text: /*
   * 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/slab.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_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;
  
  	if (vmci_host_dev->ct_type == VMCIOBJ_CONTEXT) {
  		vmci_ctx_destroy(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) {
  		/* 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. Maps the notify
   * boolean in user VA into kernel space.
   */
  static int vmci_host_setup_notify(struct vmci_ctx *context,
  				  unsigned long uva)
  {
  	int retval;
  
  	if (context->notify_page) {
  		pr_devel("%s: Notify mechanism is already set up\n", __func__);
  		return VMCI_ERROR_DUPLICATE_ENTRY;
  	}
  
  	/*
  	 * We are using 'bool' internally, but let's make sure we explicit
  	 * about the size.
  	 */
  	BUILD_BUG_ON(sizeof(bool) != sizeof(u8));
  	if (!access_ok(VERIFY_WRITE, (void __user *)uva, sizeof(u8)))
  		return VMCI_ERROR_GENERIC;
  
  	/*
  	 * Lock physical page backing a given user VA.
  	 */
  	retval = get_user_pages_fast(uva, 1, 1, &context->notify_page);
  	if (retval != 1) {
  		context->notify_page = NULL;
  		return VMCI_ERROR_GENERIC;
  	}
  
  	/*
  	 * Map the locked page and set up notify pointer.
  	 */
  	context->notify = kmap(context->notify_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 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_host_dev->context = vmci_ctx_create(init_block.cid,
  						 init_block.flags, 0,
  						 vmci_host_dev->user_version,
  						 cred);
  	put_cred(cred);
  	if (IS_ERR(vmci_host_dev->context)) {
  		retval = PTR_ERR(vmci_host_dev->context);
  		vmci_ioctl_err("error initializing context\n");
  		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_destroy(vmci_host_dev->context);
  		vmci_host_dev->context = NULL;
  		vmci_ioctl_err("error writing init block\n");
  		retval = -EFAULT;
  		goto out;
  	}
  
  	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. */
  	cid = vmci_ctx_get_id(vmci_host_dev->context);
  	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;
  
  	size = recv_info.len;
  	recv_info.result = vmci_ctx_dequeue_datagram(vmci_host_dev->context,
  						     &size, &dg);
  
  	if (recv_info.result >= VMCI_SUCCESS) {
  		void __user *ubuf = (void __user *)(uintptr_t)recv_info.addr;
  		retval = copy_to_user(ubuf, 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);
  		}
  		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) {
  		void __user *ubuf = (void __user *)(uintptr_t)get_info.cpt_buf;
  		retval = copy_to_user(ubuf, 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;
  	void __user *ubuf;
  	u32 cid;
  	int retval = 0;
  
  	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;
  
  	ubuf = (void __user *)(uintptr_t)info.db_handle_buf_uva;
  	info.result = drv_cp_harray_to_user(ubuf, &info.db_handle_buf_size,
  					    db_handle_array, &retval);
  	if (info.result == VMCI_SUCCESS && !retval) {
  		ubuf = (void __user *)(uintptr_t)info.qp_handle_buf_uva;
  		info.result = drv_cp_harray_to_user(ubuf,
  						    &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) do {			\
  		char *name = __stringify(IOCTL_VMCI_ ## ioctl_name);	\
  		return vmci_host_do_ ## ioctl_fn(			\
  			vmci_host_dev, name, uptr);			\
  	} while (0)
  
  	struct vmci_host_dev *vmci_host_dev = filp->private_data;
  	void __user *uptr = (void __user *)ioarg;
  
  	switch (iocmd) {
  	case IOCTL_VMCI_INIT_CONTEXT:
  		VMCI_DO_IOCTL(INIT_CONTEXT, init_context);
  	case IOCTL_VMCI_DATAGRAM_SEND:
  		VMCI_DO_IOCTL(DATAGRAM_SEND, send_datagram);
  	case IOCTL_VMCI_DATAGRAM_RECEIVE:
  		VMCI_DO_IOCTL(DATAGRAM_RECEIVE, receive_datagram);
  	case IOCTL_VMCI_QUEUEPAIR_ALLOC:
  		VMCI_DO_IOCTL(QUEUEPAIR_ALLOC, alloc_queuepair);
  	case IOCTL_VMCI_QUEUEPAIR_SETVA:
  		VMCI_DO_IOCTL(QUEUEPAIR_SETVA, queuepair_setva);
  	case IOCTL_VMCI_QUEUEPAIR_SETPAGEFILE:
  		VMCI_DO_IOCTL(QUEUEPAIR_SETPAGEFILE, queuepair_setpf);
  	case IOCTL_VMCI_QUEUEPAIR_DETACH:
  		VMCI_DO_IOCTL(QUEUEPAIR_DETACH, qp_detach);
  	case IOCTL_VMCI_CTX_ADD_NOTIFICATION:
  		VMCI_DO_IOCTL(CTX_ADD_NOTIFICATION, ctx_add_notify);
  	case IOCTL_VMCI_CTX_REMOVE_NOTIFICATION:
  		VMCI_DO_IOCTL(CTX_REMOVE_NOTIFICATION, ctx_remove_notify);
  	case IOCTL_VMCI_CTX_GET_CPT_STATE:
  		VMCI_DO_IOCTL(CTX_GET_CPT_STATE, ctx_get_cpt_state);
  	case IOCTL_VMCI_CTX_SET_CPT_STATE:
  		VMCI_DO_IOCTL(CTX_SET_CPT_STATE, ctx_set_cpt_state);
  	case IOCTL_VMCI_GET_CONTEXT_ID:
  		VMCI_DO_IOCTL(GET_CONTEXT_ID, get_context_id);
  	case IOCTL_VMCI_SET_NOTIFY:
  		VMCI_DO_IOCTL(SET_NOTIFY, set_notify);
  	case IOCTL_VMCI_NOTIFY_RESOURCE:
  		VMCI_DO_IOCTL(NOTIFY_RESOURCE, notify_resource);
  	case IOCTL_VMCI_NOTIFICATIONS_RECEIVE:
  		VMCI_DO_IOCTL(NOTIFICATIONS_RECEIVE, 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 = "vmci",
  	 .minor = MISC_DYNAMIC_MINOR,
  	 .fops = &vmuser_fops,
  };
  
  int __init vmci_host_init(void)
  {
  	int error;
  
  	host_context = vmci_ctx_create(VMCI_HOST_CONTEXT_ID,
  					VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS,
  					-1, VMCI_VERSION, NULL);
  	if (IS_ERR(host_context)) {
  		error = PTR_ERR(host_context);
  		pr_warn("Failed to initialize VMCIContext (error%d)\n",
  			error);
  		return error;
  	}
  
  	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_destroy(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_destroy(host_context);
  	vmci_qp_broker_exit();
  
  	pr_debug("VMCI host driver module unloaded\n");
  }
  