From 167e902624c9ccdf28920c099ee2d5e74d9c85a3 Mon Sep 17 00:00:00 2001
From: Jiaxin Wu <jiaxin.wu@intel.com>
Date: Wed, 26 Jun 2024 13:41:45 +0800
Subject: [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Impl
 IsSmmCommBufferForbiddenAddress for MM

Since all accessible NON-MMRAM memory shall be in ResourceDescriptor
HOBs, check the ResourceDescriptor HOBs to return if the Address is
forbidden or not for MM CPU.

Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Dun Tan <dun.tan@intel.com>
Cc: Hongbin1 Zhang <hongbin1.zhang@intel.com>
Cc: Wei6 Xu <wei6.xu@intel.com>
Cc: Yuanhao Xie <yuanhao.xie@intel.com>
---
 .../PiSmmCpuDxeSmm/NonMmramMapStandaloneMm.c  | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/NonMmramMapStandaloneMm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/NonMmramMapStandaloneMm.c
index 3c86c6b28a..3ae074c63d 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/NonMmramMapStandaloneMm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/NonMmramMapStandaloneMm.c
@@ -46,6 +46,34 @@ GetSmmProfileData (
   return SmmProfileDataHob.MemoryAllocation->AllocDescriptor.MemoryBaseAddress;
 }
 
+/**
+  Return if the Address is forbidden as SMM communication buffer.
+
+  @param[in] Address the address to be checked
+
+  @return TRUE  The address is forbidden as SMM communication buffer.
+  @return FALSE The address is allowed as SMM communication buffer.
+**/
+BOOLEAN
+IsSmmCommBufferForbiddenAddress (
+  IN UINT64  Address
+  )
+{
+  EFI_PEI_HOB_POINTERS  Hob;
+
+  Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
+  while (Hob.Raw != NULL) {
+    if ((Address >= Hob.ResourceDescriptor->PhysicalStart) && (Address < Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength)) {
+      return FALSE;
+    }
+
+    Hob.Raw = GET_NEXT_HOB (Hob);
+    Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
+  }
+
+  return TRUE;
+}
+
 /**
   Build Memory Region from ResourceDescriptor HOBs by excluding Logging attribute range.