OvmfPkg/Library/SmmCpuPlatformHookLibQemu/SmmCpuPlatformHookLibQemu.c

   1 /** @file
   2 SMM CPU Platform Hook library instance for QEMU.
   3
   4 Copyright (c) 2020, Red Hat, Inc.
   5 Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
   6 SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9 #include <Library/BaseLib.h>                 // AsmReadMsr64()
  10 #include <PiSmm.h>
  11 #include <Register/Intel/ArchitecturalMsr.h> // MSR_IA32_APIC_BASE_REGISTER
  12
  13 #include <Library/SmmCpuPlatformHookLib.h>
  14
  15 /**
  16   Checks if platform produces a valid SMI.
  17
  18   This function checks if platform produces a valid SMI. This function is
  19   called at SMM entry to detect if this is a spurious SMI. This function
  20   must be implemented in an MP safe way because it is called by multiple CPU
  21   threads.
  22
  23   @retval TRUE              There is a valid SMI
  24   @retval FALSE             There is no valid SMI
  25
  26 **/
  27 BOOLEAN
  28 EFIAPI
  29 PlatformValidSmi (
  30   VOID
  31   )
  32 {
  33   return TRUE;
  34 }
  35
  36 /**
  37   Clears platform top level SMI status bit.
  38
  39   This function clears platform top level SMI status bit.
  40
  41   @retval TRUE              The platform top level SMI status is cleared.
  42   @retval FALSE             The platform top level SMI status cannot be
  43                             cleared.
  44
  45 **/
  46 BOOLEAN
  47 EFIAPI
  48 ClearTopLevelSmiStatus (
  49   VOID
  50   )
  51 {
  52   return TRUE;
  53 }
  54
  55 /**
  56   Performs platform specific way of SMM BSP election.
  57
  58   This function performs platform specific way of SMM BSP election.
  59
  60   @param  IsBsp             Output parameter. TRUE: the CPU this function
  61                             executes on is elected to be the SMM BSP. FALSE:
  62                             the CPU this function executes on is to be SMM AP.
  63
  64   @retval EFI_SUCCESS       The function executes successfully.
  65   @retval EFI_NOT_READY     The function does not determine whether this CPU
  66                             should be BSP or AP. This may occur if hardware
  67                             init sequence to enable the determination is yet to
  68                             be done, or the function chooses not to do BSP
  69                             election and will let SMM CPU driver to use its
  70                             default BSP election process.
  71   @retval EFI_DEVICE_ERROR  The function cannot determine whether this CPU
  72                             should be BSP or AP due to hardware error.
  73
  74 **/
  75 EFI_STATUS
  76 EFIAPI
  77 PlatformSmmBspElection (
  78   OUT BOOLEAN     *IsBsp
  79   )
  80 {
  81   MSR_IA32_APIC_BASE_REGISTER ApicBaseMsr;
  82
  83   ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
  84   *IsBsp = (BOOLEAN)(ApicBaseMsr.Bits.BSP == 1);
  85   return EFI_SUCCESS;
  86 }
  87
  88 /**
  89   Get platform page table attribute.
  90
  91   This function gets page table attribute of platform.
  92
  93   @param  Address        Input parameter. Obtain the page table entries
  94                          attribute on this address.
  95   @param  PageSize       Output parameter. The size of the page.
  96   @param  NumOfPages     Output parameter. Number of page.
  97   @param  PageAttribute  Output parameter. Paging Attributes (WB, UC, etc).
  98
  99   @retval EFI_SUCCESS      The platform page table attribute from the address
 100                            is determined.
 101   @retval EFI_UNSUPPORTED  The platform does not support getting page table
 102                            attribute for the address.
 103
 104 **/
 105 EFI_STATUS
 106 EFIAPI
 107 GetPlatformPageTableAttribute (
 108   IN  UINT64                Address,
 109   IN OUT SMM_PAGE_SIZE_TYPE *PageSize,
 110   IN OUT UINTN              *NumOfPages,
 111   IN OUT UINTN              *PageAttribute
 112   )
 113 {
 114   return EFI_UNSUPPORTED;
 115 }