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VMCI: Remove non-blocking/pinned queuepair support
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We added this for a special case that doesn't exist on Linux.  Remove
the non-blocking/pinned queuepair code and simplify the driver in
preparation for adding virtual IOMMU support.

Acked-by: Aditya Sarwade <asarwade@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andy King authored and Greg Kroah-Hartman committed Aug 28, 2013
1 parent 440ab3b commit 45412be
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Showing 2 changed files with 22 additions and 145 deletions.
149 changes: 22 additions & 127 deletions drivers/misc/vmw_vmci/vmci_queue_pair.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -148,12 +148,10 @@ typedef int vmci_memcpy_from_queue_func(void *dest, size_t dest_offset,
struct vmci_queue_kern_if {
struct page **page;
struct page **header_page;
void *va;
struct mutex __mutex; /* Protects the queue. */
struct mutex *mutex; /* Shared by producer and consumer queues. */
bool host;
size_t num_pages;
bool mapped;
};

/*
Expand Down Expand Up @@ -267,11 +265,6 @@ static void qp_free_queue(void *q, u64 size)
if (queue) {
u64 i = DIV_ROUND_UP(size, PAGE_SIZE);

if (queue->kernel_if->mapped) {
vunmap(queue->kernel_if->va);
queue->kernel_if->va = NULL;
}

while (i)
__free_page(queue->kernel_if->page[--i]);

Expand Down Expand Up @@ -311,25 +304,13 @@ static void *qp_alloc_queue(u64 size, u32 flags)
queue->kernel_if->header_page = NULL; /* Unused in guest. */
queue->kernel_if->page = (struct page **)(queue->kernel_if + 1);
queue->kernel_if->host = false;
queue->kernel_if->va = NULL;
queue->kernel_if->mapped = false;

for (i = 0; i < num_data_pages; i++) {
queue->kernel_if->page[i] = alloc_pages(GFP_KERNEL, 0);
if (!queue->kernel_if->page[i])
goto fail;
}

if (vmci_qp_pinned(flags)) {
queue->kernel_if->va =
vmap(queue->kernel_if->page, num_data_pages, VM_MAP,
PAGE_KERNEL);
if (!queue->kernel_if->va)
goto fail;

queue->kernel_if->mapped = true;
}

return (void *)queue;

fail:
Expand Down Expand Up @@ -359,11 +340,7 @@ static int __qp_memcpy_to_queue(struct vmci_queue *queue,
void *va;
size_t to_copy;

if (!kernel_if->mapped)
va = kmap(kernel_if->page[page_index]);
else
va = (void *)((u8 *)kernel_if->va +
(page_index * PAGE_SIZE));
va = kmap(kernel_if->page[page_index]);

if (size - bytes_copied > PAGE_SIZE - page_offset)
/* Enough payload to fill up from this page. */
Expand All @@ -388,8 +365,7 @@ static int __qp_memcpy_to_queue(struct vmci_queue *queue,
}

bytes_copied += to_copy;
if (!kernel_if->mapped)
kunmap(kernel_if->page[page_index]);
kunmap(kernel_if->page[page_index]);
}

return VMCI_SUCCESS;
Expand Down Expand Up @@ -417,11 +393,7 @@ static int __qp_memcpy_from_queue(void *dest,
void *va;
size_t to_copy;

if (!kernel_if->mapped)
va = kmap(kernel_if->page[page_index]);
else
va = (void *)((u8 *)kernel_if->va +
(page_index * PAGE_SIZE));
va = kmap(kernel_if->page[page_index]);

if (size - bytes_copied > PAGE_SIZE - page_offset)
/* Enough payload to fill up this page. */
Expand All @@ -446,8 +418,7 @@ static int __qp_memcpy_from_queue(void *dest,
}

bytes_copied += to_copy;
if (!kernel_if->mapped)
kunmap(kernel_if->page[page_index]);
kunmap(kernel_if->page[page_index]);
}

return VMCI_SUCCESS;
Expand Down Expand Up @@ -634,8 +605,6 @@ static struct vmci_queue *qp_host_alloc_queue(u64 size)
queue->kernel_if->header_page =
(struct page **)((u8 *)queue + queue_size);
queue->kernel_if->page = &queue->kernel_if->header_page[1];
queue->kernel_if->va = NULL;
queue->kernel_if->mapped = false;
}

return queue;
Expand Down Expand Up @@ -1720,21 +1689,6 @@ static int qp_broker_attach(struct qp_broker_entry *entry,
if (result < VMCI_SUCCESS)
return result;

/*
* Preemptively load in the headers if non-blocking to
* prevent blocking later.
*/
if (entry->qp.flags & VMCI_QPFLAG_NONBLOCK) {
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);
return result;
}
}

entry->state = VMCIQPB_ATTACHED_MEM;
} else {
entry->state = VMCIQPB_ATTACHED_NO_MEM;
Expand All @@ -1749,24 +1703,6 @@ static int qp_broker_attach(struct qp_broker_entry *entry,

return VMCI_ERROR_UNAVAILABLE;
} else {
/*
* For non-blocking queue pairs, we cannot rely on
* enqueue/dequeue to map in the pages on the
* host-side, since it may block, so we make an
* attempt here.
*/

if (flags & VMCI_QPFLAG_NONBLOCK) {
result =
qp_host_map_queues(entry->produce_q,
entry->consume_q);
if (result < VMCI_SUCCESS)
return result;

entry->qp.flags |= flags &
(VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED);
}

/* The host side has successfully attached to a queue pair. */
entry->state = VMCIQPB_ATTACHED_MEM;
}
Expand Down Expand Up @@ -2543,42 +2479,32 @@ void vmci_qp_guest_endpoints_exit(void)
* 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.
* Note: It is assumed that QPFLAG_PINNED implies QPFLAG_NONBLOCK. Therefore
* we can use the same locking function for access to both the queue
* and the queue headers as it is the same logic. Assert this behvior.
*/
static void qp_lock(const struct vmci_qp *qpair)
{
if (vmci_can_block(qpair->flags))
qp_acquire_queue_mutex(qpair->produce_q);
qp_acquire_queue_mutex(qpair->produce_q);
}

/*
* Helper routine that unlocks the queue pair after calling
* qp_lock. Respects non-blocking and pinning flags.
* qp_lock.
*/
static void qp_unlock(const struct vmci_qp *qpair)
{
if (vmci_can_block(qpair->flags))
qp_release_queue_mutex(qpair->produce_q);
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,
bool can_block)
struct vmci_queue *consume_q)
{
int result;

if (NULL == produce_q->q_header || NULL == consume_q->q_header) {
if (can_block)
result = qp_host_map_queues(produce_q, consume_q);
else
result = VMCI_ERROR_QUEUEPAIR_NOT_READY;

result = qp_host_map_queues(produce_q, consume_q);
if (result < VMCI_SUCCESS)
return (produce_q->saved_header &&
consume_q->saved_header) ?
Expand All @@ -2601,8 +2527,7 @@ static int qp_get_queue_headers(const struct vmci_qp *qpair,
{
int result;

result = qp_map_queue_headers(qpair->produce_q, qpair->consume_q,
vmci_can_block(qpair->flags));
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;
Expand Down Expand Up @@ -2645,9 +2570,6 @@ static bool qp_wait_for_ready_queue(struct vmci_qp *qpair)
{
unsigned int generation;

if (qpair->flags & VMCI_QPFLAG_NONBLOCK)
return false;

qpair->blocked++;
generation = qpair->generation;
qp_unlock(qpair);
Expand All @@ -2674,15 +2596,14 @@ static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
const u64 produce_q_size,
const void *buf,
size_t buf_size,
vmci_memcpy_to_queue_func memcpy_to_queue,
bool can_block)
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, can_block);
result = qp_map_queue_headers(produce_q, consume_q);
if (unlikely(result != VMCI_SUCCESS))
return result;

Expand Down Expand Up @@ -2737,15 +2658,14 @@ static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
void *buf,
size_t buf_size,
vmci_memcpy_from_queue_func memcpy_from_queue,
bool update_consumer,
bool can_block)
bool update_consumer)
{
s64 buf_ready;
u64 head;
size_t read;
ssize_t result;

result = qp_map_queue_headers(produce_q, consume_q, can_block);
result = qp_map_queue_headers(produce_q, consume_q);
if (unlikely(result != VMCI_SUCCESS))
return result;

Expand Down Expand Up @@ -2842,32 +2762,11 @@ int vmci_qpair_alloc(struct vmci_qp **qpair,
route = vmci_guest_code_active() ?
VMCI_ROUTE_AS_GUEST : VMCI_ROUTE_AS_HOST;

/* If NONBLOCK or PINNED is set, we better be the guest personality. */
if ((!vmci_can_block(flags) || vmci_qp_pinned(flags)) &&
VMCI_ROUTE_AS_GUEST != route) {
pr_devel("Not guest personality w/ NONBLOCK OR PINNED set");
if (flags & (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED)) {
pr_devel("NONBLOCK OR PINNED set");
return VMCI_ERROR_INVALID_ARGS;
}

/*
* Limit the size of pinned QPs and check sanity.
*
* Pinned pages implies non-blocking mode. Mutexes aren't acquired
* when the NONBLOCK flag is set in qpair code; and also should not be
* acquired when the PINNED flagged is set. Since pinning pages
* implies we want speed, it makes no sense not to have NONBLOCK
* set if PINNED is set. Hence enforce this implication.
*/
if (vmci_qp_pinned(flags)) {
if (vmci_can_block(flags)) {
pr_err("Attempted to enable pinning w/o non-blocking");
return VMCI_ERROR_INVALID_ARGS;
}

if (produce_qsize + consume_qsize > VMCI_MAX_PINNED_QP_MEMORY)
return VMCI_ERROR_NO_RESOURCES;
}

my_qpair = kzalloc(sizeof(*my_qpair), GFP_KERNEL);
if (!my_qpair)
return VMCI_ERROR_NO_MEM;
Expand Down Expand Up @@ -3195,8 +3094,7 @@ ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
qpair->consume_q,
qpair->produce_q_size,
buf, buf_size,
qp_memcpy_to_queue,
vmci_can_block(qpair->flags));
qp_memcpy_to_queue);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3237,8 +3135,7 @@ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
qpair->consume_q,
qpair->consume_q_size,
buf, buf_size,
qp_memcpy_from_queue, true,
vmci_can_block(qpair->flags));
qp_memcpy_from_queue, true);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3280,8 +3177,7 @@ ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
qpair->consume_q,
qpair->consume_q_size,
buf, buf_size,
qp_memcpy_from_queue, false,
vmci_can_block(qpair->flags));
qp_memcpy_from_queue, false);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3323,8 +3219,7 @@ ssize_t vmci_qpair_enquev(struct vmci_qp *qpair,
qpair->consume_q,
qpair->produce_q_size,
iov, iov_size,
qp_memcpy_to_queue_iov,
vmci_can_block(qpair->flags));
qp_memcpy_to_queue_iov);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3367,7 +3262,7 @@ ssize_t vmci_qpair_dequev(struct vmci_qp *qpair,
qpair->consume_q_size,
iov, iov_size,
qp_memcpy_from_queue_iov,
true, vmci_can_block(qpair->flags));
true);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3411,7 +3306,7 @@ ssize_t vmci_qpair_peekv(struct vmci_qp *qpair,
qpair->consume_q_size,
iov, iov_size,
qp_memcpy_from_queue_iov,
false, vmci_can_block(qpair->flags));
false);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down
18 changes: 0 additions & 18 deletions drivers/misc/vmw_vmci/vmci_queue_pair.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -146,24 +146,6 @@ VMCI_QP_PAGESTORE_IS_WELLFORMED(struct vmci_qp_page_store *page_store)
return page_store->len >= 2;
}

/*
* Helper function to check if the non-blocking flag
* is set for a given queue pair.
*/
static inline bool vmci_can_block(u32 flags)
{
return !(flags & VMCI_QPFLAG_NONBLOCK);
}

/*
* Helper function to check if the queue pair is pinned
* into memory.
*/
static inline bool vmci_qp_pinned(u32 flags)
{
return flags & VMCI_QPFLAG_PINNED;
}

void vmci_qp_broker_exit(void);
int vmci_qp_broker_alloc(struct vmci_handle handle, u32 peer,
u32 flags, u32 priv_flags,
Expand Down

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