DxeSnpSystemRamValidate.c

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#include <Uefi/UefiBaseType.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/MemEncryptSevLib.h>
 
#include "SnpPageStateChange.h"
#include "VirtualMemory.h"
 
STATIC VOID  *mPscBuffer = NULL;
 
VOID
EFIAPI
MemEncryptSevSnpPreValidateSystemRam (
  IN PHYSICAL_ADDRESS  BaseAddress,
  IN UINTN             NumPages
  )
{
  EFI_STATUS  Status;
 
  if (!MemEncryptSevSnpIsEnabled ()) {
    return;
  }
 
  // DXE pre-validation may happen with the memory accept protocol.
  // The protocol should only be called outside the prevalidated ranges
  // that the PEI stage code explicitly skips. Specifically, only memory
  // ranges that are classified as unaccepted.
  if (BaseAddress >= SIZE_4GB) {
    Status = InternalMemEncryptSevCreateIdentityMap1G (
               0,
               BaseAddress,
               EFI_PAGES_TO_SIZE (NumPages)
               );
    if (EFI_ERROR (Status)) {
      ASSERT (FALSE);
      CpuDeadLoop ();
    }
  }
 
  if (mPscBuffer == NULL) {
    mPscBuffer = AllocateReservedPages (1);
    ASSERT (mPscBuffer != NULL);
  }
 
  InternalSetPageState (BaseAddress, NumPages, SevSnpPagePrivate, TRUE, mPscBuffer, EFI_PAGE_SIZE);
}