OvmfPkg/PlatformPei/FeatureControl.c

   1 /**@file
   2   Install a callback when necessary for setting the Feature Control MSR on all
   3   processors.
   4
   5   Copyright (C) 2016, Red Hat, Inc.
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8 **/
   9
  10 #include <Library/DebugLib.h>
  11 #include <Library/HobLib.h>
  12 #include <Library/PeiServicesLib.h>
  13 #include <Library/QemuFwCfgLib.h>
  14 #include <Ppi/MpServices.h>
  15 #include <Register/ArchitecturalMsr.h>
  16 #include <IndustryStandard/Tdx.h>
  17
  18 #include "Platform.h"
  19
  20 /**
  21   Write the Feature Control MSR on an Application Processor or the Boot
  22   Processor.
  23
  24   All APs execute this function in parallel. The BSP executes the function
  25   separately.
  26
  27   @param[in,out] WorkSpace  Pointer to the input/output argument workspace
  28                             shared by all processors.
  29 **/
  30 STATIC
  31 VOID
  32 EFIAPI
  33 WriteFeatureControl (
  34   IN OUT VOID  *WorkSpace
  35   )
  36 {
  37   EFI_HOB_PLATFORM_INFO  *PlatformInfoHob = WorkSpace;
  38
  39   if (TdIsEnabled ()) {
  40     TdVmCall (
  41       TDVMCALL_WRMSR,
  42       (UINT64)MSR_IA32_FEATURE_CONTROL,
  43       PlatformInfoHob->FeatureControlValue,
  44       0,
  45       0,
  46       0
  47       );
  48   } else {
  49     AsmWriteMsr64 (
  50       MSR_IA32_FEATURE_CONTROL,
  51       PlatformInfoHob->FeatureControlValue
  52       );
  53   }
  54 }
  55
  56 /**
  57   Notification function called when EFI_PEI_MP_SERVICES_PPI becomes available.
  58
  59   @param[in] PeiServices      Indirect reference to the PEI Services Table.
  60   @param[in] NotifyDescriptor Address of the notification descriptor data
  61                               structure.
  62   @param[in] Ppi              Address of the PPI that was installed.
  63
  64   @return  Status of the notification. The status code returned from this
  65            function is ignored.
  66 **/
  67 STATIC
  68 EFI_STATUS
  69 EFIAPI
  70 OnMpServicesAvailable (
  71   IN EFI_PEI_SERVICES           **PeiServices,
  72   IN EFI_PEI_NOTIFY_DESCRIPTOR  *NotifyDescriptor,
  73   IN VOID                       *Ppi
  74   )
  75 {
  76   EFI_PEI_MP_SERVICES_PPI  *MpServices;
  77   EFI_STATUS               Status;
  78   EFI_HOB_PLATFORM_INFO    *PlatformInfoHob;
  79   EFI_HOB_GUID_TYPE        *GuidHob;
  80
  81   GuidHob = GetFirstGuidHob (&gUefiOvmfPkgPlatformInfoGuid);
  82   if (GuidHob == NULL) {
  83     return EFI_UNSUPPORTED;
  84   }
  85
  86   PlatformInfoHob = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);
  87
  88   DEBUG ((DEBUG_VERBOSE, "%a: %a\n", gEfiCallerBaseName, __FUNCTION__));
  89
  90   //
  91   // Write the MSR on all the APs in parallel.
  92   //
  93   MpServices = Ppi;
  94   Status     = MpServices->StartupAllAPs (
  95                              (CONST EFI_PEI_SERVICES **)PeiServices,
  96                              MpServices,
  97                              WriteFeatureControl, // Procedure
  98                              FALSE,               // SingleThread
  99                              0,                   // TimeoutInMicroSeconds: inf.
 100                              PlatformInfoHob      // ProcedureArgument
 101                              );
 102   if (EFI_ERROR (Status) && (Status != EFI_NOT_STARTED)) {
 103     DEBUG ((DEBUG_ERROR, "%a: StartupAllAps(): %r\n", __FUNCTION__, Status));
 104     return Status;
 105   }
 106
 107   //
 108   // Now write the MSR on the BSP too.
 109   //
 110   WriteFeatureControl (PlatformInfoHob);
 111   return EFI_SUCCESS;
 112 }
 113
 114 //
 115 // Notification object for registering the callback, for when
 116 // EFI_PEI_MP_SERVICES_PPI becomes available.
 117 //
 118 STATIC CONST EFI_PEI_NOTIFY_DESCRIPTOR  mMpServicesNotify = {
 119   EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | // Flags
 120   EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
 121   &gEfiPeiMpServicesPpiGuid,               // Guid
 122   OnMpServicesAvailable                    // Notify
 123 };
 124
 125 VOID
 126 InstallFeatureControlCallback (
 127   IN OUT EFI_HOB_PLATFORM_INFO  *PlatformInfoHob
 128   )
 129 {
 130   EFI_STATUS            Status;
 131   FIRMWARE_CONFIG_ITEM  FwCfgItem;
 132   UINTN                 FwCfgSize;
 133
 134   Status = QemuFwCfgFindFile (
 135              "etc/msr_feature_control",
 136              &FwCfgItem,
 137              &FwCfgSize
 138              );
 139   if (EFI_ERROR (Status) || (FwCfgSize != sizeof (PlatformInfoHob->FeatureControlValue))) {
 140     //
 141     // Nothing to do.
 142     //
 143     return;
 144   }
 145
 146   QemuFwCfgSelectItem (FwCfgItem);
 147   QemuFwCfgReadBytes (
 148     sizeof (PlatformInfoHob->FeatureControlValue),
 149     &(PlatformInfoHob->FeatureControlValue)
 150     );
 151
 152   Status = PeiServicesNotifyPpi (&mMpServicesNotify);
 153   if (EFI_ERROR (Status)) {
 154     DEBUG ((
 155       DEBUG_ERROR,
 156       "%a: failed to set up MP Services callback: %r\n",
 157       __FUNCTION__,
 158       Status
 159       ));
 160   }
 161 }