From 76fda1def3d1baea3b01ae697687ff478d2d1b42 Mon Sep 17 00:00:00 2001
From: Min Xu <min.m.xu@intel.com>
Date: Tue, 19 Apr 2022 08:26:28 +0800
Subject: [PATCH] OvmfPkg: Call CcProbe in SecMain.c instead of TsIsEnabled

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3902

TdIsEnabled() uses the CPUID instruction. At this point, exception
handling is not established and a CPUID instruction will generate
a #VC and cause the booting guest to crash.

CcProbe() checks Ovmf work area to return the guest type. So call
of CcProbe() instead of TdIsEnabled() to fix the above issue.

Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 OvmfPkg/IntelTdx/Sec/SecMain.c   | 6 +++---
 OvmfPkg/IntelTdx/Sec/SecMain.inf | 1 +
 OvmfPkg/Sec/SecMain.c            | 5 +++--
 OvmfPkg/Sec/SecMain.inf          | 1 +
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/OvmfPkg/IntelTdx/Sec/SecMain.c b/OvmfPkg/IntelTdx/Sec/SecMain.c
index 26d56be335..ab01ec9ab1 100644
--- a/OvmfPkg/IntelTdx/Sec/SecMain.c
+++ b/OvmfPkg/IntelTdx/Sec/SecMain.c
@@ -25,7 +25,7 @@
 #include <Library/CpuExceptionHandlerLib.h>
 #include <IndustryStandard/Tdx.h>
 #include <Library/PlatformInitLib.h>
-
+#include <Library/CcProbeLib.h>
 #include <Library/PeilessStartupLib.h>
 
 #define SEC_IDT_ENTRY_COUNT  34
@@ -61,7 +61,7 @@ SecCoreStartupWithStack (
   UINT32                Index;
   volatile UINT8        *Table;
 
-  if (TdIsEnabled ()) {
+  if (CcProbe () == CcGuestTypeIntelTdx) {
     //
     // For Td guests, the memory map info is in TdHobLib. It should be processed
     // first so that the memory is accepted. Otherwise access to the unaccepted
@@ -119,7 +119,7 @@ SecCoreStartupWithStack (
   //
   AsmWriteIdtr (&IdtDescriptor);
 
-  if (TdIsEnabled ()) {
+  if (CcProbe () == CcGuestTypeIntelTdx) {
     //
     // InitializeCpuExceptionHandlers () should be called in Td guests so that
     // #VE exceptions can be handled correctly.
diff --git a/OvmfPkg/IntelTdx/Sec/SecMain.inf b/OvmfPkg/IntelTdx/Sec/SecMain.inf
index df2e749c35..9cf1249d02 100644
--- a/OvmfPkg/IntelTdx/Sec/SecMain.inf
+++ b/OvmfPkg/IntelTdx/Sec/SecMain.inf
@@ -49,6 +49,7 @@
   CpuExceptionHandlerLib
   PeilessStartupLib
   PlatformInitLib
+  CcProbeLib
 
 [Pcd]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPageTablesBase
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index ca9717a7b5..8949d10157 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -28,6 +28,7 @@
 #include <Library/CpuExceptionHandlerLib.h>
 #include <Ppi/TemporaryRamSupport.h>
 #include <Library/PlatformInitLib.h>
+#include <Library/CcProbeLib.h>
 #include "AmdSev.h"
 
 #define SEC_IDT_ENTRY_COUNT  34
@@ -738,7 +739,7 @@ SecCoreStartupWithStack (
   volatile UINT8        *Table;
 
  #if defined (TDX_GUEST_SUPPORTED)
-  if (TdIsEnabled ()) {
+  if (CcProbe () == CcGuestTypeIntelTdx) {
     //
     // For Td guests, the memory map info is in TdHobLib. It should be processed
     // first so that the memory is accepted. Otherwise access to the unaccepted
@@ -828,7 +829,7 @@ SecCoreStartupWithStack (
   }
 
  #if defined (TDX_GUEST_SUPPORTED)
-  if (TdIsEnabled ()) {
+  if (CcProbe () == CcGuestTypeIntelTdx) {
     //
     // InitializeCpuExceptionHandlers () should be called in Td guests so that
     // #VE exceptions can be handled correctly.
diff --git a/OvmfPkg/Sec/SecMain.inf b/OvmfPkg/Sec/SecMain.inf
index 4b5b089ccd..27100595ae 100644
--- a/OvmfPkg/Sec/SecMain.inf
+++ b/OvmfPkg/Sec/SecMain.inf
@@ -54,6 +54,7 @@
   LocalApicLib
   MemEncryptSevLib
   CpuExceptionHandlerLib
+  CcProbeLib
 
 [Ppis]
   gEfiTemporaryRamSupportPpiGuid                # PPI ALWAYS_PRODUCED
-- 
2.39.2