virt: Add vboxguest VMMDEV communication code

This commits adds a header describing the hardware interface for the
Virtual Box Guest PCI device used in Virtual Box virtual machines and
utility functions for talking to the Virtual Box hypervisor over this
interface.

These utility functions will used both by the vboxguest driver for the
PCI device which offers the /dev/vboxguest ioctl API and by the vboxfs
driver which offers folder sharing support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 801 insertions, 0 deletions

diff --git a/drivers/virt/vboxguest/vboxguest_utils.c b/drivers/virt/vboxguest/vboxguest_utils.c
new file mode 100644
index 000000000000..8daea691fbb5
--- /dev/null
+++ b/drivers/virt/vboxguest/vboxguest_utils.c
@@ -0,0 +1,801 @@
+/* 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/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);
+#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)
+{
+	struct vmmdev_request_header *req;
+
+	req = kmalloc(len, GFP_KERNEL | __GFP_DMA32);
+	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->reserved2 = 0;
+
+	return req;
+}
+
+/* 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,
+		     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);
+	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;
+	}
+
+	kfree(hgcm_connect);
+
+	*vbox_status = rc;
+	return 0;
+}
+EXPORT_SYMBOL(vbg_hgcm_connect);
+
+int vbg_hgcm_disconnect(struct vbg_dev *gdev, 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);
+	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;
+
+	kfree(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;
+
+	if (copy_in) {
+		ret = copy_from_user(bounce_buf, (void __user *)buf, len);
+		if (ret)
+			return -EFAULT;
+	} else {
+		memset(bounce_buf, 0, len);
+	}
+
+	*bounce_buf_ret = bounce_buf;
+	hgcm_call_add_pagelist_size(bounce_buf, len, extra);
+	return 0;
+}
+
+/**
+ * Preprocesses the HGCM call, validate parameters, alloc bounce buffers and
+ * figure out how much extra storage we need for page lists.
+ * Return: 0 or negative errno value.
+ * @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.
+ */
+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;
+}
+
+/**
+ * Translates linear address types to page list direction flags.
+ *
+ * Return: page list flags.
+ * @type:  The type.
+ */
+static u32 hgcm_call_linear_addr_type_to_pagelist_flags(
+	enum vmmdev_hgcm_function_parameter_type type)
+{
+	switch (type) {
+	default:
+		WARN_ON(1);
+		/* Fall through */
+	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]);
+}
+
+/**
+ * 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;
+		}
+	}
+}
+
+/**
+ * Tries to cancel a pending HGCM call.
+ *
+ * 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;
+}
+
+/**
+ * Performs the call and completion wait.
+ * Return: 0 or negative errno value.
+ * @gdev:        The VBoxGuest device extension.
+ * @call:        The call to execute.
+ * @timeout_ms:  Timeout in ms.
+ * @leak_it:     Where to return the leak it / free it, indicator.
+ *               Cancellation fun.
+ */
+static int vbg_hgcm_do_call(struct vbg_dev *gdev, struct vmmdev_hgcm_call *call,
+			    u32 timeout_ms, 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);
+
+	timeout = wait_event_interruptible_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;
+}
+
+/**
+ * Copies the result of the call back to the caller info structure and user
+ * buffers.
+ * Return: 0 or negative errno value.
+ * @call:            HGCM call request.
+ * @dst_parm:        Pointer to function call parameters destination.
+ * @parm_count:      Number of function call parameters.
+ * @bounce_bufs:     The bouncebuffer array.
+ */
+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 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);
+	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, &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)
+		kfree(call);
+
+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 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, 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_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_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);