OvmfPkg: Use TdInfo instead of fw_cfg to get cpu count in TDVF

Currently TDVF gets cpu count information via fw_cfg, but this information can also be retrieved by calling of TdCall.TdInfo. And TdCall is responded by tdx-module which is trust. So, from the security perspective we shall use TdCall.Tdinfo instead of fw_cfg. Cc: Erdem Aktas <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Min Xu <[email protected]> Cc: Gerd Hoffmann <[email protected]> Cc: Elena Reshetova <[email protected]> Signed-off-by: Ceping Sun <[email protected]>
tianocore · Sep 4, 2024 · d32b2f0 · d32b2f0
1 parent 1240a72
commit d32b2f0
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Showing 3 changed files with 16 additions and 2 deletions.
diff --git a/OvmfPkg/Library/PlatformInitLib/Platform.c b/OvmfPkg/Library/PlatformInitLib/Platform.c
@@ -33,6 +33,7 @@
 #include <Guid/SystemNvDataGuid.h>
 #include <Guid/VariableFormat.h>
 #include <OvmfPlatforms.h>
+#include <Library/TdxLib.h>
 
 #include <Library/PlatformInitLib.h>
 
@@ -563,6 +564,20 @@ PlatformMaxCpuCountInitialization (
   UINT16  BootCpuCount = 0;
   UINT32  MaxCpuCount;
 
+  if (TdIsEnabled ()) {
+    BootCpuCount = (UINT16)TdVCpuNum ();
+    MaxCpuCount  = TdMaxVCpuNum ();
+
+    if (BootCpuCount > MaxCpuCount) {
+      DEBUG ((DEBUG_ERROR, "%a: Failed with BootCpuCount (%d) more than MaxCpuCount(%u) \n", __func__, BootCpuCount, MaxCpuCount));
+      ASSERT (FALSE);
+    }
+
+    PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber  = MaxCpuCount;
+    PlatformInfoHob->PcdCpuBootLogicalProcessorNumber = BootCpuCount;
+    return;
+  }
+
   //
   // Try to fetch the boot CPU count.
   //

diff --git a/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf b/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
@@ -53,8 +53,6 @@
   PcdLib
   PciLib
   PeiHardwareInfoLib
-
-[LibraryClasses.X64]
   TdxLib
 
 [Guids]

diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
@@ -251,6 +251,7 @@
   AmdSvsmLib|UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.inf
   BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
   CcExitLib|UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.inf
+  TdxLib|MdePkg/Library/TdxLib/TdxLib.inf
   TdxMailboxLib|OvmfPkg/Library/TdxMailboxLib/TdxMailboxLibNull.inf
 
 [LibraryClasses.common.SEC]