[PATCH v6 10/42] UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Add base support to handle #VC exceptions.  This includes a stub routine
to invoke when a #VC exception occurs and special checks in the common
exception handlers to invoke the #VC exception handler routine.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Maurice Ma <maurice.ma@intel.com>
Cc: Guo Dong <guo.dong@intel.com>
Cc: Benjamin You <benjamin.you@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 .../DxeCpuExceptionHandlerLib.inf             |  5 ++
 .../PeiCpuExceptionHandlerLib.inf             |  5 ++
 .../SecPeiCpuExceptionHandlerLib.inf          |  5 ++
 .../SmmCpuExceptionHandlerLib.inf             |  5 ++
 .../CpuExceptionHandlerLib/AMDSevVcCommon.h   | 26 ++++++++++
 .../CpuExceptionCommon.h                      |  2 +
 .../CpuExceptionHandlerLib/AMDSevVcHandler.c  | 29 +++++++++++
 .../CpuExceptionCommon.c                      |  2 +-
 .../Ia32/ArchAMDSevVcHandler.c                | 24 +++++++++
 .../PeiDxeSmmCpuException.c                   | 16 ++++++
 .../SecPeiCpuException.c                      | 16 ++++++
 .../X64/ArchAMDSevVcHandler.c                 | 50 +++++++++++++++++++
 12 files changed, 184 insertions(+), 1 deletion(-)
 create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcCommon.h
 create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcHandler.c
 create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchAMDSevVcHandler.c
 create mode 100644 UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c

diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
index e41383573043..4d79c4910b18 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
@@ -26,17 +26,21 @@ [Sources.Ia32]
   Ia32/ExceptionTssEntryAsm.nasm
   Ia32/ArchExceptionHandler.c
   Ia32/ArchInterruptDefs.h
+  Ia32/ArchAMDSevVcHandler.c
 
 [Sources.X64]
   X64/ExceptionHandlerAsm.nasm
   X64/ArchExceptionHandler.c
   X64/ArchInterruptDefs.h
+  X64/ArchAMDSevVcHandler.c
 
 [Sources.common]
   CpuExceptionCommon.h
   CpuExceptionCommon.c
   PeiDxeSmmCpuException.c
   DxeException.c
+  AMDSevVcHandler.c
+  AMDSevVcCommon.h
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard
@@ -57,3 +61,4 @@ [LibraryClasses]
   PeCoffGetEntryPointLib
   MemoryAllocationLib
   DebugLib
+  VmgExitLib
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
index f31423ac0f91..e8445e47eaa3 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
@@ -26,17 +26,21 @@ [Sources.Ia32]
   Ia32/ExceptionTssEntryAsm.nasm
   Ia32/ArchExceptionHandler.c
   Ia32/ArchInterruptDefs.h
+  Ia32/ArchAMDSevVcHandler.c
 
 [Sources.X64]
   X64/ExceptionHandlerAsm.nasm
   X64/ArchExceptionHandler.c
   X64/ArchInterruptDefs.h
+  X64/ArchAMDSevVcHandler.c
 
 [Sources.common]
   CpuExceptionCommon.h
   CpuExceptionCommon.c
   PeiCpuException.c
   PeiDxeSmmCpuException.c
+  AMDSevVcHandler.c
+  AMDSevVcCommon.h
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -52,6 +56,7 @@ [LibraryClasses]
   HobLib
   MemoryAllocationLib
   SynchronizationLib
+  VmgExitLib
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard    # CONSUMES
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
index 6d25cafe2ca3..a15bf71b4052 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuExceptionHandlerLib.inf
@@ -26,16 +26,20 @@ [Sources.Ia32]
   Ia32/ExceptionTssEntryAsm.nasm
   Ia32/ArchExceptionHandler.c
   Ia32/ArchInterruptDefs.h
+  Ia32/ArchAMDSevVcHandler.c
 
 [Sources.X64]
   X64/ExceptionHandlerAsm.nasm
   X64/ArchExceptionHandler.c
   X64/ArchInterruptDefs.h
+  X64/ArchAMDSevVcHandler.c
 
 [Sources.common]
   CpuExceptionCommon.h
   CpuExceptionCommon.c
   SecPeiCpuException.c
+  AMDSevVcHandler.c
+  AMDSevVcCommon.h
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -48,3 +52,4 @@ [LibraryClasses]
   PrintLib
   LocalApicLib
   PeCoffGetEntryPointLib
+  VmgExitLib
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
index 66c7f59e3c91..190d7dfcd42a 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
@@ -26,17 +26,21 @@ [Sources.Ia32]
   Ia32/ExceptionTssEntryAsm.nasm
   Ia32/ArchExceptionHandler.c
   Ia32/ArchInterruptDefs.h
+  Ia32/ArchAMDSevVcHandler.c
 
 [Sources.X64]
   X64/ExceptionHandlerAsm.nasm
   X64/ArchExceptionHandler.c
   X64/ArchInterruptDefs.h
+  X64/ArchAMDSevVcHandler.c
 
 [Sources.common]
   CpuExceptionCommon.h
   CpuExceptionCommon.c
   PeiDxeSmmCpuException.c
   SmmException.c
+  AMDSevVcHandler.c
+  AMDSevVcCommon.h
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -51,4 +55,5 @@ [LibraryClasses]
   LocalApicLib
   PeCoffGetEntryPointLib
   DebugLib
+  VmgExitLib
 
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcCommon.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcCommon.h
new file mode 100644
index 000000000000..f8af23844e75
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcCommon.h
@@ -0,0 +1,26 @@
+/** @file
+  Common header file for SEV-ES #VC Exception Handler Support.
+
+  Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _AMD_SEV_VC_COMMON_H_
+#define _AMD_SEV_VC_COMMON_H_
+
+#include <Protocol/DebugSupport.h>
+#include <Register/Amd/Ghcb.h>
+
+UINTN
+DoVcException (
+  EFI_SYSTEM_CONTEXT  Context
+  );
+
+UINTN
+DoVcCommon (
+  GHCB                *Ghcb,
+  EFI_SYSTEM_CONTEXT  Context
+  );
+
+#endif
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
index 805dd9cbb4ff..0f274e7ea328 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h
@@ -24,6 +24,8 @@
 #define  CPU_INTERRUPT_NUM         256
 #define  HOOKAFTER_STUB_SIZE        16
 
+#define  VC_EXCEPTION               29
+
 //
 // Exception Error Code of Page-Fault Exception
 //
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcHandler.c
new file mode 100644
index 000000000000..e6fbbb621977
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/AMDSevVcHandler.c
@@ -0,0 +1,29 @@
+/** @file
+  SEV-ES #VC Exception Handler functon.
+
+  Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Register/Amd/Msr.h>
+#include "CpuExceptionCommon.h"
+#include "AMDSevVcCommon.h"
+
+UINTN
+DoVcException (
+  EFI_SYSTEM_CONTEXT  Context
+  )
+{
+  MSR_SEV_ES_GHCB_REGISTER  Msr;
+  GHCB                      *Ghcb;
+
+  Msr.GhcbPhysicalAddress = AsmReadMsr64 (MSR_SEV_ES_GHCB);
+  ASSERT (Msr.GhcbInfo.Function == 0);
+  ASSERT (Msr.Ghcb != 0);
+
+  Ghcb = Msr.Ghcb;
+
+  return DoVcCommon (Ghcb, Context);
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c
index 8adbd43fefb4..39e4dd9e9417 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c
@@ -14,7 +14,7 @@
 //
 // 1 means an error code will be pushed, otherwise 0
 //
-CONST UINT32 mErrorCodeFlag = 0x00227d00;
+CONST UINT32 mErrorCodeFlag = 0x20227d00;
 
 //
 // Define the maximum message length
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchAMDSevVcHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchAMDSevVcHandler.c
new file mode 100644
index 000000000000..bb00316e5cfb
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchAMDSevVcHandler.c
@@ -0,0 +1,24 @@
+/** @file
+  IA32 SEV-ES #VC Exception Handler functons.
+
+  Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include "AMDSevVcCommon.h"
+
+UINTN
+DoVcCommon (
+  GHCB                *Ghcb,
+  EFI_SYSTEM_CONTEXT  Context
+  )
+{
+  EFI_SYSTEM_CONTEXT_IA32  *Regs = Context.SystemContextIa32;
+
+  Regs->ExceptionData = 0;
+
+  return GP_EXCEPTION;
+}
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c
index 6a2670d55918..d565db547808 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c
@@ -7,6 +7,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 **/
 
 #include "CpuExceptionCommon.h"
+#include "AMDSevVcCommon.h"
 #include <Library/DebugLib.h>
 
 /**
@@ -86,6 +87,21 @@ CommonExceptionHandlerWorker (
     break;
   }
 
+  if (ExceptionType == VC_EXCEPTION) {
+    UINTN  Status;
+    //
+    // #VC must be handled for an SEV-ES guest
+    //
+    Status = DoVcException (SystemContext);
+    if (Status) {
+      // Exception not handled - Status contains the desired exception now
+      ExceptionType = Status;
+    } else {
+      // Exception handled
+      return;
+    }
+  }
+
   if (ExternalInterruptHandler != NULL &&
       ExternalInterruptHandler[ExceptionType] != NULL) {
     (ExternalInterruptHandler[ExceptionType]) (ExceptionType, SystemContext);
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
index 20148db74cf8..0716680d2f50 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
@@ -8,6 +8,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #include <PiPei.h>
 #include "CpuExceptionCommon.h"
+#include "AMDSevVcCommon.h"
 
 CONST UINTN    mDoFarReturnFlag  = 0;
 
@@ -24,6 +25,21 @@ CommonExceptionHandler (
   IN EFI_SYSTEM_CONTEXT   SystemContext
   )
 {
+  if (ExceptionType == VC_EXCEPTION) {
+    UINTN  Status;
+    //
+    // #VC must be handled for an SEV-ES guest
+    //
+    Status = DoVcException (SystemContext);
+    if (Status) {
+      // Exception not handled - Status contains the desired exception now
+      ExceptionType = Status;
+    } else {
+      // Exception handled
+      return;
+    }
+  }
+
   //
   // Initialize the serial port before dumping.
   //
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c
new file mode 100644
index 000000000000..7cbf89d9b1aa
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c
@@ -0,0 +1,50 @@
+/** @file
+  X64 SEV-ES #VC Exception Handler functons.
+
+  Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/VmgExitLib.h>
+#include "AMDSevVcCommon.h"
+
+UINTN
+DoVcCommon (
+  GHCB                *Ghcb,
+  EFI_SYSTEM_CONTEXT  Context
+  )
+{
+  EFI_SYSTEM_CONTEXT_X64   *Regs = Context.SystemContextX64;
+  UINT64                   Status;
+  UINTN                    ExitCode, VcRet;
+
+  VmgInit (Ghcb);
+
+  ExitCode = Regs->ExceptionData;
+  switch (ExitCode) {
+  default:
+    Status = VmgExit (Ghcb, SvmExitUnsupported, ExitCode, 0);
+    if (Status == 0) {
+      Regs->ExceptionData = 0;
+      VcRet = GP_EXCEPTION;
+    } else {
+      GHCB_EVENT_INJECTION  Event;
+
+      Event.Uint64 = Status;
+      if (Event.Elements.ErrorCodeValid) {
+        Regs->ExceptionData = Event.Elements.ErrorCode;
+      } else {
+        Regs->ExceptionData = 0;
+      }
+
+      VcRet = Event.Elements.Vector;
+    }
+  }
+
+  VmgDone (Ghcb);
+
+  return VcRet;
+}
-- 
2.17.1