[edk2-devel] [PATCH V6 33/42] OvmfPkg: Update PlatformInitLib for Tdx guest to publish ram regions

[Min Xu]

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

In Tdx guest, the system memory is passed in TdHob by host VMM. So
the major task of PlatformTdxPublishRamRegions is to walk thru the
TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
to the hobs in DXE phase.

MemoryAllocationHob should also be created for Mailbox and Ovmf work area.

Another update is in PlatformAddressWidthInitialization. The physical
address width that Tdx guest supports is either 48 or 52.

Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Brijesh Singh <brijesh.singh at amd.com>
Cc: Erdem Aktas <erdemaktas at google.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
 OvmfPkg/Include/Library/PlatformInitLib.h     | 14 ++++++
 OvmfPkg/Library/PlatformInitLib/IntelTdx.c    | 49 +++++++++++++++++++
 .../Library/PlatformInitLib/IntelTdxNull.c    | 16 ++++++
 OvmfPkg/Library/PlatformInitLib/MemDetect.c   | 13 +++++
 4 files changed, 92 insertions(+)

diff --git a/OvmfPkg/Include/Library/PlatformInitLib.h b/OvmfPkg/Include/Library/PlatformInitLib.h
index 538fd7aee48c..6a88a9b4a69c 100644
--- a/OvmfPkg/Include/Library/PlatformInitLib.h
+++ b/OvmfPkg/Include/Library/PlatformInitLib.h
@@ -269,4 +269,18 @@ ProcessTdxHobList (
   VOID
   );
 
+/**
+  In Tdx guest, the system memory is passed in TdHob by host VMM. So
+  the major task of PlatformTdxPublishRamRegions is to walk thru the
+  TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
+  to the hobs in DXE phase.
+
+  MemoryAllocationHob should also be created for Mailbox and Ovmf work area.
+**/
+VOID
+EFIAPI
+PlatformTdxPublishRamRegions (
+  VOID
+  );
+
 #endif // PLATFORM_INIT_LIB_H_
diff --git a/OvmfPkg/Library/PlatformInitLib/IntelTdx.c b/OvmfPkg/Library/PlatformInitLib/IntelTdx.c
index 1ee24dfe754d..e9243cfa7e37 100644
--- a/OvmfPkg/Library/PlatformInitLib/IntelTdx.c
+++ b/OvmfPkg/Library/PlatformInitLib/IntelTdx.c
@@ -502,3 +502,52 @@ TransferTdxHobList (
     Hob.Raw = GET_NEXT_HOB (Hob);
   }
 }
+
+/**
+  In Tdx guest, the system memory is passed in TdHob by host VMM. So
+  the major task of PlatformTdxPublishRamRegions is to walk thru the
+  TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
+  to the hobs in DXE phase.
+
+  MemoryAllocationHob should also be created for Mailbox and Ovmf work area.
+**/
+VOID
+EFIAPI
+PlatformTdxPublishRamRegions (
+  VOID
+  )
+{
+  if (!TdIsEnabled ()) {
+    return;
+  }
+
+  TransferTdxHobList ();
+
+  //
+  // The memory region defined by PcdOvmfSecGhcbBackupBase is pre-allocated by
+  // host VMM and used as the td mailbox at the beginning of system boot.
+  //
+  BuildMemoryAllocationHob (
+    FixedPcdGet32 (PcdOvmfSecGhcbBackupBase),
+    FixedPcdGet32 (PcdOvmfSecGhcbBackupSize),
+    EfiACPIMemoryNVS
+    );
+
+  if (FixedPcdGet32 (PcdOvmfWorkAreaSize) != 0) {
+    //
+    // Reserve the work area.
+    //
+    // Since this memory range will be used by the Reset Vector on S3
+    // resume, it must be reserved as ACPI NVS.
+    //
+    // If S3 is unsupported, then various drivers might still write to the
+    // work area. We ought to prevent DXE from serving allocation requests
+    // such that they would overlap the work area.
+    //
+    BuildMemoryAllocationHob (
+      (EFI_PHYSICAL_ADDRESS)(UINTN)FixedPcdGet32 (PcdOvmfWorkAreaBase),
+      (UINT64)(UINTN)FixedPcdGet32 (PcdOvmfWorkAreaSize),
+      EfiBootServicesData
+      );
+  }
+}
diff --git a/OvmfPkg/Library/PlatformInitLib/IntelTdxNull.c b/OvmfPkg/Library/PlatformInitLib/IntelTdxNull.c
index af90e0866e89..3ebe582af8de 100644
--- a/OvmfPkg/Library/PlatformInitLib/IntelTdxNull.c
+++ b/OvmfPkg/Library/PlatformInitLib/IntelTdxNull.c
@@ -28,3 +28,19 @@ ProcessTdxHobList (
 {
   return EFI_UNSUPPORTED;
 }
+
+/**
+  In Tdx guest, the system memory is passed in TdHob by host VMM. So
+  the major task of PlatformTdxPublishRamRegions is to walk thru the
+  TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
+  to the hobs in DXE phase.
+
+  MemoryAllocationHob should also be created for Mailbox and Ovmf work area.
+**/
+VOID
+EFIAPI
+PlatformTdxPublishRamRegions (
+  VOID
+  )
+{
+}
diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index 5a9cb6e638ed..af4c851d479d 100644
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -34,6 +34,7 @@ Module Name:
 #include <Library/MtrrLib.h>
 #include <Library/QemuFwCfgLib.h>
 #include <Library/QemuFwCfgSimpleParserLib.h>
+#include <Library/TdxLib.h>
 
 #include <Library/PlatformInitLib.h>
 
@@ -481,7 +482,19 @@ PlatformAddressWidthInitialization (
     PhysMemAddressWidth = 36;
   }
 
+ #if defined (MDE_CPU_X64)
+  if (TdIsEnabled ()) {
+    if (TdSharedPageMask () == (1ULL << 47)) {
+      PhysMemAddressWidth = 48;
+    } else {
+      PhysMemAddressWidth = 52;
+    }
+  }
+
+  ASSERT (PhysMemAddressWidth <= 52);
+ #else
   ASSERT (PhysMemAddressWidth <= 48);
+ #endif
 
   return PhysMemAddressWidth;
 }
-- 
2.29.2.windows.2



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