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authorDun Tan <dun.tan@intel.com>2023-03-16 10:34:40 +0800
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2023-03-27 08:21:58 +0000
commit4904a2b1ecb700fce6085f3e0ae18a73aed97a2e (patch)
tree74977ec86f1735e29647755752b3eb17e82ad3de
parent563a2d2695891a709394ce39af8349a2dee64b4f (diff)
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UefiCpuPkg/CpuPageTableLib: Fix the non-1:1 mapping issue
In previous code logic, when splitting a leaf parent entry to smaller granularity child page table, if the parent entry Attribute&Mask(without PageTableBaseAddress field) is equal to the input attribute&mask(without PageTableBaseAddress field), the split process won't happen. This may lead to failure in non-1:1 mapping. For example, there is a page table in which [0, 1G] is mapped(Lv4[0] ,Lv3[0,0], a non-leaf level4 entry and a leaf level3 entry). And we want to remap [0, 2M] linear address range to [1G, 1G + 2M] with the same attibute. The expected behaviour should be: split Lv3[0,0] entry into 512 level2 entries and remap the first level2 entry to cover [0, 2M]. But the split won't happen in previous code since PageTableBaseAddress of input Attribute is not checked. So, when checking if a leaf parent entry needs to be splitted, we should also check if PageTableBaseAddress calculated by parent entry is equal to the value caculated by input attribute. 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>
-rw-r--r--UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
index 127b65183f..b94ef07c56 100644
--- a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
+++ b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
@@ -274,6 +274,8 @@ PageTableLibMapInLevel (
IA32_MAP_ATTRIBUTE ChildMask;
IA32_MAP_ATTRIBUTE CurrentMask;
IA32_MAP_ATTRIBUTE LocalParentAttribute;
+ UINT64 PhysicalAddrInEntry;
+ UINT64 PhysicalAddrInAttr;
ASSERT (Level != 0);
ASSERT ((Attribute != NULL) && (Mask != NULL));
@@ -341,7 +343,15 @@ PageTableLibMapInLevel (
// This function is called when the memory length is less than the region length of the parent level.
// No need to split the page when the attributes equal.
//
- return RETURN_SUCCESS;
+ if (Mask->Bits.PageTableBaseAddress == 0) {
+ return RETURN_SUCCESS;
+ }
+
+ PhysicalAddrInEntry = IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (&PleBAttribute) + MultU64x32 (RegionLength, (UINT32)PagingEntryIndex);
+ PhysicalAddrInAttr = (IA32_MAP_ATTRIBUTE_PAGE_TABLE_BASE_ADDRESS (Attribute) + Offset) & (~RegionMask);
+ if (PhysicalAddrInEntry == PhysicalAddrInAttr) {
+ return RETURN_SUCCESS;
+ }
}
ASSERT (Buffer == NULL || *BufferSize >= SIZE_4KB);