/*
 * 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;
        }

        if (VMCI_DG_SIZE(dg) != send_info.len) {
                vmci_ioctl_err("datagram size mismatch\n");
                kfree(dg);
                return -EINVAL;
        }

        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");
}