From ae59b8ba4166384cbfa32a921aac289bcff2aef9 Mon Sep 17 00:00:00 2001 From: Dun Tan Date: Mon, 5 Feb 2024 11:35:59 +0800 Subject: [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm:Map SMRAM in 4K page granularity This patch is to map SMRAM in 4K page granularity during SMM page table initialization(SmmInitPageTable) so as to avoid the SMRAM paging-structure layout change when SMI happens (PerformRemainingTasks). The reason is to avoid the Paging-Structure change impact to the multiple Processors. Refer SDM section "4.10.4" & "4.10.5". Currently, SMM BSP needs to update the SMRAM range paging attribute in smm page table according to the SmmMemoryAttributesTable when SMM ready to lock happens. If the SMRAM range is not 4k mapped in page table, the page table update process may split 1G/2M paging entries to 4k ones.Meanwhile, all APs are still running in SMI, which might access the affected linear-address range between the time of modification and the time of invalidation access. That will be a potential problem leading exception happens. Signed-off-by: Dun Tan Reviewed-by: Ray Ni Reviewed-by: Jiaxin Wu Cc: Laszlo Ersek Cc: Rahul Kumar Cc: Gerd Hoffmann --- .../PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 122 ++++++++++++++---- 1 file changed, 95 insertions(+), 27 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c index 12f3c0b8e8..b8c356bfe8 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c @@ -1646,6 +1646,70 @@ EdkiiSmmClearMemoryAttributes ( return SmmClearMemoryAttributes (BaseAddress, Length, Attributes); } +/** + Create page table based on input PagingMode, LinearAddress and Length. + + @param[in, out] PageTable The pointer to the page table. + @param[in] PagingMode The paging mode. + @param[in] LinearAddress The start of the linear address range. + @param[in] Length The length of the linear address range. + +**/ +VOID +GenPageTable ( + IN OUT UINTN *PageTable, + IN PAGING_MODE PagingMode, + IN UINT64 LinearAddress, + IN UINT64 Length + ) +{ + RETURN_STATUS Status; + UINTN PageTableBufferSize; + VOID *PageTableBuffer; + IA32_MAP_ATTRIBUTE MapAttribute; + IA32_MAP_ATTRIBUTE MapMask; + + MapMask.Uint64 = MAX_UINT64; + MapAttribute.Uint64 = mAddressEncMask|LinearAddress; + MapAttribute.Bits.Present = 1; + MapAttribute.Bits.ReadWrite = 1; + MapAttribute.Bits.UserSupervisor = 1; + MapAttribute.Bits.Accessed = 1; + MapAttribute.Bits.Dirty = 1; + PageTableBufferSize = 0; + + Status = PageTableMap ( + PageTable, + PagingMode, + NULL, + &PageTableBufferSize, + LinearAddress, + Length, + &MapAttribute, + &MapMask, + NULL + ); + if (Status == RETURN_BUFFER_TOO_SMALL) { + DEBUG ((DEBUG_INFO, "GenSMMPageTable: 0x%x bytes needed for initial SMM page table\n", PageTableBufferSize)); + PageTableBuffer = AllocatePageTableMemory (EFI_SIZE_TO_PAGES (PageTableBufferSize)); + ASSERT (PageTableBuffer != NULL); + Status = PageTableMap ( + PageTable, + PagingMode, + PageTableBuffer, + &PageTableBufferSize, + LinearAddress, + Length, + &MapAttribute, + &MapMask, + NULL + ); + } + + ASSERT (Status == RETURN_SUCCESS); + ASSERT (PageTableBufferSize == 0); +} + /** Create page table based on input PagingMode and PhysicalAddressBits in smm. @@ -1661,35 +1725,37 @@ GenSmmPageTable ( IN UINT8 PhysicalAddressBits ) { - UINTN PageTableBufferSize; - UINTN PageTable; - VOID *PageTableBuffer; - IA32_MAP_ATTRIBUTE MapAttribute; - IA32_MAP_ATTRIBUTE MapMask; - RETURN_STATUS Status; - UINTN GuardPage; - UINTN Index; - UINT64 Length; + UINTN PageTable; + RETURN_STATUS Status; + UINTN GuardPage; + UINTN Index; + UINT64 Length; + PAGING_MODE SmramPagingMode; - Length = LShiftU64 (1, PhysicalAddressBits); - PageTable = 0; - PageTableBufferSize = 0; - MapMask.Uint64 = MAX_UINT64; - MapAttribute.Uint64 = mAddressEncMask; - MapAttribute.Bits.Present = 1; - MapAttribute.Bits.ReadWrite = 1; - MapAttribute.Bits.UserSupervisor = 1; - MapAttribute.Bits.Accessed = 1; - MapAttribute.Bits.Dirty = 1; + PageTable = 0; + Length = LShiftU64 (1, PhysicalAddressBits); + ASSERT (Length > mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize); - Status = PageTableMap (&PageTable, PagingMode, NULL, &PageTableBufferSize, 0, Length, &MapAttribute, &MapMask, NULL); - ASSERT (Status == RETURN_BUFFER_TOO_SMALL); - DEBUG ((DEBUG_INFO, "GenSMMPageTable: 0x%x bytes needed for initial SMM page table\n", PageTableBufferSize)); - PageTableBuffer = AllocatePageTableMemory (EFI_SIZE_TO_PAGES (PageTableBufferSize)); - ASSERT (PageTableBuffer != NULL); - Status = PageTableMap (&PageTable, PagingMode, PageTableBuffer, &PageTableBufferSize, 0, Length, &MapAttribute, &MapMask, NULL); - ASSERT (Status == RETURN_SUCCESS); - ASSERT (PageTableBufferSize == 0); + if (sizeof (UINTN) == sizeof (UINT64)) { + SmramPagingMode = m5LevelPagingNeeded ? Paging5Level4KB : Paging4Level4KB; + } else { + SmramPagingMode = PagingPae4KB; + } + + ASSERT (mCpuHotPlugData.SmrrBase % SIZE_4KB == 0); + ASSERT (mCpuHotPlugData.SmrrSize % SIZE_4KB == 0); + GenPageTable (&PageTable, PagingMode, 0, mCpuHotPlugData.SmrrBase); + + // + // Map smram range in 4K page granularity to avoid subsequent page split when smm ready to lock. + // If BSP are splitting the 1G/2M paging entries to 512 2M/4K paging entries, and all APs are + // still running in SMI at the same time, which might access the affected linear-address range + // between the time of modification and the time of invalidation access. That will be a potential + // problem leading exception happen. + // + GenPageTable (&PageTable, SmramPagingMode, mCpuHotPlugData.SmrrBase, mCpuHotPlugData.SmrrSize); + + GenPageTable (&PageTable, PagingMode, mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize, Length - mCpuHotPlugData.SmrrBase - mCpuHotPlugData.SmrrSize); if (FeaturePcdGet (PcdCpuSmmStackGuard)) { // @@ -1698,6 +1764,7 @@ GenSmmPageTable ( for (Index = 0; Index < gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus; Index++) { GuardPage = mSmmStackArrayBase + EFI_PAGE_SIZE + Index * (mSmmStackSize + mSmmShadowStackSize); Status = ConvertMemoryPageAttributes (PageTable, PagingMode, GuardPage, SIZE_4KB, EFI_MEMORY_RP, TRUE, NULL); + ASSERT (Status == RETURN_SUCCESS); } } @@ -1706,6 +1773,7 @@ GenSmmPageTable ( // Mark [0, 4k] as non-present // Status = ConvertMemoryPageAttributes (PageTable, PagingMode, 0, SIZE_4KB, EFI_MEMORY_RP, TRUE, NULL); + ASSERT (Status == RETURN_SUCCESS); } return (UINTN)PageTable;