[PATCH 11/12] VMCI: host side driver implementation.

[George Zhang <georgezhang@vmware.com>]

VMCI host side driver code implementation.


Signed-off-by: George Zhang <georgezhang@vmware.com>
---
 drivers/misc/vmw_vmci/vmci_host.c | 1046 +++++++++++++++++++++++++++++++++++++
 1 files changed, 1046 insertions(+), 0 deletions(-)
 create mode 100644 drivers/misc/vmw_vmci/vmci_host.c

diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c
new file mode 100644
index 0000000..9cab365
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_host.c
@@ -0,0 +1,1046 @@
+/*
+ * 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/moduleparam.h>
+#include <linux/miscdevice.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+
+#include "vmci_handle_array.h"
+#include "vmci_common_int.h"
+#include "vmci_queue_pair.h"
+#include "vmci_datagram.h"
+#include "vmci_doorbell.h"
+#include "vmci_resource.h"
+#include "vmci_context.h"
+#include "vmci_driver.h"
+#include "vmci_event.h"
+
+#define VMCI_UTIL_NUM_RESOURCES 1
+
+enum {
+	VMCI_NOTIFY_RESOURCE_QUEUE_PAIR = 0,
+	VMCI_NOTIFY_RESOURCE_DOOR_BELL = 1,
+};
+
+enum {
+	VMCI_NOTIFY_RESOURCE_ACTION_NOTIFY = 0,
+	VMCI_NOTIFY_RESOURCE_ACTION_CREATE = 1,
+	VMCI_NOTIFY_RESOURCE_ACTION_DESTROY = 2,
+};
+
+/*
+ * VMCI driver initialization. This block can also be used to
+ * pass initial group membership etc.
+ */
+struct vmci_init_blk {
+	u32 cid;
+	u32 flags;
+};
+
+/* VMCIqueue_pairAllocInfo_VMToVM */
+struct vmci_qp_alloc_info_vmvm {
+	struct vmci_handle handle;
+	u32 peer;
+	u32 flags;
+	u64 produce_size;
+	u64 consume_size;
+	u64 produce_page_file;	  /* User VA. */
+	u64 consume_page_file;	  /* User VA. */
+	u64 produce_page_file_size;  /* Size of the file name array. */
+	u64 consume_page_file_size;  /* Size of the file name array. */
+	s32 result;
+	u32 _pad;
+};
+
+/* VMCISetNotifyInfo: Used to pass notify flag's address to the host driver. */
+struct vmci_set_notify_info {
+	u64 notify_uva;
+	s32 result;
+	u32 _pad;
+};
+
+/*
+ * Per-instance host state
+ */
+struct vmci_host_dev {
+	struct vmci_ctx *context;
+	int user_version;
+	enum vmci_obj_type ct_type;
+	struct mutex lock;  /* Mutex lock for vmci context access */
+};
+
+static struct vmci_ctx *host_context;
+static bool vmci_host_device_initialized;
+static atomic_t vmci_host_active_users = ATOMIC_INIT(0);
+
+/*
+ * Determines whether the VMCI host personality is
+ * available. Since the core functionality of the host driver is
+ * always present, all guests could possibly use the host
+ * personality. However, to minimize the deviation from the
+ * pre-unified driver state of affairs, we only consider the host
+ * device active if there is no active guest device or if there
+ * are VMX'en with active VMCI contexts using the host device.
+ */
+bool vmci_host_code_active(void)
+{
+	return vmci_host_device_initialized &&
+	    (!vmci_guest_code_active() ||
+	     atomic_read(&vmci_host_active_users) > 0);
+}
+
+/*
+ * Called on open of /dev/vmci.
+ */
+static int vmci_host_open(struct inode *inode, struct file *filp)
+{
+	struct vmci_host_dev *vmci_host_dev;
+
+	vmci_host_dev = kzalloc(sizeof(struct vmci_host_dev), GFP_KERNEL);
+	if (vmci_host_dev == NULL)
+		return -ENOMEM;
+
+	vmci_host_dev->ct_type = VMCIOBJ_NOT_SET;
+	mutex_init(&vmci_host_dev->lock);
+	filp->private_data = vmci_host_dev;
+
+	return 0;
+}
+
+/*
+ * Called on close of /dev/vmci, most often when the process
+ * exits.
+ */
+static int vmci_host_close(struct inode *inode, struct file *filp)
+{
+	struct vmci_host_dev *vmci_host_dev = filp->private_data;
+
+	ASSERT(vmci_host_dev);
+
+	if (vmci_host_dev->ct_type == VMCIOBJ_CONTEXT) {
+		ASSERT(vmci_host_dev->context);
+
+		vmci_ctx_release_ctx(vmci_host_dev->context);
+		vmci_host_dev->context = NULL;
+
+		/*
+		 * The number of active contexts is used to track whether any
+		 * VMX'en are using the host personality. It is incremented when
+		 * a context is created through the IOCTL_VMCI_INIT_CONTEXT
+		 * ioctl.
+		 */
+		atomic_dec(&vmci_host_active_users);
+	}
+	vmci_host_dev->ct_type = VMCIOBJ_NOT_SET;
+
+	kfree(vmci_host_dev);
+	filp->private_data = NULL;
+	return 0;
+}
+
+/*
+ * This is used to wake up the VMX when a VMCI call arrives, or
+ * to wake up select() or poll() at the next clock tick.
+ */
+static unsigned int vmci_host_poll(struct file *filp, poll_table *wait)
+{
+	struct vmci_host_dev *vmci_host_dev = filp->private_data;
+	struct vmci_ctx *context = vmci_host_dev->context;
+	unsigned int mask = 0;
+
+	if (vmci_host_dev->ct_type == VMCIOBJ_CONTEXT) {
+		BUG_ON(!context);
+
+		/* Check for VMCI calls to this VM context. */
+		if (wait)
+			poll_wait(filp, &context->host_context.wait_queue,
+				  wait);
+
+		spin_lock(&context->lock);
+		if (context->pending_datagrams > 0 ||
+		    vmci_handle_arr_get_size(
+				context->pending_doorbell_array) > 0) {
+			mask = POLLIN;
+		}
+		spin_unlock(&context->lock);
+	}
+	return mask;
+}
+
+/*
+ * Copies the handles of a handle array into a user buffer, and
+ * returns the new length in userBufferSize. If the copy to the
+ * user buffer fails, the functions still returns VMCI_SUCCESS,
+ * but retval != 0.
+ */
+static int drv_cp_harray_to_user(void __user *user_buf_uva,
+				 u64 *user_buf_size,
+				 struct vmci_handle_arr *handle_array,
+				 int *retval)
+{
+	u32 array_size = 0;
+	struct vmci_handle *handles;
+
+	if (handle_array)
+		array_size = vmci_handle_arr_get_size(handle_array);
+
+	if (array_size * sizeof(*handles) > *user_buf_size)
+		return VMCI_ERROR_MORE_DATA;
+
+	*user_buf_size = array_size * sizeof(*handles);
+	if (*user_buf_size)
+		*retval = copy_to_user(user_buf_uva,
+				       vmci_handle_arr_get_handles
+				       (handle_array), *user_buf_size);
+
+	return VMCI_SUCCESS;
+}
+
+/*
+ * Sets up a given context for notify to work.  Calls drv_map_bool_ptr()
+ * which maps the notify boolean in user VA in kernel space.
+ */
+static int vmci_host_setup_notify(struct vmci_ctx *context,
+				  unsigned long uva)
+{
+	struct page *page;
+	int retval;
+
+	if (context->notify_page) {
+		pr_devel("%s: Notify mechanism is already set up.\n", __func__);
+		return VMCI_ERROR_DUPLICATE_ENTRY;
+	}
+
+	if (!access_ok(VERIFY_WRITE, (void __user *)uva, sizeof(bool)))
+		return VMCI_ERROR_GENERIC;
+
+	/*
+	 * Lock physical page backing a given user VA.
+	 */
+	down_read(&current->mm->mmap_sem);
+	retval = get_user_pages(current, current->mm,
+				PAGE_ALIGN(uva),
+				1, 1, 0, &page, NULL);
+	up_read(&current->mm->mmap_sem);
+	if (retval != 1)
+		return VMCI_ERROR_GENERIC;
+
+	/*
+	 * Map the locked page and set up notify pointer.
+	 */
+	context->notify = kmap(page) + (uva & (PAGE_SIZE - 1));
+	vmci_ctx_check_signal_notify(context);
+
+	return VMCI_SUCCESS;
+}
+
+static int vmci_host_get_version(struct vmci_host_dev *vmci_host_dev,
+				 unsigned int cmd, void __user *uptr)
+{
+	if (cmd == IOCTL_VMCI_VERSION2) {
+		int __user *vptr = uptr;
+		if (get_user(vmci_host_dev->user_version, vptr))
+			return -EFAULT;
+	}
+
+	/*
+	 * The basic logic here is:
+	 *
+	 * If the user sends in a version of 0 tell it our version.
+	 * If the user didn't send in a version, tell it our version.
+	 * If the user sent in an old version, tell it -its- version.
+	 * If the user sent in an newer version, tell it our version.
+	 *
+	 * The rationale behind telling the caller its version is that
+	 * Workstation 6.5 required that VMX and VMCI kernel module were
+	 * version sync'd.  All new VMX users will be programmed to
+	 * handle the VMCI kernel module version.
+	 */
+
+	if (vmci_host_dev->user_version > 0 &&
+	    vmci_host_dev->user_version < VMCI_VERSION_HOSTQP) {
+		return vmci_host_dev->user_version;
+	}
+
+	return VMCI_VERSION;
+}
+
+#define vmci_ioctl_err(fmt, ...)	\
+	pr_devel("%s: " fmt, ioctl_name, ##__VA_ARGS__)
+
+static int vmci_host_do_init_context(struct vmci_host_dev *vmci_host_dev,
+				     const char *ioctl_name,
+				     void __user *uptr)
+{
+	struct vmci_init_blk init_block;
+	const struct cred *cred;
+	int vmci_err;
+	int retval;
+
+	if (copy_from_user(&init_block, uptr, sizeof(init_block))) {
+		vmci_ioctl_err("error reading init block.\n");
+		return -EFAULT;
+	}
+
+	mutex_lock(&vmci_host_dev->lock);
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_NOT_SET) {
+		vmci_ioctl_err("received VMCI init on initialized handle.\n");
+		retval = -EINVAL;
+		goto out;
+	}
+
+	if (init_block.flags & ~VMCI_PRIVILEGE_FLAG_RESTRICTED) {
+		vmci_ioctl_err("unsupported VMCI restriction flag.\n");
+		retval = -EINVAL;
+		goto out;
+	}
+
+	cred = get_current_cred();
+	vmci_err = vmci_ctx_init_ctx(init_block.cid, init_block.flags, 0,
+				     vmci_host_dev->user_version, cred,
+				     &vmci_host_dev->context);
+	put_cred(cred);
+	if (vmci_err < VMCI_SUCCESS) {
+		vmci_ioctl_err("error initializing context.\n");
+		retval = (vmci_err == VMCI_ERROR_DUPLICATE_ENTRY) ?
+				-EEXIST : -EINVAL;
+		goto out;
+	}
+
+	/*
+	 * Copy cid to userlevel, we do this to allow the VMX
+	 * to enforce its policy on cid generation.
+	 */
+	init_block.cid = vmci_ctx_get_id(vmci_host_dev->context);
+	if (copy_to_user(uptr, &init_block, sizeof(init_block))) {
+		vmci_ctx_release_ctx(vmci_host_dev->context);
+		vmci_host_dev->context = NULL;
+		vmci_ioctl_err("error writing init block.\n");
+		retval = -EFAULT;
+		goto out;
+	}
+
+	ASSERT(init_block.cid != VMCI_INVALID_ID);
+	vmci_host_dev->ct_type = VMCIOBJ_CONTEXT;
+	atomic_inc(&vmci_host_active_users);
+
+	retval = 0;
+
+out:
+	mutex_unlock(&vmci_host_dev->lock);
+	return retval;
+}
+
+static int vmci_host_do_send_datagram(struct vmci_host_dev *vmci_host_dev,
+				      const char *ioctl_name,
+				      void __user *uptr)
+{
+	struct vmci_datagram_snd_rcv_info send_info;
+	struct vmci_datagram *dg = NULL;
+	u32 cid;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&send_info, uptr, sizeof(send_info)))
+		return -EFAULT;
+
+	if (send_info.len > VMCI_MAX_DG_SIZE) {
+		vmci_ioctl_err("datagram is too big (size=%d).\n",
+				send_info.len);
+		return -EINVAL;
+	}
+
+	if (send_info.len < sizeof(*dg)) {
+		vmci_ioctl_err("datagram is too small (size=%d).\n",
+				send_info.len);
+		return -EINVAL;
+	}
+
+	dg = kmalloc(send_info.len, GFP_KERNEL);
+	if (!dg) {
+		vmci_ioctl_err("cannot allocate memory to dispatch datagram.\n");
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(dg, (void __user *)(uintptr_t)send_info.addr,
+			   send_info.len)) {
+		vmci_ioctl_err("error getting datagram.\n");
+		kfree(dg);
+		return -EFAULT;
+	}
+
+	pr_devel("Datagram dst (handle=0x%x:0x%x) src (handle=0x%x:0x%x), payload (size=%llu bytes).\n",
+		 dg->dst.context, dg->dst.resource,
+		 dg->src.context, dg->src.resource,
+		 (unsigned long long)dg->payload_size);
+
+	/* Get source context id. */
+	ASSERT(vmci_host_dev->context);
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+	ASSERT(cid != VMCI_INVALID_ID);
+	send_info.result = vmci_datagram_dispatch(cid, dg, true);
+	kfree(dg);
+
+	return copy_to_user(uptr, &send_info, sizeof(send_info)) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_receive_datagram(struct vmci_host_dev *vmci_host_dev,
+					 const char *ioctl_name,
+					 void __user *uptr)
+{
+	struct vmci_datagram_snd_rcv_info recv_info;
+	struct vmci_datagram *dg = NULL;
+	int retval;
+	size_t size;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&recv_info, uptr, sizeof(recv_info)))
+		return -EFAULT;
+
+	ASSERT(vmci_host_dev->ct_type == VMCIOBJ_CONTEXT);
+	ASSERT(vmci_host_dev->context);
+	size = recv_info.len;
+	recv_info.result = vmci_ctx_dequeue_datagram(vmci_host_dev->context,
+						     &size, &dg);
+
+	if (recv_info.result >= VMCI_SUCCESS) {
+		ASSERT(dg);
+		retval = copy_to_user((void *)((uintptr_t)
+					       recv_info.addr),
+				      dg, VMCI_DG_SIZE(dg));
+		kfree(dg);
+		if (retval != 0)
+			return -EFAULT;
+	}
+
+	return copy_to_user(uptr, &recv_info, sizeof(recv_info)) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_alloc_queuepair(struct vmci_host_dev *vmci_host_dev,
+					const char *ioctl_name,
+					void __user *uptr)
+{
+	struct vmci_handle handle;
+	int vmci_status;
+	int __user *retptr;
+	u32 cid;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+
+	if (vmci_host_dev->user_version < VMCI_VERSION_NOVMVM) {
+		struct vmci_qp_alloc_info_vmvm alloc_info;
+		struct vmci_qp_alloc_info_vmvm __user *info = uptr;
+
+		if (copy_from_user(&alloc_info, uptr, sizeof(alloc_info)))
+			return -EFAULT;
+
+		handle = alloc_info.handle;
+		retptr = &info->result;
+
+		vmci_status = vmci_qp_broker_alloc(alloc_info.handle,
+						alloc_info.peer,
+						alloc_info.flags,
+						VMCI_NO_PRIVILEGE_FLAGS,
+						alloc_info.produce_size,
+						alloc_info.consume_size,
+						NULL,
+						vmci_host_dev->context);
+
+		if (vmci_status == VMCI_SUCCESS)
+			vmci_status = VMCI_SUCCESS_QUEUEPAIR_CREATE;
+	} else {
+		struct vmci_qp_alloc_info alloc_info;
+		struct vmci_qp_alloc_info __user *info = uptr;
+		struct vmci_qp_page_store page_store;
+
+		if (copy_from_user(&alloc_info, uptr, sizeof(alloc_info)))
+			return -EFAULT;
+
+		handle = alloc_info.handle;
+		retptr = &info->result;
+
+		page_store.pages = alloc_info.ppn_va;
+		page_store.len = alloc_info.num_ppns;
+
+		vmci_status = vmci_qp_broker_alloc(alloc_info.handle,
+						alloc_info.peer,
+						alloc_info.flags,
+						VMCI_NO_PRIVILEGE_FLAGS,
+						alloc_info.produce_size,
+						alloc_info.consume_size,
+						&page_store,
+						vmci_host_dev->context);
+	}
+
+	if (put_user(vmci_status, retptr)) {
+		if (vmci_status >= VMCI_SUCCESS) {
+			vmci_status = vmci_qp_broker_detach(handle,
+							vmci_host_dev->context);
+			BUG_ON(vmci_status < VMCI_SUCCESS);
+		}
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int vmci_host_do_queuepair_setva(struct vmci_host_dev *vmci_host_dev,
+					const char *ioctl_name,
+					void __user *uptr)
+{
+	struct vmci_qp_set_va_info set_va_info;
+	struct vmci_qp_set_va_info __user *info = uptr;
+	s32 result;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (vmci_host_dev->user_version < VMCI_VERSION_NOVMVM) {
+		vmci_ioctl_err("is not allowed.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&set_va_info, uptr, sizeof(set_va_info)))
+		return -EFAULT;
+
+	if (set_va_info.va) {
+		/*
+		 * VMX is passing down a new VA for the queue
+		 * pair mapping.
+		 */
+		result = vmci_qp_broker_map(set_va_info.handle,
+					    vmci_host_dev->context,
+					    set_va_info.va);
+	} else {
+		/*
+		 * The queue pair is about to be unmapped by
+		 * the VMX.
+		 */
+		result = vmci_qp_broker_unmap(set_va_info.handle,
+					 vmci_host_dev->context, 0);
+	}
+
+	return put_user(result, &info->result) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_queuepair_setpf(struct vmci_host_dev *vmci_host_dev,
+					const char *ioctl_name,
+					void __user *uptr)
+{
+	struct vmci_qp_page_file_info page_file_info;
+	struct vmci_qp_page_file_info __user *info = uptr;
+	s32 result;
+
+	if (vmci_host_dev->user_version < VMCI_VERSION_HOSTQP ||
+	    vmci_host_dev->user_version >= VMCI_VERSION_NOVMVM) {
+		vmci_ioctl_err("not supported on this VMX (version=%d).\n",
+				vmci_host_dev->user_version);
+		return -EINVAL;
+	}
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&page_file_info, uptr, sizeof(*info)))
+		return -EFAULT;
+
+	/*
+	 * Communicate success pre-emptively to the caller.  Note that the
+	 * basic premise is that it is incumbent upon the caller not to look at
+	 * the info.result field until after the ioctl() returns.  And then,
+	 * only if the ioctl() result indicates no error.  We send up the
+	 * SUCCESS status before calling SetPageStore() store because failing
+	 * to copy up the result code means unwinding the SetPageStore().
+	 *
+	 * It turns out the logic to unwind a SetPageStore() opens a can of
+	 * worms.  For example, if a host had created the queue_pair and a
+	 * guest attaches and SetPageStore() is successful but writing success
+	 * fails, then ... the host has to be stopped from writing (anymore)
+	 * data into the queue_pair.  That means an additional test in the
+	 * VMCI_Enqueue() code path.  Ugh.
+	 */
+
+	if (put_user(VMCI_SUCCESS, &info->result)) {
+		/*
+		 * In this case, we can't write a result field of the
+		 * caller's info block.  So, we don't even try to
+		 * SetPageStore().
+		 */
+		return -EFAULT;
+	}
+
+	result = vmci_qp_broker_set_page_store(page_file_info.handle,
+						page_file_info.produce_va,
+						page_file_info.consume_va,
+						vmci_host_dev->context);
+	if (result < VMCI_SUCCESS) {
+		if (put_user(result, &info->result)) {
+			/*
+			 * Note that in this case the SetPageStore()
+			 * call failed but we were unable to
+			 * communicate that to the caller (because the
+			 * copy_to_user() call failed).  So, if we
+			 * simply return an error (in this case
+			 * -EFAULT) then the caller will know that the
+			 *  SetPageStore failed even though we couldn't
+			 *  put the result code in the result field and
+			 *  indicate exactly why it failed.
+			 *
+			 * That says nothing about the issue where we
+			 * were once able to write to the caller's info
+			 * memory and now can't.  Something more
+			 * serious is probably going on than the fact
+			 * that SetPageStore() didn't work.
+			 */
+			return -EFAULT;
+		}
+	}
+
+	return 0;
+}
+
+static int vmci_host_do_qp_detach(struct vmci_host_dev *vmci_host_dev,
+				  const char *ioctl_name,
+				  void __user *uptr)
+{
+	struct vmci_qp_dtch_info detach_info;
+	struct vmci_qp_dtch_info __user *info = uptr;
+	s32 result;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&detach_info, uptr, sizeof(detach_info)))
+		return -EFAULT;
+
+	result = vmci_qp_broker_detach(detach_info.handle,
+				       vmci_host_dev->context);
+	if (result == VMCI_SUCCESS &&
+	    vmci_host_dev->user_version < VMCI_VERSION_NOVMVM) {
+		result = VMCI_SUCCESS_LAST_DETACH;
+	}
+
+	return put_user(result, &info->result) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_ctx_add_notify(struct vmci_host_dev *vmci_host_dev,
+				       const char *ioctl_name,
+				       void __user *uptr)
+{
+	struct vmci_ctx_info ar_info;
+	struct vmci_ctx_info __user *info = uptr;
+	s32 result;
+	u32 cid;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&ar_info, uptr, sizeof(ar_info)))
+		return -EFAULT;
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+	result = vmci_ctx_add_notification(cid, ar_info.remote_cid);
+
+	return put_user(result, &info->result) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_ctx_remove_notify(struct vmci_host_dev *vmci_host_dev,
+					  const char *ioctl_name,
+					  void __user *uptr)
+{
+	struct vmci_ctx_info ar_info;
+	struct vmci_ctx_info __user *info = uptr;
+	u32 cid;
+	int result;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&ar_info, uptr, sizeof(ar_info)))
+		return -EFAULT;
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+	result = vmci_ctx_remove_notification(cid,
+					      ar_info.remote_cid);
+
+	return put_user(result, &info->result) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_ctx_get_cpt_state(struct vmci_host_dev *vmci_host_dev,
+					  const char *ioctl_name,
+					  void __user *uptr)
+{
+	struct vmci_ctx_chkpt_buf_info get_info;
+	u32 cid;
+	void *cpt_buf;
+	int retval;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&get_info, uptr, sizeof(get_info)))
+		return -EFAULT;
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+	get_info.result = vmci_ctx_get_chkpt_state(cid, get_info.cpt_type,
+						&get_info.buf_size, &cpt_buf);
+	if (get_info.result == VMCI_SUCCESS && get_info.buf_size) {
+		retval = copy_to_user((void *)(uintptr_t)
+				      get_info.cpt_buf, cpt_buf,
+				      get_info.buf_size);
+		kfree(cpt_buf);
+
+		if (retval)
+			return -EFAULT;
+	}
+
+	return copy_to_user(uptr, &get_info, sizeof(get_info)) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_ctx_set_cpt_state(struct vmci_host_dev *vmci_host_dev,
+					  const char *ioctl_name,
+					  void __user *uptr)
+{
+	struct vmci_ctx_chkpt_buf_info set_info;
+	u32 cid;
+	void *cpt_buf;
+	int retval;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&set_info, uptr, sizeof(set_info)))
+		return -EFAULT;
+
+	cpt_buf = kmalloc(set_info.buf_size, GFP_KERNEL);
+	if (!cpt_buf) {
+		vmci_ioctl_err("cannot allocate memory to set cpt state (type=%d).\n",
+			set_info.cpt_type);
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(cpt_buf, (void __user *)(uintptr_t)set_info.cpt_buf,
+			   set_info.buf_size)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+	set_info.result = vmci_ctx_set_chkpt_state(cid, set_info.cpt_type,
+						   set_info.buf_size, cpt_buf);
+
+	retval = copy_to_user(uptr, &set_info, sizeof(set_info)) ? -EFAULT : 0;
+
+out:
+	kfree(cpt_buf);
+	return retval;
+}
+
+static int vmci_host_do_get_context_id(struct vmci_host_dev *vmci_host_dev,
+				       const char *ioctl_name,
+				       void __user *uptr)
+{
+	u32 __user *u32ptr = uptr;
+
+	return put_user(VMCI_HOST_CONTEXT_ID, u32ptr) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_set_notify(struct vmci_host_dev *vmci_host_dev,
+				   const char *ioctl_name,
+				   void __user *uptr)
+{
+	struct vmci_set_notify_info notify_info;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&notify_info, uptr, sizeof(notify_info)))
+		return -EFAULT;
+
+	if (notify_info.notify_uva) {
+		notify_info.result =
+			vmci_host_setup_notify(vmci_host_dev->context,
+					       notify_info.notify_uva);
+	} else {
+		vmci_ctx_unset_notify(vmci_host_dev->context);
+		notify_info.result = VMCI_SUCCESS;
+	}
+
+	return copy_to_user(uptr, &notify_info, sizeof(notify_info)) ?
+		-EFAULT : 0;
+}
+
+static int vmci_host_do_notify_resource(struct vmci_host_dev *vmci_host_dev,
+					const char *ioctl_name,
+					void __user *uptr)
+{
+	struct vmci_dbell_notify_resource_info info;
+	u32 cid;
+
+	if (vmci_host_dev->user_version < VMCI_VERSION_NOTIFY) {
+		vmci_ioctl_err("invalid for current VMX versions.\n");
+		return -EINVAL;
+	}
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&info, uptr, sizeof(info)))
+		return -EFAULT;
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+
+	switch (info.action) {
+	case VMCI_NOTIFY_RESOURCE_ACTION_NOTIFY:
+		if (info.resource == VMCI_NOTIFY_RESOURCE_DOOR_BELL) {
+			u32 flags = VMCI_NO_PRIVILEGE_FLAGS;
+			info.result = vmci_ctx_notify_dbell(cid, info.handle,
+							    flags);
+		} else {
+			info.result = VMCI_ERROR_UNAVAILABLE;
+		}
+		break;
+
+	case VMCI_NOTIFY_RESOURCE_ACTION_CREATE:
+		info.result = vmci_ctx_dbell_create(cid, info.handle);
+		break;
+
+	case VMCI_NOTIFY_RESOURCE_ACTION_DESTROY:
+		info.result = vmci_ctx_dbell_destroy(cid, info.handle);
+		break;
+
+	default:
+		vmci_ioctl_err("got unknown action (action=%d).\n",
+				info.action);
+		info.result = VMCI_ERROR_INVALID_ARGS;
+	}
+
+	return copy_to_user(uptr, &info, sizeof(info)) ? -EFAULT : 0;
+}
+
+static int vmci_host_do_recv_notifications(struct vmci_host_dev *vmci_host_dev,
+					   const char *ioctl_name,
+					   void __user *uptr)
+{
+	struct vmci_ctx_notify_recv_info info;
+	struct vmci_handle_arr *db_handle_array;
+	struct vmci_handle_arr *qp_handle_array;
+	u32 cid;
+	int retval;
+
+	if (vmci_host_dev->ct_type != VMCIOBJ_CONTEXT) {
+		vmci_ioctl_err("only valid for contexts.\n");
+		return -EINVAL;
+	}
+
+	if (vmci_host_dev->user_version < VMCI_VERSION_NOTIFY) {
+		vmci_ioctl_err("not supported for the current vmx version.\n");
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&info, uptr, sizeof(info)))
+		return -EFAULT;
+
+	if ((info.db_handle_buf_size && !info.db_handle_buf_uva) ||
+	    (info.qp_handle_buf_size && !info.qp_handle_buf_uva)) {
+		return -EINVAL;
+	}
+
+	cid = vmci_ctx_get_id(vmci_host_dev->context);
+
+	info.result = vmci_ctx_rcv_notifications_get(cid,
+				&db_handle_array, &qp_handle_array);
+	if (info.result != VMCI_SUCCESS)
+		return copy_to_user(uptr, &info, sizeof(info)) ? -EFAULT : 0;
+
+	info.result = drv_cp_harray_to_user((void *)(uintptr_t)
+				info.db_handle_buf_uva,
+				&info.db_handle_buf_size,
+				db_handle_array,
+				&retval);
+	if (info.result == VMCI_SUCCESS && !retval)
+		info.result = drv_cp_harray_to_user((void *)(uintptr_t)
+				info.qp_handle_buf_uva,
+				&info.qp_handle_buf_size,
+				qp_handle_array,
+				&retval);
+
+	if (!retval && copy_to_user(uptr, &info, sizeof(info)))
+		retval = -EFAULT;
+
+	vmci_ctx_rcv_notifications_release(cid,
+				db_handle_array, qp_handle_array,
+				info.result == VMCI_SUCCESS && !retval);
+
+	return retval;
+}
+
+
+static long vmci_host_unlocked_ioctl(struct file *filp,
+				     unsigned int iocmd, unsigned long ioarg)
+{
+#define VMCI_DO_IOCTL(ioctl_name, ioctl_fn)			\
+	case ioctl_name:					\
+		return ioctl_fn(vmci_host_dev,			\
+				__stringify(ioctl_name),	\
+				uptr)
+
+	struct vmci_host_dev *vmci_host_dev = filp->private_data;
+	void __user *uptr = (void __user *)ioarg;
+
+	switch (iocmd) {
+	VMCI_DO_IOCTL(IOCTL_VMCI_INIT_CONTEXT, vmci_host_do_init_context);
+	VMCI_DO_IOCTL(IOCTL_VMCI_DATAGRAM_SEND, vmci_host_do_send_datagram);
+	VMCI_DO_IOCTL(IOCTL_VMCI_DATAGRAM_RECEIVE,
+			vmci_host_do_receive_datagram);
+	VMCI_DO_IOCTL(IOCTL_VMCI_QUEUEPAIR_ALLOC, vmci_host_do_alloc_queuepair);
+	VMCI_DO_IOCTL(IOCTL_VMCI_QUEUEPAIR_SETVA, vmci_host_do_queuepair_setva);
+	VMCI_DO_IOCTL(IOCTL_VMCI_QUEUEPAIR_SETPAGEFILE,
+			vmci_host_do_queuepair_setpf);
+	VMCI_DO_IOCTL(IOCTL_VMCI_QUEUEPAIR_DETACH, vmci_host_do_qp_detach);
+	VMCI_DO_IOCTL(IOCTL_VMCI_CTX_ADD_NOTIFICATION,
+			vmci_host_do_ctx_add_notify);
+	VMCI_DO_IOCTL(IOCTL_VMCI_CTX_REMOVE_NOTIFICATION,
+			vmci_host_do_ctx_remove_notify);
+	VMCI_DO_IOCTL(IOCTL_VMCI_CTX_GET_CPT_STATE,
+			vmci_host_do_ctx_get_cpt_state);
+	VMCI_DO_IOCTL(IOCTL_VMCI_CTX_SET_CPT_STATE,
+			vmci_host_do_ctx_set_cpt_state);
+	VMCI_DO_IOCTL(IOCTL_VMCI_GET_CONTEXT_ID, vmci_host_do_get_context_id);
+	VMCI_DO_IOCTL(IOCTL_VMCI_SET_NOTIFY, vmci_host_do_set_notify);
+	VMCI_DO_IOCTL(IOCTL_VMCI_NOTIFY_RESOURCE, vmci_host_do_notify_resource);
+	VMCI_DO_IOCTL(IOCTL_VMCI_NOTIFICATIONS_RECEIVE,
+			vmci_host_do_recv_notifications);
+
+	case IOCTL_VMCI_VERSION:
+	case IOCTL_VMCI_VERSION2:
+		return vmci_host_get_version(vmci_host_dev, iocmd, uptr);
+
+	default:
+		pr_devel("%s: Unknown ioctl (iocmd=%d).\n", __func__, iocmd);
+		return -EINVAL;
+	}
+
+#undef VMCI_DO_IOCTL
+}
+
+static const struct file_operations vmuser_fops = {
+	.owner		= THIS_MODULE,
+	.open		= vmci_host_open,
+	.release	= vmci_host_close,
+	.poll		= vmci_host_poll,
+	.unlocked_ioctl	= vmci_host_unlocked_ioctl,
+	.compat_ioctl	= vmci_host_unlocked_ioctl,
+};
+
+static struct miscdevice vmci_host_miscdev = {
+	 .name = MODULE_NAME,
+	 .minor = MISC_DYNAMIC_MINOR,
+	 .fops = &vmuser_fops,
+};
+
+int __init vmci_host_init(void)
+{
+	int error;
+	int result;
+
+	result = vmci_ctx_init_ctx(VMCI_HOST_CONTEXT_ID,
+				   VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS,
+				   -1, VMCI_VERSION, NULL, &host_context);
+	if (result < VMCI_SUCCESS) {
+		pr_warn("Failed to initialize VMCIContext (result=%d).\n",
+			result);
+		return -ENOMEM;
+	}
+
+	error = misc_register(&vmci_host_miscdev);
+	if (error) {
+		pr_warn("Module registration error (name=%s, major=%d, minor=%d, err=%d).\n",
+			vmci_host_miscdev.name,
+			MISC_MAJOR, vmci_host_miscdev.minor,
+			error);
+		pr_warn("Unable to initialize host personality\n");
+		vmci_ctx_release_ctx(host_context);
+		return error;
+	}
+
+	pr_info("VMCI host device registered (name=%s, major=%d, minor=%d).\n",
+		vmci_host_miscdev.name, MISC_MAJOR, vmci_host_miscdev.minor);
+
+	vmci_host_device_initialized = true;
+	return 0;
+}
+
+void __exit vmci_host_exit(void)
+{
+	int error;
+
+	vmci_host_device_initialized = false;
+
+	error = misc_deregister(&vmci_host_miscdev);
+	if (error)
+		pr_warn("Error unregistering character device: %d\n", error);
+
+	vmci_ctx_release_ctx(host_context);
+	vmci_qp_broker_exit();
+
+	pr_debug("VMCI host driver module unloaded\n");
+}