Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2034 insertions, 0 deletions

diff --git a/include/VBox/VMMDev.h b/include/VBox/VMMDev.h
new file mode 100644
index 00000000..ed42d31c
--- /dev/null
+++ b/include/VBox/VMMDev.h
@@ -0,0 +1,2034 @@
+/** @file
+ * Virtual Device for Guest <-> VMM/Host communication (ADD,DEV).
+ */
+
+/*
+ * Copyright (C) 2006-2023 Oracle and/or its affiliates.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef VBOX_INCLUDED_VMMDev_h
+#define VBOX_INCLUDED_VMMDev_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <VBox/cdefs.h>
+#include <VBox/param.h>                 /* for the PCI IDs. */
+#include <VBox/types.h>
+#include <VBox/ostypes.h>
+#include <VBox/VMMDevCoreTypes.h>
+#include <iprt/assertcompile.h>
+#include <iprt/errcore.h>
+
+
+#pragma pack(4) /* force structure dword packing here. */
+RT_C_DECLS_BEGIN
+
+
+/** @defgroup grp_vmmdev    VMM Device
+ *
+ * @note This interface cannot be changed, it can only be extended!
+ *
+ * @{
+ */
+
+
+/** Size of VMMDev RAM region accessible by guest.
+ * Must be big enough to contain VMMDevMemory structure (see further down).
+ * For now: 4 megabyte.
+ */
+#define VMMDEV_RAM_SIZE                                     (4 * 256 * PAGE_SIZE)
+
+/** Size of VMMDev heap region accessible by guest.
+ *  (Must be a power of two (pci range).)
+ */
+#define VMMDEV_HEAP_SIZE                                    (4 * PAGE_SIZE)
+
+/** Port for generic request interface (relative offset). */
+#define VMMDEV_PORT_OFF_REQUEST                             0
+/** Port for requests that can be handled w/o going to ring-3 (relative offset).
+ * This works like VMMDevReq_AcknowledgeEvents when read.  */
+#define VMMDEV_PORT_OFF_REQUEST_FAST                        8
+
+
+/** @defgroup grp_vmmdev_req    VMMDev Generic Request Interface
+ * @{
+ */
+
+/** @name Current version of the VMMDev interface.
+ *
+ * Additions are allowed to work only if
+ * additions_major == vmmdev_current && additions_minor <= vmmdev_current.
+ * Additions version is reported to host (VMMDev) by VMMDevReq_ReportGuestInfo.
+ *
+ * @remarks These defines also live in the 16-bit and assembly versions of this
+ *          header.
+ * @{
+ */
+#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           _1M
+/** Maximum number of HGCM parameters.
+ * @note This used to be 1024, which is kind of insane.  Was changed to 32,
+ *       given that (guest) user land can only pass 61 anyway.
+ *       See comments on VBGLIOCHGCMCALL::cParms. */
+#define VMMDEV_MAX_HGCM_PARMS               32
+/** Maximum total size of hgcm buffers in one call.
+ * @note Used to be 2G, since reduced to 128MB.  */
+#define VMMDEV_MAX_HGCM_DATA_SIZE           _128M
+
+/**
+ * VMMDev request types.
+ * @note when updating this, adjust vmmdevGetRequestSize() as well
+ */
+typedef enum VMMDevRequestType
+{
+    VMMDevReq_InvalidRequest             =  0,
+    VMMDevReq_GetMouseStatus             =  1,
+    VMMDevReq_SetMouseStatus             =  2,
+    VMMDevReq_SetPointerShape            =  3,
+    VMMDevReq_GetHostVersion             =  4,
+    VMMDevReq_Idle                       =  5,
+    VMMDevReq_GetHostTime                = 10,
+    VMMDevReq_GetHypervisorInfo          = 20,
+    VMMDevReq_SetHypervisorInfo          = 21,
+    VMMDevReq_RegisterPatchMemory        = 22, /**< @since version 3.0.6 */
+    VMMDevReq_DeregisterPatchMemory      = 23, /**< @since version 3.0.6 */
+    VMMDevReq_SetPowerStatus             = 30,
+    VMMDevReq_AcknowledgeEvents          = 41,
+    VMMDevReq_CtlGuestFilterMask         = 42,
+    VMMDevReq_ReportGuestInfo            = 50,
+    VMMDevReq_ReportGuestInfo2           = 58, /**< @since version 3.2.0 */
+    VMMDevReq_ReportGuestStatus          = 59, /**< @since version 3.2.8 */
+    VMMDevReq_ReportGuestUserState       = 74, /**< @since version 4.3 */
+    /**
+     * Retrieve a display resize request sent by the host using
+     * @a IDisplay:setVideoModeHint.  Deprecated.
+     *
+     * Similar to @a VMMDevReq_GetDisplayChangeRequest2, except that it only
+     * considers host requests sent for the first virtual display.  This guest
+     * request should not be used in new guest code, and the results are
+     * undefined if a guest mixes calls to this and
+     * @a VMMDevReq_GetDisplayChangeRequest2.
+     */
+    VMMDevReq_GetDisplayChangeRequest    = 51,
+    VMMDevReq_VideoModeSupported         = 52,
+    VMMDevReq_GetHeightReduction         = 53,
+    /**
+     * Retrieve a display resize request sent by the host using
+     * @a IDisplay:setVideoModeHint.
+     *
+     * Queries a display resize request sent from the host.  If the
+     * @a eventAck member is sent to true and there is an unqueried
+     * request available for one of the virtual display then that request will
+     * be returned.  If several displays have unqueried requests the lowest
+     * numbered display will be chosen first.  Only the most recent unseen
+     * request for each display is remembered.
+     * If @a eventAck is set to false, the last host request queried with
+     * @a eventAck set is resent, or failing that the most recent received from
+     * the host.  If no host request was ever received then all zeros are
+     * returned.
+     */
+    VMMDevReq_GetDisplayChangeRequest2   = 54,
+    VMMDevReq_ReportGuestCapabilities    = 55,
+    VMMDevReq_SetGuestCapabilities       = 56,
+    VMMDevReq_VideoModeSupported2        = 57, /**< @since version 3.2.0 */
+    VMMDevReq_GetDisplayChangeRequestEx  = 80, /**< @since version 4.2.4 */
+    VMMDevReq_GetDisplayChangeRequestMulti = 81,
+#ifdef VBOX_WITH_HGCM
+    VMMDevReq_HGCMConnect                = 60,
+    VMMDevReq_HGCMDisconnect             = 61,
+    VMMDevReq_HGCMCall32                 = 62,
+    VMMDevReq_HGCMCall64                 = 63,
+# ifdef IN_GUEST
+#  if   ARCH_BITS == 64
+    VMMDevReq_HGCMCall                   = VMMDevReq_HGCMCall64,
+#  elif ARCH_BITS == 32 || ARCH_BITS == 16
+    VMMDevReq_HGCMCall                   = VMMDevReq_HGCMCall32,
+#  else
+#   error "Unsupported ARCH_BITS"
+#  endif
+# endif
+    VMMDevReq_HGCMCancel                 = 64,
+    VMMDevReq_HGCMCancel2                = 65,
+#endif
+    VMMDevReq_VideoAccelEnable           = 70,
+    VMMDevReq_VideoAccelFlush            = 71,
+    VMMDevReq_VideoSetVisibleRegion      = 72,
+    VMMDevReq_GetSeamlessChangeRequest   = 73,
+    VMMDevReq_QueryCredentials           = 100,
+    VMMDevReq_ReportCredentialsJudgement = 101,
+    VMMDevReq_ReportGuestStats           = 110,
+    VMMDevReq_GetMemBalloonChangeRequest = 111,
+    VMMDevReq_GetStatisticsChangeRequest = 112,
+    VMMDevReq_ChangeMemBalloon           = 113,
+    VMMDevReq_GetVRDPChangeRequest       = 150,
+    VMMDevReq_LogString                  = 200,
+    VMMDevReq_GetCpuHotPlugRequest       = 210,
+    VMMDevReq_SetCpuHotPlugStatus        = 211,
+    VMMDevReq_RegisterSharedModule       = 212,
+    VMMDevReq_UnregisterSharedModule     = 213,
+    VMMDevReq_CheckSharedModules         = 214,
+    VMMDevReq_GetPageSharingStatus       = 215,
+    VMMDevReq_DebugIsPageShared          = 216,
+    VMMDevReq_GetSessionId               = 217, /**< @since version 3.2.8 */
+    VMMDevReq_WriteCoreDump              = 218,
+    VMMDevReq_GuestHeartbeat             = 219,
+    VMMDevReq_HeartbeatConfigure         = 220,
+    VMMDevReq_NtBugCheck                 = 221,
+    VMMDevReq_VideoUpdateMonitorPositions= 222,
+    VMMDevReq_GetMouseStatusEx           = 223,
+    VMMDevReq_SizeHack                   = 0x7fffffff
+} VMMDevRequestType;
+
+/** Version of VMMDevRequestHeader structure. */
+#define VMMDEV_REQUEST_HEADER_VERSION (0x10001)
+
+
+/**
+ * Generic VMMDev request header.
+ *
+ * This structure is copied/mirrored by VBGLREQHDR in the VBoxGuest I/O control
+ * interface.  Changes there needs to be mirrored in it.
+ *
+ * @sa VBGLREQHDR
+ */
+typedef struct VMMDevRequestHeader
+{
+    /** IN: Size of the structure in bytes (including body).
+     * (VBGLREQHDR uses this for input size and output if reserved1 is zero). */
+    uint32_t size;
+    /** IN: Version of the structure.  */
+    uint32_t version;
+    /** IN: Type of the request.
+     * @note VBGLREQHDR uses this for optional output size. */
+    VMMDevRequestType requestType;
+    /** OUT: VBox status code. */
+    int32_t  rc;
+    /** Reserved field no.1. MBZ.
+     * @note VBGLREQHDR uses this for optional output size, however never for a
+     *       real VMMDev request, only in the I/O control interface. */
+    uint32_t reserved1;
+    /** IN: Requestor information (VMMDEV_REQUESTOR_XXX) when
+     * VBOXGSTINFO2_F_REQUESTOR_INFO is set, otherwise ignored by the host. */
+    uint32_t fRequestor;
+} VMMDevRequestHeader;
+AssertCompileSize(VMMDevRequestHeader, 24);
+
+/** @name VMMDEV_REQUESTOR_XXX - Requestor information.
+ *
+ * This is information provided to the host by the VBoxGuest device driver, so
+ * the host can implemented fine grained access to functionality if it likes.
+ * @bugref{9105}
+ *
+ * @{ */
+/** Requestor user not given. */
+#define VMMDEV_REQUESTOR_USR_NOT_GIVEN              UINT32_C(0x00000000)
+/** The kernel driver (VBoxGuest) is the requestor. */
+#define VMMDEV_REQUESTOR_USR_DRV                    UINT32_C(0x00000001)
+/** Some other kernel driver is the requestor. */
+#define VMMDEV_REQUESTOR_USR_DRV_OTHER              UINT32_C(0x00000002)
+/** The root or a admin user is the requestor. */
+#define VMMDEV_REQUESTOR_USR_ROOT                   UINT32_C(0x00000003)
+/** Requestor is the windows system user (SID S-1-5-18). */
+#define VMMDEV_REQUESTOR_USR_SYSTEM                 UINT32_C(0x00000004)
+/** Reserved requestor user \#1, treat like VMMDEV_REQUESTOR_USR_USER. */
+#define VMMDEV_REQUESTOR_USR_RESERVED1              UINT32_C(0x00000005)
+/** Regular joe user is making the request. */
+#define VMMDEV_REQUESTOR_USR_USER                   UINT32_C(0x00000006)
+/** Requestor is a guest user (or in a guest user group). */
+#define VMMDEV_REQUESTOR_USR_GUEST                  UINT32_C(0x00000007)
+/** User classification mask. */
+#define VMMDEV_REQUESTOR_USR_MASK                   UINT32_C(0x00000007)
+
+/** Kernel mode request.
+ * @note This is zero, so test for VMMDEV_REQUESTOR_USERMODE instead.  */
+#define VMMDEV_REQUESTOR_KERNEL                     UINT32_C(0x00000000)
+/** User mode request. */
+#define VMMDEV_REQUESTOR_USERMODE                   UINT32_C(0x00000008)
+
+/** Don't know the physical console association of the requestor. */
+#define VMMDEV_REQUESTOR_CON_DONT_KNOW              UINT32_C(0x00000000)
+/** The request originates with a process that is NOT associated with the
+ * physical console. */
+#define VMMDEV_REQUESTOR_CON_NO                     UINT32_C(0x00000010)
+/** Requestor process DOES is associated with the physical console. */
+#define VMMDEV_REQUESTOR_CON_YES                    UINT32_C(0x00000020)
+/** Requestor process belongs to user on the physical console, but cannot
+ * ascertain that it is associated with that login. */
+#define VMMDEV_REQUESTOR_CON_USER                   UINT32_C(0x00000030)
+/** Mask the physical console state of the request. */
+#define VMMDEV_REQUESTOR_CON_MASK                   UINT32_C(0x00000030)
+
+/** Requestor is member of special VirtualBox user group (not on windows). */
+#define VMMDEV_REQUESTOR_GRP_VBOX                   UINT32_C(0x00000080)
+/** Requestor is member of wheel / administrators group (SID S-1-5-32-544). */
+#define VMMDEV_REQUESTOR_GRP_WHEEL                  UINT32_C(0x00000100)
+
+/** Requestor trust level: Unspecified */
+#define VMMDEV_REQUESTOR_TRUST_NOT_GIVEN            UINT32_C(0x00000000)
+/** Requestor trust level: Untrusted (SID S-1-16-0) */
+#define VMMDEV_REQUESTOR_TRUST_UNTRUSTED            UINT32_C(0x00001000)
+/** Requestor trust level: Untrusted (SID S-1-16-4096) */
+#define VMMDEV_REQUESTOR_TRUST_LOW                  UINT32_C(0x00002000)
+/** Requestor trust level: Medium (SID S-1-16-8192) */
+#define VMMDEV_REQUESTOR_TRUST_MEDIUM               UINT32_C(0x00003000)
+/** Requestor trust level: Medium plus (SID S-1-16-8448) */
+#define VMMDEV_REQUESTOR_TRUST_MEDIUM_PLUS          UINT32_C(0x00004000)
+/** Requestor trust level: High (SID S-1-16-12288) */
+#define VMMDEV_REQUESTOR_TRUST_HIGH                 UINT32_C(0x00005000)
+/** Requestor trust level: System (SID S-1-16-16384) */
+#define VMMDEV_REQUESTOR_TRUST_SYSTEM               UINT32_C(0x00006000)
+/** Requestor trust level: Protected or higher (SID S-1-16-20480, S-1-16-28672)
+ * @note To avoid wasting an unnecessary bit, we combine the two top most
+ *       mandatory security labels on Windows (protected and secure). */
+#define VMMDEV_REQUESTOR_TRUST_PROTECTED            UINT32_C(0x00007000)
+/** Requestor trust level mask.
+ * The higher the value, the more the guest trusts the process. */
+#define VMMDEV_REQUESTOR_TRUST_MASK                 UINT32_C(0x00007000)
+
+/** Requestor is using the less trusted user device node (/dev/vboxuser). */
+#define VMMDEV_REQUESTOR_USER_DEVICE                UINT32_C(0x00008000)
+/** There is no user device node (/dev/vboxuser). */
+#define VMMDEV_REQUESTOR_NO_USER_DEVICE             UINT32_C(0x00010000)
+
+/** Legacy value for when VBOXGSTINFO2_F_REQUESTOR_INFO is clear.
+ * @internal Host only. */
+#define VMMDEV_REQUESTOR_LEGACY                     UINT32_MAX
+/** Lowest conceivable trust level, for error situations of getters.
+ * @internal Host only. */
+#define VMMDEV_REQUESTOR_LOWEST                     (  VMMDEV_REQUESTOR_TRUST_UNTRUSTED | VMMDEV_REQUESTOR_USER_DEVICE \
+                                                     | VMMDEV_REQUESTOR_CON_NO | VMMDEV_REQUESTOR_USERMODE \
+                                                     | VMMDEV_REQUESTOR_USR_GUEST)
+/** Used on the host to check whether a requestor value is present or not. */
+#define VMMDEV_REQUESTOR_IS_PRESENT(a_fRequestor)   ((a_fRequestor) != VMMDEV_REQUESTOR_LEGACY)
+/** @} */
+
+/** Initialize a VMMDevRequestHeader structure.
+ * Same as VBGLREQHDR_INIT_VMMDEV(). */
+#define VMMDEV_REQ_HDR_INIT(a_pHdr, a_cb, a_enmType) \
+    do { \
+        (a_pHdr)->size         = (a_cb); \
+        (a_pHdr)->version      = VMMDEV_REQUEST_HEADER_VERSION; \
+        (a_pHdr)->requestType  = (a_enmType); \
+        (a_pHdr)->rc           = VERR_INTERNAL_ERROR; \
+        (a_pHdr)->reserved1    = 0; \
+        (a_pHdr)->fRequestor   = 0; \
+    } while (0)
+
+
+/**
+ * Mouse status request structure.
+ *
+ * Used by VMMDevReq_GetMouseStatus and VMMDevReq_SetMouseStatus.
+ */
+typedef struct
+{
+    /** header */
+    VMMDevRequestHeader header;
+    /** Mouse feature mask. See VMMDEV_MOUSE_*. */
+    uint32_t mouseFeatures;
+    /** Mouse x position. */
+    int32_t pointerXPos;
+    /** Mouse y position. */
+    int32_t pointerYPos;
+} VMMDevReqMouseStatus;
+AssertCompileSize(VMMDevReqMouseStatus, 24+12);
+
+
+/** @name Mouse buttons state bits for VMMDevReqMouseStatusEx::fButtons (identical to PDMIMOUSEPORT_BUTTON_XXX).
+ * @{ */
+/** Left mouse button pressed. */
+#define VMMDEV_MOUSE_BUTTON_LEFT   RT_BIT(0)
+/** Right mouse button pressed. */
+#define VMMDEV_MOUSE_BUTTON_RIGHT  RT_BIT(1)
+/** Middle mouse button pressed. */
+#define VMMDEV_MOUSE_BUTTON_MIDDLE RT_BIT(2)
+/** X1 mouse button pressed. */
+#define VMMDEV_MOUSE_BUTTON_X1     RT_BIT(3)
+/** X2 mouse button pressed. */
+#define VMMDEV_MOUSE_BUTTON_X2     RT_BIT(4)
+/** @} */
+
+
+/**
+ * Extended mouse status request structure.
+ *
+ * Used by VMMDevReq_GetMouseStatusEx.
+ */
+typedef struct
+{
+    /** Legacy mouse status request structure. */
+    VMMDevReqMouseStatus Core;
+    /** Mouse wheel vertical mvement. */
+    int32_t dz;
+    /** Mouse wheel horizontal movement. */
+    int32_t dw;
+    /** Mouse buttons state. */
+    uint32_t fButtons;
+} VMMDevReqMouseStatusEx;
+AssertCompileSize(VMMDevReqMouseStatusEx, 24+24);
+
+
+/** @name Mouse capability bits (VMMDevReqMouseStatus::mouseFeatures).
+ * @{ */
+/** The guest can (== wants to) handle absolute coordinates.  */
+#define VMMDEV_MOUSE_GUEST_CAN_ABSOLUTE                     RT_BIT(0)
+/** The host can (== wants to) send absolute coordinates.
+ * (Input not captured.) */
+#define VMMDEV_MOUSE_HOST_WANTS_ABSOLUTE                    RT_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                RT_BIT(2)
+/** The host does NOT provide support for drawing the cursor itself. */
+#define VMMDEV_MOUSE_HOST_CANNOT_HWPOINTER                  RT_BIT(3)
+/** The guest can read VMMDev events to find out about pointer movement */
+#define VMMDEV_MOUSE_NEW_PROTOCOL                           RT_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        RT_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                       RT_BIT(6)
+/** The guest can read VMMDev events to find out about full mouse state */
+#define VMMDEV_MOUSE_GUEST_USES_FULL_STATE_PROTOCOL         RT_BIT(7)
+/** The host can provide full mouse state over VMMDev events */
+#define VMMDEV_MOUSE_HOST_USES_FULL_STATE_PROTOCOL          RT_BIT(8)
+/** The mask of all VMMDEV_MOUSE_* flags */
+#define VMMDEV_MOUSE_MASK                                   UINT32_C(0x000001ff)
+/** The mask of guest capability changes for which notification events should
+ * be sent */
+#define VMMDEV_MOUSE_NOTIFY_HOST_MASK \
+      (VMMDEV_MOUSE_GUEST_CAN_ABSOLUTE | VMMDEV_MOUSE_GUEST_NEEDS_HOST_CURSOR)
+/** The mask of all capabilities which the guest can legitimately change */
+#define VMMDEV_MOUSE_GUEST_MASK \
+      (VMMDEV_MOUSE_NOTIFY_HOST_MASK | VMMDEV_MOUSE_NEW_PROTOCOL | VMMDEV_MOUSE_GUEST_USES_FULL_STATE_PROTOCOL)
+/** The mask of host capability changes for which notification events should
+ * be sent */
+#define VMMDEV_MOUSE_NOTIFY_GUEST_MASK \
+      VMMDEV_MOUSE_HOST_WANTS_ABSOLUTE
+/** The mask of all capabilities which the host can legitimately change */
+#define VMMDEV_MOUSE_HOST_MASK \
+      (  VMMDEV_MOUSE_NOTIFY_GUEST_MASK \
+       | VMMDEV_MOUSE_HOST_CANNOT_HWPOINTER \
+       | VMMDEV_MOUSE_HOST_RECHECKS_NEEDS_HOST_CURSOR \
+       | VMMDEV_MOUSE_HOST_HAS_ABS_DEV \
+       | VMMDEV_MOUSE_HOST_USES_FULL_STATE_PROTOCOL)
+/** @} */
+
+/** @name Absolute mouse reporting range
+ * @{ */
+/** @todo Should these be here?  They are needed by both host and guest. */
+/** The minumum 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
+/** The full range our pointing device can return. */
+#define VMMDEV_MOUSE_RANGE (VMMDEV_MOUSE_RANGE_MAX - VMMDEV_MOUSE_RANGE_MIN)
+/** @} */
+
+
+/**
+ * Mouse pointer shape/visibility change request.
+ *
+ * Used by VMMDevReq_SetPointerShape. The size is variable.
+ */
+typedef struct VMMDevReqMousePointer
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** VBOX_MOUSE_POINTER_* bit flags from VBox/Graphics/VBoxVideo.h. */
+    uint32_t fFlags;
+    /** x coordinate of hot spot. */
+    uint32_t xHot;
+    /** y coordinate of hot spot. */
+    uint32_t yHot;
+    /** Width of the pointer in pixels. */
+    uint32_t width;
+    /** Height of the pointer in scanlines. */
+    uint32_t height;
+    /** Pointer data.
+     *
+     ****
+     * The data consists of 1 bpp AND mask followed by 32 bpp XOR (color) mask.
+     *
+     * For pointers without alpha channel the XOR mask pixels are 32 bit values: (lsb)BGR0(msb).
+     * For pointers with alpha channel the XOR mask consists of (lsb)BGRA(msb) 32 bit values.
+     *
+     * Guest driver must create the AND mask for pointers with alpha channel, so if host does not
+     * support alpha, the pointer could be displayed as a normal color pointer. The AND mask can
+     * be constructed from alpha values. For example alpha value >= 0xf0 means bit 0 in the AND mask.
+     *
+     * The AND mask is 1 bpp bitmap with byte aligned scanlines. Size of AND mask,
+     * therefore, is cbAnd = (width + 7) / 8 * height. The padding bits at the
+     * end of any scanline are undefined.
+     *
+     * The XOR mask follows the AND mask on the next 4 bytes aligned offset:
+     * uint8_t *pXor = pAnd + (cbAnd + 3) & ~3
+     * Bytes in the gap between the AND and the XOR mask are undefined.
+     * XOR mask scanlines have no gap between them and size of XOR mask is:
+     * cXor = width * 4 * height.
+     ****
+     *
+     * Preallocate 4 bytes for accessing actual data as p->pointerData.
+     */
+    char pointerData[4];
+} VMMDevReqMousePointer;
+AssertCompileSize(VMMDevReqMousePointer, 24+24);
+
+/**
+ * Get the size that a VMMDevReqMousePointer request should have for a given
+ * size of cursor, including the trailing cursor image and mask data.
+ * @note an "empty" request still has the four preallocated bytes of data
+ *
+ * @returns the size
+ * @param  width   the cursor width
+ * @param  height  the cursor height
+ */
+DECLINLINE(size_t) vmmdevGetMousePointerReqSize(uint32_t width, uint32_t height)
+{
+    size_t cbBase = RT_UOFFSETOF(VMMDevReqMousePointer, pointerData[0]);
+    size_t cbMask = (width + 7) / 8 * height;
+    size_t cbArgb = width * height * 4;
+    return RT_MAX(cbBase + ((cbMask + 3) & ~(size_t)3) + cbArgb,
+                  sizeof(VMMDevReqMousePointer));
+}
+
+
+/**
+ * String log request structure.
+ *
+ * Used by VMMDevReq_LogString.
+ * @deprecated  Use the IPRT logger or VbglR3WriteLog instead.
+ */
+typedef struct
+{
+    /** header */
+    VMMDevRequestHeader header;
+    /** variable length string data */
+    char szString[1];
+} VMMDevReqLogString;
+AssertCompileSize(VMMDevReqLogString, 24+4);
+
+
+/**
+ * VirtualBox host version request structure.
+ *
+ * Used by VMMDevReq_GetHostVersion.
+ *
+ * @remarks VBGL uses this to detect the precense of new features in the
+ *          interface.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Major version. */
+    uint16_t major;
+    /** Minor version. */
+    uint16_t minor;
+    /** Build number. */
+    uint32_t build;
+    /** SVN revision. */
+    uint32_t revision;
+    /** Feature mask. */
+    uint32_t features;
+} VMMDevReqHostVersion;
+AssertCompileSize(VMMDevReqHostVersion, 24+16);
+
+/** @name VMMDEV_HVF_XXX - VMMDevReqHostVersion::features
+ * @{ */
+/** Physical page lists are supported by HGCM. */
+#define VMMDEV_HVF_HGCM_PHYS_PAGE_LIST          RT_BIT_32(0)
+/** HGCM supports the embedded buffer parameter type. */
+#define VMMDEV_HVF_HGCM_EMBEDDED_BUFFERS        RT_BIT_32(1)
+/** HGCM supports the contiguous page list parameter type. */
+#define VMMDEV_HVF_HGCM_CONTIGUOUS_PAGE_LIST    RT_BIT_32(2)
+/** HGCM supports the no-bounce page list parameter type. */
+#define VMMDEV_HVF_HGCM_NO_BOUNCE_PAGE_LIST     RT_BIT_32(3)
+/** VMMDev supports fast IRQ acknowledgements. */
+#define VMMDEV_HVF_FAST_IRQ_ACK                 RT_BIT_32(31)
+/** @} */
+
+
+/**
+ * Guest capabilities structure.
+ *
+ * Used by VMMDevReq_ReportGuestCapabilities.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Capabilities (VMMDEV_GUEST_*). */
+    uint32_t caps;
+} VMMDevReqGuestCapabilities;
+AssertCompileSize(VMMDevReqGuestCapabilities, 24+4);
+
+
+/**
+ * Guest capabilities structure, version 2.
+ *
+ * Used by VMMDevReq_SetGuestCapabilities.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Mask of capabilities to be added. */
+    uint32_t u32OrMask;
+    /** Mask of capabilities to be removed. */
+    uint32_t u32NotMask;
+} VMMDevReqGuestCapabilities2;
+AssertCompileSize(VMMDevReqGuestCapabilities2, 24+8);
+
+
+/**
+ * Idle request structure.
+ *
+ * Used by VMMDevReq_Idle.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+} VMMDevReqIdle;
+AssertCompileSize(VMMDevReqIdle, 24);
+
+
+/**
+ * Host time request structure.
+ *
+ * Used by VMMDevReq_GetHostTime.
+ */
+typedef struct
+{
+    /** Header */
+    VMMDevRequestHeader header;
+    /** OUT: Time in milliseconds since unix epoch. */
+    uint64_t time;
+} VMMDevReqHostTime;
+AssertCompileSize(VMMDevReqHostTime, 24+8);
+
+
+/**
+ * Hypervisor info structure.
+ *
+ * Used by VMMDevReq_GetHypervisorInfo and VMMDevReq_SetHypervisorInfo.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest virtual address of proposed hypervisor start.
+     * Not used by VMMDevReq_GetHypervisorInfo.
+     * @todo Make this 64-bit compatible? */
+    RTGCPTR32 hypervisorStart;
+    /** Hypervisor size in bytes. */
+    uint32_t hypervisorSize;
+} VMMDevReqHypervisorInfo;
+AssertCompileSize(VMMDevReqHypervisorInfo, 24+8);
+
+/** @name Default patch memory size .
+ * Used by VMMDevReq_RegisterPatchMemory and VMMDevReq_DeregisterPatchMemory.
+ * @{ */
+#define VMMDEV_GUEST_DEFAULT_PATCHMEM_SIZE          8192
+/** @} */
+
+/**
+ * Patching memory structure. (locked executable & read-only page from the guest's perspective)
+ *
+ * Used by VMMDevReq_RegisterPatchMemory and VMMDevReq_DeregisterPatchMemory
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest virtual address of the patching page(s). */
+    RTGCPTR64           pPatchMem;
+    /** Patch page size in bytes. */
+    uint32_t            cbPatchMem;
+} VMMDevReqPatchMemory;
+AssertCompileSize(VMMDevReqPatchMemory, 24+12);
+
+
+/**
+ * Guest power requests.
+ *
+ * See VMMDevReq_SetPowerStatus and VMMDevPowerStateRequest.
+ */
+typedef enum
+{
+    VMMDevPowerState_Invalid   = 0,
+    VMMDevPowerState_Pause     = 1,
+    VMMDevPowerState_PowerOff  = 2,
+    VMMDevPowerState_SaveState = 3,
+    VMMDevPowerState_SizeHack = 0x7fffffff
+} VMMDevPowerState;
+AssertCompileSize(VMMDevPowerState, 4);
+
+/**
+ * VM power status structure.
+ *
+ * Used by VMMDevReq_SetPowerStatus.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Power state request. */
+    VMMDevPowerState powerState;
+} VMMDevPowerStateRequest;
+AssertCompileSize(VMMDevPowerStateRequest, 24+4);
+
+
+/**
+ * Pending events structure.
+ *
+ * Used by VMMDevReq_AcknowledgeEvents.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** OUT: Pending event mask. */
+    uint32_t events;
+} VMMDevEvents;
+AssertCompileSize(VMMDevEvents, 24+4);
+
+
+/**
+ * Guest event filter mask control.
+ *
+ * Used by VMMDevReq_CtlGuestFilterMask.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Mask of events to be added to the filter. */
+    uint32_t u32OrMask;
+    /** Mask of events to be removed from the filter. */
+    uint32_t u32NotMask;
+} VMMDevCtlGuestFilterMask;
+AssertCompileSize(VMMDevCtlGuestFilterMask, 24+8);
+
+
+/**
+ * Guest information structure.
+ *
+ * Used by VMMDevReportGuestInfo and PDMIVMMDEVCONNECTOR::pfnUpdateGuestVersion.
+ */
+typedef struct VBoxGuestInfo
+{
+    /** The VMMDev interface version expected by additions.
+      * *Deprecated*, do not use anymore! Will be removed. */
+    uint32_t interfaceVersion;
+    /** Guest OS type. */
+    VBOXOSTYPE osType;
+} VBoxGuestInfo;
+AssertCompileSize(VBoxGuestInfo, 8);
+
+/**
+ * Guest information report.
+ *
+ * Used by VMMDevReq_ReportGuestInfo.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest information. */
+    VBoxGuestInfo guestInfo;
+} VMMDevReportGuestInfo;
+AssertCompileSize(VMMDevReportGuestInfo, 24+8);
+
+
+/**
+ * Guest information structure, version 2.
+ *
+ * Used by VMMDevReportGuestInfo2 and PDMIVMMDEVCONNECTOR::pfnUpdateGuestVersion2.
+ */
+typedef struct VBoxGuestInfo2
+{
+    /** Major version. */
+    uint16_t additionsMajor;
+    /** Minor version. */
+    uint16_t additionsMinor;
+    /** Build number. */
+    uint32_t additionsBuild;
+    /** SVN revision. */
+    uint32_t additionsRevision;
+    /** Feature mask, VBOXGSTINFO2_F_XXX. */
+    uint32_t additionsFeatures;
+    /** 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: VBOX_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     szName[128];
+} VBoxGuestInfo2;
+AssertCompileSize(VBoxGuestInfo2, 144);
+
+/** @name VBOXGSTINFO2_F_XXX - Features
+ * @{ */
+/** Request header carries requestor information. */
+#define VBOXGSTINFO2_F_REQUESTOR_INFO       RT_BIT_32(0)
+/** @} */
+
+
+/**
+ * Guest information report, version 2.
+ *
+ * Used by VMMDevReq_ReportGuestInfo2.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest information. */
+    VBoxGuestInfo2 guestInfo;
+} VMMDevReportGuestInfo2;
+AssertCompileSize(VMMDevReportGuestInfo2, 24+144);
+
+
+/**
+ * The facility class.
+ *
+ * This needs to be kept in sync with AdditionsFacilityClass of the Main API!
+ */
+typedef enum
+{
+    VBoxGuestFacilityClass_None       = 0,
+    VBoxGuestFacilityClass_Driver     = 10,
+    VBoxGuestFacilityClass_Service    = 30,
+    VBoxGuestFacilityClass_Program    = 50,
+    VBoxGuestFacilityClass_Feature    = 100,
+    VBoxGuestFacilityClass_ThirdParty = 999,
+    VBoxGuestFacilityClass_All        = 0x7ffffffe,
+    VBoxGuestFacilityClass_SizeHack   = 0x7fffffff
+} VBoxGuestFacilityClass;
+AssertCompileSize(VBoxGuestFacilityClass, 4);
+
+/**
+ * Guest status structure.
+ *
+ * Used by VMMDevReqGuestStatus.
+ */
+typedef struct VBoxGuestStatus
+{
+    /** Facility the status is indicated for. */
+    VBoxGuestFacilityType facility;
+    /** Current guest status. */
+    VBoxGuestFacilityStatus status;
+    /** Flags, not used at the moment. */
+    uint32_t flags;
+} VBoxGuestStatus;
+AssertCompileSize(VBoxGuestStatus, 12);
+
+/**
+ * Guest Additions status structure.
+ *
+ * Used by VMMDevReq_ReportGuestStatus.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest information. */
+    VBoxGuestStatus guestStatus;
+} VMMDevReportGuestStatus;
+AssertCompileSize(VMMDevReportGuestStatus, 24+12);
+
+
+/**
+ * Guest user status updates.
+ */
+typedef struct VBoxGuestUserStatus
+{
+    /** The guest user state to send. */
+    VBoxGuestUserState  state;
+    /** Size (in bytes) of szUser. */
+    uint32_t            cbUser;
+    /** Size (in bytes) of szDomain. */
+    uint32_t            cbDomain;
+    /** Size (in bytes) of aDetails. */
+    uint32_t            cbDetails;
+    /** Note: Here begins the dynamically
+     *        allocated region. */
+    /** Guest user to report state for. */
+    char                szUser[1];
+    /** Domain the guest user is bound to. */
+    char                szDomain[1];
+    /** Optional details of the state. */
+    uint8_t             aDetails[1];
+} VBoxGuestUserStatus;
+AssertCompileSize(VBoxGuestUserStatus, 20);
+
+
+/**
+ * Guest user status structure.
+ *
+ * Used by VMMDevReq_ReportGuestUserStatus.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest user status. */
+    VBoxGuestUserStatus status;
+} VMMDevReportGuestUserState;
+AssertCompileSize(VMMDevReportGuestUserState, 24+20);
+
+
+/**
+ * Guest statistics structure.
+ *
+ * Used by VMMDevReportGuestStats and PDMIVMMDEVCONNECTOR::pfnReportStatistics.
+ */
+typedef struct VBoxGuestStatistics
+{
+    /** Virtual CPU ID. */
+    uint32_t        u32CpuId;
+    /** Reported statistics. */
+    uint32_t        u32StatCaps;
+    /** Idle CPU load (0-100) for last interval. */
+    uint32_t        u32CpuLoad_Idle;
+    /** Kernel CPU load (0-100) for last interval. */
+    uint32_t        u32CpuLoad_Kernel;
+    /** User CPU load (0-100) for last interval. */
+    uint32_t        u32CpuLoad_User;
+    /** Nr of threads. */
+    uint32_t        u32Threads;
+    /** Nr of processes. */
+    uint32_t        u32Processes;
+    /** Nr of handles. */
+    uint32_t        u32Handles;
+    /** Memory load (0-100). */
+    uint32_t        u32MemoryLoad;
+    /** Page size of guest system. */
+    uint32_t        u32PageSize;
+    /** Total physical memory (in 4KB pages). */
+    uint32_t        u32PhysMemTotal;
+    /** Available physical memory (in 4KB pages). */
+    uint32_t        u32PhysMemAvail;
+    /** Ballooned physical memory (in 4KB pages). */
+    uint32_t        u32PhysMemBalloon;
+    /** Total number of committed memory (which is not necessarily in-use) (in 4KB pages). */
+    uint32_t        u32MemCommitTotal;
+    /** Total amount of memory used by the kernel (in 4KB pages). */
+    uint32_t        u32MemKernelTotal;
+    /** Total amount of paged memory used by the kernel (in 4KB pages). */
+    uint32_t        u32MemKernelPaged;
+    /** Total amount of nonpaged memory used by the kernel (in 4KB pages). */
+    uint32_t        u32MemKernelNonPaged;
+    /** Total amount of memory used for the system cache (in 4KB pages). */
+    uint32_t        u32MemSystemCache;
+    /** Pagefile size (in 4KB pages). */
+    uint32_t        u32PageFileSize;
+} VBoxGuestStatistics;
+AssertCompileSize(VBoxGuestStatistics, 19*4);
+
+/** @name Guest statistics values (VBoxGuestStatistics::u32StatCaps).
+ * @{ */
+#define VBOX_GUEST_STAT_CPU_LOAD_IDLE       RT_BIT(0)
+#define VBOX_GUEST_STAT_CPU_LOAD_KERNEL     RT_BIT(1)
+#define VBOX_GUEST_STAT_CPU_LOAD_USER       RT_BIT(2)
+#define VBOX_GUEST_STAT_THREADS             RT_BIT(3)
+#define VBOX_GUEST_STAT_PROCESSES           RT_BIT(4)
+#define VBOX_GUEST_STAT_HANDLES             RT_BIT(5)
+#define VBOX_GUEST_STAT_MEMORY_LOAD         RT_BIT(6)
+#define VBOX_GUEST_STAT_PHYS_MEM_TOTAL      RT_BIT(7)
+#define VBOX_GUEST_STAT_PHYS_MEM_AVAIL      RT_BIT(8)
+#define VBOX_GUEST_STAT_PHYS_MEM_BALLOON    RT_BIT(9)
+#define VBOX_GUEST_STAT_MEM_COMMIT_TOTAL    RT_BIT(10)
+#define VBOX_GUEST_STAT_MEM_KERNEL_TOTAL    RT_BIT(11)
+#define VBOX_GUEST_STAT_MEM_KERNEL_PAGED    RT_BIT(12)
+#define VBOX_GUEST_STAT_MEM_KERNEL_NONPAGED RT_BIT(13)
+#define VBOX_GUEST_STAT_MEM_SYSTEM_CACHE    RT_BIT(14)
+#define VBOX_GUEST_STAT_PAGE_FILE_SIZE      RT_BIT(15)
+/** @} */
+
+/**
+ * Guest statistics command structure.
+ *
+ * Used by VMMDevReq_ReportGuestStats.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Guest information. */
+    VBoxGuestStatistics guestStats;
+} VMMDevReportGuestStats;
+AssertCompileSize(VMMDevReportGuestStats, 24+19*4);
+
+
+/** Memory balloon change request structure. */
+#define VMMDEV_MAX_MEMORY_BALLOON(PhysMemTotal)     ( (9 * (PhysMemTotal)) / 10 )
+
+/**
+ * Poll for ballooning change request.
+ *
+ * Used by VMMDevReq_GetMemBalloonChangeRequest.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Balloon size in megabytes. */
+    uint32_t            cBalloonChunks;
+    /** Guest ram size in megabytes. */
+    uint32_t            cPhysMemChunks;
+    /** Setting this to VMMDEV_EVENT_BALLOON_CHANGE_REQUEST indicates that the
+     * request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t            eventAck;
+} VMMDevGetMemBalloonChangeRequest;
+AssertCompileSize(VMMDevGetMemBalloonChangeRequest, 24+12);
+
+
+/**
+ * Change the size of the balloon.
+ *
+ * Used by VMMDevReq_ChangeMemBalloon.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** The number of pages in the array. */
+    uint32_t            cPages;
+    /** true = inflate, false = deflate.  */
+    uint32_t            fInflate;
+    /** Physical address (RTGCPHYS) of each page, variable size. */
+    RTGCPHYS            aPhysPage[1];
+} VMMDevChangeMemBalloon;
+AssertCompileSize(VMMDevChangeMemBalloon, 24+16);
+
+
+/**
+ * Guest statistics interval change request structure.
+ *
+ * Used by VMMDevReq_GetStatisticsChangeRequest.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** The interval in seconds. */
+    uint32_t            u32StatInterval;
+    /** Setting this to VMMDEV_EVENT_STATISTICS_INTERVAL_CHANGE_REQUEST indicates
+     * that the request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t            eventAck;
+} VMMDevGetStatisticsChangeRequest;
+AssertCompileSize(VMMDevGetStatisticsChangeRequest, 24+8);
+
+
+/** The size of a string field in the credentials request (including '\\0').
+ * @see VMMDevCredentials  */
+#define VMMDEV_CREDENTIALS_SZ_SIZE          128
+
+/**
+ * Credentials request structure.
+ *
+ * Used by VMMDevReq_QueryCredentials.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** IN/OUT: Request flags. */
+    uint32_t u32Flags;
+    /** OUT: User name (UTF-8). */
+    char szUserName[VMMDEV_CREDENTIALS_SZ_SIZE];
+    /** OUT: Password (UTF-8). */
+    char szPassword[VMMDEV_CREDENTIALS_SZ_SIZE];
+    /** OUT: Domain name (UTF-8). */
+    char szDomain[VMMDEV_CREDENTIALS_SZ_SIZE];
+} VMMDevCredentials;
+AssertCompileSize(VMMDevCredentials, 24+4+3*128);
+
+/** @name Credentials request flag (VMMDevCredentials::u32Flags)
+ * @{ */
+/** query from host whether credentials are present */
+#define VMMDEV_CREDENTIALS_QUERYPRESENCE     RT_BIT(1)
+/** read credentials from host (can be combined with clear) */
+#define VMMDEV_CREDENTIALS_READ              RT_BIT(2)
+/** clear credentials on host (can be combined with read) */
+#define VMMDEV_CREDENTIALS_CLEAR             RT_BIT(3)
+/** read credentials for judgement in the guest */
+#define VMMDEV_CREDENTIALS_READJUDGE         RT_BIT(8)
+/** clear credentials for judegement on the host */
+#define VMMDEV_CREDENTIALS_CLEARJUDGE        RT_BIT(9)
+/** report credentials acceptance by guest */
+#define VMMDEV_CREDENTIALS_JUDGE_OK          RT_BIT(10)
+/** report credentials denial by guest */
+#define VMMDEV_CREDENTIALS_JUDGE_DENY        RT_BIT(11)
+/** report that no judgement could be made by guest */
+#define VMMDEV_CREDENTIALS_JUDGE_NOJUDGEMENT RT_BIT(12)
+
+/** flag telling the guest that credentials are present */
+#define VMMDEV_CREDENTIALS_PRESENT           RT_BIT(16)
+/** flag telling guest that local logons should be prohibited */
+#define VMMDEV_CREDENTIALS_NOLOCALLOGON      RT_BIT(17)
+/** @} */
+
+
+/**
+ * Seamless mode change request structure.
+ *
+ * Used by VMMDevReq_GetSeamlessChangeRequest.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+
+    /** New seamless mode. */
+    VMMDevSeamlessMode mode;
+    /** Setting this to VMMDEV_EVENT_SEAMLESS_MODE_CHANGE_REQUEST indicates
+     * that the request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t eventAck;
+} VMMDevSeamlessChangeRequest;
+AssertCompileSize(VMMDevSeamlessChangeRequest, 24+8);
+AssertCompileMemberOffset(VMMDevSeamlessChangeRequest, eventAck, 24+4);
+
+
+/**
+ * Display change request structure.
+ *
+ * Used by VMMDevReq_GetDisplayChangeRequest.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Horizontal pixel resolution (0 = do not change). */
+    uint32_t xres;
+    /** Vertical pixel resolution (0 = do not change). */
+    uint32_t yres;
+    /** Bits per pixel (0 = do not change). */
+    uint32_t bpp;
+    /** Setting this to VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST indicates
+     * that the request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t eventAck;
+} VMMDevDisplayChangeRequest;
+AssertCompileSize(VMMDevDisplayChangeRequest, 24+16);
+
+
+/**
+ * Display change request structure, version 2.
+ *
+ * Used by VMMDevReq_GetDisplayChangeRequest2.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Horizontal pixel resolution (0 = do not change). */
+    uint32_t xres;
+    /** Vertical pixel resolution (0 = do not change). */
+    uint32_t yres;
+    /** Bits per pixel (0 = do not change). */
+    uint32_t bpp;
+    /** Setting this to VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST indicates
+     * that the request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t eventAck;
+    /** 0 for primary display, 1 for the first secondary, etc. */
+    uint32_t display;
+} VMMDevDisplayChangeRequest2;
+AssertCompileSize(VMMDevDisplayChangeRequest2, 24+20);
+
+
+/**
+ * Display change request structure, version Extended.
+ *
+ * Used by VMMDevReq_GetDisplayChangeRequestEx.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Horizontal pixel resolution (0 = do not change). */
+    uint32_t xres;
+    /** Vertical pixel resolution (0 = do not change). */
+    uint32_t yres;
+    /** Bits per pixel (0 = do not change). */
+    uint32_t bpp;
+    /** Setting this to VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST indicates
+     * that the request is a response to that event.
+     * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t eventAck;
+    /** 0 for primary display, 1 for the first secondary, etc. */
+    uint32_t display;
+    /** New OriginX of secondary virtual screen */
+    uint32_t cxOrigin;
+    /** New OriginY of secondary virtual screen  */
+    uint32_t cyOrigin;
+    /** Change in origin of the secondary virtaul scree is
+     *  required */
+    bool fChangeOrigin;
+    /** secondary virtual screen enabled or disabled */
+    bool fEnabled;
+} VMMDevDisplayChangeRequestEx;
+AssertCompileSize(VMMDevDisplayChangeRequestEx, 24+32);
+
+
+/** Flags for VMMDevDisplayDef::fDisplayFlags */
+#define VMMDEV_DISPLAY_PRIMARY  UINT32_C(0x00000001) /**< Primary display. */
+#define VMMDEV_DISPLAY_DISABLED UINT32_C(0x00000002) /**< Display is disabled. */
+#define VMMDEV_DISPLAY_ORIGIN   UINT32_C(0x00000004) /**< Change position of the diplay. */
+#define VMMDEV_DISPLAY_CX       UINT32_C(0x00000008) /**< Change the horizontal resolution of the display. */
+#define VMMDEV_DISPLAY_CY       UINT32_C(0x00000010) /**< Change the vertical resolution of the display. */
+#define VMMDEV_DISPLAY_BPP      UINT32_C(0x00000020) /**< Change the color depth of the display. */
+
+/** Definition of one monitor. Used by VMMDevReq_GetDisplayChangeRequestMulti. */
+typedef struct VMMDevDisplayDef
+{
+    uint32_t fDisplayFlags;             /**< VMMDEV_DISPLAY_* flags. */
+    uint32_t idDisplay;                 /**< The display number. */
+    int32_t  xOrigin;                   /**< New OriginX of the guest screen. */
+    int32_t  yOrigin;                   /**< New OriginY of the guest screen.  */
+    uint32_t cx;                        /**< Horizontal pixel resolution. */
+    uint32_t cy;                        /**< Vertical pixel resolution. */
+    uint32_t cBitsPerPixel;             /**< Bits per pixel. */
+} VMMDevDisplayDef;
+AssertCompileSize(VMMDevDisplayDef, 28);
+
+/** Multimonitor display change request structure. Used by VMMDevReq_GetDisplayChangeRequestMulti. */
+typedef struct VMMDevDisplayChangeRequestMulti
+{
+    VMMDevRequestHeader header;         /**< Header. */
+    uint32_t eventAck;                  /**< Setting this to VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST indicates
+                                         * that the request is a response to that event.
+                                         * (Don't confuse this with VMMDevReq_AcknowledgeEvents.) */
+    uint32_t cDisplays;                 /**< Number of monitors. In: how many the guest expects.
+                                         *                      Out: how many the host provided. */
+    VMMDevDisplayDef aDisplays[1];      /**< Layout of monitors. */
+} VMMDevDisplayChangeRequestMulti;
+AssertCompileSize(VMMDevDisplayChangeRequestMulti, 24+8+28);
+
+
+/**
+ * Video mode supported request structure.
+ *
+ * Used by VMMDevReq_VideoModeSupported.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** IN: Horizontal pixel resolution. */
+    uint32_t width;
+    /** IN: Vertical pixel resolution. */
+    uint32_t height;
+    /** IN: Bits per pixel. */
+    uint32_t bpp;
+    /** OUT: Support indicator. */
+    bool fSupported;
+} VMMDevVideoModeSupportedRequest;
+AssertCompileSize(VMMDevVideoModeSupportedRequest, 24+16);
+
+/**
+ * Video mode supported request structure for a specific display.
+ *
+ * Used by VMMDevReq_VideoModeSupported2.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** IN: The guest display number. */
+    uint32_t display;
+    /** IN: Horizontal pixel resolution. */
+    uint32_t width;
+    /** IN: Vertical pixel resolution. */
+    uint32_t height;
+    /** IN: Bits per pixel. */
+    uint32_t bpp;
+    /** OUT: Support indicator. */
+    bool fSupported;
+} VMMDevVideoModeSupportedRequest2;
+AssertCompileSize(VMMDevVideoModeSupportedRequest2, 24+20);
+
+/**
+ * Video modes height reduction request structure.
+ *
+ * Used by VMMDevReq_GetHeightReduction.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** OUT: Height reduction in pixels. */
+    uint32_t heightReduction;
+} VMMDevGetHeightReductionRequest;
+AssertCompileSize(VMMDevGetHeightReductionRequest, 24+4);
+
+
+/**
+ * VRDP change request structure.
+ *
+ * Used by VMMDevReq_GetVRDPChangeRequest.
+ */
+typedef struct
+{
+    /** Header */
+    VMMDevRequestHeader header;
+    /** Whether VRDP is active or not. */
+    uint8_t u8VRDPActive;
+    /** The configured experience level for active VRDP. */
+    uint32_t u32VRDPExperienceLevel;
+} VMMDevVRDPChangeRequest;
+AssertCompileSize(VMMDevVRDPChangeRequest, 24+8);
+AssertCompileMemberOffset(VMMDevVRDPChangeRequest, u8VRDPActive, 24);
+AssertCompileMemberOffset(VMMDevVRDPChangeRequest, u32VRDPExperienceLevel, 24+4);
+
+/** @name VRDP Experience level (VMMDevVRDPChangeRequest::u32VRDPExperienceLevel)
+ * @{ */
+#define VRDP_EXPERIENCE_LEVEL_ZERO     0 /**< Theming disabled. */
+#define VRDP_EXPERIENCE_LEVEL_LOW      1 /**< Full window dragging and desktop wallpaper disabled. */
+#define VRDP_EXPERIENCE_LEVEL_MEDIUM   2 /**< Font smoothing, gradients. */
+#define VRDP_EXPERIENCE_LEVEL_HIGH     3 /**< Animation effects disabled. */
+#define VRDP_EXPERIENCE_LEVEL_FULL     4 /**< Everything enabled. */
+/** @} */
+
+
+/**
+ * VBVA enable request structure.
+ *
+ * Used by VMMDevReq_VideoAccelEnable.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** 0 - disable, !0 - enable. */
+    uint32_t u32Enable;
+    /** The size of VBVAMEMORY::au8RingBuffer expected by driver.
+     *  The host will refuse to enable VBVA if the size is not equal to
+     *  VBVA_RING_BUFFER_SIZE.
+     */
+    uint32_t cbRingBuffer;
+    /** Guest initializes the status to 0. Host sets appropriate VBVA_F_STATUS_ flags. */
+    uint32_t fu32Status;
+} VMMDevVideoAccelEnable;
+AssertCompileSize(VMMDevVideoAccelEnable, 24+12);
+
+/** @name VMMDevVideoAccelEnable::fu32Status.
+ * @{ */
+#define VBVA_F_STATUS_ACCEPTED (0x01)
+#define VBVA_F_STATUS_ENABLED  (0x02)
+/** @} */
+
+
+/**
+ * VBVA flush request structure.
+ *
+ * Used by VMMDevReq_VideoAccelFlush.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+} VMMDevVideoAccelFlush;
+AssertCompileSize(VMMDevVideoAccelFlush, 24);
+
+
+/**
+ * VBVA set visible region request structure.
+ *
+ * Used by VMMDevReq_VideoSetVisibleRegion.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Number of rectangles */
+    uint32_t cRect;
+    /** Rectangle array.
+     * @todo array is spelled aRects[1].  */
+    RTRECT Rect;
+} VMMDevVideoSetVisibleRegion;
+AssertCompileSize(RTRECT, 16);
+AssertCompileSize(VMMDevVideoSetVisibleRegion, 24+4+16);
+
+/**
+ * VBVA monitor positions update request structure.
+ *
+ * Used by VMMDevReq_VideoUpdateMonitorPositions.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Number of monitor positions (monitors) */
+    uint32_t cPositions;
+    /** Positions array.*/
+    RTPOINT aPositions[1];
+} VMMDevVideoUpdateMonitorPositions;
+AssertCompileSize(RTPOINT, 8);
+AssertCompileSize(VMMDevVideoUpdateMonitorPositions, 24+4+8);
+
+/**
+ * CPU event types.
+ */
+typedef enum
+{
+    VMMDevCpuStatusType_Invalid  = 0,
+    VMMDevCpuStatusType_Disable  = 1,
+    VMMDevCpuStatusType_Enable   = 2,
+    VMMDevCpuStatusType_SizeHack = 0x7fffffff
+} VMMDevCpuStatusType;
+
+/**
+ * CPU hotplug event status request.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Status type */
+    VMMDevCpuStatusType enmStatusType;
+} VMMDevCpuHotPlugStatusRequest;
+AssertCompileSize(VMMDevCpuHotPlugStatusRequest, 24+4);
+
+/**
+ * Get the ID of the changed CPU and event type.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** Event type */
+    VMMDevCpuEventType  enmEventType;
+    /** core id of the CPU changed */
+    uint32_t            idCpuCore;
+    /** package id of the CPU changed */
+    uint32_t            idCpuPackage;
+} VMMDevGetCpuHotPlugRequest;
+AssertCompileSize(VMMDevGetCpuHotPlugRequest, 24+4+4+4);
+
+
+AssertCompileSize(VMMDEVSHAREDREGIONDESC, 16); /* structure was promoted to VBox/types.h. */
+
+#define VMMDEVSHAREDREGIONDESC_MAX          32
+
+/**
+ * Shared module registration
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** Shared module size. */
+    uint32_t                    cbModule;
+    /** Number of included region descriptors */
+    uint32_t                    cRegions;
+    /** Base address of the shared module. */
+    RTGCPTR64                   GCBaseAddr;
+    /** Guest OS type. */
+    VBOXOSFAMILY                enmGuestOS;
+    /** Alignment. */
+    uint32_t                    u32Align;
+    /** Module name */
+    char                        szName[128];
+    /** Module version */
+    char                        szVersion[16];
+    /** Shared region descriptor(s). */
+    VMMDEVSHAREDREGIONDESC      aRegions[1];
+} VMMDevSharedModuleRegistrationRequest;
+AssertCompileSize(VMMDevSharedModuleRegistrationRequest, 24+4+4+8+4+4+128+16+16);
+
+
+/**
+ * Shared module unregistration
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** Shared module size. */
+    uint32_t                    cbModule;
+    /** Align at 8 byte boundary. */
+    uint32_t                    u32Alignment;
+    /** Base address of the shared module. */
+    RTGCPTR64                   GCBaseAddr;
+    /** Module name */
+    char                        szName[128];
+    /** Module version */
+    char                        szVersion[16];
+} VMMDevSharedModuleUnregistrationRequest;
+AssertCompileSize(VMMDevSharedModuleUnregistrationRequest, 24+4+4+8+128+16);
+
+
+/**
+ * Shared module periodic check
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+} VMMDevSharedModuleCheckRequest;
+AssertCompileSize(VMMDevSharedModuleCheckRequest, 24);
+
+/**
+ * Paging sharing enabled query
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** Enabled flag (out) */
+    bool                        fEnabled;
+    /** Alignment */
+    bool                        fAlignment[3];
+} VMMDevPageSharingStatusRequest;
+AssertCompileSize(VMMDevPageSharingStatusRequest, 24+4);
+
+
+/**
+ * Page sharing status query (debug build only)
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** Page address. */
+    RTGCPTR                     GCPtrPage;
+    /** Page flags. */
+    uint64_t                    uPageFlags;
+    /** Shared flag (out) */
+    bool                        fShared;
+    /** Alignment */
+    bool                        fAlignment[3];
+} VMMDevPageIsSharedRequest;
+
+/**
+ * Session id request structure.
+ *
+ * Used by VMMDevReq_GetSessionId.
+ */
+typedef struct
+{
+    /** Header */
+    VMMDevRequestHeader         header;
+    /** OUT: unique session id; the id will be different after each start, reset or restore of the VM */
+    uint64_t                    idSession;
+} VMMDevReqSessionId;
+AssertCompileSize(VMMDevReqSessionId, 24+8);
+
+
+/**
+ * Write Core Dump request.
+ *
+ * Used by VMMDevReq_WriteCoreDump.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** Flags (reserved, MBZ). */
+    uint32_t                    fFlags;
+} VMMDevReqWriteCoreDump;
+AssertCompileSize(VMMDevReqWriteCoreDump, 24+4);
+
+
+/**
+ * Heart beat check state structure.
+ * Used by VMMDevReq_HeartbeatConfigure.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** OUT: Guest heartbeat interval in nanosec. */
+    uint64_t                    cNsInterval;
+    /** Heartbeat check flag. */
+    bool                        fEnabled;
+} VMMDevReqHeartbeat;
+AssertCompileSize(VMMDevReqHeartbeat, 24+12);
+
+
+/**
+ * NT bug check report.
+ * Used by VMMDevReq_NtBugCheck.
+ * @remarks  Can be issued with just the header if no more data is available.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader         header;
+    /** The bug check number (P0). */
+    uint64_t                    uBugCheck;
+    /** The four bug check parameters. */
+    uint64_t                    auParameters[4];
+} VMMDevReqNtBugCheck;
+AssertCompileSize(VMMDevReqNtBugCheck, 24+40);
+
+
+
+#ifdef VBOX_WITH_HGCM
+
+/** @name HGCM flags.
+ * @{
+ */
+# define VBOX_HGCM_REQ_DONE      RT_BIT_32(VBOX_HGCM_REQ_DONE_BIT)
+# define VBOX_HGCM_REQ_DONE_BIT  0
+# define VBOX_HGCM_REQ_CANCELLED (0x2)
+/** @} */
+
+/**
+ * HGCM request header.
+ */
+typedef struct VMMDevHGCMRequestHeader
+{
+    /** Request header. */
+    VMMDevRequestHeader header;
+
+    /** HGCM flags. */
+    uint32_t fu32Flags;
+
+    /** Result code. */
+    int32_t result;
+} VMMDevHGCMRequestHeader;
+AssertCompileSize(VMMDevHGCMRequestHeader, 24+8);
+
+/**
+ * HGCM connect request structure.
+ *
+ * Used by VMMDevReq_HGCMConnect.
+ */
+typedef struct
+{
+    /** HGCM request header. */
+    VMMDevHGCMRequestHeader header;
+
+    /** IN: Description of service to connect to. */
+    HGCMServiceLocation loc;
+
+    /** OUT: Client identifier assigned by local instance of HGCM. */
+    uint32_t u32ClientID;
+} VMMDevHGCMConnect;
+AssertCompileSize(VMMDevHGCMConnect, 32+132+4);
+
+
+/**
+ * HGCM disconnect request structure.
+ *
+ * Used by VMMDevReq_HGCMDisconnect.
+ */
+typedef struct
+{
+    /** HGCM request header. */
+    VMMDevHGCMRequestHeader header;
+
+    /** IN: Client identifier. */
+    uint32_t u32ClientID;
+} VMMDevHGCMDisconnect;
+AssertCompileSize(VMMDevHGCMDisconnect, 32+4);
+
+/**
+ * HGCM call request structure.
+ *
+ * Used by VMMDevReq_HGCMCall32 and VMMDevReq_HGCMCall64.
+ */
+typedef struct
+{
+    /* request header */
+    VMMDevHGCMRequestHeader header;
+
+    /** IN: Client identifier. */
+    uint32_t u32ClientID;
+    /** IN: Service function number. */
+    uint32_t u32Function;
+    /** IN: Number of parameters. */
+    uint32_t cParms;
+    /** Parameters follow in form: HGCMFunctionParameter aParms[X]; */
+} VMMDevHGCMCall;
+AssertCompileSize(VMMDevHGCMCall, 32+12);
+
+/** @name Direction of data transfer (HGCMPageListInfo::flags). Bit flags.
+ * @{ */
+#define VBOX_HGCM_F_PARM_DIRECTION_NONE      UINT32_C(0x00000000)
+#define VBOX_HGCM_F_PARM_DIRECTION_TO_HOST   UINT32_C(0x00000001)
+#define VBOX_HGCM_F_PARM_DIRECTION_FROM_HOST UINT32_C(0x00000002)
+#define VBOX_HGCM_F_PARM_DIRECTION_BOTH      UINT32_C(0x00000003)
+#define VBOX_HGCM_F_PARM_DIRECTION_MASK      UINT32_C(0x00000003)
+/** Macro for validating that the specified flags are valid. */
+#define VBOX_HGCM_F_PARM_ARE_VALID(fFlags) \
+    (   ((fFlags) & VBOX_HGCM_F_PARM_DIRECTION_MASK) \
+     && !((fFlags) & ~VBOX_HGCM_F_PARM_DIRECTION_MASK) )
+/** @} */
+
+/**
+ * VMMDevHGCMParmType_PageList points to this structure to actually describe the
+ * buffer.
+ */
+typedef struct
+{
+    uint32_t flags;        /**< VBOX_HGCM_F_PARM_*. */
+    uint16_t offFirstPage; /**< Offset in the first page where data begins. */
+    uint16_t cPages;       /**< Number of pages. */
+    RTGCPHYS64 aPages[1];  /**< Page addresses. */
+} HGCMPageListInfo;
+AssertCompileSize(HGCMPageListInfo, 4+2+2+8);
+
+
+/** Get the pointer to the first parmater of a HGCM call request.  */
+# define VMMDEV_HGCM_CALL_PARMS(a)   ((HGCMFunctionParameter *)((uint8_t *)(a) + sizeof (VMMDevHGCMCall)))
+/** Get the pointer to the first parmater of a 32-bit HGCM call request.  */
+# define VMMDEV_HGCM_CALL_PARMS32(a) ((HGCMFunctionParameter32 *)((uint8_t *)(a) + sizeof (VMMDevHGCMCall)))
+
+# ifdef VBOX_WITH_64_BITS_GUESTS
+/* Explicit defines for the host code. */
+#  ifdef VBOX_HGCM_HOST_CODE
+#   define VMMDEV_HGCM_CALL_PARMS32(a) ((HGCMFunctionParameter32 *)((uint8_t *)(a) + sizeof (VMMDevHGCMCall)))
+#   define VMMDEV_HGCM_CALL_PARMS64(a) ((HGCMFunctionParameter64 *)((uint8_t *)(a) + sizeof (VMMDevHGCMCall)))
+#  endif /* VBOX_HGCM_HOST_CODE */
+# endif /* VBOX_WITH_64_BITS_GUESTS */
+
+# define VBOX_HGCM_MAX_PARMS 32
+
+/**
+ * HGCM cancel request structure.
+ *
+ * The Cancel request is issued using the same physical memory address as was
+ * used for the corresponding initial HGCMCall.
+ *
+ * Used by VMMDevReq_HGCMCancel.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevHGCMRequestHeader header;
+} VMMDevHGCMCancel;
+AssertCompileSize(VMMDevHGCMCancel, 32);
+
+/**
+ * HGCM cancel request structure, version 2.
+ *
+ * Used by VMMDevReq_HGCMCancel2.
+ *
+ * VINF_SUCCESS when cancelled.
+ * VERR_NOT_FOUND if the specified request cannot be found.
+ * VERR_INVALID_PARAMETER if the address is invalid valid.
+ */
+typedef struct
+{
+    /** Header. */
+    VMMDevRequestHeader header;
+    /** The physical address of the request to cancel. */
+    RTGCPHYS32 physReqToCancel;
+} VMMDevHGCMCancel2;
+AssertCompileSize(VMMDevHGCMCancel2, 24+4);
+
+#endif /* VBOX_WITH_HGCM */
+
+
+/**
+ * Inline helper to determine the request size for the given operation.
+ * Returns 0 if the given operation is not handled and/or supported.
+ *
+ * @returns Size.
+ * @param   requestType     The VMMDev request type.
+ */
+DECLINLINE(size_t) vmmdevGetRequestSize(VMMDevRequestType requestType)
+{
+    switch (requestType)
+    {
+        case VMMDevReq_GetMouseStatus:
+        case VMMDevReq_SetMouseStatus:
+            return sizeof(VMMDevReqMouseStatus);
+        case VMMDevReq_GetMouseStatusEx:
+            return sizeof(VMMDevReqMouseStatusEx);
+        case VMMDevReq_SetPointerShape:
+            return sizeof(VMMDevReqMousePointer);
+        case VMMDevReq_GetHostVersion:
+            return sizeof(VMMDevReqHostVersion);
+        case VMMDevReq_Idle:
+            return sizeof(VMMDevReqIdle);
+        case VMMDevReq_GetHostTime:
+            return sizeof(VMMDevReqHostTime);
+        case VMMDevReq_GetHypervisorInfo:
+        case VMMDevReq_SetHypervisorInfo:
+            return sizeof(VMMDevReqHypervisorInfo);
+        case VMMDevReq_RegisterPatchMemory:
+        case VMMDevReq_DeregisterPatchMemory:
+            return sizeof(VMMDevReqPatchMemory);
+        case VMMDevReq_SetPowerStatus:
+            return sizeof(VMMDevPowerStateRequest);
+        case VMMDevReq_AcknowledgeEvents:
+            return sizeof(VMMDevEvents);
+        case VMMDevReq_ReportGuestInfo:
+            return sizeof(VMMDevReportGuestInfo);
+        case VMMDevReq_ReportGuestInfo2:
+            return sizeof(VMMDevReportGuestInfo2);
+        case VMMDevReq_ReportGuestStatus:
+            return sizeof(VMMDevReportGuestStatus);
+        case VMMDevReq_ReportGuestUserState:
+            return sizeof(VMMDevReportGuestUserState);
+        case VMMDevReq_GetDisplayChangeRequest:
+            return sizeof(VMMDevDisplayChangeRequest);
+        case VMMDevReq_GetDisplayChangeRequest2:
+            return sizeof(VMMDevDisplayChangeRequest2);
+        case VMMDevReq_GetDisplayChangeRequestEx:
+            return sizeof(VMMDevDisplayChangeRequestEx);
+        case VMMDevReq_GetDisplayChangeRequestMulti:
+            return RT_UOFFSETOF(VMMDevDisplayChangeRequestMulti, aDisplays[0]);
+        case VMMDevReq_VideoModeSupported:
+            return sizeof(VMMDevVideoModeSupportedRequest);
+        case VMMDevReq_GetHeightReduction:
+            return sizeof(VMMDevGetHeightReductionRequest);
+        case VMMDevReq_ReportGuestCapabilities:
+            return sizeof(VMMDevReqGuestCapabilities);
+        case VMMDevReq_SetGuestCapabilities:
+            return sizeof(VMMDevReqGuestCapabilities2);
+#ifdef VBOX_WITH_HGCM
+        case VMMDevReq_HGCMConnect:
+            return sizeof(VMMDevHGCMConnect);
+        case VMMDevReq_HGCMDisconnect:
+            return sizeof(VMMDevHGCMDisconnect);
+        case VMMDevReq_HGCMCall32:
+            return sizeof(VMMDevHGCMCall);
+# ifdef VBOX_WITH_64_BITS_GUESTS
+        case VMMDevReq_HGCMCall64:
+            return sizeof(VMMDevHGCMCall);
+# endif
+        case VMMDevReq_HGCMCancel:
+            return sizeof(VMMDevHGCMCancel);
+#endif /* VBOX_WITH_HGCM */
+        case VMMDevReq_VideoAccelEnable:
+            return sizeof(VMMDevVideoAccelEnable);
+        case VMMDevReq_VideoAccelFlush:
+            return sizeof(VMMDevVideoAccelFlush);
+        case VMMDevReq_VideoSetVisibleRegion:
+            /* The original protocol didn't consider a guest with NO visible
+             * windows */
+            return sizeof(VMMDevVideoSetVisibleRegion) - sizeof(RTRECT);
+        case VMMDevReq_GetSeamlessChangeRequest:
+            return sizeof(VMMDevSeamlessChangeRequest);
+        case VMMDevReq_QueryCredentials:
+            return sizeof(VMMDevCredentials);
+        case VMMDevReq_ReportGuestStats:
+            return sizeof(VMMDevReportGuestStats);
+        case VMMDevReq_GetMemBalloonChangeRequest:
+            return sizeof(VMMDevGetMemBalloonChangeRequest);
+        case VMMDevReq_GetStatisticsChangeRequest:
+            return sizeof(VMMDevGetStatisticsChangeRequest);
+        case VMMDevReq_ChangeMemBalloon:
+            return sizeof(VMMDevChangeMemBalloon);
+        case VMMDevReq_GetVRDPChangeRequest:
+            return sizeof(VMMDevVRDPChangeRequest);
+        case VMMDevReq_LogString:
+            return sizeof(VMMDevReqLogString);
+        case VMMDevReq_CtlGuestFilterMask:
+            return sizeof(VMMDevCtlGuestFilterMask);
+        case VMMDevReq_GetCpuHotPlugRequest:
+            return sizeof(VMMDevGetCpuHotPlugRequest);
+        case VMMDevReq_SetCpuHotPlugStatus:
+            return sizeof(VMMDevCpuHotPlugStatusRequest);
+        case VMMDevReq_RegisterSharedModule:
+            return sizeof(VMMDevSharedModuleRegistrationRequest);
+        case VMMDevReq_UnregisterSharedModule:
+            return sizeof(VMMDevSharedModuleUnregistrationRequest);
+        case VMMDevReq_CheckSharedModules:
+            return sizeof(VMMDevSharedModuleCheckRequest);
+        case VMMDevReq_GetPageSharingStatus:
+            return sizeof(VMMDevPageSharingStatusRequest);
+        case VMMDevReq_DebugIsPageShared:
+            return sizeof(VMMDevPageIsSharedRequest);
+        case VMMDevReq_GetSessionId:
+            return sizeof(VMMDevReqSessionId);
+        case VMMDevReq_HeartbeatConfigure:
+            return sizeof(VMMDevReqHeartbeat);
+        case VMMDevReq_GuestHeartbeat:
+            return sizeof(VMMDevRequestHeader);
+        case VMMDevReq_VideoUpdateMonitorPositions:
+            return sizeof(VMMDevVideoUpdateMonitorPositions);
+        default:
+            break;
+    }
+
+    return 0;
+}
+
+
+/**
+ * Initializes a request structure.
+ *
+ * @returns VBox status code.
+ * @param   req             The request structure to initialize.
+ * @param   type            The request type.
+ */
+DECLINLINE(int) vmmdevInitRequest(VMMDevRequestHeader *req, VMMDevRequestType type)
+{
+    uint32_t requestSize;
+    if (!req)
+        return VERR_INVALID_PARAMETER;
+    requestSize = (uint32_t)vmmdevGetRequestSize(type);
+    if (!requestSize)
+        return VERR_INVALID_PARAMETER;
+    req->size        = requestSize;
+    req->version     = VMMDEV_REQUEST_HEADER_VERSION;
+    req->requestType = type;
+    req->rc          = VERR_GENERAL_FAILURE;
+    req->reserved1   = 0;
+    req->fRequestor  = 0;
+    return VINF_SUCCESS;
+}
+
+
+/** @name VBVA ring defines.
+ *
+ * The VBVA ring buffer is suitable for transferring large (< 2GB) amount of
+ * data. For example big bitmaps which do not fit to the buffer.
+ *
+ * Guest starts writing to the buffer by initializing a record entry in the
+ * aRecords queue. VBVA_F_RECORD_PARTIAL indicates that the record is being
+ * written. As data is written to the ring buffer, the guest increases off32End
+ * for the record.
+ *
+ * The host reads the aRecords on flushes and processes all completed records.
+ * When host encounters situation when only a partial record presents and
+ * cbRecord & ~VBVA_F_RECORD_PARTIAL >= VBVA_RING_BUFFER_SIZE -
+ * VBVA_RING_BUFFER_THRESHOLD, the host fetched all record data and updates
+ * off32Head. After that on each flush the host continues fetching the data
+ * until the record is completed.
+ *
+ * @{ */
+#define VMMDEV_VBVA_RING_BUFFER_SIZE        (_4M - _1K)
+#define VMMDEV_VBVA_RING_BUFFER_THRESHOLD   (4 * _1K)
+
+#define VMMDEV_VBVA_MAX_RECORDS (64)
+/** @} */
+
+/**
+ * VBVA record.
+ */
+typedef struct VMMDEVVBVARECORD
+{
+    /** The length of the record. Changed by guest. */
+    uint32_t cbRecord;
+} VMMDEVVBVARECORD;
+AssertCompileSize(VMMDEVVBVARECORD, 4);
+
+#if ARCH_BITS >= 32
+
+/**
+ * VBVA memory layout.
+ *
+ * This is a subsection of the VMMDevMemory structure.
+ */
+typedef struct VBVAMEMORY
+{
+    /** VBVA_F_MODE_*. */
+    uint32_t fu32ModeFlags;
+
+    /** The offset where the data start in the buffer. */
+    uint32_t off32Data;
+    /** The offset where next data must be placed in the buffer. */
+    uint32_t off32Free;
+
+    /** The ring buffer for data. */
+    uint8_t  au8RingBuffer[VMMDEV_VBVA_RING_BUFFER_SIZE];
+
+    /** The queue of record descriptions. */
+    VMMDEVVBVARECORD aRecords[VMMDEV_VBVA_MAX_RECORDS];
+    uint32_t indexRecordFirst;
+    uint32_t indexRecordFree;
+
+    /** RDP orders supported by the client. The guest reports only them
+     * and falls back to DIRTY rects for not supported ones.
+     *
+     * (1 << VBVA_VRDP_*)
+     */
+    uint32_t fu32SupportedOrders;
+
+} VBVAMEMORY;
+AssertCompileSize(VBVAMEMORY, 12 + (_4M-_1K) + 4*64 + 12);
+
+
+/**
+ * The layout of VMMDEV RAM region that contains information for guest.
+ */
+typedef struct VMMDevMemory
+{
+    /** The size of this structure. */
+    uint32_t u32Size;
+    /** The structure version. (VMMDEV_MEMORY_VERSION) */
+    uint32_t u32Version;
+
+    union
+    {
+        struct
+        {
+            /** Flag telling that VMMDev set the IRQ and acknowlegment is required */
+            bool fHaveEvents;
+        } V1_04;
+
+        struct
+        {
+            /** Pending events flags, set by host. */
+            uint32_t u32HostEvents;
+            /** Mask of events the guest wants to see, set by guest. */
+            uint32_t u32GuestEventMask;
+        } V1_03;
+    } V;
+
+    VBVAMEMORY vbvaMemory;
+
+} VMMDevMemory;
+AssertCompileSize(VMMDevMemory, 8+8 + (12 + (_4M-_1K) + 4*64 + 12) );
+AssertCompileMemberOffset(VMMDevMemory, vbvaMemory, 16);
+
+/** Version of VMMDevMemory structure (VMMDevMemory::u32Version). */
+# define VMMDEV_MEMORY_VERSION   (1)
+
+#endif /* ARCH_BITS >= 32 */
+
+/** @} */
+
+/** @} */
+RT_C_DECLS_END
+#pragma pack()
+
+#endif /* !VBOX_INCLUDED_VMMDev_h */