1 files changed, 155 insertions, 0 deletions
diff --git a/roms/edk2/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c b/roms/edk2/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c
new file mode 100644
index 000000000..02b8eb225
--- /dev/null
+++ b/roms/edk2/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c
@@ -0,0 +1,155 @@
+/** @file
+
+  Secure Encrypted Virtualization (SEV) library helper function
+
+  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemEncryptSevLib.h>
+#include <Library/PcdLib.h>
+#include <Register/Amd/Cpuid.h>
+#include <Register/Amd/Msr.h>
+#include <Register/Cpuid.h>
+#include <Register/QemuSmramSaveStateMap.h>
+#include <Register/SmramSaveStateMap.h>
+#include <Uefi/UefiBaseType.h>
+
+STATIC BOOLEAN mSevStatus = FALSE;
+STATIC BOOLEAN mSevEsStatus = FALSE;
+STATIC BOOLEAN mSevStatusChecked = FALSE;
+
+/**
+  Reads and sets the status of SEV features.
+
+  **/
+STATIC
+VOID
+EFIAPI
+InternalMemEncryptSevStatus (
+  VOID
+  )
+{
+  UINT32                            RegEax;
+  MSR_SEV_STATUS_REGISTER           Msr;
+  CPUID_MEMORY_ENCRYPTION_INFO_EAX  Eax;
+
+  //
+  // Check if memory encryption leaf exist
+  //
+  AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
+  if (RegEax >= CPUID_MEMORY_ENCRYPTION_INFO) {
+    //
+    // CPUID Fn8000_001F[EAX] Bit 1 (Sev supported)
+    //
+    AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, &Eax.Uint32, NULL, NULL, NULL);
+
+    if (Eax.Bits.SevBit) {
+      //
+      // Check MSR_0xC0010131 Bit 0 (Sev Enabled)
+      //
+      Msr.Uint32 = AsmReadMsr32 (MSR_SEV_STATUS);
+      if (Msr.Bits.SevBit) {
+        mSevStatus = TRUE;
+      }
+
+      //
+      // Check MSR_0xC0010131 Bit 1 (Sev-Es Enabled)
+      //
+      if (Msr.Bits.SevEsBit) {
+        mSevEsStatus = TRUE;
+      }
+    }
+  }
+
+  mSevStatusChecked = TRUE;
+}
+
+/**
+  Returns a boolean to indicate whether SEV-ES is enabled.
+
+  @retval TRUE           SEV-ES is enabled
+  @retval FALSE          SEV-ES is not enabled
+**/
+BOOLEAN
+EFIAPI
+MemEncryptSevEsIsEnabled (
+  VOID
+  )
+{
+  if (!mSevStatusChecked) {
+    InternalMemEncryptSevStatus ();
+  }
+
+  return mSevEsStatus;
+}
+
+/**
+  Returns a boolean to indicate whether SEV is enabled.
+
+  @retval TRUE           SEV is enabled
+  @retval FALSE          SEV is not enabled
+**/
+BOOLEAN
+EFIAPI
+MemEncryptSevIsEnabled (
+  VOID
+  )
+{
+  if (!mSevStatusChecked) {
+    InternalMemEncryptSevStatus ();
+  }
+
+  return mSevStatus;
+}
+
+
+/**
+  Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM
+  Save State Map.
+
+  @param[out] BaseAddress     The base address of the lowest-address page that
+                              covers the initial SMRAM Save State Map.
+
+  @param[out] NumberOfPages   The number of pages in the page range that covers
+                              the initial SMRAM Save State Map.
+
+  @retval RETURN_SUCCESS      BaseAddress and NumberOfPages have been set on
+                              output.
+
+  @retval RETURN_UNSUPPORTED  SMM is unavailable.
+**/
+RETURN_STATUS
+EFIAPI
+MemEncryptSevLocateInitialSmramSaveStateMapPages (
+  OUT UINTN *BaseAddress,
+  OUT UINTN *NumberOfPages
+  )
+{
+  UINTN MapStart;
+  UINTN MapEnd;
+  UINTN MapPagesStart; // MapStart rounded down to page boundary
+  UINTN MapPagesEnd;   // MapEnd rounded up to page boundary
+  UINTN MapPagesSize;  // difference between MapPagesStart and MapPagesEnd
+
+  if (!FeaturePcdGet (PcdSmmSmramRequire)) {
+    return RETURN_UNSUPPORTED;
+  }
+
+  MapStart      = SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET;
+  MapEnd        = MapStart + sizeof (QEMU_SMRAM_SAVE_STATE_MAP);
+  MapPagesStart = MapStart & ~(UINTN)EFI_PAGE_MASK;
+  MapPagesEnd   = ALIGN_VALUE (MapEnd, EFI_PAGE_SIZE);
+  MapPagesSize  = MapPagesEnd - MapPagesStart;
+
+  ASSERT ((MapPagesSize & EFI_PAGE_MASK) == 0);
+
+  *BaseAddress   = MapPagesStart;
+  *NumberOfPages = MapPagesSize >> EFI_PAGE_SHIFT;
+
+  return RETURN_SUCCESS;
+}