From d50d9e55498c7ce8826316631cd4daa9a291f8b3 Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Wed, 2 Mar 2022 21:31:35 +0800
Subject: [PATCH] OvmfPkg: CloudHv: Retrieve RSDP address from PVH

Instead of hardcoding the address of the RSDP in the firmware, let's
rely on the PVH structure hvm_start_info to retrieve this information.

Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---
 OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf |  2 ++
 OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c       | 39 ++++++++++++++-------
 OvmfPkg/CloudHv/CloudHvX64.fdf              |  3 ++
 OvmfPkg/Include/IndustryStandard/CloudHv.h  |  5 ---
 4 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf b/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
index b36b8413e0..f22bd7cb6d 100644
--- a/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
+++ b/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
@@ -56,6 +56,8 @@
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdPciDisableBusEnumeration
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
+  gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtr
+  gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtrSize
 
 [Depex]
   gEfiAcpiTableProtocolGuid
diff --git a/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c b/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
index 44a6bb70fe..ff59600d3e 100644
--- a/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
+++ b/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
@@ -7,9 +7,11 @@
 
 **/
 
-#include <IndustryStandard/CloudHv.h> // CLOUDHV_RSDP_ADDRESS
-#include <Library/BaseLib.h>          // CpuDeadLoop()
-#include <Library/DebugLib.h>         // DEBUG()
+#include <IndustryStandard/CloudHv.h>                     // CLOUDHV_RSDP_ADDRESS
+#include <IndustryStandard/Xen/arch-x86/hvm/start_info.h> // hvm_start_info
+#include <Library/BaseLib.h>                              // CpuDeadLoop()
+#include <Library/DebugLib.h>                             // DEBUG()
+#include <Library/PcdLib.h>                               // PcdGet32()
 
 #include "AcpiPlatform.h"
 
@@ -23,20 +25,33 @@ InstallCloudHvTables (
   EFI_STATUS  Status;
   UINTN       TableHandle;
 
-  EFI_ACPI_DESCRIPTION_HEADER                *Xsdt;
-  VOID                                       *CurrentTableEntry;
-  UINTN                                      CurrentTablePointer;
-  EFI_ACPI_DESCRIPTION_HEADER                *CurrentTable;
-  UINTN                                      Index;
-  UINTN                                      NumberOfTableEntries;
-  EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE  *Fadt2Table;
-  EFI_ACPI_DESCRIPTION_HEADER                *DsdtTable;
+  EFI_ACPI_DESCRIPTION_HEADER                   *Xsdt;
+  VOID                                          *CurrentTableEntry;
+  UINTN                                         CurrentTablePointer;
+  EFI_ACPI_DESCRIPTION_HEADER                   *CurrentTable;
+  UINTN                                         Index;
+  UINTN                                         NumberOfTableEntries;
+  EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt2Table;
+  EFI_ACPI_DESCRIPTION_HEADER                   *DsdtTable;
+  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *AcpiRsdpStructurePtr;
+  UINT32                                        *PVHResetVectorData;
+  struct hvm_start_info                         *pvh_start_info;
 
   Fadt2Table           = NULL;
   DsdtTable            = NULL;
   TableHandle          = 0;
   NumberOfTableEntries = 0;
-  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *AcpiRsdpStructurePtr = (VOID *)CLOUDHV_RSDP_ADDRESS;
+  AcpiRsdpStructurePtr = NULL;
+  PVHResetVectorData   = NULL;
+  pvh_start_info       = NULL;
+
+  PVHResetVectorData = (VOID *)(UINTN)PcdGet32 (PcdXenPvhStartOfDayStructPtr);
+  if (PVHResetVectorData == 0) {
+    return EFI_NOT_FOUND;
+  }
+
+  pvh_start_info       = (struct hvm_start_info *)(UINTN)PVHResetVectorData[0];
+  AcpiRsdpStructurePtr = (EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER *)(UINTN)pvh_start_info->rsdp_paddr;
 
   // If XSDT table is found, just install its tables.
   // Otherwise, try to find and install the RSDT tables.
diff --git a/OvmfPkg/CloudHv/CloudHvX64.fdf b/OvmfPkg/CloudHv/CloudHvX64.fdf
index 282bcf8634..d80e13ae90 100644
--- a/OvmfPkg/CloudHv/CloudHvX64.fdf
+++ b/OvmfPkg/CloudHv/CloudHvX64.fdf
@@ -73,6 +73,9 @@ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase|gUefiOvmfPkgTokenSpaceGuid.PcdO
 0x00E000|0x001000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
 
+0x00F000|0x001000
+gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtr|gUefiOvmfPkgTokenSpaceGuid.PcdXenPvhStartOfDayStructPtrSize
+
 0x010000|0x010000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
 
diff --git a/OvmfPkg/Include/IndustryStandard/CloudHv.h b/OvmfPkg/Include/IndustryStandard/CloudHv.h
index 86404cc97e..d31ecc9eec 100644
--- a/OvmfPkg/Include/IndustryStandard/CloudHv.h
+++ b/OvmfPkg/Include/IndustryStandard/CloudHv.h
@@ -38,9 +38,4 @@
 //
 #define CLOUDHV_SMBIOS_ADDRESS  0xf0000
 
-//
-// RSDP address
-//
-#define CLOUDHV_RSDP_ADDRESS  0xa0000
-
 #endif // __CLOUDHV_H__