[edk2-devel] [PATCH 09/10] OvmfPkg: Update DxeAcpiTimerLib to read HostBridgeDevId in PlatformInfoHob

[Min Xu]

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

The entrypoint of DxeAcpiTimerLib checks HostBridgeDevId by reading
PcdOvmfHostBridgePciDevId. If the DevId is not set, ASSERT is
triggered. Normally this DevId is set in PlatformPei which is executed
in PEI phase. But Tdvf Config-B skips PEI phase so there is no chance
to set this DevId.

A word-round is that in Tdx guest HostBridgeDevId is set in
PlatformInfoHob (in SecPlatformLibQemuTdx). So we can check if
PlatformInfoHob exists and if HostBridgeDevId is set in this Hob.

Cc: Michael D Kinney <michael.d.kinney 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>
---
 .../Library/AcpiTimerLib/DxeAcpiTimerLib.c    | 23 ++++++++++++++++---
 .../Library/AcpiTimerLib/DxeAcpiTimerLib.inf  |  4 ++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c b/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
index 115846187455..5c7011f2dd3d 100644
--- a/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
+++ b/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
@@ -6,10 +6,16 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent
 **/
 
+#include <Uefi/UefiBaseType.h>
+#include <Uefi/UefiMultiPhase.h>
+#include <Pi/PiBootMode.h>
+#include <Pi/PiHob.h>
+#include <Library/HobLib.h>
 #include <Library/DebugLib.h>
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
 #include <Library/PciLib.h>
+#include <IndustryStandard/IntelTdx.h>
 #include <OvmfPlatforms.h>
 
 //
@@ -36,13 +42,24 @@ AcpiTimerLibConstructor (
   VOID
   )
 {
-  UINT16  HostBridgeDevId;
-  UINTN   Pmba;
+  UINT16                 HostBridgeDevId;
+  UINTN                  Pmba;
+  EFI_HOB_GUID_TYPE      *GuidHob;
+  EFI_HOB_PLATFORM_INFO  *PlatformInfo = NULL;
 
   //
   // Query Host Bridge DID to determine platform type
+  // Tdx guest stores the HostBridgePciDevId in a GuidHob.
+  // So we first check if this HOB exists
   //
-  HostBridgeDevId = PcdGet16 (PcdOvmfHostBridgePciDevId);
+  GuidHob = GetFirstGuidHob (&gUefiOvmfPkgTdxPlatformGuid);
+  if (GuidHob != NULL) {
+    PlatformInfo    = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);
+    HostBridgeDevId = PlatformInfo->HostBridgePciDevId;
+  } else {
+    HostBridgeDevId = PcdGet16 (PcdOvmfHostBridgePciDevId);
+  }
+
   switch (HostBridgeDevId) {
     case INTEL_82441_DEVICE_ID:
       Pmba = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
diff --git a/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf b/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
index e29872add3c7..44a4423a9ddd 100644
--- a/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
+++ b/OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
@@ -33,3 +33,7 @@
   BaseLib
   PciLib
   IoLib
+  HobLib
+
+[Guids]
+  gUefiOvmfPkgTdxPlatformGuid                      ## CONSUMES
-- 
2.29.2.windows.2



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