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Subject[vmw_vmci 08/11] Apply VMCI queue pairs
Date
VMCI queue pairs allow for bi-directional ordered communication between
host and guests.

Signed-off-by: Andrew Stiegmann (stieg) <astiegmann@vmware.com>
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 3548 +++++++++++++++++++++++++++++++
drivers/misc/vmw_vmci/vmci_queue_pair.h | 182 ++
2 files changed, 3730 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/vmw_vmci/vmci_queue_pair.c
create mode 100644 drivers/misc/vmw_vmci/vmci_queue_pair.h

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
new file mode 100644
index 0000000..11d111b
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -0,0 +1,3548 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/device-mapper.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+#include <linux/socket.h>
+#include <linux/vmw_vmci_api.h>
+#include <linux/vmw_vmci_defs.h>
+
+#include "vmci_common_int.h"
+#include "vmci_context.h"
+#include "vmci_datagram.h"
+#include "vmci_driver.h"
+#include "vmci_event.h"
+#include "vmci_handle_array.h"
+#include "vmci_hash_table.h"
+#include "vmci_queue_pair.h"
+#include "vmci_resource.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 VMCIMemcpyToQueueFunc(struct vmci_queue *queue,
+ uint64_t queueOffset, const void *src,
+ size_t srcOffset, size_t size);
+typedef int VMCIMemcpyFromQueueFunc(void *dest, size_t destOffset,
+ const struct vmci_queue *queue,
+ uint64_t queueOffset, size_t size);
+
+/* The Kernel specific component of the struct vmci_queue structure. */
+struct vmci_queue_kern_if {
+ struct page **page;
+ struct page **headerPage;
+ void *va;
+ struct semaphore __mutex;
+ struct semaphore *mutex;
+ bool host;
+ size_t numPages;
+ bool mapped;
+};
+
+/*
+ * This structure is opaque to the clients.
+ */
+struct vmci_qp {
+ struct vmci_handle handle;
+ struct vmci_queue *produceQ;
+ struct vmci_queue *consumeQ;
+ uint64_t produceQSize;
+ uint64_t consumeQSize;
+ uint32_t peer;
+ uint32_t flags;
+ uint32_t privFlags;
+ bool guestEndpoint;
+ uint32_t blocked;
+ 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 listItem;
+ struct vmci_handle handle;
+ uint32_t peer;
+ uint32_t flags;
+ uint64_t produceSize;
+ uint64_t consumeSize;
+ uint32_t refCount;
+};
+
+struct qp_broker_entry {
+ struct qp_entry qp;
+ uint32_t createId;
+ uint32_t attachId;
+ enum qp_broker_state state;
+ bool requireTrustedAttach;
+ bool createdByTrusted;
+ bool vmciPageFiles; /* Created by VMX using VMCI page files */
+ struct vmci_queue *produceQ;
+ struct vmci_queue *consumeQ;
+ struct vmci_queue_header savedProduceQ;
+ struct vmci_queue_header savedConsumeQ;
+ VMCIEventReleaseCB wakeupCB;
+ void *clientData;
+ void *localMem; /* Kernel memory for local queue pair */
+};
+
+struct qp_guest_endpoint {
+ struct qp_entry qp;
+ uint64_t numPPNs;
+ void *produceQ;
+ void *consumeQ;
+ struct PPNSet ppnSet;
+};
+
+struct qp_list {
+ struct list_head head;
+ struct semaphore mutex;
+};
+
+static struct qp_list qpBrokerList;
+static struct qp_list qpGuestEndpoints;
+
+#define INVALID_VMCI_GUEST_MEM_ID 0
+#define QPE_NUM_PAGES(_QPE) ((uint32_t) \
+ (dm_div_up(_QPE.produceSize, PAGE_SIZE) + \
+ dm_div_up(_QPE.consumeSize, 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,
+ uint64_t size)
+{
+ struct vmci_queue *queue = q;
+
+ if (queue) {
+ uint64_t i = dm_div_up(size, PAGE_SIZE);
+
+ if (queue->kernelIf->mapped) {
+ ASSERT(queue->kernelIf->va);
+ vunmap(queue->kernelIf->va);
+ queue->kernelIf->va = NULL;
+ }
+
+ while (i)
+ __free_page(queue->kernelIf->page[--i]);
+
+ vfree(queue->qHeader);
+ }
+}
+
+
+/*
+ * Allocates kernel VA space of specified size, plus space for the
+ * queue structure/kernel interface and the queue header. Allocates
+ * physical pages for the queue data pages.
+ *
+ * PAGE m: struct vmci_queue_header (struct vmci_queue->qHeader)
+ * PAGE m+1: struct vmci_queue
+ * PAGE m+1+q: struct vmci_queue_kern_if (struct vmci_queue->kernelIf)
+ * PAGE n-size: Data pages (struct vmci_queue->kernelIf->page[])
+ */
+static void *qp_alloc_queue(uint64_t size,
+ uint32_t flags)
+{
+ uint64_t i;
+ struct vmci_queue *queue;
+ struct vmci_queue_header *qHeader;
+ const uint64_t numDataPages = dm_div_up(size, PAGE_SIZE);
+ const uint queueSize =
+ PAGE_SIZE +
+ sizeof(*queue) + sizeof(*(queue->kernelIf)) +
+ numDataPages * sizeof(*(queue->kernelIf->page));
+
+ ASSERT(size <= VMCI_MAX_GUEST_QP_MEMORY);
+ ASSERT(!QP_PINNED(flags) || size <= VMCI_MAX_PINNED_QP_MEMORY);
+
+ qHeader = vmalloc(queueSize);
+ if (!qHeader)
+ return NULL;
+
+ queue = (struct vmci_queue *)((uint8_t *) qHeader + PAGE_SIZE);
+ queue->qHeader = qHeader;
+ queue->savedHeader = NULL;
+ queue->kernelIf = (struct vmci_queue_kern_if *)((uint8_t *) queue +
+ sizeof(*queue));
+ queue->kernelIf->headerPage = NULL; /* Unused in guest. */
+ queue->kernelIf->page =
+ (struct page **)((uint8_t *) queue->kernelIf +
+ sizeof(*(queue->kernelIf)));
+ queue->kernelIf->host = false;
+ queue->kernelIf->va = NULL;
+ queue->kernelIf->mapped = false;
+
+ for (i = 0; i < numDataPages; i++) {
+ queue->kernelIf->page[i] = alloc_pages(GFP_KERNEL, 0);
+ if (!queue->kernelIf->page[i])
+ goto fail;
+ }
+
+ if (QP_PINNED(flags)) {
+ queue->kernelIf->va = vmap(queue->kernelIf->page, numDataPages,
+ VM_MAP, PAGE_KERNEL);
+ if (!queue->kernelIf->va)
+ goto fail;
+
+ queue->kernelIf->mapped = true;
+ }
+
+ return (void *)queue;
+
+fail:
+ qp_free_queue(queue, i * PAGE_SIZE);
+ return NULL;
+}
+
+/*
+ * 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,
+ uint64_t queueOffset,
+ const void *src,
+ size_t size,
+ bool isIovec)
+{
+ struct vmci_queue_kern_if *kernelIf = queue->kernelIf;
+ size_t bytesCopied = 0;
+
+ while (bytesCopied < size) {
+ uint64_t pageIndex = (queueOffset + bytesCopied) / PAGE_SIZE;
+ size_t pageOffset =
+ (queueOffset + bytesCopied) & (PAGE_SIZE - 1);
+ void *va;
+ size_t toCopy;
+
+ if (!kernelIf->mapped)
+ va = kmap(kernelIf->page[pageIndex]);
+ else
+ va = (void *)((uint8_t *)kernelIf->va +
+ (pageIndex * PAGE_SIZE));
+
+ if (size - bytesCopied > PAGE_SIZE - pageOffset) {
+ /* Enough payload to fill up from this page. */
+ toCopy = PAGE_SIZE - pageOffset;
+ } else {
+ toCopy = size - bytesCopied;
+ }
+
+ if (isIovec) {
+ struct iovec *iov = (struct iovec *)src;
+ int err;
+
+ /* The iovec will track bytesCopied internally. */
+ err = memcpy_fromiovec((uint8_t *) va + pageOffset,
+ iov, toCopy);
+ if (err != 0) {
+ kunmap(kernelIf->page[pageIndex]);
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+ } else {
+ memcpy((uint8_t *) va + pageOffset,
+ (uint8_t *) src + bytesCopied, toCopy);
+ }
+
+ bytesCopied += toCopy;
+ if (!kernelIf->mapped)
+ kunmap(kernelIf->page[pageIndex]);
+ }
+
+ 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,
+ uint64_t queueOffset,
+ size_t size,
+ bool isIovec)
+{
+ struct vmci_queue_kern_if *kernelIf = queue->kernelIf;
+ size_t bytesCopied = 0;
+
+ while (bytesCopied < size) {
+ uint64_t pageIndex = (queueOffset + bytesCopied) / PAGE_SIZE;
+ size_t pageOffset =
+ (queueOffset + bytesCopied) & (PAGE_SIZE - 1);
+ void *va;
+ size_t toCopy;
+
+ if (!kernelIf->mapped)
+ va = kmap(kernelIf->page[pageIndex]);
+ else
+ va = (void *)((uint8_t *)kernelIf->va +
+ (pageIndex * PAGE_SIZE));
+
+ if (size - bytesCopied > PAGE_SIZE - pageOffset) {
+ /* Enough payload to fill up this page. */
+ toCopy = PAGE_SIZE - pageOffset;
+ } else {
+ toCopy = size - bytesCopied;
+ }
+
+ if (isIovec) {
+ struct iovec *iov = (struct iovec *)dest;
+ int err;
+
+ /* The iovec will track bytesCopied internally. */
+ err = memcpy_toiovec(iov, (uint8_t *) va + pageOffset,
+ toCopy);
+ if (err != 0) {
+ kunmap(kernelIf->page[pageIndex]);
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+ } else {
+ memcpy((uint8_t *) dest + bytesCopied,
+ (uint8_t *) va + pageOffset, toCopy);
+ }
+
+ bytesCopied += toCopy;
+ if (!kernelIf->mapped)
+ kunmap(kernelIf->page[pageIndex]);
+ }
+
+ 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 *prodQ,
+ uint64_t numProducePages,
+ void *consQ,
+ uint64_t numConsumePages,
+ struct PPNSet *ppnSet)
+{
+ uint32_t *producePPNs;
+ uint32_t *consumePPNs;
+ struct vmci_queue *produceQ = prodQ;
+ struct vmci_queue *consumeQ = consQ;
+ uint64_t i;
+
+ if (!produceQ || !numProducePages || !consumeQ ||
+ !numConsumePages || !ppnSet)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ if (ppnSet->initialized)
+ return VMCI_ERROR_ALREADY_EXISTS;
+
+ producePPNs =
+ kmalloc(numProducePages * sizeof *producePPNs, GFP_KERNEL);
+ if (!producePPNs)
+ return VMCI_ERROR_NO_MEM;
+
+ consumePPNs =
+ kmalloc(numConsumePages * sizeof *consumePPNs, GFP_KERNEL);
+ if (!consumePPNs) {
+ kfree(producePPNs);
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ producePPNs[0] = page_to_pfn(vmalloc_to_page(produceQ->qHeader));
+ for (i = 1; i < numProducePages; i++) {
+ unsigned long pfn;
+
+ producePPNs[i] = pfn =
+ page_to_pfn(produceQ->kernelIf->page[i - 1]);
+
+ /* Fail allocation if PFN isn't supported by hypervisor. */
+ if (sizeof pfn > sizeof *producePPNs && pfn != producePPNs[i])
+ goto ppnError;
+ }
+
+ consumePPNs[0] = page_to_pfn(vmalloc_to_page(consumeQ->qHeader));
+ for (i = 1; i < numConsumePages; i++) {
+ unsigned long pfn;
+
+ consumePPNs[i] = pfn =
+ page_to_pfn(consumeQ->kernelIf->page[i - 1]);
+
+ /* Fail allocation if PFN isn't supported by hypervisor. */
+ if (sizeof pfn > sizeof *consumePPNs && pfn != consumePPNs[i])
+ goto ppnError;
+ }
+
+ ppnSet->numProducePages = numProducePages;
+ ppnSet->numConsumePages = numConsumePages;
+ ppnSet->producePPNs = producePPNs;
+ ppnSet->consumePPNs = consumePPNs;
+ ppnSet->initialized = true;
+ return VMCI_SUCCESS;
+
+ppnError:
+ kfree(producePPNs);
+ kfree(consumePPNs);
+ return VMCI_ERROR_INVALID_ARGS;
+}
+
+/*
+ * Frees the two list of PPNs for a queue pair.
+ */
+static void qp_free_ppn_set(struct PPNSet *ppnSet)
+{
+ ASSERT(ppnSet);
+ if (ppnSet->initialized) {
+ /* Do not call these functions on NULL inputs. */
+ ASSERT(ppnSet->producePPNs && ppnSet->consumePPNs);
+ kfree(ppnSet->producePPNs);
+ kfree(ppnSet->consumePPNs);
+ }
+ memset(ppnSet, 0, sizeof *ppnSet);
+}
+
+/*
+ * 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(uint8_t *callBuf,
+ const struct PPNSet *ppnSet)
+{
+ ASSERT(callBuf && ppnSet && ppnSet->initialized);
+ memcpy(callBuf, ppnSet->producePPNs,
+ ppnSet->numProducePages * sizeof *ppnSet->producePPNs);
+ memcpy(callBuf +
+ ppnSet->numProducePages * sizeof *ppnSet->producePPNs,
+ ppnSet->consumePPNs,
+ ppnSet->numConsumePages * sizeof *ppnSet->consumePPNs);
+
+ return VMCI_SUCCESS;
+}
+
+static int qp_memcpy_to_queue(struct vmci_queue *queue,
+ uint64_t queueOffset,
+ const void *src,
+ size_t srcOffset,
+ size_t size)
+{
+ return __qp_memcpy_to_queue(queue, queueOffset,
+ (uint8_t *) src + srcOffset, size, false);
+}
+
+static int qp_memcpy_from_queue(void *dest,
+ size_t destOffset,
+ const struct vmci_queue *queue,
+ uint64_t queueOffset,
+ size_t size)
+{
+ return __qp_memcpy_from_queue((uint8_t *) dest + destOffset,
+ queue, queueOffset, size, false);
+}
+
+/*
+ * Copies from a given iovec from a VMCI Queue.
+ */
+static int qp_memcpy_to_queue_iov(struct vmci_queue *queue,
+ uint64_t queueOffset,
+ const void *src,
+ size_t srcOffset,
+ size_t size)
+{
+
+ /*
+ * We ignore srcOffset because src is really a struct iovec * and will
+ * maintain offset internally.
+ */
+ return __qp_memcpy_to_queue(queue, queueOffset, src, size, true);
+}
+
+/*
+ * Copies to a given iovec from a VMCI Queue.
+ */
+static int qp_memcpy_from_queue_iov(void *dest,
+ size_t destOffset,
+ const struct vmci_queue *queue,
+ uint64_t queueOffset,
+ size_t size)
+{
+ /*
+ * We ignore destOffset because dest is really a struct iovec * and will
+ * maintain offset internally.
+ */
+ return __qp_memcpy_from_queue(dest, queue, queueOffset, 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(uint64_t size)
+{
+ struct vmci_queue *queue;
+ const size_t numPages = dm_div_up(size, PAGE_SIZE) + 1;
+ const size_t queueSize = sizeof(*queue) + sizeof(*(queue->kernelIf));
+ const size_t queuePageSize = numPages * sizeof(*queue->kernelIf->page);
+
+ queue = kzalloc(queueSize + queuePageSize, GFP_KERNEL);
+ if (queue) {
+ queue->qHeader = NULL;
+ queue->savedHeader = NULL;
+ queue->kernelIf =
+ (struct vmci_queue_kern_if *)((uint8_t *) queue +
+ sizeof(*queue));
+ queue->kernelIf->host = true;
+ queue->kernelIf->mutex = NULL;
+ queue->kernelIf->numPages = numPages;
+ queue->kernelIf->headerPage =
+ (struct page **)((uint8_t *) queue + queueSize);
+ queue->kernelIf->page = &queue->kernelIf->headerPage[1];
+ queue->kernelIf->va = NULL;
+ queue->kernelIf->mapped = false;
+ }
+
+ return queue;
+}
+
+/*
+ * Frees kernel memory for a given queue (header plus translation
+ * structure).
+ */
+static void qp_host_free_queue(struct vmci_queue *queue,
+ uint64_t queueSize)
+{
+ kfree(queue);
+}
+
+/*
+ * Initialize the mutex for the pair of queues. This mutex is used to
+ * protect the qHeader 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 *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ ASSERT(produceQ);
+ ASSERT(consumeQ);
+ ASSERT(produceQ->kernelIf);
+ ASSERT(consumeQ->kernelIf);
+
+ /*
+ * Only the host queue has shared state - the guest queues do not
+ * need to synchronize access using a queue mutex.
+ */
+
+ if (produceQ->kernelIf->host) {
+ produceQ->kernelIf->mutex = &produceQ->kernelIf->__mutex;
+ consumeQ->kernelIf->mutex = &produceQ->kernelIf->__mutex;
+ sema_init(produceQ->kernelIf->mutex, 1);
+ }
+}
+
+/*
+ * Cleans up the mutex for the pair of queues.
+ */
+static void qp_cleanup_queue_mutex(struct vmci_queue *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ ASSERT(produceQ);
+ ASSERT(consumeQ);
+ ASSERT(produceQ->kernelIf);
+ ASSERT(consumeQ->kernelIf);
+
+ if (produceQ->kernelIf->host) {
+ produceQ->kernelIf->mutex = NULL;
+ consumeQ->kernelIf->mutex = NULL;
+ }
+}
+
+/*
+ * Acquire the mutex for the queue. Note that the produceQ and
+ * the consumeQ 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)
+{
+ ASSERT(queue);
+ ASSERT(queue->kernelIf);
+
+ if (queue->kernelIf->host) {
+ ASSERT(queue->kernelIf->mutex);
+ down(queue->kernelIf->mutex);
+ }
+}
+
+/*
+ * Release the mutex for the queue. Note that the produceQ and
+ * the consumeQ 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)
+{
+ ASSERT(queue);
+ ASSERT(queue->kernelIf);
+
+ if (queue->kernelIf->host) {
+ ASSERT(queue->kernelIf->mutex);
+ up(queue->kernelIf->mutex);
+ }
+}
+
+/*
+ * Helper function to release pages in the PageStoreAttachInfo
+ * previously obtained using get_user_pages.
+ */
+static void qp_release_pages(struct page **pages,
+ uint64_t numPages,
+ bool dirty)
+{
+ int i;
+
+ for (i = 0; i < numPages; i++) {
+ ASSERT(pages[i]);
+
+ if (dirty)
+ set_page_dirty(pages[i]);
+
+ page_cache_release(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(uint64_t produceUVA,
+ uint64_t consumeUVA,
+ struct vmci_queue *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ int retval;
+ int err = VMCI_SUCCESS;
+
+ down_write(&current->mm->mmap_sem);
+ retval = get_user_pages(current,
+ current->mm,
+ (uintptr_t) produceUVA,
+ produceQ->kernelIf->numPages,
+ 1, 0, produceQ->kernelIf->headerPage, NULL);
+ if (retval < produceQ->kernelIf->numPages) {
+ pr_warn("get_user_pages(produce) failed (retval=%d)",
+ retval);
+ qp_release_pages(produceQ->kernelIf->headerPage, retval, false);
+ err = VMCI_ERROR_NO_MEM;
+ goto out;
+ }
+
+ retval = get_user_pages(current,
+ current->mm,
+ (uintptr_t) consumeUVA,
+ consumeQ->kernelIf->numPages,
+ 1, 0, consumeQ->kernelIf->headerPage, NULL);
+ if (retval < consumeQ->kernelIf->numPages) {
+ pr_warn("get_user_pages(consume) failed (retval=%d)",
+ retval);
+ qp_release_pages(consumeQ->kernelIf->headerPage, retval, false);
+ qp_release_pages(produceQ->kernelIf->headerPage,
+ produceQ->kernelIf->numPages, false);
+ err = VMCI_ERROR_NO_MEM;
+ }
+
+out:
+ up_write(&current->mm->mmap_sem);
+
+ 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 *pageStore,
+ struct vmci_queue *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ uint64_t produceUVA;
+ uint64_t consumeUVA;
+
+ ASSERT(produceQ->kernelIf->headerPage
+ && consumeQ->kernelIf->headerPage);
+
+ /*
+ * 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.
+ */
+ produceUVA = pageStore->pages;
+ consumeUVA = pageStore->pages +
+ produceQ->kernelIf->numPages * PAGE_SIZE;
+ return qp_host_get_user_memory(produceUVA, consumeUVA, produceQ,
+ consumeQ);
+}
+
+/*
+ * 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 *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ ASSERT(produceQ->kernelIf);
+ ASSERT(consumeQ->kernelIf);
+ ASSERT(!produceQ->qHeader && !consumeQ->qHeader);
+
+ qp_release_pages(produceQ->kernelIf->headerPage,
+ produceQ->kernelIf->numPages, true);
+ memset(produceQ->kernelIf->headerPage, 0,
+ sizeof *produceQ->kernelIf->headerPage *
+ produceQ->kernelIf->numPages);
+ qp_release_pages(consumeQ->kernelIf->headerPage,
+ consumeQ->kernelIf->numPages, true);
+ memset(consumeQ->kernelIf->headerPage, 0,
+ sizeof *consumeQ->kernelIf->headerPage *
+ consumeQ->kernelIf->numPages);
+}
+
+/*
+ * 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 *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ int result;
+
+ if (!produceQ->qHeader || !consumeQ->qHeader) {
+ struct page *headers[2];
+
+ if (produceQ->qHeader != consumeQ->qHeader)
+ return VMCI_ERROR_QUEUEPAIR_MISMATCH;
+
+ if (produceQ->kernelIf->headerPage == NULL ||
+ *produceQ->kernelIf->headerPage == NULL)
+ return VMCI_ERROR_UNAVAILABLE;
+
+ ASSERT(*produceQ->kernelIf->headerPage
+ && *consumeQ->kernelIf->headerPage);
+
+ headers[0] = *produceQ->kernelIf->headerPage;
+ headers[1] = *consumeQ->kernelIf->headerPage;
+
+ produceQ->qHeader = vmap(headers, 2, VM_MAP, PAGE_KERNEL);
+ if (produceQ->qHeader != NULL) {
+ consumeQ->qHeader =
+ (struct vmci_queue_header *)((uint8_t *)
+ produceQ->qHeader +
+ PAGE_SIZE);
+ result = VMCI_SUCCESS;
+ } else {
+ pr_warn("vmap failed.");
+ 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(uint32_t gid,
+ struct vmci_queue *produceQ,
+ struct vmci_queue *consumeQ)
+{
+ if (produceQ->qHeader) {
+ ASSERT(consumeQ->qHeader);
+
+ if (produceQ->qHeader < consumeQ->qHeader)
+ vunmap(produceQ->qHeader);
+ else
+ vunmap(consumeQ->qHeader);
+
+ produceQ->qHeader = NULL;
+ consumeQ->qHeader = 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 *qpList,
+ struct vmci_handle handle)
+{
+ struct qp_entry *entry;
+
+ if (VMCI_HANDLE_INVALID(handle))
+ return NULL;
+
+ list_for_each_entry(entry, &qpList->head, listItem) {
+ if (VMCI_HANDLE_EQUAL(entry->handle, handle))
+ return entry;
+ }
+
+ return NULL;
+}
+
+/*
+ * Dispatches a queue pair event message directly into the local event
+ * queue.
+ */
+static int qp_notify_peer_local(bool attach,
+ struct vmci_handle handle)
+{
+ struct vmci_event_msg *eMsg;
+ struct vmci_event_payld_qp *ePayload;
+ /* buf is only 48 bytes. */
+ char buf[sizeof *eMsg + sizeof *ePayload];
+ uint32_t contextId;
+
+ contextId = VMCI_GetContextID();
+
+ eMsg = (struct vmci_event_msg *)buf;
+ ePayload = vmci_event_data_payload(&eMsg->eventData);
+
+ eMsg->hdr.dst = vmci_make_handle(contextId, VMCI_EVENT_HANDLER);
+ eMsg->hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+ VMCI_CONTEXT_RESOURCE_ID);
+ eMsg->hdr.payloadSize =
+ sizeof *eMsg + sizeof *ePayload - sizeof eMsg->hdr;
+ eMsg->eventData.event =
+ attach ? VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
+ ePayload->peerId = contextId;
+ ePayload->handle = handle;
+
+ return vmci_event_dispatch((struct vmci_dg *)eMsg);
+}
+
+/*
+ * Allocates and initializes a qp_guest_endpoint structure.
+ * Allocates a QueuePair 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,
+ uint32_t peer,
+ uint32_t flags,
+ uint64_t produceSize,
+ uint64_t consumeSize,
+ void *produceQ,
+ void *consumeQ)
+{
+ static uint32_t queuePairRID = VMCI_RESERVED_RESOURCE_ID_MAX + 1;
+ struct qp_guest_endpoint *entry;
+ /* One page each for the queue headers. */
+ const uint64_t numPPNs = dm_div_up(produceSize, PAGE_SIZE) +
+ dm_div_up(consumeSize, PAGE_SIZE) + 2;
+
+ ASSERT((produceSize || consumeSize) && produceQ && consumeQ);
+
+ if (VMCI_HANDLE_INVALID(handle)) {
+ uint32_t contextID = VMCI_GetContextID();
+ uint32_t oldRID = queuePairRID;
+
+ /*
+ * Generate a unique QueuePair rid. Keep on trying
+ * until we wrap around in the RID space.
+ */
+ ASSERT(oldRID > VMCI_RESERVED_RESOURCE_ID_MAX);
+ do {
+ handle = vmci_make_handle(contextID, queuePairRID);
+ entry = (struct qp_guest_endpoint *)
+ qp_list_find(&qpGuestEndpoints, handle);
+ queuePairRID++;
+
+ if (unlikely(!queuePairRID))
+ /* Skip the reserved rids. */
+ queuePairRID =
+ VMCI_RESERVED_RESOURCE_ID_MAX + 1;
+
+ } while (entry && queuePairRID != oldRID);
+
+ if (unlikely(entry != NULL)) {
+ ASSERT(queuePairRID == oldRID);
+ /*
+ * We wrapped around --- no rids were free.
+ */
+ return NULL;
+ }
+ }
+
+ ASSERT(!VMCI_HANDLE_INVALID(handle) &&
+ qp_list_find(&qpGuestEndpoints, handle) == NULL);
+ entry = kzalloc(sizeof *entry, GFP_KERNEL);
+ if (entry) {
+ entry->qp.handle = handle;
+ entry->qp.peer = peer;
+ entry->qp.flags = flags;
+ entry->qp.produceSize = produceSize;
+ entry->qp.consumeSize = consumeSize;
+ entry->qp.refCount = 0;
+ entry->numPPNs = numPPNs;
+ entry->produceQ = produceQ;
+ entry->consumeQ = consumeQ;
+ INIT_LIST_HEAD(&entry->qp.listItem);
+ }
+ return entry;
+}
+
+/*
+ * Frees a qp_guest_endpoint structure.
+ */
+static void qp_guest_endpoint_destroy(struct qp_guest_endpoint *entry)
+{
+ ASSERT(entry);
+ ASSERT(entry->qp.refCount == 0);
+
+ qp_free_ppn_set(&entry->ppnSet);
+ qp_cleanup_queue_mutex(entry->produceQ, entry->consumeQ);
+ qp_free_queue(entry->produceQ, entry->qp.produceSize);
+ qp_free_queue(entry->consumeQ, entry->qp.consumeSize);
+ kfree(entry);
+}
+
+/*
+ * Helper to make a QueuePairAlloc 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 *allocMsg;
+ size_t msgSize;
+ int result;
+
+ if (!entry || entry->numPPNs <= 2)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ ASSERT(!(entry->qp.flags & VMCI_QPFLAG_LOCAL));
+
+ msgSize = sizeof *allocMsg + (size_t) entry->numPPNs * sizeof(uint32_t);
+ allocMsg = kmalloc(msgSize, GFP_KERNEL);
+ if (!allocMsg)
+ return VMCI_ERROR_NO_MEM;
+
+ allocMsg->hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+ VMCI_QUEUEPAIR_ALLOC);
+ allocMsg->hdr.src = VMCI_ANON_SRC_HANDLE;
+ allocMsg->hdr.payloadSize = msgSize - VMCI_DG_HEADERSIZE;
+ allocMsg->handle = entry->qp.handle;
+ allocMsg->peer = entry->qp.peer;
+ allocMsg->flags = entry->qp.flags;
+ allocMsg->produceSize = entry->qp.produceSize;
+ allocMsg->consumeSize = entry->qp.consumeSize;
+ allocMsg->numPPNs = entry->numPPNs;
+
+ result =
+ qp_populate_ppn_set((uint8_t *) allocMsg + sizeof *allocMsg,
+ &entry->ppnSet);
+ if (result == VMCI_SUCCESS)
+ result = vmci_send_dg((struct vmci_dg *)allocMsg);
+
+ kfree(allocMsg);
+
+ return result;
+}
+
+/*
+ * Helper to make a QueuePairDetach hypercall when the driver is
+ * supporting a guest device.
+ */
+static int qp_detatch_hypercall(struct vmci_handle handle)
+{
+ struct vmci_qp_detach_msg detachMsg;
+
+ detachMsg.hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+ VMCI_QUEUEPAIR_DETACH);
+ detachMsg.hdr.src = VMCI_ANON_SRC_HANDLE;
+ detachMsg.hdr.payloadSize = sizeof handle;
+ detachMsg.handle = handle;
+
+ return vmci_send_dg((struct vmci_dg *)&detachMsg);
+}
+
+/*
+ * Adds the given entry to the list. Assumes that the list is locked.
+ */
+static void qp_list_add_entry(struct qp_list *qpList,
+ struct qp_entry *entry)
+{
+ if (entry)
+ list_add(&entry->listItem, &qpList->head);
+}
+
+/*
+ * Removes the given entry from the list. Assumes that the list is locked.
+ */
+static void qp_list_remove_entry(struct qp_list *qpList,
+ struct qp_entry *entry)
+{
+ if (entry)
+ list_del(&entry->listItem);
+}
+
+/*
+ * Helper for VMCI QueuePair 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;
+ uint32_t refCount = ~0; /* To avoid compiler warning below */
+
+ ASSERT(!VMCI_HANDLE_INVALID(handle));
+
+ down(&qpGuestEndpoints.mutex);
+
+ entry = (struct qp_guest_endpoint *)
+ qp_list_find(&qpGuestEndpoints, handle);
+ if (!entry) {
+ up(&qpGuestEndpoints.mutex);
+ return VMCI_ERROR_NOT_FOUND;
+ }
+
+ ASSERT(entry->qp.refCount >= 1);
+
+ if (entry->qp.flags & VMCI_QPFLAG_LOCAL) {
+ result = VMCI_SUCCESS;
+
+ if (entry->qp.refCount > 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 VMCIQueuePair_Exit() if necessary
+ * (assuming we are going away, otherwise why
+ * did this fail?).
+ */
+
+ up(&qpGuestEndpoints.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.refCount--;
+ if (entry->qp.refCount == 0)
+ qp_list_remove_entry(&qpGuestEndpoints, &entry->qp);
+
+ /* If we didn't remove the entry, this could change once we unlock. */
+ if (entry)
+ refCount = entry->qp.refCount;
+
+ up(&qpGuestEndpoints.mutex);
+
+ if (refCount == 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 **produceQ,
+ uint64_t produceSize,
+ struct vmci_queue **consumeQ,
+ uint64_t consumeSize,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags)
+{
+ const uint64_t numProducePages = dm_div_up(produceSize, PAGE_SIZE) + 1;
+ const uint64_t numConsumePages = dm_div_up(consumeSize, PAGE_SIZE) + 1;
+ void *myProduceQ = NULL;
+ void *myConsumeQ = NULL;
+ int result;
+ struct qp_guest_endpoint *queuePairEntry = NULL;
+
+ ASSERT(handle && produceQ && consumeQ && (produceSize || consumeSize));
+
+ if (privFlags != VMCI_NO_PRIVILEGE_FLAGS)
+ return VMCI_ERROR_NO_ACCESS;
+
+ down(&qpGuestEndpoints.mutex);
+
+ queuePairEntry = (struct qp_guest_endpoint *)qp_list_find(
+ &qpGuestEndpoints, *handle);
+ if (queuePairEntry) {
+ if (queuePairEntry->qp.flags & VMCI_QPFLAG_LOCAL) {
+ /* Local attach case. */
+ if (queuePairEntry->qp.refCount > 1) {
+ pr_devel("Error attempting to attach more " \
+ "than once.");
+ result = VMCI_ERROR_UNAVAILABLE;
+ goto errorKeepEntry;
+ }
+
+ if (queuePairEntry->qp.produceSize != consumeSize
+ || queuePairEntry->qp.consumeSize !=
+ produceSize
+ || queuePairEntry->qp.flags !=
+ (flags & ~VMCI_QPFLAG_ATTACH_ONLY)) {
+ pr_devel("Error mismatched queue pair in " \
+ "local attach.");
+ result = VMCI_ERROR_QUEUEPAIR_MISMATCH;
+ goto errorKeepEntry;
+ }
+
+ /*
+ * 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 errorKeepEntry;
+
+ myProduceQ = queuePairEntry->consumeQ;
+ myConsumeQ = queuePairEntry->produceQ;
+ goto out;
+ }
+
+ result = VMCI_ERROR_ALREADY_EXISTS;
+ goto errorKeepEntry;
+ }
+
+ myProduceQ = qp_alloc_queue(produceSize, flags);
+ if (!myProduceQ) {
+ pr_warn("Error allocating pages for produce queue.");
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ myConsumeQ = qp_alloc_queue(consumeSize, flags);
+ if (!myConsumeQ) {
+ pr_warn("Error allocating pages for consume queue.");
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ queuePairEntry = qp_guest_endpoint_create(*handle, peer, flags,
+ produceSize, consumeSize,
+ myProduceQ, myConsumeQ);
+ if (!queuePairEntry) {
+ pr_warn("Error allocating memory in %s.", __func__);
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ result = qp_alloc_ppn_set(myProduceQ, numProducePages, myConsumeQ,
+ numConsumePages, &queuePairEntry->ppnSet);
+ if (result < VMCI_SUCCESS) {
+ pr_warn("qp_alloc_ppn_set failed.");
+ goto error;
+ }
+
+ /*
+ * It's only necessary to notify the host if this queue pair will be
+ * attached to from another context.
+ */
+ if (queuePairEntry->qp.flags & VMCI_QPFLAG_LOCAL) {
+ /* Local create case. */
+ uint32_t contextId = VMCI_GetContextID();
+
+ /*
+ * 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 (queuePairEntry->qp.handle.context != contextId ||
+ (queuePairEntry->qp.peer != VMCI_INVALID_ID &&
+ queuePairEntry->qp.peer != contextId)) {
+ result = VMCI_ERROR_NO_ACCESS;
+ goto error;
+ }
+
+ if (queuePairEntry->qp.flags & VMCI_QPFLAG_ATTACH_ONLY) {
+ result = VMCI_ERROR_NOT_FOUND;
+ goto error;
+ }
+ } else {
+ result = qp_alloc_hypercall(queuePairEntry);
+ if (result < VMCI_SUCCESS) {
+ pr_warn("qp_alloc_hypercall result = %d.",
+ result);
+ goto error;
+ }
+ }
+
+ qp_init_queue_mutex((struct vmci_queue *)myProduceQ,
+ (struct vmci_queue *)myConsumeQ);
+
+ qp_list_add_entry(&qpGuestEndpoints, &queuePairEntry->qp);
+
+out:
+ queuePairEntry->qp.refCount++;
+ *handle = queuePairEntry->qp.handle;
+ *produceQ = (struct vmci_queue *)myProduceQ;
+ *consumeQ = (struct vmci_queue *)myConsumeQ;
+
+ /*
+ * 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 ((queuePairEntry->qp.flags & VMCI_QPFLAG_LOCAL) &&
+ queuePairEntry->qp.refCount == 1) {
+ vmci_q_header_init((*produceQ)->qHeader, *handle);
+ vmci_q_header_init((*consumeQ)->qHeader, *handle);
+ }
+
+ up(&qpGuestEndpoints.mutex);
+
+ return VMCI_SUCCESS;
+
+error:
+ up(&qpGuestEndpoints.mutex);
+ if (queuePairEntry) {
+ /* The queues will be freed inside the destroy routine. */
+ qp_guest_endpoint_destroy(queuePairEntry);
+ } else {
+ qp_free_queue(myProduceQ, produceSize);
+ qp_free_queue(myConsumeQ, consumeSize);
+ }
+ return result;
+
+errorKeepEntry:
+ /* This path should only be used when an existing entry was found. */
+ ASSERT(queuePairEntry->qp.refCount > 0);
+ up(&qpGuestEndpoints.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 pageStore. 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 pageStore of NULL should be
+ * used.
+ *
+ * If the creator is the host, a pageStore 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,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ uint64_t produceSize,
+ uint64_t consumeSize,
+ struct vmci_qp_page_store *pageStore,
+ struct vmci_ctx *context,
+ VMCIEventReleaseCB wakeupCB,
+ void *clientData,
+ struct qp_broker_entry **ent)
+{
+ struct qp_broker_entry *entry = NULL;
+ const uint32_t contextId = vmci_ctx_get_id(context);
+ bool isLocal = flags & VMCI_QPFLAG_LOCAL;
+ int result;
+ uint64_t guestProduceSize;
+ uint64_t guestConsumeSize;
+
+ /* 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 != contextId && handle.context != peer)
+ return VMCI_ERROR_NO_ACCESS;
+
+ if (VMCI_CONTEXT_IS_VM(contextId) && 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 (isLocal && peer != VMCI_INVALID_ID && contextId != 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 && !isLocal) {
+ /*
+ * 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.
+ */
+
+ guestProduceSize = consumeSize;
+ guestConsumeSize = produceSize;
+ } else {
+ guestProduceSize = produceSize;
+ guestConsumeSize = consumeSize;
+ }
+
+ entry->qp.handle = handle;
+ entry->qp.peer = peer;
+ entry->qp.flags = flags;
+ entry->qp.produceSize = guestProduceSize;
+ entry->qp.consumeSize = guestConsumeSize;
+ entry->qp.refCount = 1;
+ entry->createId = contextId;
+ entry->attachId = VMCI_INVALID_ID;
+ entry->state = VMCIQPB_NEW;
+ entry->requireTrustedAttach =
+ !!(context->privFlags & VMCI_PRIVILEGE_FLAG_RESTRICTED);
+ entry->createdByTrusted = !!(privFlags & VMCI_PRIVILEGE_FLAG_TRUSTED);
+ entry->vmciPageFiles = false;
+ entry->wakeupCB = wakeupCB;
+ entry->clientData = clientData;
+ entry->produceQ = qp_host_alloc_queue(guestProduceSize);
+ if (entry->produceQ == NULL) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+ entry->consumeQ = qp_host_alloc_queue(guestConsumeSize);
+ if (entry->consumeQ == NULL) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+
+ qp_init_queue_mutex(entry->produceQ, entry->consumeQ);
+
+ INIT_LIST_HEAD(&entry->qp.listItem);
+
+ if (isLocal) {
+ uint8_t *tmp;
+ ASSERT(pageStore == NULL);
+
+ entry->localMem = kcalloc(QPE_NUM_PAGES(entry->qp),
+ PAGE_SIZE, GFP_KERNEL);
+ if (entry->localMem == NULL) {
+ result = VMCI_ERROR_NO_MEM;
+ goto error;
+ }
+ entry->state = VMCIQPB_CREATED_MEM;
+ entry->produceQ->qHeader = entry->localMem;
+ tmp = (uint8_t *) entry->localMem + PAGE_SIZE *
+ (dm_div_up(entry->qp.produceSize, PAGE_SIZE) + 1);
+ entry->consumeQ->qHeader = (struct vmci_queue_header *) tmp;
+
+ vmci_q_header_init(entry->produceQ->qHeader, handle);
+ vmci_q_header_init(entry->consumeQ->qHeader, handle);
+ } else if (pageStore) {
+ ASSERT(entry->createId != VMCI_HOST_CONTEXT_ID || isLocal);
+
+ /*
+ * The VMX already initialized the queue pair headers, so no
+ * need for the kernel side to do that.
+ */
+ result = qp_host_register_user_memory(pageStore,
+ entry->produceQ,
+ entry->consumeQ);
+ if (result < VMCI_SUCCESS)
+ goto error;
+
+ entry->state = VMCIQPB_CREATED_MEM;
+ } else {
+ /*
+ * A create without a pageStore 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(&qpBrokerList, &entry->qp);
+ if (ent != NULL)
+ *ent = entry;
+
+ vmci_ctx_qp_create(context, handle);
+
+ return VMCI_SUCCESS;
+
+error:
+ if (entry != NULL) {
+ qp_host_free_queue(entry->produceQ, guestProduceSize);
+ qp_host_free_queue(entry->consumeQ, guestConsumeSize);
+ 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,
+ uint32_t myId,
+ uint32_t peerId)
+{
+ int rv;
+ struct vmci_event_msg *eMsg;
+ struct vmci_event_payld_qp *evPayload;
+ char buf[sizeof *eMsg + sizeof *evPayload];
+
+ if (VMCI_HANDLE_INVALID(handle) || myId == VMCI_INVALID_ID ||
+ peerId == VMCI_INVALID_ID)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ /*
+ * Notification message contains: queue pair handle and
+ * attaching/detaching VM's context id.
+ */
+ eMsg = (struct vmci_event_msg *)buf;
+
+ /*
+ * In vmci_ctx_enqueue_dg() 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.
+ */
+
+ /* Clear out any garbage. */
+ memset(eMsg, 0, sizeof buf);
+
+ eMsg->hdr.dst = vmci_make_handle(peerId, VMCI_EVENT_HANDLER);
+ eMsg->hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+ VMCI_CONTEXT_RESOURCE_ID);
+ eMsg->hdr.payloadSize = sizeof *eMsg + sizeof *evPayload -
+ sizeof eMsg->hdr;
+ eMsg->eventData.event = attach ?
+ VMCI_EVENT_QP_PEER_ATTACH : VMCI_EVENT_QP_PEER_DETACH;
+ evPayload = vmci_event_data_payload(&eMsg->eventData);
+ evPayload->handle = handle;
+ evPayload->peerId = myId;
+
+ rv = vmci_dg_dispatch(VMCI_HYPERVISOR_CONTEXT_ID,
+ (struct vmci_dg *)eMsg, false);
+ if (rv < VMCI_SUCCESS)
+ pr_warn("Failed to enqueue QueuePair %s event datagram " \
+ "for context (ID=0x%x).", attach ? "ATTACH" : "DETACH",
+ peerId);
+
+ 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 pageStore. 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 pageStore 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 pageStore 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,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ uint64_t produceSize,
+ uint64_t consumeSize,
+ struct vmci_qp_page_store *pageStore,
+ struct vmci_ctx *context,
+ VMCIEventReleaseCB wakeupCB,
+ void *clientData,
+ struct qp_broker_entry **ent)
+{
+ const uint32_t contextId = vmci_ctx_get_id(context);
+ bool isLocal = flags & VMCI_QPFLAG_LOCAL;
+ int result;
+
+ if (entry->state != VMCIQPB_CREATED_NO_MEM &&
+ entry->state != VMCIQPB_CREATED_MEM)
+ return VMCI_ERROR_UNAVAILABLE;
+
+ if (isLocal) {
+ if (!(entry->qp.flags & VMCI_QPFLAG_LOCAL) ||
+ contextId != entry->createId) {
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+ } else if (contextId == entry->createId ||
+ contextId == entry->attachId) {
+ return VMCI_ERROR_ALREADY_EXISTS;
+ }
+
+ ASSERT(entry->qp.refCount < 2);
+ ASSERT(entry->attachId == VMCI_INVALID_ID);
+
+ if (VMCI_CONTEXT_IS_VM(contextId) &&
+ VMCI_CONTEXT_IS_VM(entry->createId))
+ 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->privFlags & VMCI_PRIVILEGE_FLAG_RESTRICTED) &&
+ !entry->createdByTrusted)
+ 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->requireTrustedAttach &&
+ (!(privFlags & 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 != contextId)
+ return VMCI_ERROR_NO_ACCESS;
+
+ if (entry->createId == 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 (contextId == VMCI_HOST_CONTEXT_ID) {
+ struct vmci_ctx *createContext;
+ bool supportsHostQP;
+
+ /*
+ * Do not attach a host to a user created queue pair if that
+ * user doesn't support host queue pair end points.
+ */
+
+ createContext = vmci_ctx_get(entry->createId);
+ supportsHostQP = vmci_ctx_supports_host_qp(createContext);
+ vmci_ctx_release(createContext);
+
+ if (!supportsHostQP)
+ return VMCI_ERROR_INVALID_RESOURCE;
+ }
+
+ if ((entry->qp.flags & ~VMCI_QP_ASYMM) != (flags & ~VMCI_QP_ASYMM_PEER))
+ return VMCI_ERROR_QUEUEPAIR_MISMATCH;
+
+ if (contextId != 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.produceSize != produceSize ||
+ entry->qp.consumeSize != consumeSize) {
+ return VMCI_ERROR_QUEUEPAIR_MISMATCH;
+ }
+ } else if (entry->qp.produceSize != consumeSize ||
+ entry->qp.consumeSize != produceSize) {
+ return VMCI_ERROR_QUEUEPAIR_MISMATCH;
+ }
+
+ if (contextId != 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 (pageStore != 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(pageStore,
+ entry->produceQ,
+ entry->consumeQ);
+ 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->produceQ,
+ entry->consumeQ);
+ if (result < VMCI_SUCCESS) {
+ qp_host_unregister_user_memory(
+ entry->produceQ,
+ entry->consumeQ);
+ 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 {
+ /*
+ * 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->produceQ,
+ entry->consumeQ);
+ 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;
+ }
+
+ if (entry->state == VMCIQPB_ATTACHED_MEM) {
+ result =
+ qp_notify_peer(true, entry->qp.handle, contextId,
+ entry->createId);
+ if (result < VMCI_SUCCESS)
+ pr_warn("Failed to notify peer (ID=0x%x) of " \
+ "attach to queue pair (handle=0x%x:0x%x).",
+ entry->createId, entry->qp.handle.context,
+ entry->qp.handle.resource);
+ }
+
+ entry->attachId = contextId;
+ entry->qp.refCount++;
+ if (wakeupCB) {
+ ASSERT(!entry->wakeupCB);
+ entry->wakeupCB = wakeupCB;
+ entry->clientData = clientData;
+ }
+
+ /*
+ * When attaching to local queue pairs, the context already has
+ * an entry tracking the queue pair, so don't add another one.
+ */
+ if (!isLocal)
+ vmci_ctx_qp_create(context, entry->qp.handle);
+ else
+ ASSERT(vmci_ctx_qp_exists(context, entry->qp.handle));
+
+ if (ent != NULL)
+ *ent = entry;
+
+ return VMCI_SUCCESS;
+}
+
+/*
+ * QueuePair_Alloc for use when setting up queue pair endpoints
+ * on the host.
+ */
+static int qp_broker_alloc(struct vmci_handle handle,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ uint64_t produceSize,
+ uint64_t consumeSize,
+ struct vmci_qp_page_store *pageStore,
+ struct vmci_ctx *context,
+ VMCIEventReleaseCB wakeupCB,
+ void *clientData,
+ struct qp_broker_entry **ent,
+ bool *swap)
+{
+ const uint32_t contextId = vmci_ctx_get_id(context);
+ bool create;
+ struct qp_broker_entry *entry;
+ bool isLocal = flags & VMCI_QPFLAG_LOCAL;
+ int result;
+
+ if (VMCI_HANDLE_INVALID(handle) ||
+ (flags & ~VMCI_QP_ALL_FLAGS) || isLocal ||
+ !(produceSize || consumeSize) ||
+ !context || contextId == VMCI_INVALID_ID ||
+ handle.context == VMCI_INVALID_ID) {
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ if (pageStore && !VMCI_QP_PAGESTORE_IS_WELLFORMED(pageStore))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ /*
+ * In the initial argument check, we ensure that non-vmkernel hosts
+ * are not allowed to create local queue pairs.
+ */
+
+ ASSERT(!isLocal);
+
+ down(&qpBrokerList.mutex);
+
+ if (!isLocal && vmci_ctx_qp_exists(context, handle)) {
+ pr_devel("Context (ID=0x%x) already attached to queue " \
+ "pair (handle=0x%x:0x%x).", contextId,
+ handle.context, handle.resource);
+ up(&qpBrokerList.mutex);
+ return VMCI_ERROR_ALREADY_EXISTS;
+ }
+
+ entry = (struct qp_broker_entry *)
+ qp_list_find(&qpBrokerList, handle);
+ if (!entry) {
+ create = true;
+ result =
+ qp_broker_create(handle, peer, flags, privFlags,
+ produceSize, consumeSize, pageStore,
+ context, wakeupCB, clientData, ent);
+ } else {
+ create = false;
+ result =
+ qp_broker_attach(entry, peer, flags, privFlags,
+ produceSize, consumeSize, pageStore,
+ context, wakeupCB, clientData, ent);
+ }
+
+ up(&qpBrokerList.mutex);
+
+ if (swap)
+ *swap = (contextId == VMCI_HOST_CONTEXT_ID) &&
+ !(create && isLocal);
+
+
+ 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 **produceQ,
+ uint64_t produceSize,
+ struct vmci_queue **consumeQ,
+ uint64_t consumeSize,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ VMCIEventReleaseCB wakeupCB,
+ void *clientData)
+{
+ struct vmci_ctx *context;
+ struct qp_broker_entry *entry;
+ int result;
+ bool swap;
+
+ if (VMCI_HANDLE_INVALID(*handle)) {
+ uint32_t resourceID;
+
+ resourceID = vmci_resource_get_id(VMCI_HOST_CONTEXT_ID);
+ if (resourceID == VMCI_INVALID_ID)
+ return VMCI_ERROR_NO_HANDLE;
+
+ *handle = vmci_make_handle(VMCI_HOST_CONTEXT_ID, resourceID);
+ }
+
+ context = vmci_ctx_get(VMCI_HOST_CONTEXT_ID);
+ ASSERT(context);
+
+ entry = NULL;
+ result =
+ qp_broker_alloc(*handle, peer, flags, privFlags,
+ produceSize, consumeSize, NULL, context,
+ wakeupCB, clientData, &entry, &swap);
+ if (result == VMCI_SUCCESS) {
+ if (swap) {
+ /*
+ * If this is a local queue pair, the attacher
+ * will swap around produce and consume
+ * queues.
+ */
+
+ *produceQ = entry->consumeQ;
+ *consumeQ = entry->produceQ;
+ } else {
+ *produceQ = entry->produceQ;
+ *consumeQ = entry->consumeQ;
+ }
+ } else {
+ *handle = VMCI_INVALID_HANDLE;
+ pr_devel("queue pair broker failed to alloc (result=%d).",
+ result);
+ }
+ vmci_ctx_release(context);
+ return result;
+}
+
+/*
+ * Allocates a VMCI QueuePair. 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 **produceQ,
+ uint64_t produceSize,
+ struct vmci_queue **consumeQ,
+ uint64_t consumeSize,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ bool guestEndpoint,
+ VMCIEventReleaseCB wakeupCB,
+ void *clientData)
+{
+ if (!handle || !produceQ || !consumeQ || (!produceSize && !consumeSize)
+ || (flags & ~VMCI_QP_ALL_FLAGS))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ if (guestEndpoint)
+ return qp_alloc_guest_work(handle, produceQ,
+ produceSize, consumeQ,
+ consumeSize, peer,
+ flags, privFlags);
+ else
+ return qp_alloc_host_work(handle, produceQ,
+ produceSize, consumeQ,
+ consumeSize, peer, flags,
+ privFlags, wakeupCB,
+ clientData);
+}
+
+/*
+ * 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_release(context);
+ return result;
+}
+
+/*
+ * Detaches from a VMCI QueuePair. 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 guestEndpoint)
+{
+ if (VMCI_HANDLE_INVALID(handle))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ if (guestEndpoint)
+ return qp_detatch_guest_work(handle);
+ else
+ return qp_detatch_host_work(handle);
+}
+
+/*
+ * Initializes the list of QueuePairs.
+ */
+static int qp_list_init(struct qp_list *qpList)
+{
+ INIT_LIST_HEAD(&qpList->head);
+ sema_init(&qpList->mutex, 1);
+ return VMCI_SUCCESS;
+}
+
+/*
+ * 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 *qpList)
+{
+ if (!list_empty(&qpList->head)) {
+ struct qp_entry *entry =
+ list_first_entry(&qpList->head, struct qp_entry,
+ listItem);
+ return entry;
+ }
+
+ return NULL;
+}
+
+int __init vmci_qp_broker_init(void)
+{
+ return qp_list_init(&qpBrokerList);
+}
+
+void vmci_qp_broker_exit(void)
+{
+ struct qp_broker_entry *entry;
+
+ down(&qpBrokerList.mutex);
+
+ while ((entry = (struct qp_broker_entry *)
+ qp_list_get_head(&qpBrokerList))) {
+ qp_list_remove_entry(&qpBrokerList, &entry->qp);
+ kfree(entry);
+ }
+
+ up(&qpBrokerList.mutex);
+ INIT_LIST_HEAD(&(qpBrokerList.head));
+}
+
+/*
+ * 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 QueuePair. Assumes that the queue pair
+ * broker lock is held.
+ */
+int vmci_qp_broker_alloc(struct vmci_handle handle,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags,
+ uint64_t produceSize,
+ uint64_t consumeSize,
+ struct vmci_qp_page_store *pageStore,
+ struct vmci_ctx *context)
+{
+ return qp_broker_alloc(handle, peer, flags, privFlags,
+ produceSize, consumeSize,
+ pageStore, 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,
+ uint64_t produceUVA,
+ uint64_t consumeUVA,
+ struct vmci_ctx *context)
+{
+ struct qp_broker_entry *entry;
+ int result;
+ const uint32_t contextId = vmci_ctx_get_id(context);
+
+ if (VMCI_HANDLE_INVALID(handle) || !context
+ || contextId == 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 (produceUVA == 0 || consumeUVA == 0)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ down(&qpBrokerList.mutex);
+
+ if (!vmci_ctx_qp_exists(context, handle)) {
+ pr_warn("Context (ID=0x%x) not attached to queue pair " \
+ "(handle=0x%x:0x%x).", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ entry = (struct qp_broker_entry *)
+ qp_list_find(&qpBrokerList, 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 QueuePair and I'm the attached peer
+ * then I can set the page store.
+ */
+ if (entry->createId != contextId &&
+ (entry->createId != VMCI_HOST_CONTEXT_ID ||
+ entry->attachId != contextId)) {
+ 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(produceUVA, consumeUVA,
+ entry->produceQ, entry->consumeQ);
+ if (result < VMCI_SUCCESS)
+ goto out;
+
+ result = qp_host_map_queues(entry->produceQ, entry->consumeQ);
+ if (result < VMCI_SUCCESS) {
+ qp_host_unregister_user_memory(entry->produceQ,
+ entry->consumeQ);
+ goto out;
+ }
+
+ if (entry->state == VMCIQPB_CREATED_NO_MEM) {
+ entry->state = VMCIQPB_CREATED_MEM;
+ } else {
+ ASSERT(entry->state == VMCIQPB_ATTACHED_NO_MEM);
+ entry->state = VMCIQPB_ATTACHED_MEM;
+ }
+ entry->vmciPageFiles = true;
+
+ if (entry->state == VMCIQPB_ATTACHED_MEM) {
+ result =
+ qp_notify_peer(true, handle, contextId,
+ entry->createId);
+ if (result < VMCI_SUCCESS) {
+ pr_warn("Failed to notify peer (ID=0x%x) of " \
+ "attach to queue pair (handle=0x%x:0x%x).",
+ entry->createId, entry->qp.handle.context,
+ entry->qp.handle.resource);
+ }
+ }
+
+ result = VMCI_SUCCESS;
+out:
+ up(&qpBrokerList.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->produceQ->savedHeader = NULL;
+ entry->consumeQ->savedHeader = 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 uint32_t contextId = vmci_ctx_get_id(context);
+ uint32_t peerId;
+ bool isLocal = false;
+ int result;
+
+ if (VMCI_HANDLE_INVALID(handle) || !context
+ || contextId == VMCI_INVALID_ID) {
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ down(&qpBrokerList.mutex);
+
+ if (!vmci_ctx_qp_exists(context, handle)) {
+ pr_devel("Context (ID=0x%x) not attached to queue pair " \
+ "(handle=0x%x:0x%x).", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ entry = (struct qp_broker_entry *)
+ qp_list_find(&qpBrokerList, 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.", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ if (contextId != entry->createId && contextId != entry->attachId) {
+ result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
+ goto out;
+ }
+
+ if (contextId == entry->createId) {
+ peerId = entry->attachId;
+ entry->createId = VMCI_INVALID_ID;
+ } else {
+ peerId = entry->createId;
+ entry->attachId = VMCI_INVALID_ID;
+ }
+ entry->qp.refCount--;
+
+ isLocal = entry->qp.flags & VMCI_QPFLAG_LOCAL;
+
+ if (contextId != VMCI_HOST_CONTEXT_ID) {
+ bool headersMapped;
+
+ ASSERT(!isLocal);
+
+ /*
+ * 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->produceQ);
+ headersMapped = entry->produceQ->qHeader
+ || entry->consumeQ->qHeader;
+ if (QPBROKERSTATE_HAS_MEM(entry)) {
+ result = qp_host_unmap_queues(
+ INVALID_VMCI_GUEST_MEM_ID, entry->produceQ,
+ entry->consumeQ);
+ if (result < VMCI_SUCCESS)
+ pr_warn("Failed to unmap queue headers " \
+ "for queue pair " \
+ "(handle=0x%x:0x%x,result=%d).",
+ handle.context, handle.resource,
+ result);
+
+ if (entry->vmciPageFiles) {
+ qp_host_unregister_user_memory(entry->produceQ,
+ entry->consumeQ);
+ } else {
+ qp_host_unregister_user_memory(entry->produceQ,
+ entry->consumeQ);
+ }
+ }
+
+ if (!headersMapped)
+ qp_reset_saved_headers(entry);
+
+ qp_release_queue_mutex(entry->produceQ);
+
+ if (!headersMapped && entry->wakeupCB)
+ entry->wakeupCB(entry->clientData);
+
+ } else {
+ if (entry->wakeupCB) {
+ entry->wakeupCB = NULL;
+ entry->clientData = NULL;
+ }
+ }
+
+ if (entry->qp.refCount == 0) {
+ qp_list_remove_entry(&qpBrokerList, &entry->qp);
+
+ if (isLocal)
+ kfree(entry->localMem);
+
+ qp_cleanup_queue_mutex(entry->produceQ, entry->consumeQ);
+ qp_host_free_queue(entry->produceQ, entry->qp.produceSize);
+ qp_host_free_queue(entry->consumeQ, entry->qp.consumeSize);
+ kfree(entry);
+
+ vmci_ctx_qp_destroy(context, handle);
+ } else {
+ ASSERT(peerId != VMCI_INVALID_ID);
+ qp_notify_peer(false, handle, contextId, peerId);
+ if (contextId == VMCI_HOST_CONTEXT_ID
+ && QPBROKERSTATE_HAS_MEM(entry)) {
+ entry->state = VMCIQPB_SHUTDOWN_MEM;
+ } else {
+ entry->state = VMCIQPB_SHUTDOWN_NO_MEM;
+ }
+
+ if (!isLocal)
+ vmci_ctx_qp_destroy(context, handle);
+
+ }
+ result = VMCI_SUCCESS;
+out:
+ up(&qpBrokerList.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,
+ uint64_t guestMem)
+{
+ struct qp_broker_entry *entry;
+ const uint32_t contextId = vmci_ctx_get_id(context);
+ bool isLocal = false;
+ int result;
+
+ if (VMCI_HANDLE_INVALID(handle) || !context
+ || contextId == VMCI_INVALID_ID)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ down(&qpBrokerList.mutex);
+
+ if (!vmci_ctx_qp_exists(context, handle)) {
+ pr_devel("Context (ID=0x%x) not attached to queue pair " \
+ "(handle=0x%x:0x%x).", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ entry = (struct qp_broker_entry *)
+ qp_list_find(&qpBrokerList, 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.", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ if (contextId != entry->createId && contextId != entry->attachId) {
+ result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
+ goto out;
+ }
+
+ isLocal = entry->qp.flags & VMCI_QPFLAG_LOCAL;
+ result = VMCI_SUCCESS;
+
+ if (contextId != VMCI_HOST_CONTEXT_ID) {
+ struct vmci_qp_page_store pageStore;
+
+ ASSERT(entry->state == VMCIQPB_CREATED_NO_MEM ||
+ entry->state == VMCIQPB_SHUTDOWN_NO_MEM ||
+ entry->state == VMCIQPB_ATTACHED_NO_MEM);
+ ASSERT(!isLocal);
+
+ pageStore.pages = guestMem;
+ pageStore.len = QPE_NUM_PAGES(entry->qp);
+
+ qp_acquire_queue_mutex(entry->produceQ);
+ qp_reset_saved_headers(entry);
+ result =
+ qp_host_register_user_memory(&pageStore,
+ entry->produceQ,
+ entry->consumeQ);
+ qp_release_queue_mutex(entry->produceQ);
+ if (result == VMCI_SUCCESS) {
+ /* Move state from *_NO_MEM to *_MEM */
+
+ entry->state++;
+
+ ASSERT(entry->state == VMCIQPB_CREATED_MEM ||
+ entry->state == VMCIQPB_SHUTDOWN_MEM ||
+ entry->state == VMCIQPB_ATTACHED_MEM);
+
+ if (entry->wakeupCB)
+ entry->wakeupCB(entry->clientData);
+ }
+ }
+
+out:
+ up(&qpBrokerList.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->produceQ->savedHeader != NULL &&
+ entry->consumeQ->savedHeader != 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->produceQ->qHeader
+ || NULL == entry->consumeQ->qHeader) {
+ result = qp_host_map_queues(entry->produceQ, entry->consumeQ);
+ if (result < VMCI_SUCCESS)
+ return result;
+ }
+
+ memcpy(&entry->savedProduceQ, entry->produceQ->qHeader,
+ sizeof entry->savedProduceQ);
+ entry->produceQ->savedHeader = &entry->savedProduceQ;
+ memcpy(&entry->savedConsumeQ, entry->consumeQ->qHeader,
+ sizeof entry->savedConsumeQ);
+ entry->consumeQ->savedHeader = &entry->savedConsumeQ;
+
+ 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,
+ uint32_t gid)
+{
+ struct qp_broker_entry *entry;
+ const uint32_t contextId = vmci_ctx_get_id(context);
+ bool isLocal = false;
+ int result;
+
+ if (VMCI_HANDLE_INVALID(handle) || !context
+ || contextId == VMCI_INVALID_ID)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ down(&qpBrokerList.mutex);
+
+ if (!vmci_ctx_qp_exists(context, handle)) {
+ pr_devel("Context (ID=0x%x) not attached to queue pair " \
+ "(handle=0x%x:0x%x).", contextId,
+ handle.context, handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ entry = (struct qp_broker_entry *)
+ qp_list_find(&qpBrokerList, 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.", contextId, handle.context,
+ handle.resource);
+ result = VMCI_ERROR_NOT_FOUND;
+ goto out;
+ }
+
+ if (contextId != entry->createId && contextId != entry->attachId) {
+ result = VMCI_ERROR_QUEUEPAIR_NOTATTACHED;
+ goto out;
+ }
+
+ isLocal = entry->qp.flags & VMCI_QPFLAG_LOCAL;
+
+ if (contextId != VMCI_HOST_CONTEXT_ID) {
+ ASSERT(entry->state != VMCIQPB_CREATED_NO_MEM &&
+ entry->state != VMCIQPB_SHUTDOWN_NO_MEM &&
+ entry->state != VMCIQPB_ATTACHED_NO_MEM);
+ ASSERT(!isLocal);
+
+ qp_acquire_queue_mutex(entry->produceQ);
+ 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).",
+ handle.context, handle.resource, result);
+
+ qp_host_unmap_queues(gid, entry->produceQ, entry->consumeQ);
+
+ /*
+ * 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->produceQ,
+ entry->consumeQ);
+
+ /*
+ * Move state from *_MEM to *_NO_MEM.
+ */
+ entry->state--;
+
+ qp_release_queue_mutex(entry->produceQ);
+ }
+
+ result = VMCI_SUCCESS;
+
+out:
+ up(&qpBrokerList.mutex);
+ return result;
+}
+
+int __devinit vmci_qp_guest_endpoints_init(void)
+{
+ return qp_list_init(&qpGuestEndpoints);
+}
+
+/*
+ * 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_guest_endpoint *entry;
+
+ down(&qpGuestEndpoints.mutex);
+
+ while ((entry = (struct qp_guest_endpoint *)
+ qp_list_get_head(&qpGuestEndpoints))) {
+
+ /* Don't make a hypercall for local QueuePairs. */
+ if (!(entry->qp.flags & VMCI_QPFLAG_LOCAL))
+ qp_detatch_hypercall(entry->qp.handle);
+
+ /* We cannot fail the exit, so let's reset refCount. */
+ entry->qp.refCount = 0;
+ qp_list_remove_entry(&qpGuestEndpoints, &entry->qp);
+ qp_guest_endpoint_destroy(entry);
+ }
+
+ up(&qpGuestEndpoints.mutex);
+ INIT_LIST_HEAD(&(qpGuestEndpoints.head));
+}
+
+/*
+ * 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.
+ * 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)
+{
+ ASSERT(!QP_PINNED(qpair->flags) ||
+ (QP_PINNED(qpair->flags) && !CAN_BLOCK(qpair->flags)));
+
+ if (CAN_BLOCK(qpair->flags))
+ qp_acquire_queue_mutex(qpair->produceQ);
+}
+
+/*
+ * Helper routine that unlocks the queue pair after calling
+ * qp_lock. Respects non-blocking and pinning flags.
+ */
+static void qp_unlock(const struct vmci_qp *qpair)
+{
+ if (CAN_BLOCK(qpair->flags))
+ qp_release_queue_mutex(qpair->produceQ);
+}
+
+/*
+ * 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 *produceQ,
+ struct vmci_queue *consumeQ,
+ bool canBlock)
+{
+ int result;
+
+ if (NULL == produceQ->qHeader || NULL == consumeQ->qHeader) {
+ if (canBlock)
+ result = qp_host_map_queues(produceQ, consumeQ);
+ else
+ result = VMCI_ERROR_QUEUEPAIR_NOT_READY;
+
+ if (result < VMCI_SUCCESS)
+ return (produceQ->savedHeader &&
+ consumeQ->savedHeader) ?
+ 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 **produceQHeader,
+ struct vmci_queue_header **consumeQHeader)
+{
+ int result;
+
+ result = qp_map_queue_headers(qpair->produceQ, qpair->consumeQ,
+ CAN_BLOCK(qpair->flags));
+ if (result == VMCI_SUCCESS) {
+ *produceQHeader = qpair->produceQ->qHeader;
+ *consumeQHeader = qpair->consumeQ->qHeader;
+ } else if (qpair->produceQ->savedHeader &&
+ qpair->consumeQ->savedHeader) {
+ ASSERT(!qpair->guestEndpoint);
+ *produceQHeader = qpair->produceQ->savedHeader;
+ *consumeQHeader = qpair->consumeQ->savedHeader;
+ 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 *clientData)
+{
+ struct vmci_qp *qpair = (struct vmci_qp *)clientData;
+ ASSERT(qpair);
+
+ qp_lock(qpair);
+ while (qpair->blocked > 0) {
+ qpair->blocked--;
+ wake_up(&qpair->event);
+ }
+ qp_unlock(qpair);
+
+ return VMCI_SUCCESS;
+}
+
+/*
+ * Callback from VMCI_WaitOnEvent releasing the queue pair mutex
+ * protecting the queue pair header state.
+ */
+static int qp_release_mutex_cb(void *clientData)
+{
+ struct vmci_qp *qpair = (struct vmci_qp *)clientData;
+ ASSERT(qpair);
+ qp_unlock(qpair);
+ return 0;
+}
+
+/*
+ * 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)
+{
+ if (unlikely(qpair->guestEndpoint))
+ ASSERT(false);
+
+ if (qpair->flags & VMCI_QPFLAG_NONBLOCK)
+ return false;
+
+ qpair->blocked++;
+ vmci_drv_wait_on_event_intr(&qpair->event, qp_release_mutex_cb,
+ qpair);
+ 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 *produceQ,
+ struct vmci_queue *consumeQ,
+ const uint64_t produceQSize,
+ const void *buf,
+ size_t bufSize,
+ VMCIMemcpyToQueueFunc memcpyToQueue,
+ bool canBlock)
+{
+ int64_t freeSpace;
+ uint64_t tail;
+ size_t written;
+ ssize_t result;
+
+ result = qp_map_queue_headers(produceQ, consumeQ, canBlock);
+ if (unlikely(result != VMCI_SUCCESS))
+ return result;
+
+ freeSpace = vmci_q_header_free_space(produceQ->qHeader,
+ consumeQ->qHeader, produceQSize);
+ if (freeSpace == 0)
+ return VMCI_ERROR_QUEUEPAIR_NOSPACE;
+
+ if (freeSpace < VMCI_SUCCESS)
+ return (ssize_t) freeSpace;
+
+ written = (size_t) (freeSpace > bufSize ? bufSize : freeSpace);
+ tail = vmci_q_header_producer_tail(produceQ->qHeader);
+ if (likely(tail + written < produceQSize)) {
+ result = memcpyToQueue(produceQ, tail, buf, 0, written);
+ } else {
+ /* Tail pointer wraps around. */
+
+ const size_t tmp = (size_t) (produceQSize - tail);
+
+ result = memcpyToQueue(produceQ, tail, buf, 0, tmp);
+ if (result >= VMCI_SUCCESS)
+ result = memcpyToQueue(produceQ, 0, buf, tmp,
+ written - tmp);
+ }
+
+ if (result < VMCI_SUCCESS)
+ return result;
+
+ vmci_q_header_add_producer_tail(produceQ->qHeader, written,
+ produceQSize);
+ 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 *produceQ,
+ struct vmci_queue *consumeQ,
+ const uint64_t consumeQSize,
+ void *buf,
+ size_t bufSize,
+ VMCIMemcpyFromQueueFunc memcpyFromQueue,
+ bool updateConsumer,
+ bool canBlock)
+{
+ int64_t bufReady;
+ uint64_t head;
+ size_t read;
+ ssize_t result;
+
+ result = qp_map_queue_headers(produceQ, consumeQ, canBlock);
+ if (unlikely(result != VMCI_SUCCESS))
+ return result;
+
+ bufReady = vmci_q_header_buf_ready(consumeQ->qHeader,
+ produceQ->qHeader, consumeQSize);
+ if (bufReady == 0)
+ return VMCI_ERROR_QUEUEPAIR_NODATA;
+
+ if (bufReady < VMCI_SUCCESS)
+ return (ssize_t) bufReady;
+
+ read = (size_t) (bufReady > bufSize ? bufSize : bufReady);
+ head = vmci_q_header_consumer_head(produceQ->qHeader);
+ if (likely(head + read < consumeQSize)) {
+ result = memcpyFromQueue(buf, 0, consumeQ, head, read);
+ } else {
+ /* Head pointer wraps around. */
+
+ const size_t tmp = (size_t) (consumeQSize - head);
+
+ result = memcpyFromQueue(buf, 0, consumeQ, head, tmp);
+ if (result >= VMCI_SUCCESS) {
+ result = memcpyFromQueue(buf, tmp, consumeQ, 0,
+ read - tmp);
+ }
+ }
+
+ if (result < VMCI_SUCCESS)
+ return result;
+
+ if (updateConsumer)
+ vmci_q_header_add_consumer_head(produceQ->qHeader,
+ read, consumeQSize);
+
+ return read;
+}
+
+/**
+ * VMCIQPair_Alloc() - Allocates a queue pair.
+ * @qpair: Pointer for the new vmci_qp struct.
+ * @handle: Handle to track the resource.
+ * @produceQSize: Desired size of the producer queue.
+ * @consumeQSize: Desired size of the consumer queue.
+ * @peer: ContextID of the peer.
+ * @flags: VMCI flags.
+ * @privFlags: 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 VMCIQPair_Alloc(struct vmci_qp **qpair,
+ struct vmci_handle *handle,
+ uint64_t produceQSize,
+ uint64_t consumeQSize,
+ uint32_t peer,
+ uint32_t flags,
+ uint32_t privFlags)
+{
+ struct vmci_qp *myQPair;
+ int retval;
+ struct vmci_handle src = VMCI_INVALID_HANDLE;
+ struct vmci_handle dst = vmci_make_handle(peer, VMCI_INVALID_ID);
+ enum vmci_route route;
+ VMCIEventReleaseCB wakeupCB;
+ void *clientData;
+
+ /*
+ * 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 (produceQSize + consumeQSize < max(produceQSize, consumeQSize) ||
+ produceQSize + consumeQSize > 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 NONBLOCK or PINNED is set, we better be the guest personality. */
+ if ((!CAN_BLOCK(flags) || QP_PINNED(flags)) &&
+ VMCI_ROUTE_AS_GUEST != route) {
+ pr_devel("Not guest personality w/ 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 (QP_PINNED(flags)) {
+ if (CAN_BLOCK(flags)) {
+ pr_err("Attempted to enable pinning w/o non-blocking");
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ if (produceQSize + consumeQSize > VMCI_MAX_PINNED_QP_MEMORY)
+ return VMCI_ERROR_NO_RESOURCES;
+ }
+
+ myQPair = kzalloc(sizeof *myQPair, GFP_KERNEL);
+ if (!myQPair)
+ return VMCI_ERROR_NO_MEM;
+
+ myQPair->produceQSize = produceQSize;
+ myQPair->consumeQSize = consumeQSize;
+ myQPair->peer = peer;
+ myQPair->flags = flags;
+ myQPair->privFlags = privFlags;
+
+ wakeupCB = clientData = NULL;
+ if (VMCI_ROUTE_AS_HOST == route) {
+ myQPair->guestEndpoint = false;
+ if (!(flags & VMCI_QPFLAG_LOCAL)) {
+ myQPair->blocked = 0;
+ init_waitqueue_head(&myQPair->event);
+ wakeupCB = qp_wakeup_cb;
+ clientData = (void *)myQPair;
+ }
+ } else {
+ myQPair->guestEndpoint = true;
+ }
+
+ retval = vmci_qp_alloc(handle,
+ &myQPair->produceQ,
+ myQPair->produceQSize,
+ &myQPair->consumeQ,
+ myQPair->consumeQSize,
+ myQPair->peer,
+ myQPair->flags,
+ myQPair->privFlags,
+ myQPair->guestEndpoint,
+ wakeupCB, clientData);
+
+ if (retval < VMCI_SUCCESS) {
+ kfree(myQPair);
+ return retval;
+ }
+
+ *qpair = myQPair;
+ myQPair->handle = *handle;
+
+ return retval;
+}
+EXPORT_SYMBOL(VMCIQPair_Alloc);
+
+/**
+ * VMCIQPair_Detatch() - 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 VMCIQPair_Detach(struct vmci_qp **qpair)
+{
+ int result;
+ struct vmci_qp *oldQPair;
+
+ if (!qpair || !(*qpair))
+ return VMCI_ERROR_INVALID_ARGS;
+
+ oldQPair = *qpair;
+ result = qp_detatch(oldQPair->handle, oldQPair->guestEndpoint);
+
+ /*
+ * 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(oldQPair, 0, sizeof *oldQPair);
+ oldQPair->handle = VMCI_INVALID_HANDLE;
+ oldQPair->peer = VMCI_INVALID_ID;
+ kfree(oldQPair);
+ *qpair = NULL;
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_Detach);
+
+/**
+ * VMCIQPair_GetProduceIndexes() - Retrieves the indexes of the producer.
+ * @qpair: Pointer to the queue pair struct.
+ * @producerTail: Reference used for storing producer tail index.
+ * @consumerHead: 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 VMCIQPair_GetProduceIndexes(const struct vmci_qp *qpair,
+ uint64_t *producerTail,
+ uint64_t *consumerHead)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS)
+ vmci_q_header_get_pointers(produceQHeader, consumeQHeader,
+ producerTail, consumerHead);
+ qp_unlock(qpair);
+
+ if (result == VMCI_SUCCESS &&
+ ((producerTail && *producerTail >= qpair->produceQSize) ||
+ (consumerHead && *consumerHead >= qpair->produceQSize)))
+ return VMCI_ERROR_INVALID_SIZE;
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_GetProduceIndexes);
+
+/**
+ * VMCIQPair_GetConsumeIndexes() - Retrieves the indexes of the comsumer.
+ * @qpair: Pointer to the queue pair struct.
+ * @consumerTail: Reference used for storing consumer tail index.
+ * @producerHead: 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 VMCIQPair_GetConsumeIndexes(const struct vmci_qp *qpair,
+ uint64_t *consumerTail,
+ uint64_t *producerHead)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS)
+ vmci_q_header_get_pointers(consumeQHeader, produceQHeader,
+ consumerTail, producerHead);
+ qp_unlock(qpair);
+
+ if (result == VMCI_SUCCESS &&
+ ((consumerTail && *consumerTail >= qpair->consumeQSize) ||
+ (producerHead && *producerHead >= qpair->consumeQSize)))
+ return VMCI_ERROR_INVALID_SIZE;
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_GetConsumeIndexes);
+
+/**
+ * VMCIQPair_ProduceFreeSpace() - 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.
+ */
+int64_t VMCIQPair_ProduceFreeSpace(const struct vmci_qp *qpair)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int64_t result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS) {
+ result = vmci_q_header_free_space(produceQHeader,
+ consumeQHeader,
+ qpair->produceQSize);
+ } else {
+ result = 0;
+ }
+ qp_unlock(qpair);
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_ProduceFreeSpace);
+
+/**
+ * VMCIQPair_ConsumeFreeSpace() - 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.
+ */
+int64_t VMCIQPair_ConsumeFreeSpace(const struct vmci_qp *qpair)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int64_t result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS) {
+ result = vmci_q_header_free_space(consumeQHeader,
+ produceQHeader,
+ qpair->consumeQSize);
+ } else {
+ result = 0;
+ }
+ qp_unlock(qpair);
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_ConsumeFreeSpace);
+
+/**
+ * VMCIQPair_ProduceBufReady() - 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.
+ */
+int64_t VMCIQPair_ProduceBufReady(const struct vmci_qp *qpair)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int64_t result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS) {
+ result = vmci_q_header_buf_ready(produceQHeader,
+ consumeQHeader,
+ qpair->produceQSize);
+ } else {
+ result = 0;
+ }
+ qp_unlock(qpair);
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_ProduceBufReady);
+
+/**
+ * VMCIQPair_ConsumeBufReady() - 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.
+ */
+int64_t VMCIQPair_ConsumeBufReady(const struct vmci_qp *qpair)
+{
+ struct vmci_queue_header *produceQHeader;
+ struct vmci_queue_header *consumeQHeader;
+ int64_t result;
+
+ if (!qpair)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+ result = qp_get_queue_headers(qpair, &produceQHeader, &consumeQHeader);
+ if (result == VMCI_SUCCESS) {
+ result = vmci_q_header_buf_ready(consumeQHeader,
+ produceQHeader,
+ qpair->consumeQSize);
+ } else {
+ result = 0;
+ }
+ qp_unlock(qpair);
+
+ return result;
+}
+EXPORT_SYMBOL(VMCIQPair_ConsumeBufReady);
+
+/**
+ * VMCIQPair_Enqueue() - Throw data on the queue.
+ * @qpair: Pointer to the queue pair struct.
+ * @buf: Pointer to buffer containing data
+ * @bufSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_Enqueue(struct vmci_qp *qpair,
+ const void *buf,
+ size_t bufSize,
+ int bufType)
+{
+ ssize_t result;
+
+ if (!qpair || !buf)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+
+ do {
+ result = qp_enqueue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->produceQSize,
+ buf, bufSize,
+ qp_memcpy_to_queue,
+ CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_Enqueue);
+
+/**
+ * VMCIQPair_Dequeue() - Get data from the queue.
+ * @qpair: Pointer to the queue pair struct.
+ * @buf: Pointer to buffer for the data
+ * @bufSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_Dequeue(struct vmci_qp *qpair,
+ void *buf,
+ size_t bufSize,
+ int bufType)
+{
+ ssize_t result;
+
+ if (!qpair || !buf)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+
+ do {
+ result = qp_dequeue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->consumeQSize,
+ buf, bufSize,
+ qp_memcpy_from_queue, true,
+ CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_Dequeue);
+
+/**
+ * VMCIQPair_Peek() - Peek at the data in the queue.
+ * @qpair: Pointer to the queue pair struct.
+ * @buf: Pointer to buffer for the data
+ * @bufSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_Peek(struct vmci_qp *qpair,
+ void *buf,
+ size_t bufSize,
+ int bufType)
+{
+ ssize_t result;
+
+ if (!qpair || !buf)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+
+ do {
+ result = qp_dequeue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->consumeQSize,
+ buf, bufSize,
+ qp_memcpy_from_queue, false,
+ CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_Peek);
+
+/**
+ * VMCIQPair_EnqueueV() - Throw data on the queue using iov.
+ * @qpair: Pointer to the queue pair struct.
+ * @iov: Pointer to buffer containing data
+ * @iovSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_EnqueueV(struct vmci_qp *qpair,
+ void *iov,
+ size_t iovSize,
+ int bufType)
+{
+ ssize_t result;
+
+ if (!qpair || !iov)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+
+ do {
+ result = qp_enqueue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->produceQSize,
+ iov, iovSize,
+ qp_memcpy_to_queue_iov,
+ CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_EnqueueV);
+
+
+/**
+ * VMCIQPair_DequeueV() - Get data from the queue using iov.
+ * @qpair: Pointer to the queue pair struct.
+ * @iov: Pointer to buffer for the data
+ * @iovSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_DequeueV(struct vmci_qp *qpair,
+ void *iov,
+ size_t iovSize,
+ int bufType)
+{
+ ssize_t result;
+
+ qp_lock(qpair);
+
+ if (!qpair || !iov)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ do {
+ result = qp_dequeue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->consumeQSize,
+ iov, iovSize,
+ qp_memcpy_from_queue_iov,
+ true, CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_DequeueV);
+
+/**
+ * VMCIQPair_PeekV() - Peek at the data in the queue using iov.
+ * @qpair: Pointer to the queue pair struct.
+ * @iov: Pointer to buffer for the data
+ * @iovSize: Length of buffer.
+ * @bufType: 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 VMCIQPair_PeekV(struct vmci_qp *qpair,
+ void *iov,
+ size_t iovSize,
+ int bufType)
+{
+ ssize_t result;
+
+ if (!qpair || !iov)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ qp_lock(qpair);
+
+ do {
+ result = qp_dequeue_locked(qpair->produceQ,
+ qpair->consumeQ,
+ qpair->consumeQSize,
+ iov, iovSize,
+ qp_memcpy_from_queue_iov,
+ false, CAN_BLOCK(qpair->flags));
+
+ 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(VMCIQPair_PeekV);
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.h b/drivers/misc/vmw_vmci/vmci_queue_pair.h
new file mode 100644
index 0000000..b4f39e4
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.h
@@ -0,0 +1,182 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _VMCI_QUEUE_PAIR_H_
+#define _VMCI_QUEUE_PAIR_H_
+
+#include <linux/vmw_vmci_defs.h>
+
+#include "vmci_context.h"
+
+/* Callback needed for correctly waiting on events. */
+typedef int (*VMCIEventReleaseCB) (void *clientData);
+
+/* Guest device port I/O. */
+struct PPNSet {
+ uint64_t numProducePages;
+ uint64_t numConsumePages;
+ uint32_t *producePPNs;
+ uint32_t *consumePPNs;
+ bool initialized;
+};
+
+
+/* VMCIQueuePairAllocInfo */
+struct vmci_qp_alloc_info {
+ struct vmci_handle handle;
+ uint32_t peer;
+ uint32_t flags;
+ uint64_t produceSize;
+ uint64_t consumeSize;
+ uint64_t ppnVA; /* Start VA of queue pair PPNs. */
+ uint64_t numPPNs;
+ int32_t result;
+ uint32_t version;
+};
+
+/* VMCIQueuePairSetVAInfo */
+struct vmci_qp_set_va_info {
+ struct vmci_handle handle;
+ uint64_t va; /* Start VA of queue pair PPNs. */
+ uint64_t numPPNs;
+ uint32_t version;
+ int32_t result;
+};
+
+/*
+ * For backwards compatibility, here is a version of the
+ * VMCIQueuePairPageFileInfo before host support end-points was added.
+ * Note that the current version of that structure requires VMX to
+ * pass down the VA of the mapped file. Before host support was added
+ * there was nothing of the sort. So, when the driver sees the ioctl
+ * with a parameter that is the sizeof
+ * VMCIQueuePairPageFileInfo_NoHostQP then it can infer that the version
+ * of VMX running can't attach to host end points because it doesn't
+ * provide the VA of the mapped files.
+ *
+ * The Linux driver doesn't get an indication of the size of the
+ * structure passed down from user space. So, to fix a long standing
+ * but unfiled bug, the _pad field has been renamed to version.
+ * Existing versions of VMX always initialize the PageFileInfo
+ * structure so that _pad, er, version is set to 0.
+ *
+ * A version value of 1 indicates that the size of the structure has
+ * been increased to include two UVA's: produceUVA and consumeUVA.
+ * These UVA's are of the mmap()'d queue contents backing files.
+ *
+ * In addition, if when VMX is sending down the
+ * VMCIQueuePairPageFileInfo structure it gets an error then it will
+ * try again with the _NoHostQP version of the file to see if an older
+ * VMCI kernel module is running.
+ */
+
+/* VMCIQueuePairPageFileInfo */
+struct vmci_qp_page_file_info {
+ struct vmci_handle handle;
+ uint64_t producePageFile; /* User VA. */
+ uint64_t consumePageFile; /* User VA. */
+ uint64_t producePageFileSize; /* Size of the file name array. */
+ uint64_t consumePageFileSize; /* Size of the file name array. */
+ int32_t result;
+ uint32_t version; /* Was _pad. */
+ uint64_t produceVA; /* User VA of the mapped file. */
+ uint64_t consumeVA; /* User VA of the mapped file. */
+};
+
+/* VMCIQueuePairDetachInfo */
+struct vmci_qp_dtch_info {
+ struct vmci_handle handle;
+ int32_t result;
+ uint32_t _pad;
+};
+
+/*
+ * struct vmci_qp_page_store describes how the memory of a given queue pair
+ * is backed. When the queue pair is between the host and a guest, the
+ * page store consists of references to the guest pages. On vmkernel,
+ * this is a list of PPNs, and on hosted, it is a user VA where the
+ * queue pair is mapped into the VMX address space.
+ */
+struct vmci_qp_page_store {
+ /* Reference to pages backing the queue pair. */
+ uint64_t pages;
+ /* Length of pageList/virtual addres range (in pages). */
+ uint32_t len;
+};
+
+/*
+ * This data type contains the information about a queue.
+ * There are two queues (hence, queue pairs) per transaction model between a
+ * pair of end points, A & B. One queue is used by end point A to transmit
+ * commands and responses to B. The other queue is used by B to transmit
+ * commands and responses.
+ *
+ * struct vmci_queue_kern_if is a per-OS defined Queue structure. It contains
+ * either a direct pointer to the linear address of the buffer contents or a
+ * pointer to structures which help the OS locate those data pages. See
+ * vmciKernelIf.c for each platform for its definition.
+ */
+struct vmci_queue {
+ struct vmci_queue_header *qHeader;
+ struct vmci_queue_header *savedHeader;
+ struct vmci_queue_kern_if *kernelIf;
+};
+
+/*
+ * Utility function that checks whether the fields of the page
+ * store contain valid values.
+ * Result:
+ * true if the page store is wellformed. false otherwise.
+ */
+static inline bool
+VMCI_QP_PAGESTORE_IS_WELLFORMED(struct vmci_qp_page_store *pageStore)
+{
+ return pageStore->len >= 2;
+}
+
+
+
+int vmci_qp_broker_init(void);
+void vmci_qp_broker_exit(void);
+int vmci_qp_broker_alloc(struct vmci_handle handle, uint32_t peer,
+ uint32_t flags, uint32_t privFlags,
+ uint64_t produceSize, uint64_t consumeSize,
+ struct vmci_qp_page_store *pageStore,
+ struct vmci_ctx *context);
+int vmci_qp_broker_set_page_store(struct vmci_handle handle,
+ uint64_t produceUVA, uint64_t consumeUVA,
+ struct vmci_ctx *context);
+int vmci_qp_broker_detach(struct vmci_handle handle,
+ struct vmci_ctx *context);
+
+int vmci_qp_guest_endpoints_init(void);
+void vmci_qp_guest_endpoints_exit(void);
+
+int vmci_qp_alloc(struct vmci_handle *handle,
+ struct vmci_queue **produceQ, uint64_t produceSize,
+ struct vmci_queue **consumeQ, uint64_t consumeSize,
+ uint32_t peer, uint32_t flags, uint32_t privFlags,
+ bool guestEndpoint, VMCIEventReleaseCB wakeupCB,
+ void *clientData);
+int vmci_qp_broker_map(struct vmci_handle handle,
+ struct vmci_ctx *context, uint64_t guestMem);
+int vmci_qp_broker_unmap(struct vmci_handle handle,
+ struct vmci_ctx *context, uint32_t gid);
+
+#endif /* _VMCI_QUEUE_PAIR_H_ */
--
1.7.0.4


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