[mirror_edk2.git] / OvmfPkg / VirtioGpuDxe / Commands.c

/** @file\r
\r
  VirtIo GPU initialization, and commands (primitives) for the GPU device.\r
\r
  Copyright (C) 2016, Red Hat, Inc.\r
  Copyright (c) 2017, AMD Inc, All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Library/VirtioLib.h>\r
\r
#include "VirtioGpu.h"\r
\r
/**\r
  Configure the VirtIo GPU device that underlies VgpuDev.\r
\r
  @param[in,out] VgpuDev  The VGPU_DEV object to set up VirtIo messaging for.\r
                          On input, the caller is responsible for having\r
                          initialized VgpuDev->VirtIo. On output, VgpuDev->Ring\r
                          has been initialized, and synchronous VirtIo GPU\r
                          commands (primitives) can be submitted to the device.\r
\r
  @retval EFI_SUCCESS      VirtIo GPU configuration successful.\r
\r
  @retval EFI_UNSUPPORTED  The host-side configuration of the VirtIo GPU is not\r
                           supported by this driver.\r
\r
  @retval                  Error codes from underlying functions.\r
**/\r
EFI_STATUS\r
VirtioGpuInit (\r
  IN OUT VGPU_DEV *VgpuDev\r
  )\r
{\r
  UINT8      NextDevStat;\r
  EFI_STATUS Status;\r
  UINT64     Features;\r
  UINT16     QueueSize;\r
  UINT64     RingBaseShift;\r
\r
  //\r
  // Execute virtio-v1.0-cs04, 3.1.1 Driver Requirements: Device\r
  // Initialization.\r
  //\r
  // 1. Reset the device.\r
  //\r
  NextDevStat = 0;\r
  Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // 2. Set the ACKNOWLEDGE status bit [...]\r
  //\r
  NextDevStat |= VSTAT_ACK;\r
  Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // 3. Set the DRIVER status bit [...]\r
  //\r
  NextDevStat |= VSTAT_DRIVER;\r
  Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // 4. Read device feature bits...\r
  //\r
  Status = VgpuDev->VirtIo->GetDeviceFeatures (VgpuDev->VirtIo, &Features);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
  if ((Features & VIRTIO_F_VERSION_1) == 0) {\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
  //\r
  // We only want the most basic 2D features.\r
  //\r
  Features &= VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM;\r
\r
  //\r
  // ... and write the subset of feature bits understood by the [...] driver to\r
  // the device. [...]\r
  // 5. Set the FEATURES_OK status bit.\r
  // 6. Re-read device status to ensure the FEATURES_OK bit is still set [...]\r
  //\r
  Status = Virtio10WriteFeatures (VgpuDev->VirtIo, Features, &NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // 7. Perform device-specific setup, including discovery of virtqueues for\r
  // the device [...]\r
  //\r
  Status = VgpuDev->VirtIo->SetQueueSel (VgpuDev->VirtIo,\r
                              VIRTIO_GPU_CONTROL_QUEUE);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
  Status = VgpuDev->VirtIo->GetQueueNumMax (VgpuDev->VirtIo, &QueueSize);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
\r
  //\r
  // We implement each VirtIo GPU command that we use with two descriptors:\r
  // request, response.\r
  //\r
  if (QueueSize < 2) {\r
    Status = EFI_UNSUPPORTED;\r
    goto Failed;\r
  }\r
\r
  //\r
  // [...] population of virtqueues [...]\r
  //\r
  Status = VirtioRingInit (VgpuDev->VirtIo, QueueSize, &VgpuDev->Ring);\r
  if (EFI_ERROR (Status)) {\r
    goto Failed;\r
  }\r
  //\r
  // If anything fails from here on, we have to release the ring.\r
  //\r
  Status = VirtioRingMap (\r
             VgpuDev->VirtIo,\r
             &VgpuDev->Ring,\r
             &RingBaseShift,\r
             &VgpuDev->RingMap\r
             );\r
  if (EFI_ERROR (Status)) {\r
    goto ReleaseQueue;\r
  }\r
  //\r
  // If anything fails from here on, we have to unmap the ring.\r
  //\r
  Status = VgpuDev->VirtIo->SetQueueAddress (\r
                              VgpuDev->VirtIo,\r
                              &VgpuDev->Ring,\r
                              RingBaseShift\r
                              );\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  //\r
  // 8. Set the DRIVER_OK status bit.\r
  //\r
  NextDevStat |= VSTAT_DRIVER_OK;\r
  Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapQueue;\r
  }\r
\r
  return EFI_SUCCESS;\r
\r
UnmapQueue:\r
  VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, VgpuDev->RingMap);\r
\r
ReleaseQueue:\r
  VirtioRingUninit (VgpuDev->VirtIo, &VgpuDev->Ring);\r
\r
Failed:\r
  //\r
  // If any of these steps go irrecoverably wrong, the driver SHOULD set the\r
  // FAILED status bit to indicate that it has given up on the device (it can\r
  // reset the device later to restart if desired). [...]\r
  //\r
  // VirtIo access failure here should not mask the original error.\r
  //\r
  NextDevStat |= VSTAT_FAILED;\r
  VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);\r
\r
  return Status;\r
}\r
\r
/**\r
  De-configure the VirtIo GPU device that underlies VgpuDev.\r
\r
  @param[in,out] VgpuDev  The VGPU_DEV object to tear down VirtIo messaging\r
                          for. On input, the caller is responsible for having\r
                          called VirtioGpuInit(). On output, VgpuDev->Ring has\r
                          been uninitialized; VirtIo GPU commands (primitives)\r
                          can no longer be submitted to the device.\r
**/\r
VOID\r
VirtioGpuUninit (\r
  IN OUT VGPU_DEV *VgpuDev\r
  )\r
{\r
  //\r
  // Resetting the VirtIo device makes it release its resources and forget its\r
  // configuration.\r
  //\r
  VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, 0);\r
  VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, VgpuDev->RingMap);\r
  VirtioRingUninit (VgpuDev->VirtIo, &VgpuDev->Ring);\r
}\r
\r
/**\r
  Allocate, zero and map memory, for bus master common buffer operation, to be\r
  attached as backing store to a host-side VirtIo GPU resource.\r
\r
  @param[in]  VgpuDev        The VGPU_DEV object that represents the VirtIo GPU\r
                             device.\r
\r
  @param[in]  NumberOfPages  The number of whole pages to allocate and map.\r
\r
  @param[out] HostAddress    The system memory address of the allocated area.\r
\r
  @param[out] DeviceAddress  The bus master device address of the allocated\r
                             area. The VirtIo GPU device may be programmed to\r
                             access the allocated area through DeviceAddress;\r
                             DeviceAddress is to be passed to the\r
                             VirtioGpuResourceAttachBacking() function, as the\r
                             BackingStoreDeviceAddress parameter.\r
\r
  @param[out] Mapping        A resulting token to pass to\r
                             VirtioGpuUnmapAndFreeBackingStore().\r
\r
  @retval EFI_SUCCESS  The requested number of pages has been allocated, zeroed\r
                       and mapped.\r
\r
  @return              Status codes propagated from\r
                       VgpuDev->VirtIo->AllocateSharedPages() and\r
                       VirtioMapAllBytesInSharedBuffer().\r
**/\r
EFI_STATUS\r
VirtioGpuAllocateZeroAndMapBackingStore (\r
  IN  VGPU_DEV             *VgpuDev,\r
  IN  UINTN                NumberOfPages,\r
  OUT VOID                 **HostAddress,\r
  OUT EFI_PHYSICAL_ADDRESS *DeviceAddress,\r
  OUT VOID                 **Mapping\r
  )\r
{\r
  EFI_STATUS Status;\r
  VOID       *NewHostAddress;\r
\r
  Status = VgpuDev->VirtIo->AllocateSharedPages (\r
                              VgpuDev->VirtIo,\r
                              NumberOfPages,\r
                              &NewHostAddress\r
                              );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Avoid exposing stale data to the device even temporarily: zero the area\r
  // before mapping it.\r
  //\r
  ZeroMem (NewHostAddress, EFI_PAGES_TO_SIZE (NumberOfPages));\r
\r
  Status = VirtioMapAllBytesInSharedBuffer (\r
             VgpuDev->VirtIo,                      // VirtIo\r
             VirtioOperationBusMasterCommonBuffer, // Operation\r
             NewHostAddress,                       // HostAddress\r
             EFI_PAGES_TO_SIZE (NumberOfPages),    // NumberOfBytes\r
             DeviceAddress,                        // DeviceAddress\r
             Mapping                               // Mapping\r
             );\r
  if (EFI_ERROR (Status)) {\r
    goto FreeSharedPages;\r
  }\r
\r
  *HostAddress = NewHostAddress;\r
  return EFI_SUCCESS;\r
\r
FreeSharedPages:\r
  VgpuDev->VirtIo->FreeSharedPages (\r
                     VgpuDev->VirtIo,\r
                     NumberOfPages,\r
                     NewHostAddress\r
                     );\r
  return Status;\r
}\r
\r
/**\r
  Unmap and free memory originally allocated and mapped with\r
  VirtioGpuAllocateZeroAndMapBackingStore().\r
\r
  If the memory allocated and mapped with\r
  VirtioGpuAllocateZeroAndMapBackingStore() was attached to a host-side VirtIo\r
  GPU resource with VirtioGpuResourceAttachBacking(), then the caller is\r
  responsible for detaching the backing store from the same resource, with\r
  VirtioGpuResourceDetachBacking(), before calling this function.\r
\r
  @param[in] VgpuDev        The VGPU_DEV object that represents the VirtIo GPU\r
                            device.\r
\r
  @param[in] NumberOfPages  The NumberOfPages parameter originally passed to\r
                            VirtioGpuAllocateZeroAndMapBackingStore().\r
\r
  @param[in] HostAddress    The HostAddress value originally output by\r
                            VirtioGpuAllocateZeroAndMapBackingStore().\r
\r
  @param[in] Mapping        The token that was originally output by\r
                            VirtioGpuAllocateZeroAndMapBackingStore().\r
**/\r
VOID\r
VirtioGpuUnmapAndFreeBackingStore (\r
  IN VGPU_DEV *VgpuDev,\r
  IN UINTN    NumberOfPages,\r
  IN VOID     *HostAddress,\r
  IN VOID     *Mapping\r
  )\r
{\r
  VgpuDev->VirtIo->UnmapSharedBuffer (\r
                     VgpuDev->VirtIo,\r
                     Mapping\r
                     );\r
  VgpuDev->VirtIo->FreeSharedPages (\r
                     VgpuDev->VirtIo,\r
                     NumberOfPages,\r
                     HostAddress\r
                     );\r
}\r
\r
/**\r
  EFI_EVENT_NOTIFY function for the VGPU_DEV.ExitBoot event. It resets the\r
  VirtIo device, causing it to release its resources and to forget its\r
  configuration.\r
\r
  This function may only be called (that is, VGPU_DEV.ExitBoot may only be\r
  signaled) after VirtioGpuInit() returns and before VirtioGpuUninit() is\r
  called.\r
\r
  @param[in] Event    Event whose notification function is being invoked.\r
\r
  @param[in] Context  Pointer to the associated VGPU_DEV object.\r
**/\r
VOID\r
EFIAPI\r
VirtioGpuExitBoot (\r
  IN EFI_EVENT Event,\r
  IN VOID      *Context\r
  )\r
{\r
  VGPU_DEV *VgpuDev;\r
\r
  DEBUG ((DEBUG_VERBOSE, "%a: Context=0x%p\n", __FUNCTION__, Context));\r
  VgpuDev = Context;\r
  VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, 0);\r
}\r
\r
/**\r
  Internal utility function that sends a request to the VirtIo GPU device\r
  model, awaits the answer from the host, and returns a status.\r
\r
  @param[in,out] VgpuDev  The VGPU_DEV object that represents the VirtIo GPU\r
                          device. The caller is responsible to have\r
                          successfully invoked VirtioGpuInit() on VgpuDev\r
                          previously, while VirtioGpuUninit() must not have\r
                          been called on VgpuDev.\r
\r
  @param[in] RequestType  The type of the request. The caller is responsible\r
                          for providing a VirtioGpuCmd* RequestType which, on\r
                          success, elicits a VirtioGpuRespOkNodata response\r
                          from the host.\r
\r
  @param[in] Fence        Whether to enable fencing for this request. Fencing\r
                          forces the host to complete the command before\r
                          producing a response. If Fence is TRUE, then\r
                          VgpuDev->FenceId is consumed, and incremented.\r
\r
  @param[in,out] Header   Pointer to the caller-allocated request object. The\r
                          request must start with VIRTIO_GPU_CONTROL_HEADER.\r
                          This function overwrites all fields of Header before\r
                          submitting the request to the host:\r
\r
                          - it sets Type from RequestType,\r
\r
                          - it sets Flags and FenceId based on Fence,\r
\r
                          - it zeroes CtxId and Padding.\r
\r
  @param[in] RequestSize  Size of the entire caller-allocated request object,\r
                          including the leading VIRTIO_GPU_CONTROL_HEADER.\r
\r
  @retval EFI_SUCCESS            Operation successful.\r
\r
  @retval EFI_DEVICE_ERROR       The host rejected the request. The host error\r
                                 code has been logged on the DEBUG_ERROR level.\r
\r
  @return                        Codes for unexpected errors in VirtIo\r
                                 messaging, or request/response\r
                                 mapping/unmapping.\r
**/\r
STATIC\r
EFI_STATUS\r
VirtioGpuSendCommand (\r
  IN OUT VGPU_DEV                           *VgpuDev,\r
  IN     VIRTIO_GPU_CONTROL_TYPE            RequestType,\r
  IN     BOOLEAN                            Fence,\r
  IN OUT volatile VIRTIO_GPU_CONTROL_HEADER *Header,\r
  IN     UINTN                              RequestSize\r
  )\r
{\r
  DESC_INDICES                       Indices;\r
  volatile VIRTIO_GPU_CONTROL_HEADER Response;\r
  EFI_STATUS                         Status;\r
  UINT32                             ResponseSize;\r
  EFI_PHYSICAL_ADDRESS               RequestDeviceAddress;\r
  VOID                               *RequestMap;\r
  EFI_PHYSICAL_ADDRESS               ResponseDeviceAddress;\r
  VOID                               *ResponseMap;\r
\r
  //\r
  // Initialize Header.\r
  //\r
  Header->Type      = RequestType;\r
  if (Fence) {\r
    Header->Flags   = VIRTIO_GPU_FLAG_FENCE;\r
    Header->FenceId = VgpuDev->FenceId++;\r
  } else {\r
    Header->Flags   = 0;\r
    Header->FenceId = 0;\r
  }\r
  Header->CtxId     = 0;\r
  Header->Padding   = 0;\r
\r
  ASSERT (RequestSize >= sizeof *Header);\r
  ASSERT (RequestSize <= MAX_UINT32);\r
\r
  //\r
  // Map request and response to bus master device addresses.\r
  //\r
  Status = VirtioMapAllBytesInSharedBuffer (\r
             VgpuDev->VirtIo,\r
             VirtioOperationBusMasterRead,\r
             (VOID *)Header,\r
             RequestSize,\r
             &RequestDeviceAddress,\r
             &RequestMap\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  Status = VirtioMapAllBytesInSharedBuffer (\r
             VgpuDev->VirtIo,\r
             VirtioOperationBusMasterWrite,\r
             (VOID *)&Response,\r
             sizeof Response,\r
             &ResponseDeviceAddress,\r
             &ResponseMap\r
             );\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapRequest;\r
  }\r
\r
  //\r
  // Compose the descriptor chain.\r
  //\r
  VirtioPrepare (&VgpuDev->Ring, &Indices);\r
  VirtioAppendDesc (\r
    &VgpuDev->Ring,\r
    RequestDeviceAddress,\r
    (UINT32)RequestSize,\r
    VRING_DESC_F_NEXT,\r
    &Indices\r
    );\r
  VirtioAppendDesc (\r
    &VgpuDev->Ring,\r
    ResponseDeviceAddress,\r
    (UINT32)sizeof Response,\r
    VRING_DESC_F_WRITE,\r
    &Indices\r
    );\r
\r
  //\r
  // Send the command.\r
  //\r
  Status = VirtioFlush (VgpuDev->VirtIo, VIRTIO_GPU_CONTROL_QUEUE,\r
             &VgpuDev->Ring, &Indices, &ResponseSize);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapResponse;\r
  }\r
\r
  //\r
  // Verify response size.\r
  //\r
  if (ResponseSize != sizeof Response) {\r
    DEBUG ((DEBUG_ERROR, "%a: malformed response to Request=0x%x\n",\r
      __FUNCTION__, (UINT32)RequestType));\r
    Status = EFI_PROTOCOL_ERROR;\r
    goto UnmapResponse;\r
  }\r
\r
  //\r
  // Unmap response and request, in reverse order of mapping. On error, the\r
  // respective mapping is invalidated anyway, only the data may not have been\r
  // committed to system memory (in case of VirtioOperationBusMasterWrite).\r
  //\r
  Status = VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, ResponseMap);\r
  if (EFI_ERROR (Status)) {\r
    goto UnmapRequest;\r
  }\r
  Status = VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, RequestMap);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Parse the response.\r
  //\r
  if (Response.Type == VirtioGpuRespOkNodata) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  DEBUG ((DEBUG_ERROR, "%a: Request=0x%x Response=0x%x\n", __FUNCTION__,\r
    (UINT32)RequestType, Response.Type));\r
  return EFI_DEVICE_ERROR;\r
\r
UnmapResponse:\r
  VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, ResponseMap);\r
\r
UnmapRequest:\r
  VgpuDev->VirtIo->UnmapSharedBuffer (VgpuDev->VirtIo, RequestMap);\r
\r
  return Status;\r
}\r
\r
/**\r
  The following functions send requests to the VirtIo GPU device model, await\r
  the answer from the host, and return a status. They share the following\r
  interface details:\r
\r
  @param[in,out] VgpuDev  The VGPU_DEV object that represents the VirtIo GPU\r
                          device. The caller is responsible to have\r
                          successfully invoked VirtioGpuInit() on VgpuDev\r
                          previously, while VirtioGpuUninit() must not have\r
                          been called on VgpuDev.\r
\r
  @retval EFI_INVALID_PARAMETER  Invalid command-specific parameters were\r
                                 detected by this driver.\r
\r
  @retval EFI_SUCCESS            Operation successful.\r
\r
  @retval EFI_DEVICE_ERROR       The host rejected the request. The host error\r
                                 code has been logged on the DEBUG_ERROR level.\r
\r
  @return                        Codes for unexpected errors in VirtIo\r
                                 messaging.\r
\r
  For the command-specific parameters, please consult the GPU Device section of\r
  the VirtIo 1.0 specification (see references in\r
  "OvmfPkg/Include/IndustryStandard/VirtioGpu.h").\r
**/\r
EFI_STATUS\r
VirtioGpuResourceCreate2d (\r
  IN OUT VGPU_DEV           *VgpuDev,\r
  IN     UINT32             ResourceId,\r
  IN     VIRTIO_GPU_FORMATS Format,\r
  IN     UINT32             Width,\r
  IN     UINT32             Height\r
  )\r
{\r
  volatile VIRTIO_GPU_RESOURCE_CREATE_2D Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.ResourceId = ResourceId;\r
  Request.Format     = (UINT32)Format;\r
  Request.Width      = Width;\r
  Request.Height     = Height;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdResourceCreate2d,\r
           FALSE,                        // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuResourceUnref (\r
  IN OUT VGPU_DEV *VgpuDev,\r
  IN     UINT32   ResourceId\r
  )\r
{\r
  volatile VIRTIO_GPU_RESOURCE_UNREF Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.ResourceId = ResourceId;\r
  Request.Padding    = 0;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdResourceUnref,\r
           FALSE,                     // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuResourceAttachBacking (\r
  IN OUT VGPU_DEV             *VgpuDev,\r
  IN     UINT32               ResourceId,\r
  IN     EFI_PHYSICAL_ADDRESS BackingStoreDeviceAddress,\r
  IN     UINTN                NumberOfPages\r
  )\r
{\r
  volatile VIRTIO_GPU_RESOURCE_ATTACH_BACKING Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.ResourceId    = ResourceId;\r
  Request.NrEntries     = 1;\r
  Request.Entry.Addr    = BackingStoreDeviceAddress;\r
  Request.Entry.Length  = (UINT32)EFI_PAGES_TO_SIZE (NumberOfPages);\r
  Request.Entry.Padding = 0;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdResourceAttachBacking,\r
           FALSE,                             // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuResourceDetachBacking (\r
  IN OUT VGPU_DEV *VgpuDev,\r
  IN     UINT32   ResourceId\r
  )\r
{\r
  volatile VIRTIO_GPU_RESOURCE_DETACH_BACKING Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.ResourceId = ResourceId;\r
  Request.Padding    = 0;\r
\r
  //\r
  // In this case, we set Fence to TRUE, because after this function returns,\r
  // the caller might reasonably want to repurpose the backing pages\r
  // immediately. Thus we should ensure that the host releases all references\r
  // to the backing pages before we return.\r
  //\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdResourceDetachBacking,\r
           TRUE,                              // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuSetScanout (\r
  IN OUT VGPU_DEV *VgpuDev,\r
  IN     UINT32   X,\r
  IN     UINT32   Y,\r
  IN     UINT32   Width,\r
  IN     UINT32   Height,\r
  IN     UINT32   ScanoutId,\r
  IN     UINT32   ResourceId\r
  )\r
{\r
  volatile VIRTIO_GPU_SET_SCANOUT Request;\r
\r
  //\r
  // Unlike for most other commands, ResourceId=0 is valid; it\r
  // is used to disable a scanout.\r
  //\r
  Request.Rectangle.X      = X;\r
  Request.Rectangle.Y      = Y;\r
  Request.Rectangle.Width  = Width;\r
  Request.Rectangle.Height = Height;\r
  Request.ScanoutId        = ScanoutId;\r
  Request.ResourceId       = ResourceId;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdSetScanout,\r
           FALSE,                  // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuTransferToHost2d (\r
  IN OUT VGPU_DEV *VgpuDev,\r
  IN     UINT32   X,\r
  IN     UINT32   Y,\r
  IN     UINT32   Width,\r
  IN     UINT32   Height,\r
  IN     UINT64   Offset,\r
  IN     UINT32   ResourceId\r
  )\r
{\r
  volatile VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.Rectangle.X      = X;\r
  Request.Rectangle.Y      = Y;\r
  Request.Rectangle.Width  = Width;\r
  Request.Rectangle.Height = Height;\r
  Request.Offset           = Offset;\r
  Request.ResourceId       = ResourceId;\r
  Request.Padding          = 0;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdTransferToHost2d,\r
           FALSE,                        // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r
\r
EFI_STATUS\r
VirtioGpuResourceFlush (\r
  IN OUT VGPU_DEV *VgpuDev,\r
  IN     UINT32   X,\r
  IN     UINT32   Y,\r
  IN     UINT32   Width,\r
  IN     UINT32   Height,\r
  IN     UINT32   ResourceId\r
  )\r
{\r
  volatile VIRTIO_GPU_RESOURCE_FLUSH Request;\r
\r
  if (ResourceId == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Request.Rectangle.X      = X;\r
  Request.Rectangle.Y      = Y;\r
  Request.Rectangle.Width  = Width;\r
  Request.Rectangle.Height = Height;\r
  Request.ResourceId       = ResourceId;\r
  Request.Padding          = 0;\r
\r
  return VirtioGpuSendCommand (\r
           VgpuDev,\r
           VirtioGpuCmdResourceFlush,\r
           FALSE,                     // Fence\r
           &Request.Header,\r
           sizeof Request\r
           );\r
}\r