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Subject[PATCH 02/11] vmci_datagram.patch: VMCI datagram entity handling.


Signed-off-by: George Zhang <georgezhang@vmware.com>
---
drivers/misc/vmw_vmci/vmci_datagram.c | 583 +++++++++++++++++++++++++++++++++
drivers/misc/vmw_vmci/vmci_datagram.h | 55 +++
2 files changed, 638 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/vmw_vmci/vmci_datagram.c
create mode 100644 drivers/misc/vmw_vmci/vmci_datagram.h

diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c
new file mode 100644
index 0000000..21ee66d
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_datagram.c
@@ -0,0 +1,583 @@
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/vmw_vmci_api.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/bug.h>
+
+#include "vmci_common_int.h"
+#include "vmci_hash_table.h"
+#include "vmci_datagram.h"
+#include "vmci_resource.h"
+#include "vmci_context.h"
+#include "vmci_driver.h"
+#include "vmci_event.h"
+#include "vmci_route.h"
+
+/*
+ * struct datagram_entry describes the datagram entity. It is used for datagram
+ * entities created only on the host.
+ */
+struct datagram_entry {
+ struct vmci_resource resource;
+ u32 flags;
+ bool runDelayed;
+ vmci_datagram_recv_cb recvCB;
+ void *clientData;
+ wait_queue_head_t destroyEvent;
+ u32 privFlags;
+};
+
+struct delayed_datagram_info {
+ bool inDGHostQueue;
+ struct datagram_entry *entry;
+ struct vmci_datagram msg;
+};
+
+static atomic_t delayedDGHostQueueSize;
+
+static void dg_free_cb(void *clientData)
+{
+ struct datagram_entry *entry = (struct datagram_entry *)clientData;
+ ASSERT(entry);
+
+ /*
+ * Entry is freed in VMCIDatagram_DestroyHnd, who waits for
+ * the signal.
+ */
+ wake_up(&entry->destroyEvent);
+}
+
+static int dg_release_cb(void *clientData)
+{
+ struct datagram_entry *entry = (struct datagram_entry *)clientData;
+ ASSERT(entry);
+ vmci_resource_release(&entry->resource);
+ return 0;
+}
+
+/*
+ * Create a datagram entry given a handle pointer.
+ */
+static int dg_create_handle(u32 resourceID,
+ u32 flags,
+ u32 privFlags,
+ vmci_datagram_recv_cb recvCB,
+ void *clientData,
+ struct vmci_handle *outHandle)
+{
+ int result;
+ u32 contextID;
+ struct vmci_handle handle;
+ struct datagram_entry *entry;
+
+ ASSERT(recvCB != NULL);
+ ASSERT(outHandle != NULL);
+ ASSERT(!(privFlags & ~VMCI_PRIVILEGE_ALL_FLAGS));
+
+ if ((flags & VMCI_FLAG_WELLKNOWN_DG_HND) != 0) {
+ return VMCI_ERROR_INVALID_ARGS;
+ } else {
+ if ((flags & VMCI_FLAG_ANYCID_DG_HND) != 0) {
+ contextID = VMCI_INVALID_ID;
+ } else {
+ contextID = vmci_get_context_id();
+ if (contextID == VMCI_INVALID_ID)
+ return VMCI_ERROR_NO_RESOURCES;
+ }
+
+ if (resourceID == VMCI_INVALID_ID) {
+ resourceID = vmci_resource_get_id(contextID);
+ if (resourceID == VMCI_INVALID_ID)
+ return VMCI_ERROR_NO_HANDLE;
+ }
+
+ handle = vmci_make_handle(contextID, resourceID);
+ }
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (entry == NULL) {
+ pr_warn("Failed allocating memory for datagram entry.");
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ entry->runDelayed = (flags & VMCI_FLAG_DG_DELAYED_CB) ? true : false;
+ entry->flags = flags;
+ entry->recvCB = recvCB;
+ entry->clientData = clientData;
+ init_waitqueue_head(&entry->destroyEvent);
+ entry->privFlags = privFlags;
+
+ /* Make datagram resource live. */
+ result = vmci_resource_add(&entry->resource,
+ VMCI_RESOURCE_TYPE_DATAGRAM,
+ handle, dg_free_cb, entry);
+ if (result != VMCI_SUCCESS) {
+ pr_warn("Failed to add new resource (handle=0x%x:0x%x).",
+ handle.context, handle.resource);
+ kfree(entry);
+ return result;
+ }
+ *outHandle = handle;
+
+ return VMCI_SUCCESS;
+}
+
+int __init vmci_datagram_init(void)
+{
+ atomic_set(&delayedDGHostQueueSize, 0);
+ return VMCI_SUCCESS;
+}
+
+/*
+ * Internal utilility function with the same purpose as
+ * vmci_datagram_get_priv_flags that also takes a contextID.
+ */
+static int vmci_datagram_get_priv_flags(u32 contextID,
+ struct vmci_handle handle,
+ u32 *privFlags)
+{
+ ASSERT(privFlags);
+ ASSERT(contextID != VMCI_INVALID_ID);
+
+ if (contextID == VMCI_HOST_CONTEXT_ID) {
+ struct datagram_entry *srcEntry;
+ struct vmci_resource *resource;
+
+ resource =
+ vmci_resource_get(handle, VMCI_RESOURCE_TYPE_DATAGRAM);
+ if (resource == NULL)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ srcEntry = container_of(resource, struct datagram_entry,
+ resource);
+ *privFlags = srcEntry->privFlags;
+ vmci_resource_release(resource);
+ } else if (contextID == VMCI_HYPERVISOR_CONTEXT_ID) {
+ *privFlags = VMCI_MAX_PRIVILEGE_FLAGS;
+ } else {
+ *privFlags = vmci_context_get_priv_flags(contextID);
+ }
+
+ return VMCI_SUCCESS;
+}
+
+/*
+ * Calls the specified callback in a delayed context.
+ */
+static void dg_delayed_dispatch_cb(void *data)
+{
+ bool inDGHostQueue;
+ struct delayed_datagram_info *dgInfo =
+ (struct delayed_datagram_info *)data;
+
+ ASSERT(data);
+
+ dgInfo->entry->recvCB(dgInfo->entry->clientData, &dgInfo->msg);
+
+ vmci_resource_release(&dgInfo->entry->resource);
+
+ inDGHostQueue = dgInfo->inDGHostQueue;
+ kfree(dgInfo);
+
+ if (inDGHostQueue)
+ atomic_dec(&delayedDGHostQueueSize);
+}
+
+/*
+ * Dispatch datagram as a host, to the host, or other vm context. This
+ * function cannot dispatch to hypervisor context handlers. This should
+ * have been handled before we get here by VMCIDatagramDispatch.
+ * Returns number of bytes sent on success, error code otherwise.
+ */
+static int dg_dispatch_as_host(u32 contextID,
+ struct vmci_datagram *dg)
+{
+ int retval;
+ size_t dgSize;
+ u32 srcPrivFlags;
+
+ ASSERT(dg);
+ ASSERT(vmci_host_code_active());
+
+ dgSize = VMCI_DG_SIZE(dg);
+
+ if (contextID == VMCI_HOST_CONTEXT_ID &&
+ dg->dst.context == VMCI_HYPERVISOR_CONTEXT_ID)
+ return VMCI_ERROR_DST_UNREACHABLE;
+
+ ASSERT(dg->dst.context != VMCI_HYPERVISOR_CONTEXT_ID);
+
+ /* Check that source handle matches sending context. */
+ if (dg->src.context != contextID) {
+ pr_devel("Sender context (ID=0x%x) is not owner of src " \
+ "datagram entry (handle=0x%x:0x%x).",
+ contextID, dg->src.context, dg->src.resource);
+ return VMCI_ERROR_NO_ACCESS;
+ }
+
+ /* Get hold of privileges of sending endpoint. */
+ retval = vmci_datagram_get_priv_flags(contextID, dg->src, &srcPrivFlags);
+ if (retval != VMCI_SUCCESS) {
+ pr_warn("Couldn't get privileges (handle=0x%x:0x%x).",
+ dg->src.context, dg->src.resource);
+ return retval;
+ }
+
+ /* Determine if we should route to host or guest destination. */
+ if (dg->dst.context == VMCI_HOST_CONTEXT_ID) {
+ /* Route to host datagram entry. */
+ struct datagram_entry *dstEntry;
+ struct vmci_resource *resource;
+
+ if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
+ dg->dst.resource == VMCI_EVENT_HANDLER) {
+ return vmci_event_dispatch(dg);
+ }
+
+ resource = vmci_resource_get(dg->dst,
+ VMCI_RESOURCE_TYPE_DATAGRAM);
+ if (resource == NULL) {
+ pr_devel("Sending to invalid destination " \
+ "(handle=0x%x:0x%x).", dg->dst.context,
+ dg->dst.resource);
+ return VMCI_ERROR_INVALID_RESOURCE;
+ }
+ dstEntry =
+ container_of(resource, struct datagram_entry,
+ resource);
+ if (vmci_deny_interaction(srcPrivFlags, dstEntry->privFlags)) {
+ vmci_resource_release(resource);
+ return VMCI_ERROR_NO_ACCESS;
+ }
+ ASSERT(dstEntry->recvCB);
+
+ /*
+ * If a VMCI datagram destined for the host is also sent by the
+ * host, we always run it delayed. This ensures that no locks
+ * are held when the datagram callback runs.
+ */
+ if (dstEntry->runDelayed ||
+ dg->src.context == VMCI_HOST_CONTEXT_ID) {
+ struct delayed_datagram_info *dgInfo;
+
+ if (atomic_add_return(1, &delayedDGHostQueueSize)
+ == VMCI_MAX_DELAYED_DG_HOST_QUEUE_SIZE) {
+ atomic_dec(&delayedDGHostQueueSize);
+ vmci_resource_release(resource);
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ dgInfo =
+ kmalloc(sizeof(*dgInfo) +
+ (size_t) dg->payloadSize, GFP_ATOMIC);
+ if (NULL == dgInfo) {
+ atomic_dec(&delayedDGHostQueueSize);
+ vmci_resource_release(resource);
+ return VMCI_ERROR_NO_MEM;
+ }
+
+ dgInfo->inDGHostQueue = true;
+ dgInfo->entry = dstEntry;
+ memcpy(&dgInfo->msg, dg, dgSize);
+ retval =
+ vmci_drv_schedule_delayed_work(dg_delayed_dispatch_cb,
+ dgInfo);
+ if (retval < VMCI_SUCCESS) {
+ pr_warn("Failed to schedule delayed " \
+ "work for datagram (result=%d).",
+ retval);
+ kfree(dgInfo);
+ vmci_resource_release(resource);
+ atomic_dec(&delayedDGHostQueueSize);
+ return retval;
+ }
+ } else {
+ retval = dstEntry->recvCB(dstEntry->clientData, dg);
+ vmci_resource_release(resource);
+ if (retval < VMCI_SUCCESS)
+ return retval;
+ }
+ } else {
+ /* Route to destination VM context. */
+ struct vmci_datagram *newDG;
+
+ if (contextID != dg->dst.context) {
+ if (vmci_deny_interaction(srcPrivFlags,
+ vmci_context_get_priv_flags
+ (dg->dst.context))) {
+ return VMCI_ERROR_NO_ACCESS;
+ } else if (VMCI_CONTEXT_IS_VM(contextID)) {
+ /*
+ * If the sending context is a VM, it
+ * cannot reach another VM.
+ */
+
+ pr_devel("Datagram communication between VMs " \
+ "not supported (src=0x%x, dst=0x%x).",
+ contextID, dg->dst.context);
+ return VMCI_ERROR_DST_UNREACHABLE;
+ }
+ }
+
+ /* We make a copy to enqueue. */
+ newDG = kmalloc(dgSize, GFP_KERNEL);
+ if (newDG == NULL)
+ return VMCI_ERROR_NO_MEM;
+
+ memcpy(newDG, dg, dgSize);
+ retval = vmci_ctx_enqueue_datagram(dg->dst.context, newDG);
+ if (retval < VMCI_SUCCESS) {
+ kfree(newDG);
+ return retval;
+ }
+ }
+
+ /*
+ * We currently truncate the size to signed 32 bits. This doesn't
+ * matter for this handler as it only support 4Kb messages.
+ */
+ return (int)dgSize;
+}
+
+/*
+ * Dispatch datagram as a guest, down through the VMX and potentially to
+ * the host.
+ * Returns number of bytes sent on success, error code otherwise.
+ */
+static int dg_dispatch_as_guest(struct vmci_datagram *dg)
+{
+ int retval;
+ struct vmci_resource *resource;
+
+ resource = vmci_resource_get(dg->src, VMCI_RESOURCE_TYPE_DATAGRAM);
+ if (NULL == resource)
+ return VMCI_ERROR_NO_HANDLE;
+
+ retval = vmci_send_datagram(dg);
+ vmci_resource_release(resource);
+ return retval;
+}
+
+/*
+ * Dispatch datagram. This will determine the routing for the datagram
+ * and dispatch it accordingly.
+ * Returns number of bytes sent on success, error code otherwise.
+ */
+int vmci_datagram_dispatch(u32 contextID,
+ struct vmci_datagram *dg, bool fromGuest)
+{
+ int retval;
+ enum vmci_route route;
+
+ ASSERT(dg);
+ BUILD_BUG_ON(sizeof(struct vmci_datagram) != 24);
+
+ if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
+ pr_devel("Payload (size=%llu bytes) too big to " \
+ "send.", (unsigned long long) dg->payloadSize);
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ retval = vmci_route(&dg->src, &dg->dst, fromGuest, &route);
+ if (retval < VMCI_SUCCESS) {
+ pr_devel("Failed to route datagram (src=0x%x, dst=0x%x, " \
+ "err=%d).", dg->src.context, dg->dst.context,
+ retval);
+ return retval;
+ }
+
+ if (VMCI_ROUTE_AS_HOST == route) {
+ if (VMCI_INVALID_ID == contextID)
+ contextID = VMCI_HOST_CONTEXT_ID;
+ return dg_dispatch_as_host(contextID, dg);
+ }
+
+ if (VMCI_ROUTE_AS_GUEST == route)
+ return dg_dispatch_as_guest(dg);
+
+ pr_warn("Unknown route (%d) for datagram.", route);
+ return VMCI_ERROR_DST_UNREACHABLE;
+}
+
+/*
+ * Invoke the handler for the given datagram. This is intended to be
+ * called only when acting as a guest and receiving a datagram from the
+ * virtual device.
+ */
+int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg)
+{
+ int retval;
+ struct vmci_resource *resource;
+ struct datagram_entry *dstEntry;
+
+ ASSERT(dg);
+
+ resource = vmci_resource_get(dg->dst, VMCI_RESOURCE_TYPE_DATAGRAM);
+ if (NULL == resource) {
+ pr_devel("destination (handle=0x%x:0x%x) doesn't exist.",
+ dg->dst.context, dg->dst.resource);
+ return VMCI_ERROR_NO_HANDLE;
+ }
+
+ dstEntry =
+ container_of(resource, struct datagram_entry, resource);
+ if (dstEntry->runDelayed) {
+ struct delayed_datagram_info *dgInfo;
+
+ dgInfo =
+ kmalloc(sizeof(*dgInfo) + (size_t) dg->payloadSize,
+ GFP_ATOMIC);
+ if (NULL == dgInfo) {
+ vmci_resource_release(resource);
+ retval = VMCI_ERROR_NO_MEM;
+ goto exit;
+ }
+
+ dgInfo->inDGHostQueue = false;
+ dgInfo->entry = dstEntry;
+ memcpy(&dgInfo->msg, dg, VMCI_DG_SIZE(dg));
+
+ retval =
+ vmci_drv_schedule_delayed_work(dg_delayed_dispatch_cb,
+ dgInfo);
+ if (retval < VMCI_SUCCESS) {
+ pr_warn("Failed to schedule delayed work for " \
+ "datagram (result=%d).", retval);
+ kfree(dgInfo);
+ vmci_resource_release(resource);
+ dgInfo = NULL;
+ goto exit;
+ }
+ } else {
+ dstEntry->recvCB(dstEntry->clientData, dg);
+ vmci_resource_release(resource);
+ retval = VMCI_SUCCESS;
+ }
+
+exit:
+ return retval;
+}
+
+/**
+ * vmci_datagram_create_handle_priv() - Create host context datagram endpoint
+ * @resource_id: The resource ID.
+ * @flags: Datagram Flags.
+ * @priv_flags: Privilege Flags.
+ * @recv_cb: Callback when receiving datagrams.
+ * @client_data: Pointer for a datagram_entry struct
+ * @out_handle: vmci_handle that is populated as a result of this function.
+ *
+ * Creates a host context datagram endpoint and returns a handle to it.
+ */
+int vmci_datagram_create_handle_priv(u32 resource_id,
+ u32 flags,
+ u32 priv_flags,
+ vmci_datagram_recv_cb recv_cb,
+ void *client_data,
+ struct vmci_handle *out_handle)
+{
+ if (out_handle == NULL)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ if (recv_cb == NULL) {
+ pr_devel("Client callback needed when creating " \
+ "datagram.");
+ return VMCI_ERROR_INVALID_ARGS;
+ }
+
+ if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ return dg_create_handle(resource_id, flags, priv_flags, recv_cb,
+ client_data, out_handle);
+}
+EXPORT_SYMBOL(vmci_datagram_create_handle_priv);
+
+/**
+ * vmci_datagram_create_handle() - Create host context datagram endpoint
+ * @resource_id: Resource ID.
+ * @flags: Datagram Flags.
+ * @recv_cb: Callback when receiving datagrams.
+ * @client_ata: Pointer for a datagram_entry struct
+ * @out_handle: vmci_handle that is populated as a result of this function.
+ *
+ * Creates a host context datagram endpoint and returns a handle to
+ * it. Same as vmci_datagram_create_handle_priv without the priviledge
+ * flags argument.
+ */
+int vmci_datagram_create_handle(u32 resource_id,
+ u32 flags,
+ vmci_datagram_recv_cb recv_cb,
+ void *client_data,
+ struct vmci_handle *out_handle)
+{
+ return vmci_datagram_create_handle_priv(resource_id, flags,
+ VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS,
+ recv_cb, client_data, out_handle);
+}
+EXPORT_SYMBOL(vmci_datagram_create_handle);
+
+/**
+ * vmci_datagram_destroy_handle() - Destroys datagram handle
+ * @handle: vmci_handle to be destroyed and reaped.
+ *
+ * Use this function to destroy any datagram handles created by
+ * vmci_datagram_create_handle{,Priv} functions.
+ */
+int vmci_datagram_destroy_handle(struct vmci_handle handle)
+{
+ struct datagram_entry *entry;
+ struct vmci_resource *resource;
+
+ resource = vmci_resource_get(handle, VMCI_RESOURCE_TYPE_DATAGRAM);
+ if (resource == NULL) {
+ pr_devel("Failed to destroy datagram (handle=0x%x:0x%x)" \
+ ".", handle.context, handle.resource);
+ return VMCI_ERROR_NOT_FOUND;
+ }
+
+ entry = container_of(resource, struct datagram_entry, resource);
+ vmci_resource_remove(handle, VMCI_RESOURCE_TYPE_DATAGRAM);
+
+ /*
+ * We now wait on the destroyEvent and release the reference we got
+ * above.
+ */
+ vmci_drv_wait_on_event_intr(&entry->destroyEvent, dg_release_cb,
+ entry);
+ kfree(entry);
+
+ return VMCI_SUCCESS;
+}
+EXPORT_SYMBOL(vmci_datagram_destroy_handle);
+
+/**
+ * vmci_datagram_send() - Send a datagram
+ * @msg: The datagram to send.
+ *
+ * Sends the provided datagram on its merry way.
+ */
+int vmci_datagram_send(struct vmci_datagram *msg)
+{
+ if (msg == NULL)
+ return VMCI_ERROR_INVALID_ARGS;
+
+ return vmci_datagram_dispatch(VMCI_INVALID_ID, msg, false);
+}
+EXPORT_SYMBOL(vmci_datagram_send);
diff --git a/drivers/misc/vmw_vmci/vmci_datagram.h b/drivers/misc/vmw_vmci/vmci_datagram.h
new file mode 100644
index 0000000..d88fe7d
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_datagram.h
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+
+#ifndef _VMCI_DATAGRAM_H_
+#define _VMCI_DATAGRAM_H_
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+#include "vmci_context.h"
+
+#define VMCI_MAX_DELAYED_DG_HOST_QUEUE_SIZE 256
+
+/*
+ * The struct vmci_datagram_queue_entry is a queue header for the in-kernel VMCI
+ * datagram queues. It is allocated in non-paged memory, as the
+ * content is accessed while holding a spinlock. The pending datagram
+ * itself may be allocated from paged memory. We shadow the size of
+ * the datagram in the non-paged queue entry as this size is used
+ * while holding the same spinlock as above.
+ */
+struct vmci_datagram_queue_entry {
+ struct list_head listItem; /* For queuing. */
+ size_t dgSize; /* Size of datagram. */
+ struct vmci_datagram *dg; /* Pending datagram. */
+};
+
+/* VMCIDatagramSendRecvInfo */
+struct vmci_datagram_snd_rcv_info {
+ uint64_t addr;
+ uint32_t len;
+ int32_t result;
+};
+
+/* Init functions. */
+int vmci_datagram_init(void);
+
+/* Datagram API for non-public use. */
+int vmci_datagram_dispatch(uint32_t contextID, struct vmci_datagram *dg,
+ bool fromGuest);
+int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg);
+
+#endif /* _VMCI_DATAGRAM_H_ */


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