VMCI: host side driver implementation.

VMCI host side driver code implementation.

Signed-off-by: George Zhang <georgezhang@vmware.com>
Acked-by: Andy king <acking@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1042 insertions, 0 deletions

diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c
new file mode 100644
index 000000000000..16e7f547555f
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_host.c
@@ -0,0 +1,1042 @@
+/*
+ * 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_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.  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;
+        }
+
+        /*
+         * 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.
+         */
+        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 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");
+}