UefiCpuPkg/CpuPageTableLib: Add OUTPUT IsModified parameter.

Add OUTPUT IsModified parameter in PageTableMap() to indicate
if page table has been modified. With this parameter, caller
can know if need to call FlushTlb when the page table is in CR3.

Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 41 insertions, 5 deletions

diff --git a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
index 76c3719cdf..64383cc522 100644
--- a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
+++ b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
@@ -274,6 +274,7 @@ IsAttributesAndMaskValidForNonPresentEntry (
                                     Page table entries that map the linear address range are reset to 0 before set to the new attribute

                                     when a new physical base address is set.

   @param[in]      Mask              The mask used for attribute. The corresponding field in Attribute is ignored if that in Mask is 0.

+  @param[out]     IsModified        TRUE means page table is modified. FALSE means page table is not modified.

 

   @retval RETURN_INVALID_PARAMETER  For non-present range, Mask->Bits.Present is 0 but some other attributes are provided.

   @retval RETURN_INVALID_PARAMETER  For non-present range, Mask->Bits.Present is 1, Attribute->Bits.Present is 1 but some other attributes are not provided.

@@ -292,7 +293,8 @@ PageTableLibMapInLevel (
   IN     UINT64              Length,

   IN     UINT64              Offset,

   IN     IA32_MAP_ATTRIBUTE  *Attribute,

-  IN     IA32_MAP_ATTRIBUTE  *Mask

+  IN     IA32_MAP_ATTRIBUTE  *Mask,

+  OUT    BOOLEAN             *IsModified

   )

 {

   RETURN_STATUS       Status;

@@ -318,6 +320,8 @@ PageTableLibMapInLevel (
   IA32_MAP_ATTRIBUTE  LocalParentAttribute;

   UINT64              PhysicalAddrInEntry;

   UINT64              PhysicalAddrInAttr;

+  IA32_PAGING_ENTRY   OriginalParentPagingEntry;

+  IA32_PAGING_ENTRY   OriginalCurrentPagingEntry;

 

   ASSERT (Level != 0);

   ASSERT ((Attribute != NULL) && (Mask != NULL));

@@ -333,6 +337,8 @@ PageTableLibMapInLevel (
   LocalParentAttribute.Uint64 = ParentAttribute->Uint64;

   ParentAttribute             = &LocalParentAttribute;

 

+  OriginalParentPagingEntry.Uint64 = ParentPagingEntry->Uint64;

+

   //

   // RegionLength: 256T (1 << 48) 512G (1 << 39), 1G (1 << 30), 2M (1 << 21) or 4K (1 << 12).

   //

@@ -568,7 +574,15 @@ PageTableLibMapInLevel (
           ASSERT (CreateNew || (Mask->Bits.Nx == 0) || (Attribute->Bits.Nx == 1));

         }

 

+        //

+        // Check if any leaf PagingEntry is modified.

+        //

+        OriginalCurrentPagingEntry.Uint64 = CurrentPagingEntry->Uint64;

         PageTableLibSetPle (Level, CurrentPagingEntry, Offset, Attribute, &CurrentMask);

+

+        if (OriginalCurrentPagingEntry.Uint64 != CurrentPagingEntry->Uint64) {

+          *IsModified = TRUE;

+        }

       }

     } else {

       //

@@ -591,7 +605,8 @@ PageTableLibMapInLevel (
                  Length,

                  Offset,

                  Attribute,

-                 Mask

+                 Mask,

+                 IsModified

                  );

       if (RETURN_ERROR (Status)) {

         return Status;

@@ -603,6 +618,14 @@ PageTableLibMapInLevel (
     Index++;

   }

 

+  //

+  // Check if ParentPagingEntry entry is modified here is enough. Except the changes happen in leaf PagingEntry during

+  // the while loop, if there is any other change happens in page table, the ParentPagingEntry must has been modified.

+  //

+  if (OriginalParentPagingEntry.Uint64 != ParentPagingEntry->Uint64) {

+    *IsModified = TRUE;

+  }

+

   return RETURN_SUCCESS;

 }

 

@@ -623,6 +646,7 @@ PageTableLibMapInLevel (
                                  Page table entries that map the linear address range are reset to 0 before set to the new attribute

                                  when a new physical base address is set.

   @param[in]      Mask           The mask used for attribute. The corresponding field in Attribute is ignored if that in Mask is 0.

+  @param[out]     IsModified     TRUE means page table is modified. FALSE means page table is not modified.

 

   @retval RETURN_UNSUPPORTED        PagingMode is not supported.

   @retval RETURN_INVALID_PARAMETER  PageTable, BufferSize, Attribute or Mask is NULL.

@@ -646,7 +670,8 @@ PageTableMap (
   IN     UINT64              LinearAddress,

   IN     UINT64              Length,

   IN     IA32_MAP_ATTRIBUTE  *Attribute,

-  IN     IA32_MAP_ATTRIBUTE  *Mask

+  IN     IA32_MAP_ATTRIBUTE  *Mask,

+  OUT    BOOLEAN             *IsModified   OPTIONAL

   )

 {

   RETURN_STATUS       Status;

@@ -656,6 +681,7 @@ PageTableMap (
   IA32_PAGE_LEVEL     MaxLevel;

   IA32_PAGE_LEVEL     MaxLeafLevel;

   IA32_MAP_ATTRIBUTE  ParentAttribute;

+  BOOLEAN             LocalIsModified;

 

   if (Length == 0) {

     return RETURN_SUCCESS;

@@ -718,6 +744,12 @@ PageTableMap (
     TopPagingEntry.Pce.Nx             = 0;

   }

 

+  if (IsModified == NULL) {

+    IsModified = &LocalIsModified;

+  }

+

+  *IsModified = FALSE;

+

   ParentAttribute.Uint64                    = 0;

   ParentAttribute.Bits.PageTableBaseAddress = 1;

   ParentAttribute.Bits.Present              = 1;

@@ -741,8 +773,10 @@ PageTableMap (
                    Length,

                    0,

                    Attribute,

-                   Mask

+                   Mask,

+                   IsModified

                    );

+  ASSERT (*IsModified == FALSE);

   if (RETURN_ERROR (Status)) {

     return Status;

   }

@@ -773,8 +807,10 @@ PageTableMap (
              Length,

              0,

              Attribute,

-             Mask

+             Mask,

+             IsModified

              );

+

   if (!RETURN_ERROR (Status)) {

     *PageTable = (UINTN)(TopPagingEntry.Uintn & IA32_PE_BASE_ADDRESS_MASK_40);

   }