From a00b71b009a60947fec8ace0ac56ab2ece887d97 Mon Sep 17 00:00:00 2001
From: Min M Xu <min.m.xu@intel.com>
Date: Tue, 20 Dec 2022 16:42:35 +0800
Subject: [PATCH] OvmfPkg/TdxMailboxLib: Delete global variables

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4172

TdxMailboxLib once was designed to be used in DXE phase. But now it is
going to be used in SEC/PEI phase (in the following patches). Global
variables are not allowed. The library is refactored after those global
variables are deleted.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---
 OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c b/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
index 74cb55611f..c580a28856 100644
--- a/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
@@ -13,14 +13,10 @@
 #include <Library/UefiCpuLib.h>
 #include <Library/SynchronizationLib.h>
 #include <Uefi/UefiBaseType.h>
-#include <Library/TdxLib.h>
 #include <IndustryStandard/IntelTdx.h>
 #include <IndustryStandard/Tdx.h>
 #include <Library/TdxMailboxLib.h>
 
-volatile VOID  *mMailBox  = NULL;
-UINT32         mNumOfCpus = 0;
-
 /**
   This function will be called by BSP to get the CPU number.
 
@@ -32,11 +28,17 @@ GetCpusNum (
   VOID
   )
 {
-  if (mNumOfCpus == 0) {
-    mNumOfCpus = TdVCpuNum ();
+  UINT64          Status;
+  TD_RETURN_DATA  TdReturnData;
+
+  Status = TdCall (TDCALL_TDINFO, 0, 0, 0, &TdReturnData);
+  if (Status == TDX_EXIT_REASON_SUCCESS) {
+    return TdReturnData.TdInfo.NumVcpus;
+  } else {
+    DEBUG ((DEBUG_ERROR, "Failed call TDCALL_TDINFO. %llx\n", Status));
   }
 
-  return mNumOfCpus;
+  return 0;
 }
 
 /**
@@ -48,11 +50,7 @@ GetTdxMailBox (
   VOID
   )
 {
-  if (mMailBox == NULL) {
-    mMailBox = (VOID *)(UINTN)PcdGet32 (PcdOvmfSecGhcbBackupBase);
-  }
-
-  return mMailBox;
+  return (VOID *)(UINTN)PcdGet32 (PcdOvmfSecGhcbBackupBase);
 }
 
 /**