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>

MAINTAINERS

@@ -14562,7 +14562,9 @@ M:	Hans de Goede <hdegoede@redhat.com>
 M:	Arnd Bergmann <arnd@arndb.de>
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 S:	Maintained
+F:	include/linux/vbox_utils.h
 F:	include/uapi/linux/vbox*.h
+F:	drivers/virt/vboxguest/
 
 VIRTUAL SERIO DEVICE DRIVER
 M:	Stephen Chandler Paul <thatslyude@gmail.com>

drivers/virt/vboxguest/vboxguest_utils.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/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);

drivers/virt/vboxguest/vmmdev.h

+/* SPDX-License-Identifier: (GPL-2.0 OR CDDL-1.0) */
+/*
+ * Virtual Device for Guest <-> VMM/Host communication interface
+ *
+ * Copyright (C) 2006-2016 Oracle Corporation
+ */
+
+#ifndef __VBOX_VMMDEV_H__
+#define __VBOX_VMMDEV_H__
+
+#include <asm/bitsperlong.h>
+#include <linux/sizes.h>
+#include <linux/types.h>
+#include <linux/vbox_vmmdev_types.h>
+
+/* Port for generic request interface (relative offset). */
+#define VMMDEV_PORT_OFF_REQUEST                             0
+
+/** Layout of VMMDEV RAM region that contains information for guest. */
+struct vmmdev_memory {
+	/** The size of this structure. */
+	u32 size;
+	/** The structure version. (VMMDEV_MEMORY_VERSION) */
+	u32 version;
+
+	union {
+		struct {
+			/** Flag telling that VMMDev has events pending. */
+			u8 have_events;
+			/** Explicit padding, MBZ. */
+			u8 padding[3];
+		} V1_04;
+
+		struct {
+			/** Pending events flags, set by host. */
+			u32 host_events;
+			/** Mask of events the guest wants, set by guest. */
+			u32 guest_event_mask;
+		} V1_03;
+	} V;
+
+	/* struct vbva_memory, not used */
+};
+VMMDEV_ASSERT_SIZE(vmmdev_memory, 8 + 8);
+
+/** Version of vmmdev_memory structure (vmmdev_memory::version). */
+#define VMMDEV_MEMORY_VERSION   (1)
+
+/* Host mouse capabilities has been changed. */
+#define VMMDEV_EVENT_MOUSE_CAPABILITIES_CHANGED             BIT(0)
+/* HGCM event. */
+#define VMMDEV_EVENT_HGCM                                   BIT(1)
+/* A display change request has been issued. */
+#define VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST                 BIT(2)
+/* Credentials are available for judgement. */
+#define VMMDEV_EVENT_JUDGE_CREDENTIALS                      BIT(3)
+/* The guest has been restored. */
+#define VMMDEV_EVENT_RESTORED                               BIT(4)
+/* Seamless mode state changed. */
+#define VMMDEV_EVENT_SEAMLESS_MODE_CHANGE_REQUEST           BIT(5)
+/* Memory balloon size changed. */
+#define VMMDEV_EVENT_BALLOON_CHANGE_REQUEST                 BIT(6)
+/* Statistics interval changed. */
+#define VMMDEV_EVENT_STATISTICS_INTERVAL_CHANGE_REQUEST     BIT(7)
+/* VRDP status changed. */
+#define VMMDEV_EVENT_VRDP                                   BIT(8)
+/* New mouse position data available. */
+#define VMMDEV_EVENT_MOUSE_POSITION_CHANGED                 BIT(9)
+/* CPU hotplug event occurred. */
+#define VMMDEV_EVENT_CPU_HOTPLUG                            BIT(10)
+/* The mask of valid events, for sanity checking. */
+#define VMMDEV_EVENT_VALID_EVENT_MASK                       0x000007ffU
+
+/*
+ * Additions are allowed to work only if additions_major == vmmdev_current &&
+ * additions_minor <= vmmdev_current. Additions version is reported to host
+ * (VMMDev) by VMMDEVREQ_REPORT_GUEST_INFO.
+ */
+#define VMMDEV_VERSION                      0x00010004
+#define VMMDEV_VERSION_MAJOR                (VMMDEV_VERSION >> 16)
+#define VMMDEV_VERSION_MINOR                (VMMDEV_VERSION & 0xffff)
+
+/* Maximum request packet size. */
+#define VMMDEV_MAX_VMMDEVREQ_SIZE           1048576
+
+/* Version of vmmdev_request_header structure. */
+#define VMMDEV_REQUEST_HEADER_VERSION       0x10001
+
+/** struct vmmdev_request_header - Generic VMMDev request header. */
+struct vmmdev_request_header {
+	/** IN: Size of the structure in bytes (including body). */
+	u32 size;
+	/** IN: Version of the structure.  */
+	u32 version;
+	/** IN: Type of the request. */
+	enum vmmdev_request_type request_type;
+	/** OUT: Return code. */
+	s32 rc;
+	/** Reserved field no.1. MBZ. */
+	u32 reserved1;
+	/** Reserved field no.2. MBZ. */
+	u32 reserved2;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_request_header, 24);
+
+/**
+ * struct vmmdev_mouse_status - Mouse status request structure.
+ *
+ * Used by VMMDEVREQ_GET_MOUSE_STATUS and VMMDEVREQ_SET_MOUSE_STATUS.
+ */
+struct vmmdev_mouse_status {
+	/** header */
+	struct vmmdev_request_header header;
+	/** Mouse feature mask. See VMMDEV_MOUSE_*. */
+	u32 mouse_features;
+	/** Mouse x position. */
+	s32 pointer_pos_x;
+	/** Mouse y position. */
+	s32 pointer_pos_y;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_mouse_status, 24 + 12);
+
+/* The guest can (== wants to) handle absolute coordinates.  */
+#define VMMDEV_MOUSE_GUEST_CAN_ABSOLUTE                     BIT(0)
+/*
+ * The host can (== wants to) send absolute coordinates.
+ * (Input not captured.)
+ */
+#define VMMDEV_MOUSE_HOST_WANTS_ABSOLUTE                    BIT(1)
+/*
+ * The guest can *NOT* switch to software cursor and therefore depends on the
+ * host cursor.
+ *
+ * When guest additions are installed and the host has promised to display the
+ * cursor itself, the guest installs a hardware mouse driver. Don't ask the
+ * guest to switch to a software cursor then.
+ */
+#define VMMDEV_MOUSE_GUEST_NEEDS_HOST_CURSOR                BIT(2)
+/* The host does NOT provide support for drawing the cursor itself. */
+#define VMMDEV_MOUSE_HOST_CANNOT_HWPOINTER                  BIT(3)
+/* The guest can read VMMDev events to find out about pointer movement */
+#define VMMDEV_MOUSE_NEW_PROTOCOL                           BIT(4)
+/*
+ * If the guest changes the status of the VMMDEV_MOUSE_GUEST_NEEDS_HOST_CURSOR
+ * bit, the host will honour this.
+ */
+#define VMMDEV_MOUSE_HOST_RECHECKS_NEEDS_HOST_CURSOR        BIT(5)
+/*
+ * The host supplies an absolute pointing device.  The Guest Additions may
+ * wish to use this to decide whether to install their own driver.
+ */
+#define VMMDEV_MOUSE_HOST_HAS_ABS_DEV                       BIT(6)
+
+/* The minimum value our pointing device can return. */
+#define VMMDEV_MOUSE_RANGE_MIN 0
+/* The maximum value our pointing device can return. */
+#define VMMDEV_MOUSE_RANGE_MAX 0xFFFF
+
+/**
+ * struct vmmdev_host_version - VirtualBox host version request structure.
+ *
+ * VBG uses this to detect the precense of new features in the interface.
+ */
+struct vmmdev_host_version {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Major version. */
+	u16 major;
+	/** Minor version. */
+	u16 minor;
+	/** Build number. */
+	u32 build;
+	/** SVN revision. */
+	u32 revision;
+	/** Feature mask. */
+	u32 features;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_host_version, 24 + 16);
+
+/* Physical page lists are supported by HGCM. */
+#define VMMDEV_HVF_HGCM_PHYS_PAGE_LIST  BIT(0)
+
+/**
+ * struct vmmdev_mask - Structure to set / clear bits in a mask used for
+ * VMMDEVREQ_SET_GUEST_CAPABILITIES and VMMDEVREQ_CTL_GUEST_FILTER_MASK.
+ */
+struct vmmdev_mask {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Mask of bits to be set. */
+	u32 or_mask;
+	/** Mask of bits to be cleared. */
+	u32 not_mask;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_mask, 24 + 8);
+
+/* The guest supports seamless display rendering. */
+#define VMMDEV_GUEST_SUPPORTS_SEAMLESS                      BIT(0)
+/* The guest supports mapping guest to host windows. */
+#define VMMDEV_GUEST_SUPPORTS_GUEST_HOST_WINDOW_MAPPING     BIT(1)
+/*
+ * The guest graphical additions are active.
+ * Used for fast activation and deactivation of certain graphical operations
+ * (e.g. resizing & seamless). The legacy VMMDEVREQ_REPORT_GUEST_CAPABILITIES
+ * request sets this automatically, but VMMDEVREQ_SET_GUEST_CAPABILITIES does
+ * not.
+ */
+#define VMMDEV_GUEST_SUPPORTS_GRAPHICS                      BIT(2)
+
+/** struct vmmdev_hypervisorinfo - Hypervisor info structure. */
+struct vmmdev_hypervisorinfo {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/**
+	 * Guest virtual address of proposed hypervisor start.
+	 * Not used by VMMDEVREQ_GET_HYPERVISOR_INFO.
+	 */
+	u32 hypervisor_start;
+	/** Hypervisor size in bytes. */
+	u32 hypervisor_size;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hypervisorinfo, 24 + 8);
+
+/** struct vmmdev_events - Pending events structure. */
+struct vmmdev_events {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** OUT: Pending event mask. */
+	u32 events;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_events, 24 + 4);
+
+#define VMMDEV_OSTYPE_LINUX26		0x53000
+#define VMMDEV_OSTYPE_X64		BIT(8)
+
+/** struct vmmdev_guestinfo - Guest information report. */
+struct vmmdev_guest_info {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/**
+	 * The VMMDev interface version expected by additions.
+	 * *Deprecated*, do not use anymore! Will be removed.
+	 */
+	u32 interface_version;
+	/** Guest OS type. */
+	u32 os_type;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_guest_info, 24 + 8);
+
+/** struct vmmdev_guestinfo2 - Guest information report, version 2. */
+struct vmmdev_guest_info2 {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Major version. */
+	u16 additions_major;
+	/** Minor version. */
+	u16 additions_minor;
+	/** Build number. */
+	u32 additions_build;
+	/** SVN revision. */
+	u32 additions_revision;
+	/** Feature mask, currently unused. */
+	u32 additions_features;
+	/**
+	 * The intentional meaning of this field was:
+	 * Some additional information, for example 'Beta 1' or something like
+	 * that.
+	 *
+	 * The way it was implemented was implemented: VBG_VERSION_STRING.
+	 *
+	 * This means the first three members are duplicated in this field (if
+	 * the guest build config is sane). So, the user must check this and
+	 * chop it off before usage. There is, because of the Main code's blind
+	 * trust in the field's content, no way back.
+	 */
+	char name[128];
+};
+VMMDEV_ASSERT_SIZE(vmmdev_guest_info2, 24 + 144);
+
+enum vmmdev_guest_facility_type {
+	VBOXGUEST_FACILITY_TYPE_UNKNOWN          = 0,
+	VBOXGUEST_FACILITY_TYPE_VBOXGUEST_DRIVER = 20,
+	/* VBoxGINA / VBoxCredProv / pam_vbox. */
+	VBOXGUEST_FACILITY_TYPE_AUTO_LOGON       = 90,
+	VBOXGUEST_FACILITY_TYPE_VBOX_SERVICE     = 100,
+	/* VBoxTray (Windows), VBoxClient (Linux, Unix). */
+	VBOXGUEST_FACILITY_TYPE_VBOX_TRAY_CLIENT = 101,
+	VBOXGUEST_FACILITY_TYPE_SEAMLESS         = 1000,
+	VBOXGUEST_FACILITY_TYPE_GRAPHICS         = 1100,
+	VBOXGUEST_FACILITY_TYPE_ALL              = 0x7ffffffe,
+	/* Ensure the enum is a 32 bit data-type */
+	VBOXGUEST_FACILITY_TYPE_SIZEHACK         = 0x7fffffff
+};
+
+enum vmmdev_guest_facility_status {
+	VBOXGUEST_FACILITY_STATUS_INACTIVE    = 0,
+	VBOXGUEST_FACILITY_STATUS_PAUSED      = 1,
+	VBOXGUEST_FACILITY_STATUS_PRE_INIT    = 20,
+	VBOXGUEST_FACILITY_STATUS_INIT        = 30,
+	VBOXGUEST_FACILITY_STATUS_ACTIVE      = 50,
+	VBOXGUEST_FACILITY_STATUS_TERMINATING = 100,
+	VBOXGUEST_FACILITY_STATUS_TERMINATED  = 101,
+	VBOXGUEST_FACILITY_STATUS_FAILED      = 800,
+	VBOXGUEST_FACILITY_STATUS_UNKNOWN     = 999,
+	/* Ensure the enum is a 32 bit data-type */
+	VBOXGUEST_FACILITY_STATUS_SIZEHACK    = 0x7fffffff
+};
+
+/** struct vmmdev_guest_status - Guest Additions status structure. */
+struct vmmdev_guest_status {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Facility the status is indicated for. */
+	enum vmmdev_guest_facility_type facility;
+	/** Current guest status. */
+	enum vmmdev_guest_facility_status status;
+	/** Flags, not used at the moment. */
+	u32 flags;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_guest_status, 24 + 12);
+
+#define VMMDEV_MEMORY_BALLOON_CHUNK_SIZE             (1048576)
+#define VMMDEV_MEMORY_BALLOON_CHUNK_PAGES            (1048576 / 4096)
+
+/** struct vmmdev_memballoon_info - Memory-balloon info structure. */
+struct vmmdev_memballoon_info {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Balloon size in megabytes. */
+	u32 balloon_chunks;
+	/** Guest ram size in megabytes. */
+	u32 phys_mem_chunks;
+	/**
+	 * Setting this to VMMDEV_EVENT_BALLOON_CHANGE_REQUEST indicates that
+	 * the request is a response to that event.
+	 * (Don't confuse this with VMMDEVREQ_ACKNOWLEDGE_EVENTS.)
+	 */
+	u32 event_ack;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_memballoon_info, 24 + 12);
+
+/** struct vmmdev_memballoon_change - Change the size of the balloon. */
+struct vmmdev_memballoon_change {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** The number of pages in the array. */
+	u32 pages;
+	/** true = inflate, false = deflate.  */
+	u32 inflate;
+	/** Physical address (u64) of each page. */
+	u64 phys_page[VMMDEV_MEMORY_BALLOON_CHUNK_PAGES];
+};
+
+/** struct vmmdev_write_core_dump - Write Core Dump request data. */
+struct vmmdev_write_core_dump {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** Flags (reserved, MBZ). */
+	u32 flags;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_write_core_dump, 24 + 4);
+
+/** struct vmmdev_heartbeat - Heart beat check state structure. */
+struct vmmdev_heartbeat {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** OUT: Guest heartbeat interval in nanosec. */
+	u64 interval_ns;
+	/** Heartbeat check flag. */
+	u8 enabled;
+	/** Explicit padding, MBZ. */
+	u8 padding[3];
+} __packed;
+VMMDEV_ASSERT_SIZE(vmmdev_heartbeat, 24 + 12);
+
+#define VMMDEV_HGCM_REQ_DONE      BIT(0)
+#define VMMDEV_HGCM_REQ_CANCELLED BIT(1)
+
+/** struct vmmdev_hgcmreq_header - vmmdev HGCM requests header. */
+struct vmmdev_hgcmreq_header {
+	/** Request header. */
+	struct vmmdev_request_header header;
+
+	/** HGCM flags. */
+	u32 flags;
+
+	/** Result code. */
+	s32 result;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hgcmreq_header, 24 + 8);
+
+/** struct vmmdev_hgcm_connect - HGCM connect request structure. */
+struct vmmdev_hgcm_connect {
+	/** HGCM request header. */
+	struct vmmdev_hgcmreq_header header;
+
+	/** IN: Description of service to connect to. */
+	struct vmmdev_hgcm_service_location loc;
+
+	/** OUT: Client identifier assigned by local instance of HGCM. */
+	u32 client_id;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hgcm_connect, 32 + 132 + 4);
+
+/** struct vmmdev_hgcm_disconnect - HGCM disconnect request structure. */
+struct vmmdev_hgcm_disconnect {
+	/** HGCM request header. */
+	struct vmmdev_hgcmreq_header header;
+
+	/** IN: Client identifier. */
+	u32 client_id;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hgcm_disconnect, 32 + 4);
+
+#define VMMDEV_HGCM_MAX_PARMS 32
+
+/** struct vmmdev_hgcm_call - HGCM call request structure. */
+struct vmmdev_hgcm_call {
+	/* request header */
+	struct vmmdev_hgcmreq_header header;
+
+	/** IN: Client identifier. */
+	u32 client_id;
+	/** IN: Service function number. */
+	u32 function;
+	/** IN: Number of parameters. */
+	u32 parm_count;
+	/** Parameters follow in form: HGCMFunctionParameter32|64 parms[X]; */
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hgcm_call, 32 + 12);
+
+/**
+ * struct vmmdev_hgcm_cancel2 - HGCM cancel request structure, version 2.
+ *
+ * After the request header.rc will be:
+ *
+ * VINF_SUCCESS when cancelled.
+ * VERR_NOT_FOUND if the specified request cannot be found.
+ * VERR_INVALID_PARAMETER if the address is invalid valid.
+ */
+struct vmmdev_hgcm_cancel2 {
+	/** Header. */
+	struct vmmdev_request_header header;
+	/** The physical address of the request to cancel. */
+	u32 phys_req_to_cancel;
+};
+VMMDEV_ASSERT_SIZE(vmmdev_hgcm_cancel2, 24 + 4);
+
+#endif

include/linux/vbox_utils.h

+/* SPDX-License-Identifier: (GPL-2.0 OR CDDL-1.0) */
+/* Copyright (C) 2006-2016 Oracle Corporation */
+
+#ifndef __VBOX_UTILS_H__
+#define __VBOX_UTILS_H__
+
+#include <linux/printk.h>
+#include <linux/vbox_vmmdev_types.h>
+
+struct vbg_dev;
+
+/**
+ * vboxguest logging functions, these log both to the backdoor and call
+ * the equivalent kernel pr_foo function.
+ */
+__printf(1, 2) void vbg_info(const char *fmt, ...);
+__printf(1, 2) void vbg_warn(const char *fmt, ...);
+__printf(1, 2) void vbg_err(const char *fmt, ...);
+
+/* Only use backdoor logging for non-dynamic debug builds */
+#if defined(DEBUG) && !defined(CONFIG_DYNAMIC_DEBUG)
+__printf(1, 2) void vbg_debug(const char *fmt, ...);
+#else
+#define vbg_debug pr_debug
+#endif
+
+/**
+ * Allocate memory for generic request and initialize the request header.
+ *
+ * Return: the allocated memory
+ * @len:		Size of memory block required for the request.
+ * @req_type:		The generic request type.
+ */
+void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type);
+
+/**
+ * Perform a generic request.
+ *
+ * Return: VBox status code
+ * @gdev:		The Guest extension device.
+ * @req:		Pointer to the request structure.
+ */
+int vbg_req_perform(struct vbg_dev *gdev, void *req);
+
+int vbg_hgcm_connect(struct vbg_dev *gdev,
+		     struct vmmdev_hgcm_service_location *loc,
+		     u32 *client_id, int *vbox_status);
+
+int vbg_hgcm_disconnect(struct vbg_dev *gdev, u32 client_id, int *vbox_status);
+
+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);
+
+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);
+
+/**
+ * Convert a VirtualBox status code to a standard Linux kernel return value.
+ * Return: 0 or negative errno value.
+ * @rc:			VirtualBox status code to convert.
+ */
+int vbg_status_code_to_errno(int rc);
+
+/**
+ * Helper for the vboxsf driver to get a reference to the guest device.
+ * Return: a pointer to the gdev; or a ERR_PTR value on error.
+ */
+struct vbg_dev *vbg_get_gdev(void);
+
+/**
+ * Helper for the vboxsf driver to put a guest device reference.
+ * @gdev:		Reference returned by vbg_get_gdev to put.
+ */
+void vbg_put_gdev(struct vbg_dev *gdev);
+
+#endif