From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by mx.groups.io with SMTP id smtpd.web10.50603.1680255441226956235 for ; Fri, 31 Mar 2023 02:37:26 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="unable to parse pub key" header.i=@intel.com header.s=intel header.b=I4DOfsp2; spf=pass (domain: intel.com, ip: 192.55.52.120, mailfrom: dun.tan@intel.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680255446; x=1711791446; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=guji0DKZE5EgFaPBGbk6OEhcQ1Omwo1yb6NMvVZoI1g=; b=I4DOfsp2Msgezu4pO8Il7eQf0L75UoNh+CDBSjY0IEsDOjcKnu9QtPWy UdNxWJtsaYiqvaLNVMZvRpsvs+8O9+f7StRMRknKEfM3D6vcCULoEIYB9 qnAvRS9zwrqiNb5L/Gxv/xVsn5BLn1gyRHYh1ohK33HgWBTEu0wQUJ2AC JUBlV9iSR3E2YZB4FU1nHNbGaOJzpU+u3fvY8WVEFQm7PEAl/FH0S4U0B hlAY88c3S1n632zqHZfl0EySxmvh0PrRBZW0Q2adFquZ3f7kb7rqib0v8 ZWooRKvyt/jlM3KO9rjOmm4BQW7zFv/BlEam50/cYXG9gZjaPu1gcpFlY Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10665"; a="340133853" X-IronPort-AV: E=Sophos;i="5.98,307,1673942400"; d="scan'208";a="340133853" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2023 02:36:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10665"; a="635229553" X-IronPort-AV: E=Sophos;i="5.98,307,1673942400"; d="scan'208";a="635229553" Received: from shwdeopenlab702.ccr.corp.intel.com ([10.239.55.92]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2023 02:36:52 -0700 From: "duntan" To: devel@edk2.groups.io Cc: Dandan Bi , Liming Gao , Ray Ni , Jian J Wang Subject: [Patch V2 6/8] MdeModulePkg/DxeIpl: Create page table by CpuPageTableLib Date: Fri, 31 Mar 2023 17:33:42 +0800 Message-Id: <20230331093344.2609-7-dun.tan@intel.com> X-Mailer: git-send-email 2.31.1.windows.1 In-Reply-To: <20230331093344.2609-1-dun.tan@intel.com> References: <20230331093344.2609-1-dun.tan@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Modify CreateIdentityMappingPageTables() to create page table based on CpuPageTableLib in DxeIpl module. This function can be used to create both IA32 PAE paging and long mode 4-level, 5-level paging structure. With the PageTableMap() API in the CpuPageTableLib, we can remove the complicated page table manipulating code. This commit doesn't change any functionality. Signed-off-by: Dun Tan Cc: Dandan Bi Cc: Liming Gao Cc: Ray Ni Cc: Jian J Wang --- MdeModulePkg/Core/DxeIplPeim/DxeIpl.h | 3 ++- MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf | 4 +++- MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c | 109 ++++--------------------------------------------------------------------------------------------------------- MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c | 5 +++-- MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c | 558 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h | 167 ++++++++++------------------------------------------------------------------------------------------------------------------------------------------------------------- 6 files changed, 167 insertions(+), 679 deletions(-) diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.h b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.h index 2f015befce..03e6f8cff7 100644 --- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.h +++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.h @@ -2,7 +2,7 @@ Master header file for DxeIpl PEIM. All source files in this module should include this file for common definitions. -Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ @@ -42,6 +42,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent #include #include #include +#include #define STACK_SIZE 0x20000 #define BSP_STORE_SIZE 0x4000 diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf index 052ea0ec1a..60623b4f66 100644 --- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf +++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf @@ -5,7 +5,7 @@ # PPI to discover and dispatch the DXE Foundation and components that are # needed to run the DXE Foundation. # -# Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
+# Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
# Copyright (c) 2017, AMD Incorporated. All rights reserved.
# Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.
# Copyright (c) 2022, Loongson Technology Corporation Limited. All rights reserved.
@@ -60,6 +60,7 @@ [Packages] MdePkg/MdePkg.dec MdeModulePkg/MdeModulePkg.dec + UefiCpuPkg/UefiCpuPkg.dec [Packages.ARM, Packages.AARCH64] ArmPkg/ArmPkg.dec @@ -79,6 +80,7 @@ DebugAgentLib PeiServicesTablePointerLib PerformanceLib + CpuPageTableLib [LibraryClasses.ARM, LibraryClasses.AARCH64] ArmMmuLib diff --git a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c index fdeaaa39d8..af1e1e3d02 100644 --- a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c @@ -1,7 +1,7 @@ /** @file Ia32-specific functionality for DxeLoad. -Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
Copyright (c) 2017, AMD Incorporated. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent @@ -70,107 +70,6 @@ GLOBAL_REMOVE_IF_UNREFERENCED IA32_DESCRIPTOR gLidtDescriptor = { 0 }; -/** - Allocates and fills in the Page Directory and Page Table Entries to - establish a 4G page table. - - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - - @return The address of page table. - -**/ -UINTN -Create4GPageTablesIa32Pae ( - IN EFI_PHYSICAL_ADDRESS StackBase, - IN UINTN StackSize - ) -{ - UINT8 PhysicalAddressBits; - EFI_PHYSICAL_ADDRESS PhysicalAddress; - UINTN IndexOfPdpEntries; - UINTN IndexOfPageDirectoryEntries; - UINT32 NumberOfPdpEntriesNeeded; - PAGE_MAP_AND_DIRECTORY_POINTER *PageMap; - PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry; - PAGE_TABLE_ENTRY *PageDirectoryEntry; - UINTN TotalPagesNum; - UINTN PageAddress; - UINT64 AddressEncMask; - - // - // Make sure AddressEncMask is contained to smallest supported address field - // - AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64; - - PhysicalAddressBits = 32; - - // - // Calculate the table entries needed. - // - NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30)); - - TotalPagesNum = NumberOfPdpEntriesNeeded + 1; - PageAddress = (UINTN)AllocatePageTableMemory (TotalPagesNum); - ASSERT (PageAddress != 0); - - PageMap = (VOID *)PageAddress; - PageAddress += SIZE_4KB; - - PageDirectoryPointerEntry = PageMap; - PhysicalAddress = 0; - - for (IndexOfPdpEntries = 0; IndexOfPdpEntries < NumberOfPdpEntriesNeeded; IndexOfPdpEntries++, PageDirectoryPointerEntry++) { - // - // Each Directory Pointer entries points to a page of Page Directory entires. - // So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop. - // - PageDirectoryEntry = (VOID *)PageAddress; - PageAddress += SIZE_4KB; - - // - // Fill in a Page Directory Pointer Entries - // - PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry | AddressEncMask; - PageDirectoryPointerEntry->Bits.Present = 1; - - for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress += SIZE_2MB) { - if ( (IsNullDetectionEnabled () && (PhysicalAddress == 0)) - || ( (PhysicalAddress < StackBase + StackSize) - && ((PhysicalAddress + SIZE_2MB) > StackBase))) - { - // - // Need to split this 2M page that covers stack range. - // - Split2MPageTo4K (PhysicalAddress, (UINT64 *)PageDirectoryEntry, StackBase, StackSize, 0, 0); - } else { - // - // Fill in the Page Directory entries - // - PageDirectoryEntry->Uint64 = (UINT64)PhysicalAddress | AddressEncMask; - PageDirectoryEntry->Bits.ReadWrite = 1; - PageDirectoryEntry->Bits.Present = 1; - PageDirectoryEntry->Bits.MustBe1 = 1; - } - } - } - - for ( ; IndexOfPdpEntries < 512; IndexOfPdpEntries++, PageDirectoryPointerEntry++) { - ZeroMem ( - PageDirectoryPointerEntry, - sizeof (PAGE_MAP_AND_DIRECTORY_POINTER) - ); - } - - // - // Protect the page table by marking the memory used for page table to be - // read-only. - // - EnablePageTableProtection ((UINTN)PageMap, FALSE); - - return (UINTN)PageMap; -} - /** The function will check if IA32 PAE is supported. @@ -299,9 +198,9 @@ HandOffToDxeCore ( // AsmWriteGdtr (&gGdt); // - // Create page table and save PageMapLevel4 to CR3 + // Create page table and save PageMapLevel4 or PageMapLevel5 to CR3 // - PageTables = CreateIdentityMappingPageTables (BaseOfStack, STACK_SIZE, 0, 0); + PageTables = CreateIdentityMappingPageTables (TRUE, BaseOfStack, STACK_SIZE, 0, 0); // // End of PEI phase signal @@ -422,7 +321,7 @@ HandOffToDxeCore ( PageTables = 0; BuildPageTablesIa32Pae = ToBuildPageTable (); if (BuildPageTablesIa32Pae) { - PageTables = Create4GPageTablesIa32Pae (BaseOfStack, STACK_SIZE); + PageTables = CreateIdentityMappingPageTables (FALSE, BaseOfStack, STACK_SIZE, 0, 0); if (IsEnableNonExecNeeded ()) { EnableExecuteDisableBit (); } diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c index fa2050cf02..2642092ee5 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c @@ -1,7 +1,7 @@ /** @file x64-specifc functionality for DxeLoad. -Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ @@ -91,9 +91,10 @@ HandOffToDxeCore ( PageTables = 0; if (FeaturePcdGet (PcdDxeIplBuildPageTables)) { // - // Create page table and save PageMapLevel4 to CR3 + // Create page table and save PageMapLevel4 or PageMapLevel5 to CR3 // PageTables = CreateIdentityMappingPageTables ( + TRUE, (EFI_PHYSICAL_ADDRESS)(UINTN)BaseOfStack, STACK_SIZE, (EFI_PHYSICAL_ADDRESS)(UINTN)GhcbBase, diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c index 18b121d768..ecdbd2ca24 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c @@ -15,7 +15,7 @@ 2) IA-32 Intel(R) Architecture Software Developer's Manual Volume 2:Instruction Set Reference, Intel 3) IA-32 Intel(R) Architecture Software Developer's Manual Volume 3:System Programmer's Guide, Intel -Copyright (c) 2006 - 2022, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
Copyright (c) 2017, AMD Incorporated. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent @@ -186,55 +186,6 @@ EnableExecuteDisableBit ( } } -/** - The function will check if page table entry should be splitted to smaller - granularity. - - @param Address Physical memory address. - @param Size Size of the given physical memory. - @param StackBase Base address of stack. - @param StackSize Size of stack. - @param GhcbBase Base address of GHCB pages. - @param GhcbSize Size of GHCB area. - - @retval TRUE Page table should be split. - @retval FALSE Page table should not be split. -**/ -BOOLEAN -ToSplitPageTable ( - IN EFI_PHYSICAL_ADDRESS Address, - IN UINTN Size, - IN EFI_PHYSICAL_ADDRESS StackBase, - IN UINTN StackSize, - IN EFI_PHYSICAL_ADDRESS GhcbBase, - IN UINTN GhcbSize - ) -{ - if (IsNullDetectionEnabled () && (Address == 0)) { - return TRUE; - } - - if (PcdGetBool (PcdCpuStackGuard)) { - if ((StackBase >= Address) && (StackBase < (Address + Size))) { - return TRUE; - } - } - - if (PcdGetBool (PcdSetNxForStack)) { - if ((Address < StackBase + StackSize) && ((Address + Size) > StackBase)) { - return TRUE; - } - } - - if (GhcbBase != 0) { - if ((Address < GhcbBase + GhcbSize) && ((Address + Size) > GhcbBase)) { - return TRUE; - } - } - - return FALSE; -} - /** Initialize a buffer pool for page table use only. @@ -341,143 +292,42 @@ AllocatePageTableMemory ( } /** - Split 2M page to 4K. - - @param[in] PhysicalAddress Start physical address the 2M page covered. - @param[in, out] PageEntry2M Pointer to 2M page entry. - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - @param[in] GhcbBase GHCB page area base address. - @param[in] GhcbSize GHCB page area size. - + This function create new page table or modifies the page MapAttribute for the memory region + specified by BaseAddress and Length from their current attributes to the attributes specified + by MapAttribute and Mask. + + @param[in] PageTable Pointer to Page table address. + @param[in] PagingMode The paging mode. + @param[in] BaseAddress The start of the linear address range. + @param[in] Length The length of the linear address range. + @param[in] MapAttribute The attribute of the linear address range. + @param[in] MapMask The mask used for attribute. **/ VOID -Split2MPageTo4K ( - IN EFI_PHYSICAL_ADDRESS PhysicalAddress, - IN OUT UINT64 *PageEntry2M, - IN EFI_PHYSICAL_ADDRESS StackBase, - IN UINTN StackSize, - IN EFI_PHYSICAL_ADDRESS GhcbBase, - IN UINTN GhcbSize +CreateOrUpdatePageTable ( + IN UINTN *PageTable, + IN PAGING_MODE PagingMode, + IN PHYSICAL_ADDRESS BaseAddress, + IN UINT64 Length, + IN IA32_MAP_ATTRIBUTE *MapAttribute, + IN IA32_MAP_ATTRIBUTE *MapMask ) { - EFI_PHYSICAL_ADDRESS PhysicalAddress4K; - UINTN IndexOfPageTableEntries; - PAGE_TABLE_4K_ENTRY *PageTableEntry; - UINT64 AddressEncMask; - - // - // Make sure AddressEncMask is contained to smallest supported address field - // - AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64; - - PageTableEntry = AllocatePageTableMemory (1); - ASSERT (PageTableEntry != NULL); - - // - // Fill in 2M page entry. - // - *PageEntry2M = (UINT64)(UINTN)PageTableEntry | AddressEncMask | IA32_PG_P | IA32_PG_RW; - - PhysicalAddress4K = PhysicalAddress; - for (IndexOfPageTableEntries = 0; IndexOfPageTableEntries < 512; IndexOfPageTableEntries++, PageTableEntry++, PhysicalAddress4K += SIZE_4KB) { - // - // Fill in the Page Table entries - // - PageTableEntry->Uint64 = (UINT64)PhysicalAddress4K; - - // - // The GHCB range consists of two pages per CPU, the GHCB and a - // per-CPU variable page. The GHCB page needs to be mapped as an - // unencrypted page while the per-CPU variable page needs to be - // mapped encrypted. These pages alternate in assignment. - // - if ( (GhcbBase == 0) - || (PhysicalAddress4K < GhcbBase) - || (PhysicalAddress4K >= GhcbBase + GhcbSize) - || (((PhysicalAddress4K - GhcbBase) & SIZE_4KB) != 0)) - { - PageTableEntry->Uint64 |= AddressEncMask; - } - - PageTableEntry->Bits.ReadWrite = 1; - - if ((IsNullDetectionEnabled () && (PhysicalAddress4K == 0)) || - (PcdGetBool (PcdCpuStackGuard) && (PhysicalAddress4K == StackBase))) - { - PageTableEntry->Bits.Present = 0; - } else { - PageTableEntry->Bits.Present = 1; - } - - if ( PcdGetBool (PcdSetNxForStack) - && (PhysicalAddress4K >= StackBase) - && (PhysicalAddress4K < StackBase + StackSize)) - { - // - // Set Nx bit for stack. - // - PageTableEntry->Bits.Nx = 1; - } + RETURN_STATUS Status; + UINTN PageTableBufferSize; + VOID *PageTableBuffer; + + PageTableBufferSize = 0; + Status = PageTableMap (PageTable, PagingMode, NULL, &PageTableBufferSize, BaseAddress, Length, MapAttribute, MapMask, NULL); + if (Status == RETURN_BUFFER_TOO_SMALL) { + PageTableBuffer = AllocatePageTableMemory (EFI_SIZE_TO_PAGES (PageTableBufferSize)); + DEBUG ((DEBUG_INFO, "DxeIpl: 0x%x bytes needed for page table\n", PageTableBufferSize)); + ASSERT (PageTableBuffer != NULL); + Status = PageTableMap (PageTable, PagingMode, PageTableBuffer, &PageTableBufferSize, BaseAddress, Length, MapAttribute, MapMask, NULL); } -} - -/** - Split 1G page to 2M. - @param[in] PhysicalAddress Start physical address the 1G page covered. - @param[in, out] PageEntry1G Pointer to 1G page entry. - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - @param[in] GhcbBase GHCB page area base address. - @param[in] GhcbSize GHCB page area size. - -**/ -VOID -Split1GPageTo2M ( - IN EFI_PHYSICAL_ADDRESS PhysicalAddress, - IN OUT UINT64 *PageEntry1G, - IN EFI_PHYSICAL_ADDRESS StackBase, - IN UINTN StackSize, - IN EFI_PHYSICAL_ADDRESS GhcbBase, - IN UINTN GhcbSize - ) -{ - EFI_PHYSICAL_ADDRESS PhysicalAddress2M; - UINTN IndexOfPageDirectoryEntries; - PAGE_TABLE_ENTRY *PageDirectoryEntry; - UINT64 AddressEncMask; - - // - // Make sure AddressEncMask is contained to smallest supported address field - // - AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64; - - PageDirectoryEntry = AllocatePageTableMemory (1); - ASSERT (PageDirectoryEntry != NULL); - - // - // Fill in 1G page entry. - // - *PageEntry1G = (UINT64)(UINTN)PageDirectoryEntry | AddressEncMask | IA32_PG_P | IA32_PG_RW; - - PhysicalAddress2M = PhysicalAddress; - for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M += SIZE_2MB) { - if (ToSplitPageTable (PhysicalAddress2M, SIZE_2MB, StackBase, StackSize, GhcbBase, GhcbSize)) { - // - // Need to split this 2M page that covers NULL or stack range. - // - Split2MPageTo4K (PhysicalAddress2M, (UINT64 *)PageDirectoryEntry, StackBase, StackSize, GhcbBase, GhcbSize); - } else { - // - // Fill in the Page Directory entries - // - PageDirectoryEntry->Uint64 = (UINT64)PhysicalAddress2M | AddressEncMask; - PageDirectoryEntry->Bits.ReadWrite = 1; - PageDirectoryEntry->Bits.Present = 1; - PageDirectoryEntry->Bits.MustBe1 = 1; - } - } + ASSERT_RETURN_ERROR (Status); + ASSERT (PageTableBufferSize == 0); } /** @@ -657,19 +507,20 @@ EnablePageTableProtection ( } /** - Allocates and fills in the Page Directory and Page Table Entries to + Create IA32 PAE paging or 4-level/5-level paging for long mode to establish a 1:1 Virtual to Physical mapping. - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - @param[in] GhcbBase GHCB base address. - @param[in] GhcbSize GHCB size. - - @return The address of 4 level page map. + @param[in] Is64BitPageTable Whether to create 64-bit page table. + @param[in] StackBase Stack base address. + @param[in] StackSize Stack size. + @param[in] GhcbBase GHCB base address. + @param[in] GhcbSize GHCB size. + @return PageTable Address **/ UINTN CreateIdentityMappingPageTables ( + IN BOOLEAN Is64BitPageTable, IN EFI_PHYSICAL_ADDRESS StackBase, IN UINTN StackSize, IN EFI_PHYSICAL_ADDRESS GhcbBase, @@ -680,274 +531,155 @@ CreateIdentityMappingPageTables ( CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_ECX EcxFlags; UINT32 RegEdx; UINT8 PhysicalAddressBits; - EFI_PHYSICAL_ADDRESS PageAddress; - UINTN IndexOfPml5Entries; - UINTN IndexOfPml4Entries; - UINTN IndexOfPdpEntries; - UINTN IndexOfPageDirectoryEntries; - UINT32 NumberOfPml5EntriesNeeded; - UINT32 NumberOfPml4EntriesNeeded; - UINT32 NumberOfPdpEntriesNeeded; - PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel5Entry; - PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry; - PAGE_MAP_AND_DIRECTORY_POINTER *PageMap; - PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry; - PAGE_TABLE_ENTRY *PageDirectoryEntry; - UINTN TotalPagesNum; - UINTN BigPageAddress; VOID *Hob; BOOLEAN Page5LevelSupport; BOOLEAN Page1GSupport; - PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry; UINT64 AddressEncMask; IA32_CR4 Cr4; - - // - // Set PageMapLevel5Entry to suppress incorrect compiler/analyzer warnings - // - PageMapLevel5Entry = NULL; + PAGING_MODE PagingMode; + UINTN PageTable; + IA32_MAP_ATTRIBUTE MapAttribute; + IA32_MAP_ATTRIBUTE MapMask; + EFI_PHYSICAL_ADDRESS GhcbBase4K; // // Make sure AddressEncMask is contained to smallest supported address field // - AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64; - - Page1GSupport = FALSE; - if (PcdGetBool (PcdUse1GPageTable)) { - AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL); - if (RegEax >= 0x80000001) { - AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx); - if ((RegEdx & BIT26) != 0) { - Page1GSupport = TRUE; + AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64; + Page5LevelSupport = FALSE; + Page1GSupport = FALSE; + + if (!Is64BitPageTable) { + PagingMode = PagingPae; + PhysicalAddressBits = 32; + } else { + if (PcdGetBool (PcdUse1GPageTable)) { + AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL); + if (RegEax >= 0x80000001) { + AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx); + if ((RegEdx & BIT26) != 0) { + Page1GSupport = TRUE; + } } } - } - // - // Get physical address bits supported. - // - Hob = GetFirstHob (EFI_HOB_TYPE_CPU); - if (Hob != NULL) { - PhysicalAddressBits = ((EFI_HOB_CPU *)Hob)->SizeOfMemorySpace; - } else { - AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL); - if (RegEax >= 0x80000008) { - AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL); - PhysicalAddressBits = (UINT8)RegEax; + // + // Get physical address bits supported. + // + Hob = GetFirstHob (EFI_HOB_TYPE_CPU); + if (Hob != NULL) { + PhysicalAddressBits = ((EFI_HOB_CPU *)Hob)->SizeOfMemorySpace; } else { - PhysicalAddressBits = 36; + AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL); + if (RegEax >= 0x80000008) { + AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL); + PhysicalAddressBits = (UINT8)RegEax; + } else { + PhysicalAddressBits = 36; + } } - } - Page5LevelSupport = FALSE; - if (PcdGetBool (PcdUse5LevelPageTable)) { - AsmCpuidEx ( - CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, - CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, - NULL, - NULL, - &EcxFlags.Uint32, - NULL - ); - if (EcxFlags.Bits.FiveLevelPage != 0) { - Page5LevelSupport = TRUE; + if (PcdGetBool (PcdUse5LevelPageTable)) { + AsmCpuidEx ( + CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, + CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, + NULL, + NULL, + &EcxFlags.Uint32, + NULL + ); + if (EcxFlags.Bits.FiveLevelPage != 0) { + Page5LevelSupport = TRUE; + } } - } - - DEBUG ((DEBUG_INFO, "AddressBits=%u 5LevelPaging=%u 1GPage=%u\n", PhysicalAddressBits, Page5LevelSupport, Page1GSupport)); - // - // IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses - // when 5-Level Paging is disabled, - // due to either unsupported by HW, or disabled by PCD. - // - ASSERT (PhysicalAddressBits <= 52); - if (!Page5LevelSupport && (PhysicalAddressBits > 48)) { - PhysicalAddressBits = 48; - } - - // - // Calculate the table entries needed. - // - NumberOfPml5EntriesNeeded = 1; - if (PhysicalAddressBits > 48) { - NumberOfPml5EntriesNeeded = (UINT32)LShiftU64 (1, PhysicalAddressBits - 48); - PhysicalAddressBits = 48; - } + if (Page5LevelSupport) { + if (Page1GSupport) { + PagingMode = Paging5Level1GB; + } else { + PagingMode = Paging5Level; + } + } else { + if (Page1GSupport) { + PagingMode = Paging4Level1GB; + } else { + PagingMode = Paging4Level; + } + } - NumberOfPml4EntriesNeeded = 1; - if (PhysicalAddressBits > 39) { - NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, PhysicalAddressBits - 39); - PhysicalAddressBits = 39; + DEBUG ((DEBUG_INFO, "AddressBits=%u 5LevelPaging=%u 1GPage=%u\n", PhysicalAddressBits, Page5LevelSupport, Page1GSupport)); + // + // IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses + // when 5-Level Paging is disabled, due to either unsupported by HW, or disabled by PCD. + // + ASSERT (PhysicalAddressBits <= 52); + if (!Page5LevelSupport && (PhysicalAddressBits > 48)) { + PhysicalAddressBits = 48; + } } - NumberOfPdpEntriesNeeded = 1; - ASSERT (PhysicalAddressBits > 30); - NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, PhysicalAddressBits - 30); + PageTable = 0; + MapAttribute.Uint64 = AddressEncMask; + MapAttribute.Bits.Present = 1; + MapAttribute.Bits.ReadWrite = 1; + MapMask.Uint64 = MAX_UINT64; + CreateOrUpdatePageTable (&PageTable, PagingMode, 0, LShiftU64 (1, PhysicalAddressBits), &MapAttribute, &MapMask); - // - // Pre-allocate big pages to avoid later allocations. - // - if (!Page1GSupport) { - TotalPagesNum = ((NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1) * NumberOfPml5EntriesNeeded + 1; - } else { - TotalPagesNum = (NumberOfPml4EntriesNeeded + 1) * NumberOfPml5EntriesNeeded + 1; - } - - // - // Substract the one page occupied by PML5 entries if 5-Level Paging is disabled. - // - if (!Page5LevelSupport) { - TotalPagesNum--; + if ((GhcbBase > 0) && (GhcbSize > 0) && (AddressEncMask != 0)) { + // + // The GHCB range consists of two pages per CPU, the GHCB and a + // per-CPU variable page. The GHCB page needs to be mapped as an + // unencrypted page while the per-CPU variable page needs to be + // mapped encrypted. These pages alternate in assignment. + // + ASSERT (Is64BitPageTable == TRUE); + GhcbBase4K = ALIGN_VALUE (GhcbBase, SIZE_4KB); + MapAttribute.Uint64 = GhcbBase4K; + MapMask.Uint64 = 0; + MapMask.Bits.PageTableBaseAddressLow = 1; + CreateOrUpdatePageTable (&PageTable, PagingMode, GhcbBase4K, SIZE_4KB, &MapAttribute, &MapMask); } - DEBUG (( - DEBUG_INFO, - "Pml5=%u Pml4=%u Pdp=%u TotalPage=%Lu\n", - NumberOfPml5EntriesNeeded, - NumberOfPml4EntriesNeeded, - NumberOfPdpEntriesNeeded, - (UINT64)TotalPagesNum - )); - - BigPageAddress = (UINTN)AllocatePageTableMemory (TotalPagesNum); - ASSERT (BigPageAddress != 0); - - // - // By architecture only one PageMapLevel4 exists - so lets allocate storage for it. - // - PageMap = (VOID *)BigPageAddress; - if (Page5LevelSupport) { + if (PcdGetBool (PcdSetNxForStack)) { // - // By architecture only one PageMapLevel5 exists - so lets allocate storage for it. + // Set the stack as Nx in page table. // - PageMapLevel5Entry = PageMap; - BigPageAddress += SIZE_4KB; + MapAttribute.Uint64 = 0; + MapAttribute.Bits.Nx = 1; + MapMask.Uint64 = 0; + MapMask.Bits.Nx = 1; + CreateOrUpdatePageTable (&PageTable, PagingMode, StackBase, StackSize, &MapAttribute, &MapMask); } - PageAddress = 0; - - for ( IndexOfPml5Entries = 0 - ; IndexOfPml5Entries < NumberOfPml5EntriesNeeded - ; IndexOfPml5Entries++) - { + MapAttribute.Uint64 = 0; + MapAttribute.Bits.Present = 0; + MapMask.Uint64 = 0; + MapMask.Bits.Present = 1; + if (IsNullDetectionEnabled ()) { // - // Each PML5 entry points to a page of PML4 entires. - // So lets allocate space for them and fill them in in the IndexOfPml4Entries loop. - // When 5-Level Paging is disabled, below allocation happens only once. + // Set [0, 4KB] as not-present in page table. // - PageMapLevel4Entry = (VOID *)BigPageAddress; - BigPageAddress += SIZE_4KB; - - if (Page5LevelSupport) { - // - // Make a PML5 Entry - // - PageMapLevel5Entry->Uint64 = (UINT64)(UINTN)PageMapLevel4Entry | AddressEncMask; - PageMapLevel5Entry->Bits.ReadWrite = 1; - PageMapLevel5Entry->Bits.Present = 1; - PageMapLevel5Entry++; - } - - for ( IndexOfPml4Entries = 0 - ; IndexOfPml4Entries < (NumberOfPml5EntriesNeeded == 1 ? NumberOfPml4EntriesNeeded : 512) - ; IndexOfPml4Entries++, PageMapLevel4Entry++) - { - // - // Each PML4 entry points to a page of Page Directory Pointer entires. - // So lets allocate space for them and fill them in in the IndexOfPdpEntries loop. - // - PageDirectoryPointerEntry = (VOID *)BigPageAddress; - BigPageAddress += SIZE_4KB; - - // - // Make a PML4 Entry - // - PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry | AddressEncMask; - PageMapLevel4Entry->Bits.ReadWrite = 1; - PageMapLevel4Entry->Bits.Present = 1; - - if (Page1GSupport) { - PageDirectory1GEntry = (VOID *)PageDirectoryPointerEntry; - - for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectory1GEntry++, PageAddress += SIZE_1GB) { - if (ToSplitPageTable (PageAddress, SIZE_1GB, StackBase, StackSize, GhcbBase, GhcbSize)) { - Split1GPageTo2M (PageAddress, (UINT64 *)PageDirectory1GEntry, StackBase, StackSize, GhcbBase, GhcbSize); - } else { - // - // Fill in the Page Directory entries - // - PageDirectory1GEntry->Uint64 = (UINT64)PageAddress | AddressEncMask; - PageDirectory1GEntry->Bits.ReadWrite = 1; - PageDirectory1GEntry->Bits.Present = 1; - PageDirectory1GEntry->Bits.MustBe1 = 1; - } - } - } else { - for ( IndexOfPdpEntries = 0 - ; IndexOfPdpEntries < (NumberOfPml4EntriesNeeded == 1 ? NumberOfPdpEntriesNeeded : 512) - ; IndexOfPdpEntries++, PageDirectoryPointerEntry++) - { - // - // Each Directory Pointer entries points to a page of Page Directory entires. - // So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop. - // - PageDirectoryEntry = (VOID *)BigPageAddress; - BigPageAddress += SIZE_4KB; - - // - // Fill in a Page Directory Pointer Entries - // - PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry | AddressEncMask; - PageDirectoryPointerEntry->Bits.ReadWrite = 1; - PageDirectoryPointerEntry->Bits.Present = 1; - - for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += SIZE_2MB) { - if (ToSplitPageTable (PageAddress, SIZE_2MB, StackBase, StackSize, GhcbBase, GhcbSize)) { - // - // Need to split this 2M page that covers NULL or stack range. - // - Split2MPageTo4K (PageAddress, (UINT64 *)PageDirectoryEntry, StackBase, StackSize, GhcbBase, GhcbSize); - } else { - // - // Fill in the Page Directory entries - // - PageDirectoryEntry->Uint64 = (UINT64)PageAddress | AddressEncMask; - PageDirectoryEntry->Bits.ReadWrite = 1; - PageDirectoryEntry->Bits.Present = 1; - PageDirectoryEntry->Bits.MustBe1 = 1; - } - } - } - - // - // Fill with null entry for unused PDPTE - // - ZeroMem (PageDirectoryPointerEntry, (512 - IndexOfPdpEntries) * sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)); - } - } + CreateOrUpdatePageTable (&PageTable, PagingMode, 0, SIZE_4KB, &MapAttribute, &MapMask); + } + if (PcdGetBool (PcdCpuStackGuard)) { // - // For the PML4 entries we are not using fill in a null entry. + // Set the the last 4KB of stack as not-present in page table. // - ZeroMem (PageMapLevel4Entry, (512 - IndexOfPml4Entries) * sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)); + CreateOrUpdatePageTable (&PageTable, PagingMode, StackBase, SIZE_4KB, &MapAttribute, &MapMask); } if (Page5LevelSupport) { Cr4.UintN = AsmReadCr4 (); Cr4.Bits.LA57 = 1; AsmWriteCr4 (Cr4.UintN); - // - // For the PML5 entries we are not using fill in a null entry. - // - ZeroMem (PageMapLevel5Entry, (512 - IndexOfPml5Entries) * sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)); } // // Protect the page table by marking the memory used for page table to be // read-only. // - EnablePageTableProtection ((UINTN)PageMap, TRUE); + EnablePageTableProtection ((UINTN)PageTable, TRUE); // // Set IA32_EFER.NXE if necessary. @@ -956,5 +688,5 @@ CreateIdentityMappingPageTables ( EnableExecuteDisableBit (); } - return (UINTN)PageMap; + return PageTable; } diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h index 616ebe42b0..a6cf31811d 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h @@ -7,7 +7,7 @@ 3) IA-32 Intel(R) Architecture Software Developer's Manual Volume 3:System Programmer's Guide, Intel 4) AMD64 Architecture Programmer's Manual Volume 2: System Programming -Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2023, Intel Corporation. All rights reserved.
Copyright (c) 2017, AMD Incorporated. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent @@ -46,99 +46,6 @@ typedef struct { UINT32 Reserved; } X64_IDT_GATE_DESCRIPTOR; -// -// Page-Map Level-4 Offset (PML4) and -// Page-Directory-Pointer Offset (PDPE) entries 4K & 2MB -// - -typedef union { - struct { - UINT64 Present : 1; // 0 = Not present in memory, 1 = Present in memory - UINT64 ReadWrite : 1; // 0 = Read-Only, 1= Read/Write - UINT64 UserSupervisor : 1; // 0 = Supervisor, 1=User - UINT64 WriteThrough : 1; // 0 = Write-Back caching, 1=Write-Through caching - UINT64 CacheDisabled : 1; // 0 = Cached, 1=Non-Cached - UINT64 Accessed : 1; // 0 = Not accessed, 1 = Accessed (set by CPU) - UINT64 Reserved : 1; // Reserved - UINT64 MustBeZero : 2; // Must Be Zero - UINT64 Available : 3; // Available for use by system software - UINT64 PageTableBaseAddress : 40; // Page Table Base Address - UINT64 AvabilableHigh : 11; // Available for use by system software - UINT64 Nx : 1; // No Execute bit - } Bits; - UINT64 Uint64; -} PAGE_MAP_AND_DIRECTORY_POINTER; - -// -// Page Table Entry 4KB -// -typedef union { - struct { - UINT64 Present : 1; // 0 = Not present in memory, 1 = Present in memory - UINT64 ReadWrite : 1; // 0 = Read-Only, 1= Read/Write - UINT64 UserSupervisor : 1; // 0 = Supervisor, 1=User - UINT64 WriteThrough : 1; // 0 = Write-Back caching, 1=Write-Through caching - UINT64 CacheDisabled : 1; // 0 = Cached, 1=Non-Cached - UINT64 Accessed : 1; // 0 = Not accessed, 1 = Accessed (set by CPU) - UINT64 Dirty : 1; // 0 = Not Dirty, 1 = written by processor on access to page - UINT64 PAT : 1; // - UINT64 Global : 1; // 0 = Not global page, 1 = global page TLB not cleared on CR3 write - UINT64 Available : 3; // Available for use by system software - UINT64 PageTableBaseAddress : 40; // Page Table Base Address - UINT64 AvabilableHigh : 11; // Available for use by system software - UINT64 Nx : 1; // 0 = Execute Code, 1 = No Code Execution - } Bits; - UINT64 Uint64; -} PAGE_TABLE_4K_ENTRY; - -// -// Page Table Entry 2MB -// -typedef union { - struct { - UINT64 Present : 1; // 0 = Not present in memory, 1 = Present in memory - UINT64 ReadWrite : 1; // 0 = Read-Only, 1= Read/Write - UINT64 UserSupervisor : 1; // 0 = Supervisor, 1=User - UINT64 WriteThrough : 1; // 0 = Write-Back caching, 1=Write-Through caching - UINT64 CacheDisabled : 1; // 0 = Cached, 1=Non-Cached - UINT64 Accessed : 1; // 0 = Not accessed, 1 = Accessed (set by CPU) - UINT64 Dirty : 1; // 0 = Not Dirty, 1 = written by processor on access to page - UINT64 MustBe1 : 1; // Must be 1 - UINT64 Global : 1; // 0 = Not global page, 1 = global page TLB not cleared on CR3 write - UINT64 Available : 3; // Available for use by system software - UINT64 PAT : 1; // - UINT64 MustBeZero : 8; // Must be zero; - UINT64 PageTableBaseAddress : 31; // Page Table Base Address - UINT64 AvabilableHigh : 11; // Available for use by system software - UINT64 Nx : 1; // 0 = Execute Code, 1 = No Code Execution - } Bits; - UINT64 Uint64; -} PAGE_TABLE_ENTRY; - -// -// Page Table Entry 1GB -// -typedef union { - struct { - UINT64 Present : 1; // 0 = Not present in memory, 1 = Present in memory - UINT64 ReadWrite : 1; // 0 = Read-Only, 1= Read/Write - UINT64 UserSupervisor : 1; // 0 = Supervisor, 1=User - UINT64 WriteThrough : 1; // 0 = Write-Back caching, 1=Write-Through caching - UINT64 CacheDisabled : 1; // 0 = Cached, 1=Non-Cached - UINT64 Accessed : 1; // 0 = Not accessed, 1 = Accessed (set by CPU) - UINT64 Dirty : 1; // 0 = Not Dirty, 1 = written by processor on access to page - UINT64 MustBe1 : 1; // Must be 1 - UINT64 Global : 1; // 0 = Not global page, 1 = global page TLB not cleared on CR3 write - UINT64 Available : 3; // Available for use by system software - UINT64 PAT : 1; // - UINT64 MustBeZero : 17; // Must be zero; - UINT64 PageTableBaseAddress : 22; // Page Table Base Address - UINT64 AvabilableHigh : 11; // Available for use by system software - UINT64 Nx : 1; // 0 = Execute Code, 1 = No Code Execution - } Bits; - UINT64 Uint64; -} PAGE_TABLE_1G_ENTRY; - #pragma pack() #define CR0_WP BIT16 @@ -194,44 +101,25 @@ EnableExecuteDisableBit ( ); /** - Split 2M page to 4K. - - @param[in] PhysicalAddress Start physical address the 2M page covered. - @param[in, out] PageEntry2M Pointer to 2M page entry. - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - @param[in] GhcbBase GHCB page area base address. - @param[in] GhcbSize GHCB page area size. - -**/ -VOID -Split2MPageTo4K ( - IN EFI_PHYSICAL_ADDRESS PhysicalAddress, - IN OUT UINT64 *PageEntry2M, - IN EFI_PHYSICAL_ADDRESS StackBase, - IN UINTN StackSize, - IN EFI_PHYSICAL_ADDRESS GhcbBase, - IN UINTN GhcbSize - ); - -/** - Allocates and fills in the Page Directory and Page Table Entries to + Create IA32 PAE paging or 4-level/5-level paging for long mode to establish a 1:1 Virtual to Physical mapping. - @param[in] StackBase Stack base address. - @param[in] StackSize Stack size. - @param[in] GhcbBase GHCB page area base address. - @param[in] GhcbSize GHCB page area size. + @param[in] Is64BitPageTable Whether to create 64-bit page table. + @param[in] StackBase Stack base address. + @param[in] StackSize Stack size. + @param[in] GhcbBase GHCB page area base address. + @param[in] GhcbSize GHCB page area size. - @return The address of 4 level page map. + @return The address of page table. **/ UINTN CreateIdentityMappingPageTables ( + IN BOOLEAN Is64BitPageTable, IN EFI_PHYSICAL_ADDRESS StackBase, IN UINTN StackSize, IN EFI_PHYSICAL_ADDRESS GhcbBase, - IN UINTN GhcbkSize + IN UINTN GhcbSize ); /** @@ -289,39 +177,4 @@ IsNullDetectionEnabled ( VOID ); -/** - Prevent the memory pages used for page table from been overwritten. - - @param[in] PageTableBase Base address of page table (CR3). - @param[in] Level4Paging Level 4 paging flag. - -**/ -VOID -EnablePageTableProtection ( - IN UINTN PageTableBase, - IN BOOLEAN Level4Paging - ); - -/** - This API provides a way to allocate memory for page table. - - This API can be called more than once to allocate memory for page tables. - - Allocates the number of 4KB pages and returns a pointer to the allocated - buffer. The buffer returned is aligned on a 4KB boundary. - - If Pages is 0, then NULL is returned. - If there is not enough memory remaining to satisfy the request, then NULL is - returned. - - @param Pages The number of 4 KB pages to allocate. - - @return A pointer to the allocated buffer or NULL if allocation fails. - -**/ -VOID * -AllocatePageTableMemory ( - IN UINTN Pages - ); - #endif -- 2.31.1.windows.1