OvmfPkg/QemuFwCfgLib: Support Tdx in QemuFwCfgDxe

[mirror_edk2.git] / OvmfPkg / Library / QemuFwCfgLib / QemuFwCfgDxe.c

/** @file\r
\r
  Stateful and implicitly initialized fw_cfg library implementation.\r
\r
  Copyright (C) 2013, Red Hat, Inc.\r
  Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <Uefi.h>\r
\r
#include <Protocol/IoMmu.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/MemEncryptTdxLib.h>\r
#include <Library/MemEncryptSevLib.h>\r
\r
#include "QemuFwCfgLibInternal.h"\r
\r
STATIC BOOLEAN  mQemuFwCfgSupported = FALSE;\r
STATIC BOOLEAN  mQemuFwCfgDmaSupported;\r
\r
STATIC EDKII_IOMMU_PROTOCOL  *mIoMmuProtocol;\r
\r
/**\r
  Returns a boolean indicating if the firmware configuration interface\r
  is available or not.\r
\r
  This function may change fw_cfg state.\r
\r
  @retval    TRUE   The interface is available\r
  @retval    FALSE  The interface is not available\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
QemuFwCfgIsAvailable (\r
  VOID\r
  )\r
{\r
  return InternalQemuFwCfgIsAvailable ();\r
}\r
\r
RETURN_STATUS\r
EFIAPI\r
QemuFwCfgInitialize (\r
  VOID\r
  )\r
{\r
  UINT32  Signature;\r
  UINT32  Revision;\r
\r
  //\r
  // Enable the access routines while probing to see if it is supported.\r
  // For probing we always use the IO Port (IoReadFifo8()) access method.\r
  //\r
  mQemuFwCfgSupported    = TRUE;\r
  mQemuFwCfgDmaSupported = FALSE;\r
\r
  QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r
  Signature = QemuFwCfgRead32 ();\r
  DEBUG ((DEBUG_INFO, "FW CFG Signature: 0x%x\n", Signature));\r
  QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r
  Revision = QemuFwCfgRead32 ();\r
  DEBUG ((DEBUG_INFO, "FW CFG Revision: 0x%x\n", Revision));\r
  if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r
      (Revision < 1)\r
      )\r
  {\r
    DEBUG ((DEBUG_INFO, "QemuFwCfg interface not supported.\n"));\r
    mQemuFwCfgSupported = FALSE;\r
    return RETURN_SUCCESS;\r
  }\r
\r
  if ((Revision & FW_CFG_F_DMA) == 0) {\r
    DEBUG ((DEBUG_INFO, "QemuFwCfg interface (IO Port) is supported.\n"));\r
  } else {\r
    mQemuFwCfgDmaSupported = TRUE;\r
    DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n"));\r
  }\r
\r
  if (mQemuFwCfgDmaSupported && (MemEncryptSevIsEnabled () || (MemEncryptTdxIsEnabled ()))) {\r
    EFI_STATUS  Status;\r
\r
    //\r
    // IoMmuDxe driver must have installed the IOMMU protocol. If we are not\r
    // able to locate the protocol then something must have gone wrong.\r
    //\r
    Status = gBS->LocateProtocol (\r
                    &gEdkiiIoMmuProtocolGuid,\r
                    NULL,\r
                    (VOID **)&mIoMmuProtocol\r
                    );\r
    if (EFI_ERROR (Status)) {\r
      DEBUG ((\r
        DEBUG_ERROR,\r
        "QemuFwCfgDma %a:%a Failed to locate IOMMU protocol.\n",\r
        gEfiCallerBaseName,\r
        __FUNCTION__\r
        ));\r
      ASSERT (FALSE);\r
      CpuDeadLoop ();\r
    }\r
  }\r
\r
  return RETURN_SUCCESS;\r
}\r
\r
/**\r
  Returns a boolean indicating if the firmware configuration interface is\r
  available for library-internal purposes.\r
\r
  This function never changes fw_cfg state.\r
\r
  @retval    TRUE   The interface is available internally.\r
  @retval    FALSE  The interface is not available internally.\r
**/\r
BOOLEAN\r
InternalQemuFwCfgIsAvailable (\r
  VOID\r
  )\r
{\r
  return mQemuFwCfgSupported;\r
}\r
\r
/**\r
  Returns a boolean indicating whether QEMU provides the DMA-like access method\r
  for fw_cfg.\r
\r
  @retval    TRUE   The DMA-like access method is available.\r
  @retval    FALSE  The DMA-like access method is unavailable.\r
**/\r
BOOLEAN\r
InternalQemuFwCfgDmaIsAvailable (\r
  VOID\r
  )\r
{\r
  return mQemuFwCfgDmaSupported;\r
}\r
\r
/**\r
  Function is used for allocating a bi-directional FW_CFG_DMA_ACCESS used\r
  between Host and device to exchange the information. The buffer must be free'd\r
  using FreeFwCfgDmaAccessBuffer ().\r
\r
**/\r
STATIC\r
VOID\r
AllocFwCfgDmaAccessBuffer (\r
  OUT   VOID  **Access,\r
  OUT   VOID  **MapInfo\r
  )\r
{\r
  UINTN                 Size;\r
  UINTN                 NumPages;\r
  EFI_STATUS            Status;\r
  VOID                  *HostAddress;\r
  EFI_PHYSICAL_ADDRESS  DmaAddress;\r
  VOID                  *Mapping;\r
\r
  Size     = sizeof (FW_CFG_DMA_ACCESS);\r
  NumPages = EFI_SIZE_TO_PAGES (Size);\r
\r
  //\r
  // As per UEFI spec, in order to map a host address with\r
  // BusMasterCommonBuffer64, the buffer must be allocated using the IOMMU\r
  // AllocateBuffer()\r
  //\r
  Status = mIoMmuProtocol->AllocateBuffer (\r
                             mIoMmuProtocol,\r
                             AllocateAnyPages,\r
                             EfiBootServicesData,\r
                             NumPages,\r
                             &HostAddress,\r
                             EDKII_IOMMU_ATTRIBUTE_DUAL_ADDRESS_CYCLE\r
                             );\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to allocate FW_CFG_DMA_ACCESS\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  //\r
  // Avoid exposing stale data even temporarily: zero the area before mapping\r
  // it.\r
  //\r
  ZeroMem (HostAddress, Size);\r
\r
  //\r
  // Map the host buffer with BusMasterCommonBuffer64\r
  //\r
  Status = mIoMmuProtocol->Map (\r
                             mIoMmuProtocol,\r
                             EdkiiIoMmuOperationBusMasterCommonBuffer64,\r
                             HostAddress,\r
                             &Size,\r
                             &DmaAddress,\r
                             &Mapping\r
                             );\r
  if (EFI_ERROR (Status)) {\r
    mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, HostAddress);\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to Map() FW_CFG_DMA_ACCESS\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  if (Size < sizeof (FW_CFG_DMA_ACCESS)) {\r
    mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
    mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, HostAddress);\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to Map() - requested 0x%Lx got 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      (UINT64)sizeof (FW_CFG_DMA_ACCESS),\r
      (UINT64)Size\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  *Access  = HostAddress;\r
  *MapInfo = Mapping;\r
}\r
\r
/**\r
  Function is to used for freeing the Access buffer allocated using\r
  AllocFwCfgDmaAccessBuffer()\r
\r
**/\r
STATIC\r
VOID\r
FreeFwCfgDmaAccessBuffer (\r
  IN  VOID  *Access,\r
  IN  VOID  *Mapping\r
  )\r
{\r
  UINTN       NumPages;\r
  EFI_STATUS  Status;\r
\r
  NumPages = EFI_SIZE_TO_PAGES (sizeof (FW_CFG_DMA_ACCESS));\r
\r
  Status = mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to UnMap() Mapping 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      (UINT64)(UINTN)Mapping\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  Status = mIoMmuProtocol->FreeBuffer (mIoMmuProtocol, NumPages, Access);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to Free() 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      (UINT64)(UINTN)Access\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
}\r
\r
/**\r
  Function is used for mapping host address to device address. The buffer must\r
  be unmapped with UnmapDmaDataBuffer ().\r
\r
**/\r
STATIC\r
VOID\r
MapFwCfgDmaDataBuffer (\r
  IN  BOOLEAN               IsWrite,\r
  IN  VOID                  *HostAddress,\r
  IN  UINT32                Size,\r
  OUT EFI_PHYSICAL_ADDRESS  *DeviceAddress,\r
  OUT VOID                  **MapInfo\r
  )\r
{\r
  EFI_STATUS            Status;\r
  UINTN                 NumberOfBytes;\r
  VOID                  *Mapping;\r
  EFI_PHYSICAL_ADDRESS  PhysicalAddress;\r
\r
  NumberOfBytes = Size;\r
  Status        = mIoMmuProtocol->Map (\r
                                    mIoMmuProtocol,\r
                                    (IsWrite ?\r
                                     EdkiiIoMmuOperationBusMasterRead64 :\r
                                     EdkiiIoMmuOperationBusMasterWrite64),\r
                                    HostAddress,\r
                                    &NumberOfBytes,\r
                                    &PhysicalAddress,\r
                                    &Mapping\r
                                    );\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to Map() Address 0x%Lx Size 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      (UINT64)(UINTN)HostAddress,\r
      (UINT64)Size\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  if (NumberOfBytes < Size) {\r
    mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to Map() - requested 0x%x got 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      Size,\r
      (UINT64)NumberOfBytes\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
\r
  *DeviceAddress = PhysicalAddress;\r
  *MapInfo       = Mapping;\r
}\r
\r
STATIC\r
VOID\r
UnmapFwCfgDmaDataBuffer (\r
  IN  VOID  *Mapping\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  Status = mIoMmuProtocol->Unmap (mIoMmuProtocol, Mapping);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((\r
      DEBUG_ERROR,\r
      "%a:%a failed to UnMap() Mapping 0x%Lx\n",\r
      gEfiCallerBaseName,\r
      __FUNCTION__,\r
      (UINT64)(UINTN)Mapping\r
      ));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
}\r
\r
/**\r
  Transfer an array of bytes, or skip a number of bytes, using the DMA\r
  interface.\r
\r
  @param[in]     Size     Size in bytes to transfer or skip.\r
\r
  @param[in,out] Buffer   Buffer to read data into or write data from. Ignored,\r
                          and may be NULL, if Size is zero, or Control is\r
                          FW_CFG_DMA_CTL_SKIP.\r
\r
  @param[in]     Control  One of the following:\r
                          FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r
                          FW_CFG_DMA_CTL_READ  - read from fw_cfg into Buffer.\r
                          FW_CFG_DMA_CTL_SKIP  - skip bytes in fw_cfg.\r
**/\r
VOID\r
InternalQemuFwCfgDmaBytes (\r
  IN     UINT32  Size,\r
  IN OUT VOID    *Buffer OPTIONAL,\r
  IN     UINT32  Control\r
  )\r
{\r
  volatile FW_CFG_DMA_ACCESS  LocalAccess;\r
  volatile FW_CFG_DMA_ACCESS  *Access;\r
  UINT32                      AccessHigh, AccessLow;\r
  UINT32                      Status;\r
  VOID                        *AccessMapping, *DataMapping;\r
  VOID                        *DataBuffer;\r
\r
  ASSERT (\r
    Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||\r
    Control == FW_CFG_DMA_CTL_SKIP\r
    );\r
\r
  if (Size == 0) {\r
    return;\r
  }\r
\r
  Access        = &LocalAccess;\r
  AccessMapping = NULL;\r
  DataMapping   = NULL;\r
  DataBuffer    = Buffer;\r
\r
  //\r
  // When SEV or TDX is enabled, map Buffer to DMA address before issuing the DMA\r
  // request\r
  //\r
  if (MemEncryptSevIsEnabled () || MemEncryptTdxIsEnabled ()) {\r
    VOID                  *AccessBuffer;\r
    EFI_PHYSICAL_ADDRESS  DataBufferAddress;\r
\r
    //\r
    // Allocate DMA Access buffer\r
    //\r
    AllocFwCfgDmaAccessBuffer (&AccessBuffer, &AccessMapping);\r
\r
    Access = AccessBuffer;\r
\r
    //\r
    // Map actual data buffer\r
    //\r
    if (Control != FW_CFG_DMA_CTL_SKIP) {\r
      MapFwCfgDmaDataBuffer (\r
        Control == FW_CFG_DMA_CTL_WRITE,\r
        Buffer,\r
        Size,\r
        &DataBufferAddress,\r
        &DataMapping\r
        );\r
\r
      DataBuffer = (VOID *)(UINTN)DataBufferAddress;\r
    }\r
  }\r
\r
  Access->Control = SwapBytes32 (Control);\r
  Access->Length  = SwapBytes32 (Size);\r
  Access->Address = SwapBytes64 ((UINTN)DataBuffer);\r
\r
  //\r
  // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
  // write, from writes to Buffer by the caller.\r
  //\r
  MemoryFence ();\r
\r
  //\r
  // Start the transfer.\r
  //\r
  AccessHigh = (UINT32)RShiftU64 ((UINTN)Access, 32);\r
  AccessLow  = (UINT32)(UINTN)Access;\r
  IoWrite32 (FW_CFG_IO_DMA_ADDRESS, SwapBytes32 (AccessHigh));\r
  IoWrite32 (FW_CFG_IO_DMA_ADDRESS + 4, SwapBytes32 (AccessLow));\r
\r
  //\r
  // Don't look at Access.Control before starting the transfer.\r
  //\r
  MemoryFence ();\r
\r
  //\r
  // Wait for the transfer to complete.\r
  //\r
  do {\r
    Status = SwapBytes32 (Access->Control);\r
    ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
  } while (Status != 0);\r
\r
  //\r
  // After a read, the caller will want to use Buffer.\r
  //\r
  MemoryFence ();\r
\r
  //\r
  // If Access buffer was dynamically allocated then free it.\r
  //\r
  if (AccessMapping != NULL) {\r
    FreeFwCfgDmaAccessBuffer ((VOID *)Access, AccessMapping);\r
  }\r
\r
  //\r
  // If DataBuffer was mapped then unmap it.\r
  //\r
  if (DataMapping != NULL) {\r
    UnmapFwCfgDmaDataBuffer (DataMapping);\r
  }\r
}\r