Quelle  vboxguest_utils.c   Sprache: C

/* SPDX-License-Identifier: (GPL-2.0 OR CDDL-1.0) */
/*
 * vboxguest vmm-req and hgcm-call code, VBoxGuestR0LibHGCMInternal.cpp,
 * VBoxGuestR0LibGenericRequest.cpp and RTErrConvertToErrno.cpp in vbox svn.
 *
 * Copyright (C) 2006-2016 Oracle Corporation
 */

#include <linux/errno.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/vbox_err.h>
#include <linux/vbox_utils.h>
#include "vboxguest_core.h"

/* Get the pointer to the first parameter of a HGCM call request. */
#define VMMDEV_HGCM_CALL_PARMS(a) \
 ((struct vmmdev_hgcm_function_parameter *)( \
  (u8 *)(a) + sizeof(struct vmmdev_hgcm_call)))

/* The max parameter buffer size for a user request. */
#define VBG_MAX_HGCM_USER_PARM  (24 * SZ_1M)
/* The max parameter buffer size for a kernel request. */
#define VBG_MAX_HGCM_KERNEL_PARM (16 * SZ_1M)

#define VBG_DEBUG_PORT   0x504

/* This protects vbg_log_buf and serializes VBG_DEBUG_PORT accesses */
static DEFINE_SPINLOCK(vbg_log_lock);
static char vbg_log_buf[128];

#define VBG_LOG(name, pr_func) \
void name(const char *fmt, ...)      \
{         \
 unsigned long flags;      \
 va_list args;       \
 int i, count;       \
         \
 va_start(args, fmt);      \
 spin_lock_irqsave(&vbg_log_lock, flags);   \
         \
 count = vscnprintf(vbg_log_buf, sizeof(vbg_log_buf), fmt, args);\
 for (i = 0; i < count; i++)     \
  outb(vbg_log_buf[i], VBG_DEBUG_PORT);   \
         \
 pr_func("%s", vbg_log_buf);     \
         \
 spin_unlock_irqrestore(&vbg_log_lock, flags);   \
 va_end(args);       \
}         \
EXPORT_SYMBOL(name)

VBG_LOG(vbg_info, pr_info);
VBG_LOG(vbg_warn, pr_warn);
VBG_LOG(vbg_err, pr_err);
VBG_LOG(vbg_err_ratelimited, pr_err_ratelimited);
#if defined(DEBUG) && !defined(CONFIG_DYNAMIC_DEBUG)
VBG_LOG(vbg_debug, pr_debug);
#endif

void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type,
      u32 requestor)
{
 struct vmmdev_request_header *req;
 int order = get_order(PAGE_ALIGN(len));

 req = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA32, order);
 if (!req)
  return NULL;

 memset(req, 0xaa, len);

 req->size = len;
 req->version = VMMDEV_REQUEST_HEADER_VERSION;
 req->request_type = req_type;
 req->rc = VERR_GENERAL_FAILURE;
 req->reserved1 = 0;
 req->requestor = requestor;

 return req;
}

void vbg_req_free(void *req, size_t len)
{
 if (!req)
  return;

 free_pages((unsigned long)req, get_order(PAGE_ALIGN(len)));
}

/* Note this function returns a VBox status code, not a negative errno!! */
int vbg_req_perform(struct vbg_dev *gdev, void *req)
{
 unsigned long phys_req = virt_to_phys(req);

 outl(phys_req, gdev->io_port + VMMDEV_PORT_OFF_REQUEST);
 /*
 * The host changes the request as a result of the outl, make sure
 * the outl and any reads of the req happen in the correct order.
 */
 mb();

 return ((struct vmmdev_request_header *)req)->rc;
}

static bool hgcm_req_done(struct vbg_dev *gdev,
     struct vmmdev_hgcmreq_header *header)
{
 unsigned long flags;
 bool done;

 spin_lock_irqsave(&gdev->event_spinlock, flags);
 done = header->flags & VMMDEV_HGCM_REQ_DONE;
 spin_unlock_irqrestore(&gdev->event_spinlock, flags);

 return done;
}

int vbg_hgcm_connect(struct vbg_dev *gdev, u32 requestor,
       struct vmmdev_hgcm_service_location *loc,
       u32 *client_id, int *vbox_status)
{
 struct vmmdev_hgcm_connect *hgcm_connect = NULL;
 int rc;

 hgcm_connect = vbg_req_alloc(sizeof(*hgcm_connect),
         VMMDEVREQ_HGCM_CONNECT, requestor);
 if (!hgcm_connect)
  return -ENOMEM;

 hgcm_connect->header.flags = 0;
 memcpy(&hgcm_connect->loc, loc, sizeof(*loc));
 hgcm_connect->client_id = 0;

 rc = vbg_req_perform(gdev, hgcm_connect);

 if (rc == VINF_HGCM_ASYNC_EXECUTE)
  wait_event(gdev->hgcm_wq,
      hgcm_req_done(gdev, &hgcm_connect->header));

 if (rc >= 0) {
  *client_id = hgcm_connect->client_id;
  rc = hgcm_connect->header.result;
 }

 vbg_req_free(hgcm_connect, sizeof(*hgcm_connect));

 *vbox_status = rc;
 return 0;
}
EXPORT_SYMBOL(vbg_hgcm_connect);

int vbg_hgcm_disconnect(struct vbg_dev *gdev, u32 requestor,
   u32 client_id, int *vbox_status)
{
 struct vmmdev_hgcm_disconnect *hgcm_disconnect = NULL;
 int rc;

 hgcm_disconnect = vbg_req_alloc(sizeof(*hgcm_disconnect),
     VMMDEVREQ_HGCM_DISCONNECT,
     requestor);
 if (!hgcm_disconnect)
  return -ENOMEM;

 hgcm_disconnect->header.flags = 0;
 hgcm_disconnect->client_id = client_id;

 rc = vbg_req_perform(gdev, hgcm_disconnect);

 if (rc == VINF_HGCM_ASYNC_EXECUTE)
  wait_event(gdev->hgcm_wq,
      hgcm_req_done(gdev, &hgcm_disconnect->header));

 if (rc >= 0)
  rc = hgcm_disconnect->header.result;

 vbg_req_free(hgcm_disconnect, sizeof(*hgcm_disconnect));

 *vbox_status = rc;
 return 0;
}
EXPORT_SYMBOL(vbg_hgcm_disconnect);

static u32 hgcm_call_buf_size_in_pages(void *buf, u32 len)
{
 u32 size = PAGE_ALIGN(len + ((unsigned long)buf & ~PAGE_MASK));

 return size >> PAGE_SHIFT;
}

static void hgcm_call_add_pagelist_size(void *buf, u32 len, size_t *extra)
{
 u32 page_count;

 page_count = hgcm_call_buf_size_in_pages(buf, len);
 *extra += offsetof(struct vmmdev_hgcm_pagelist, pages[page_count]);
}

static int hgcm_call_preprocess_linaddr(
 const struct vmmdev_hgcm_function_parameter *src_parm,
 void **bounce_buf_ret, size_t *extra)
{
 void *buf, *bounce_buf;
 bool copy_in;
 u32 len;
 int ret;

 buf = (void *)src_parm->u.pointer.u.linear_addr;
 len = src_parm->u.pointer.size;
 copy_in = src_parm->type != VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT;

 if (len > VBG_MAX_HGCM_USER_PARM)
  return -E2BIG;

 bounce_buf = kvmalloc(len, GFP_KERNEL);
 if (!bounce_buf)
  return -ENOMEM;

 *bounce_buf_ret = bounce_buf;

 if (copy_in) {
  ret = copy_from_user(bounce_buf, (void __user *)buf, len);
  if (ret)
   return -EFAULT;
 } else {
  memset(bounce_buf, 0, len);
 }

 hgcm_call_add_pagelist_size(bounce_buf, len, extra);
 return 0;
}

/**
 * hgcm_call_preprocess - Preprocesses the HGCM call, validate parameters,
 * alloc bounce buffers and figure out how much extra storage we need for
 * page lists.
 * @src_parm:         Pointer to source function call parameters
 * @parm_count:       Number of function call parameters.
 * @bounce_bufs_ret:  Where to return the allocated bouncebuffer array
 * @extra:            Where to return the extra request space needed for
 *                    physical page lists.
 *
 * Return: %0 or negative errno value.
 */
static int hgcm_call_preprocess(
 const struct vmmdev_hgcm_function_parameter *src_parm,
 u32 parm_count, void ***bounce_bufs_ret, size_t *extra)
{
 void *buf, **bounce_bufs = NULL;
 u32 i, len;
 int ret;

 for (i = 0; i < parm_count; i++, src_parm++) {
  switch (src_parm->type) {
  case VMMDEV_HGCM_PARM_TYPE_32BIT:
  case VMMDEV_HGCM_PARM_TYPE_64BIT:
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
   if (!bounce_bufs) {
    bounce_bufs = kcalloc(parm_count,
            sizeof(void *),
            GFP_KERNEL);
    if (!bounce_bufs)
     return -ENOMEM;

    *bounce_bufs_ret = bounce_bufs;
   }

   ret = hgcm_call_preprocess_linaddr(src_parm,
          &bounce_bufs[i],
          extra);
   if (ret)
    return ret;

   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT:
   buf = (void *)src_parm->u.pointer.u.linear_addr;
   len = src_parm->u.pointer.size;
   if (WARN_ON(len > VBG_MAX_HGCM_KERNEL_PARM))
    return -E2BIG;

   hgcm_call_add_pagelist_size(buf, len, extra);
   break;

  default:
   return -EINVAL;
  }
 }

 return 0;
}

/**
 * hgcm_call_linear_addr_type_to_pagelist_flags - Translates linear address
 * types to page list direction flags.
 * @type:  The type.
 *
 * Return: page list flags.
 */
static u32 hgcm_call_linear_addr_type_to_pagelist_flags(
 enum vmmdev_hgcm_function_parameter_type type)
{
 switch (type) {
 default:
  WARN_ON(1);
  fallthrough;
 case VMMDEV_HGCM_PARM_TYPE_LINADDR:
 case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL:
  return VMMDEV_HGCM_F_PARM_DIRECTION_BOTH;

 case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
 case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN:
  return VMMDEV_HGCM_F_PARM_DIRECTION_TO_HOST;

 case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
 case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT:
  return VMMDEV_HGCM_F_PARM_DIRECTION_FROM_HOST;
 }
}

static void hgcm_call_init_linaddr(struct vmmdev_hgcm_call *call,
 struct vmmdev_hgcm_function_parameter *dst_parm, void *buf, u32 len,
 enum vmmdev_hgcm_function_parameter_type type, u32 *off_extra)
{
 struct vmmdev_hgcm_pagelist *dst_pg_lst;
 struct page *page;
 bool is_vmalloc;
 u32 i, page_count;

 dst_parm->type = type;

 if (len == 0) {
  dst_parm->u.pointer.size = 0;
  dst_parm->u.pointer.u.linear_addr = 0;
  return;
 }

 dst_pg_lst = (void *)call + *off_extra;
 page_count = hgcm_call_buf_size_in_pages(buf, len);
 is_vmalloc = is_vmalloc_addr(buf);

 dst_parm->type = VMMDEV_HGCM_PARM_TYPE_PAGELIST;
 dst_parm->u.page_list.size = len;
 dst_parm->u.page_list.offset = *off_extra;
 dst_pg_lst->flags = hgcm_call_linear_addr_type_to_pagelist_flags(type);
 dst_pg_lst->offset_first_page = (unsigned long)buf & ~PAGE_MASK;
 dst_pg_lst->page_count = page_count;

 for (i = 0; i < page_count; i++) {
  if (is_vmalloc)
   page = vmalloc_to_page(buf);
  else
   page = virt_to_page(buf);

  dst_pg_lst->pages[i] = page_to_phys(page);
  buf += PAGE_SIZE;
 }

 *off_extra += offsetof(struct vmmdev_hgcm_pagelist, pages[page_count]);
}

/**
 * hgcm_call_init_call - Initializes the call request that we're sending
 * to the host.
 * @call:            The call to initialize.
 * @client_id:       The client ID of the caller.
 * @function:        The function number of the function to call.
 * @src_parm:        Pointer to source function call parameters.
 * @parm_count:      Number of function call parameters.
 * @bounce_bufs:     The bouncebuffer array.
 */
static void hgcm_call_init_call(
 struct vmmdev_hgcm_call *call, u32 client_id, u32 function,
 const struct vmmdev_hgcm_function_parameter *src_parm,
 u32 parm_count, void **bounce_bufs)
{
 struct vmmdev_hgcm_function_parameter *dst_parm =
  VMMDEV_HGCM_CALL_PARMS(call);
 u32 i, off_extra = (uintptr_t)(dst_parm + parm_count) - (uintptr_t)call;
 void *buf;

 call->header.flags = 0;
 call->header.result = VINF_SUCCESS;
 call->client_id = client_id;
 call->function = function;
 call->parm_count = parm_count;

 for (i = 0; i < parm_count; i++, src_parm++, dst_parm++) {
  switch (src_parm->type) {
  case VMMDEV_HGCM_PARM_TYPE_32BIT:
  case VMMDEV_HGCM_PARM_TYPE_64BIT:
   *dst_parm = *src_parm;
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
   hgcm_call_init_linaddr(call, dst_parm, bounce_bufs[i],
            src_parm->u.pointer.size,
            src_parm->type, &off_extra);
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT:
   buf = (void *)src_parm->u.pointer.u.linear_addr;
   hgcm_call_init_linaddr(call, dst_parm, buf,
            src_parm->u.pointer.size,
            src_parm->type, &off_extra);
   break;

  default:
   WARN_ON(1);
   dst_parm->type = VMMDEV_HGCM_PARM_TYPE_INVALID;
  }
 }
}

/**
 * hgcm_cancel_call - Tries to cancel a pending HGCM call.
 * @gdev:        The VBoxGuest device extension.
 * @call:        The call to cancel.
 *
 * Return: VBox status code
 */
static int hgcm_cancel_call(struct vbg_dev *gdev, struct vmmdev_hgcm_call *call)
{
 int rc;

 /*
 * We use a pre-allocated request for cancellations, which is
 * protected by cancel_req_mutex. This means that all cancellations
 * get serialized, this should be fine since they should be rare.
 */
 mutex_lock(&gdev->cancel_req_mutex);
 gdev->cancel_req->phys_req_to_cancel = virt_to_phys(call);
 rc = vbg_req_perform(gdev, gdev->cancel_req);
 mutex_unlock(&gdev->cancel_req_mutex);

 if (rc == VERR_NOT_IMPLEMENTED) {
  call->header.flags |= VMMDEV_HGCM_REQ_CANCELLED;
  call->header.header.request_type = VMMDEVREQ_HGCM_CANCEL;

  rc = vbg_req_perform(gdev, call);
  if (rc == VERR_INVALID_PARAMETER)
   rc = VERR_NOT_FOUND;
 }

 if (rc >= 0)
  call->header.flags |= VMMDEV_HGCM_REQ_CANCELLED;

 return rc;
}

/**
 * vbg_hgcm_do_call - Performs the call and completion wait.
 * @gdev:        The VBoxGuest device extension.
 * @call:        The call to execute.
 * @timeout_ms:  Timeout in ms.
 * @interruptible: whether this call is interruptible
 * @leak_it:     Where to return the leak it / free it, indicator.
 *               Cancellation fun.
 *
 * Return: %0 or negative errno value.
 */
static int vbg_hgcm_do_call(struct vbg_dev *gdev, struct vmmdev_hgcm_call *call,
       u32 timeout_ms, bool interruptible, bool *leak_it)
{
 int rc, cancel_rc, ret;
 long timeout;

 *leak_it = false;

 rc = vbg_req_perform(gdev, call);

 /*
 * If the call failed, then pretend success. Upper layers will
 * interpret the result code in the packet.
 */
 if (rc < 0) {
  call->header.result = rc;
  return 0;
 }

 if (rc != VINF_HGCM_ASYNC_EXECUTE)
  return 0;

 /* Host decided to process the request asynchronously, wait for it */
 if (timeout_ms == U32_MAX)
  timeout = MAX_SCHEDULE_TIMEOUT;
 else
  timeout = msecs_to_jiffies(timeout_ms);

 if (interruptible) {
  timeout = wait_event_interruptible_timeout(gdev->hgcm_wq,
          hgcm_req_done(gdev, &call->header),
          timeout);
 } else {
  timeout = wait_event_timeout(gdev->hgcm_wq,
          hgcm_req_done(gdev, &call->header),
          timeout);
 }

 /* timeout > 0 means hgcm_req_done has returned true, so success */
 if (timeout > 0)
  return 0;

 if (timeout == 0)
  ret = -ETIMEDOUT;
 else
  ret = -EINTR;

 /* Cancel the request */
 cancel_rc = hgcm_cancel_call(gdev, call);
 if (cancel_rc >= 0)
  return ret;

 /*
 * Failed to cancel, this should mean that the cancel has lost the
 * race with normal completion, wait while the host completes it.
 */
 if (cancel_rc == VERR_NOT_FOUND || cancel_rc == VERR_SEM_DESTROYED)
  timeout = msecs_to_jiffies(500);
 else
  timeout = msecs_to_jiffies(2000);

 timeout = wait_event_timeout(gdev->hgcm_wq,
         hgcm_req_done(gdev, &call->header),
         timeout);

 if (WARN_ON(timeout == 0)) {
  /* We really should never get here */
  vbg_err("%s: Call timedout and cancellation failed, leaking the request\n",
   __func__);
  *leak_it = true;
  return ret;
 }

 /* The call has completed normally after all */
 return 0;
}

/**
 * hgcm_call_copy_back_result - Copies the result of the call back to
 * the caller info structure and user buffers.
 * @call:            HGCM call request.
 * @dst_parm:        Pointer to function call parameters destination.
 * @parm_count:      Number of function call parameters.
 * @bounce_bufs:     The bouncebuffer array.
 *
 * Return: %0 or negative errno value.
 */
static int hgcm_call_copy_back_result(
 const struct vmmdev_hgcm_call *call,
 struct vmmdev_hgcm_function_parameter *dst_parm,
 u32 parm_count, void **bounce_bufs)
{
 const struct vmmdev_hgcm_function_parameter *src_parm =
  VMMDEV_HGCM_CALL_PARMS(call);
 void __user *p;
 int ret;
 u32 i;

 /* Copy back parameters. */
 for (i = 0; i < parm_count; i++, src_parm++, dst_parm++) {
  switch (dst_parm->type) {
  case VMMDEV_HGCM_PARM_TYPE_32BIT:
  case VMMDEV_HGCM_PARM_TYPE_64BIT:
   *dst_parm = *src_parm;
   break;

  case VMMDEV_HGCM_PARM_TYPE_PAGELIST:
   dst_parm->u.page_list.size = src_parm->u.page_list.size;
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_IN:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_KERNEL_OUT:
   dst_parm->u.pointer.size = src_parm->u.pointer.size;
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
   dst_parm->u.pointer.size = src_parm->u.pointer.size;

   p = (void __user *)dst_parm->u.pointer.u.linear_addr;
   ret = copy_to_user(p, bounce_bufs[i],
        min(src_parm->u.pointer.size,
            dst_parm->u.pointer.size));
   if (ret)
    return -EFAULT;
   break;

  default:
   WARN_ON(1);
   return -EINVAL;
  }
 }

 return 0;
}

int vbg_hgcm_call(struct vbg_dev *gdev, u32 requestor, u32 client_id,
    u32 function, u32 timeout_ms,
    struct vmmdev_hgcm_function_parameter *parms, u32 parm_count,
    int *vbox_status)
{
 struct vmmdev_hgcm_call *call;
 void **bounce_bufs = NULL;
 bool leak_it;
 size_t size;
 int i, ret;

 size = sizeof(struct vmmdev_hgcm_call) +
     parm_count * sizeof(struct vmmdev_hgcm_function_parameter);
 /*
 * Validate and buffer the parameters for the call. This also increases
 * call_size with the amount of extra space needed for page lists.
 */
 ret = hgcm_call_preprocess(parms, parm_count, &bounce_bufs, &size);
 if (ret) {
  /* Even on error bounce bufs may still have been allocated */
  goto free_bounce_bufs;
 }

 call = vbg_req_alloc(size, VMMDEVREQ_HGCM_CALL, requestor);
 if (!call) {
  ret = -ENOMEM;
  goto free_bounce_bufs;
 }

 hgcm_call_init_call(call, client_id, function, parms, parm_count,
       bounce_bufs);

 ret = vbg_hgcm_do_call(gdev, call, timeout_ms,
          requestor & VMMDEV_REQUESTOR_USERMODE, &leak_it);
 if (ret == 0) {
  *vbox_status = call->header.result;
  ret = hgcm_call_copy_back_result(call, parms, parm_count,
       bounce_bufs);
 }

 if (!leak_it)
  vbg_req_free(call, size);

free_bounce_bufs:
 if (bounce_bufs) {
  for (i = 0; i < parm_count; i++)
   kvfree(bounce_bufs[i]);
  kfree(bounce_bufs);
 }

 return ret;
}
EXPORT_SYMBOL(vbg_hgcm_call);

#ifdef CONFIG_COMPAT
int vbg_hgcm_call32(
 struct vbg_dev *gdev, u32 requestor, u32 client_id, u32 function,
 u32 timeout_ms, struct vmmdev_hgcm_function_parameter32 *parm32,
 u32 parm_count, int *vbox_status)
{
 struct vmmdev_hgcm_function_parameter *parm64 = NULL;
 u32 i, size;
 int ret = 0;

 /* KISS allocate a temporary request and convert the parameters. */
 size = parm_count * sizeof(struct vmmdev_hgcm_function_parameter);
 parm64 = kzalloc(size, GFP_KERNEL);
 if (!parm64)
  return -ENOMEM;

 for (i = 0; i < parm_count; i++) {
  switch (parm32[i].type) {
  case VMMDEV_HGCM_PARM_TYPE_32BIT:
   parm64[i].type = VMMDEV_HGCM_PARM_TYPE_32BIT;
   parm64[i].u.value32 = parm32[i].u.value32;
   break;

  case VMMDEV_HGCM_PARM_TYPE_64BIT:
   parm64[i].type = VMMDEV_HGCM_PARM_TYPE_64BIT;
   parm64[i].u.value64 = parm32[i].u.value64;
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
   parm64[i].type = parm32[i].type;
   parm64[i].u.pointer.size = parm32[i].u.pointer.size;
   parm64[i].u.pointer.u.linear_addr =
       parm32[i].u.pointer.u.linear_addr;
   break;

  default:
   ret = -EINVAL;
  }
  if (ret < 0)
   goto out_free;
 }

 ret = vbg_hgcm_call(gdev, requestor, client_id, function, timeout_ms,
       parm64, parm_count, vbox_status);
 if (ret < 0)
  goto out_free;

 /* Copy back. */
 for (i = 0; i < parm_count; i++, parm32++, parm64++) {
  switch (parm64[i].type) {
  case VMMDEV_HGCM_PARM_TYPE_32BIT:
   parm32[i].u.value32 = parm64[i].u.value32;
   break;

  case VMMDEV_HGCM_PARM_TYPE_64BIT:
   parm32[i].u.value64 = parm64[i].u.value64;
   break;

  case VMMDEV_HGCM_PARM_TYPE_LINADDR_OUT:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR:
  case VMMDEV_HGCM_PARM_TYPE_LINADDR_IN:
   parm32[i].u.pointer.size = parm64[i].u.pointer.size;
   break;

  default:
   WARN_ON(1);
   ret = -EINVAL;
  }
 }

out_free:
 kfree(parm64);
 return ret;
}
#endif

static const int vbg_status_code_to_errno_table[] = {
 [-VERR_ACCESS_DENIED]                            = -EPERM,
 [-VERR_FILE_NOT_FOUND]                           = -ENOENT,
 [-VERR_PROCESS_NOT_FOUND]                        = -ESRCH,
 [-VERR_INTERRUPTED]                              = -EINTR,
 [-VERR_DEV_IO_ERROR]                             = -EIO,
 [-VERR_TOO_MUCH_DATA]                            = -E2BIG,
 [-VERR_BAD_EXE_FORMAT]                           = -ENOEXEC,
 [-VERR_INVALID_HANDLE]                           = -EBADF,
 [-VERR_TRY_AGAIN]                                = -EAGAIN,
 [-VERR_NO_MEMORY]                                = -ENOMEM,
 [-VERR_INVALID_POINTER]                          = -EFAULT,
 [-VERR_RESOURCE_BUSY]                            = -EBUSY,
 [-VERR_ALREADY_EXISTS]                           = -EEXIST,
 [-VERR_NOT_SAME_DEVICE]                          = -EXDEV,
 [-VERR_NOT_A_DIRECTORY]                          = -ENOTDIR,
 [-VERR_PATH_NOT_FOUND]                           = -ENOTDIR,
 [-VERR_INVALID_NAME]                             = -ENOENT,
 [-VERR_IS_A_DIRECTORY]                           = -EISDIR,
 [-VERR_INVALID_PARAMETER]                        = -EINVAL,
 [-VERR_TOO_MANY_OPEN_FILES]                      = -ENFILE,
 [-VERR_INVALID_FUNCTION]                         = -ENOTTY,
 [-VERR_SHARING_VIOLATION]                        = -ETXTBSY,
 [-VERR_FILE_TOO_BIG]                             = -EFBIG,
 [-VERR_DISK_FULL]                                = -ENOSPC,
 [-VERR_SEEK_ON_DEVICE]                           = -ESPIPE,
 [-VERR_WRITE_PROTECT]                            = -EROFS,
 [-VERR_BROKEN_PIPE]                              = -EPIPE,
 [-VERR_DEADLOCK]                                 = -EDEADLK,
 [-VERR_FILENAME_TOO_LONG]                        = -ENAMETOOLONG,
 [-VERR_FILE_LOCK_FAILED]                         = -ENOLCK,
 [-VERR_NOT_IMPLEMENTED]                          = -ENOSYS,
 [-VERR_NOT_SUPPORTED]                            = -ENOSYS,
 [-VERR_DIR_NOT_EMPTY]                            = -ENOTEMPTY,
 [-VERR_TOO_MANY_SYMLINKS]                        = -ELOOP,
 [-VERR_NO_MORE_FILES]     = -ENODATA,
 [-VERR_NO_DATA]                                  = -ENODATA,
 [-VERR_NET_NO_NETWORK]                           = -ENONET,
 [-VERR_NET_NOT_UNIQUE_NAME]                      = -ENOTUNIQ,
 [-VERR_NO_TRANSLATION]                           = -EILSEQ,
 [-VERR_NET_NOT_SOCKET]                           = -ENOTSOCK,
 [-VERR_NET_DEST_ADDRESS_REQUIRED]                = -EDESTADDRREQ,
 [-VERR_NET_MSG_SIZE]                             = -EMSGSIZE,
 [-VERR_NET_PROTOCOL_TYPE]                        = -EPROTOTYPE,
 [-VERR_NET_PROTOCOL_NOT_AVAILABLE]               = -ENOPROTOOPT,
 [-VERR_NET_PROTOCOL_NOT_SUPPORTED]               = -EPROTONOSUPPORT,
 [-VERR_NET_SOCKET_TYPE_NOT_SUPPORTED]            = -ESOCKTNOSUPPORT,
 [-VERR_NET_OPERATION_NOT_SUPPORTED]              = -EOPNOTSUPP,
 [-VERR_NET_PROTOCOL_FAMILY_NOT_SUPPORTED]        = -EPFNOSUPPORT,
 [-VERR_NET_ADDRESS_FAMILY_NOT_SUPPORTED]         = -EAFNOSUPPORT,
 [-VERR_NET_ADDRESS_IN_USE]                       = -EADDRINUSE,
 [-VERR_NET_ADDRESS_NOT_AVAILABLE]                = -EADDRNOTAVAIL,
 [-VERR_NET_DOWN]                                 = -ENETDOWN,
 [-VERR_NET_UNREACHABLE]                          = -ENETUNREACH,
 [-VERR_NET_CONNECTION_RESET]                     = -ENETRESET,
 [-VERR_NET_CONNECTION_ABORTED]                   = -ECONNABORTED,
 [-VERR_NET_CONNECTION_RESET_BY_PEER]             = -ECONNRESET,
 [-VERR_NET_NO_BUFFER_SPACE]                      = -ENOBUFS,
 [-VERR_NET_ALREADY_CONNECTED]                    = -EISCONN,
 [-VERR_NET_NOT_CONNECTED]                        = -ENOTCONN,
 [-VERR_NET_SHUTDOWN]                             = -ESHUTDOWN,
 [-VERR_NET_TOO_MANY_REFERENCES]                  = -ETOOMANYREFS,
 [-VERR_TIMEOUT]                                  = -ETIMEDOUT,
 [-VERR_NET_CONNECTION_REFUSED]                   = -ECONNREFUSED,
 [-VERR_NET_HOST_DOWN]                            = -EHOSTDOWN,
 [-VERR_NET_HOST_UNREACHABLE]                     = -EHOSTUNREACH,
 [-VERR_NET_ALREADY_IN_PROGRESS]                  = -EALREADY,
 [-VERR_NET_IN_PROGRESS]                          = -EINPROGRESS,
 [-VERR_MEDIA_NOT_PRESENT]                        = -ENOMEDIUM,
 [-VERR_MEDIA_NOT_RECOGNIZED]                     = -EMEDIUMTYPE,
};

int vbg_status_code_to_errno(int rc)
{
 if (rc >= 0)
  return 0;

 rc = -rc;
 if (rc >= ARRAY_SIZE(vbg_status_code_to_errno_table) ||
     vbg_status_code_to_errno_table[rc] == 0) {
  vbg_warn("%s: Unhandled err %d\n", __func__, -rc);
  return -EPROTO;
 }

 return vbg_status_code_to_errno_table[rc];
}
EXPORT_SYMBOL(vbg_status_code_to_errno);