf, buf_size,
qp_memcpy_from_queue, 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, iov_size,
qp_memcpy_to_queue_iov);
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, iov_size,
qp_memcpy_from_queue_iov,
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, iov_size,
qp_memcpy_from_queue_iov,
false);
if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
result = VMCI_ERROR_WOULD_BLOCK;
} while (result == VMCI_ERROR_QUEUEPAIR_NOT_READY);
qp_unlock(qpair);
return result;
}
EXPORT_SYMBOL_GPL(vmci_qpair_peekv);
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