X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=UefiCpuPkg%2FCpuDxe%2FCpuDxe.c;h=6ae2dcd1c71136bd6fa364ba906dd80a6befcde6;hp=4e8fa100e0e225435d635fd6e4952416f815e4df;hb=147fd35c3e389ecd025dbfd243312bf5b22da7c9;hpb=c1cab54ce57c2608b8b3ea051c7041f036f21153

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
index 4e8fa100e0..6ae2dcd1c7 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.c
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
@@ -25,6 +25,7 @@
 BOOLEAN                   InterruptState = FALSE;
 EFI_HANDLE                mCpuHandle = NULL;
 BOOLEAN                   mIsFlushingGCD;
+BOOLEAN                   mIsAllocatingPageTable = FALSE;
 UINT64                    mValidMtrrAddressMask;
 UINT64                    mValidMtrrBitsMask;
 UINT64                    mTimerPeriod = 0;
@@ -407,6 +408,20 @@ CpuSetMemoryAttributes (
     return EFI_SUCCESS;
   }
 
+  //
+  // During memory attributes updating, new pages may be allocated to setup
+  // smaller granularity of page table. Page allocation action might then cause
+  // another calling of CpuSetMemoryAttributes() recursively, due to memory
+  // protection policy configured (such as PcdDxeNxMemoryProtectionPolicy).
+  // Since this driver will always protect memory used as page table by itself,
+  // there's no need to apply protection policy requested from memory service.
+  // So it's safe to just return EFI_SUCCESS if this time of calling is caused
+  // by page table memory allocation.
+  //
+  if (mIsAllocatingPageTable) {
+    DEBUG((DEBUG_VERBOSE, "  Allocating page table memory\n"));
+    return EFI_SUCCESS;
+  }
 
   CacheAttributes = Attributes & CACHE_ATTRIBUTE_MASK;
   MemoryAttributes = Attributes & MEMORY_ATTRIBUTE_MASK;
@@ -487,7 +502,7 @@ CpuSetMemoryAttributes (
   //
   // Set memory attribute by page table
   //
-  return AssignMemoryPageAttributes (NULL, BaseAddress, Length, MemoryAttributes, AllocatePages);
+  return AssignMemoryPageAttributes (NULL, BaseAddress, Length, MemoryAttributes, NULL);
 }
 
 /**
@@ -683,7 +698,7 @@ SetGcdMemorySpaceAttributes (
 
 **/
 VOID
-RefreshGcdMemoryAttributes (
+RefreshMemoryAttributesFromMtrr (
   VOID
   )
 {
@@ -704,14 +719,9 @@ RefreshGcdMemoryAttributes (
   UINT32                              FirmwareVariableMtrrCount;
   UINT8                               DefaultMemoryType;
 
-  if (!IsMtrrSupported ()) {
-    return;
-  }
-
   FirmwareVariableMtrrCount = GetFirmwareVariableMtrrCount ();
   ASSERT (FirmwareVariableMtrrCount <= MTRR_NUMBER_OF_VARIABLE_MTRR);
 
-  mIsFlushingGCD = TRUE;
   MemorySpaceMap = NULL;
 
   //
@@ -862,11 +872,46 @@ RefreshGcdMemoryAttributes (
   if (MemorySpaceMap != NULL) {
     FreePool (MemorySpaceMap);
   }
+}
 
-  //
-  // Update page attributes
-  //
-  RefreshGcdMemoryAttributesFromPaging();
+/**
+ Check if paging is enabled or not.
+**/
+BOOLEAN
+IsPagingAndPageAddressExtensionsEnabled (
+  VOID
+  )
+{
+  IA32_CR0  Cr0;
+  IA32_CR4  Cr4;
+
+  Cr0.UintN = AsmReadCr0 ();
+  Cr4.UintN = AsmReadCr4 ();
+
+  return ((Cr0.Bits.PG != 0) && (Cr4.Bits.PAE != 0));
+}
+
+/**
+  Refreshes the GCD Memory Space attributes according to MTRRs and Paging.
+
+  This function refreshes the GCD Memory Space attributes according to MTRRs
+  and page tables.
+
+**/
+VOID
+RefreshGcdMemoryAttributes (
+  VOID
+  )
+{
+  mIsFlushingGCD = TRUE;
+
+  if (IsMtrrSupported ()) {
+    RefreshMemoryAttributesFromMtrr ();
+  }
+
+  if (IsPagingAndPageAddressExtensionsEnabled ()) {
+    RefreshGcdMemoryAttributesFromPaging ();
+  }
 
   mIsFlushingGCD = FALSE;
 }