diff options
Diffstat (limited to 'UefiPayloadPkg/UefiPayloadEntry/X64/VirtualMemory.c')
| -rw-r--r-- | UefiPayloadPkg/UefiPayloadEntry/X64/VirtualMemory.c | 939 |
1 files changed, 939 insertions, 0 deletions
diff --git a/UefiPayloadPkg/UefiPayloadEntry/X64/VirtualMemory.c b/UefiPayloadPkg/UefiPayloadEntry/X64/VirtualMemory.c new file mode 100644 index 0000000000..a1c4ad6ff4 --- /dev/null +++ b/UefiPayloadPkg/UefiPayloadEntry/X64/VirtualMemory.c @@ -0,0 +1,939 @@ +/** @file
+ x64 Virtual Memory Management Services in the form of an IA-32 driver.
+ Used to establish a 1:1 Virtual to Physical Mapping that is required to
+ enter Long Mode (x64 64-bit mode).
+
+ While we make a 1:1 mapping (identity mapping) for all physical pages
+ we still need to use the MTRR's to ensure that the cachability attributes
+ for all memory regions is correct.
+
+ The basic idea is to use 2MB page table entries where ever possible. If
+ more granularity of cachability is required then 4K page tables are used.
+
+ References:
+ 1) IA-32 Intel(R) Architecture Software Developer's Manual Volume 1:Basic Architecture, Intel
+ 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 - 2020, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
+#include <Library/HobLib.h>
+#include <Register/Intel/Cpuid.h>
+#include "VirtualMemory.h"
+
+//
+// Global variable to keep track current available memory used as page table.
+//
+PAGE_TABLE_POOL *mPageTablePool = NULL;
+
+/**
+ Clear legacy memory located at the first 4K-page, if available.
+
+ This function traverses the whole HOB list to check if memory from 0 to 4095
+ exists and has not been allocated, and then clear it if so.
+
+ @param HobStart The start of HobList passed to DxeCore.
+
+**/
+VOID
+ClearFirst4KPage (
+ IN VOID *HobStart
+ )
+{
+ EFI_PEI_HOB_POINTERS RscHob;
+ EFI_PEI_HOB_POINTERS MemHob;
+ BOOLEAN DoClear;
+
+ RscHob.Raw = HobStart;
+ MemHob.Raw = HobStart;
+ DoClear = FALSE;
+
+ //
+ // Check if page 0 exists and free
+ //
+ while ((RscHob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR,
+ RscHob.Raw)) != NULL) {
+ if (RscHob.ResourceDescriptor->ResourceType == EFI_RESOURCE_SYSTEM_MEMORY &&
+ RscHob.ResourceDescriptor->PhysicalStart == 0) {
+ DoClear = TRUE;
+ //
+ // Make sure memory at 0-4095 has not been allocated.
+ //
+ while ((MemHob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION,
+ MemHob.Raw)) != NULL) {
+ if (MemHob.MemoryAllocation->AllocDescriptor.MemoryBaseAddress
+ < EFI_PAGE_SIZE) {
+ DoClear = FALSE;
+ break;
+ }
+ MemHob.Raw = GET_NEXT_HOB (MemHob);
+ }
+ break;
+ }
+ RscHob.Raw = GET_NEXT_HOB (RscHob);
+ }
+
+ if (DoClear) {
+ DEBUG ((DEBUG_INFO, "Clearing first 4K-page!\r\n"));
+ SetMem (NULL, EFI_PAGE_SIZE, 0);
+ }
+
+ return;
+}
+
+/**
+ Return configure status of NULL pointer detection feature.
+
+ @return TRUE NULL pointer detection feature is enabled
+ @return FALSE NULL pointer detection feature is disabled
+
+**/
+BOOLEAN
+IsNullDetectionEnabled (
+ VOID
+ )
+{
+ return ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) != 0);
+}
+
+/**
+ The function will check if Execute Disable Bit is available.
+
+ @retval TRUE Execute Disable Bit is available.
+ @retval FALSE Execute Disable Bit is not available.
+
+**/
+BOOLEAN
+IsExecuteDisableBitAvailable (
+ VOID
+ )
+{
+ UINT32 RegEax;
+ UINT32 RegEdx;
+ BOOLEAN Available;
+
+ Available = FALSE;
+ AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
+ if (RegEax >= 0x80000001) {
+ AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);
+ if ((RegEdx & BIT20) != 0) {
+ //
+ // Bit 20: Execute Disable Bit available.
+ //
+ Available = TRUE;
+ }
+ }
+
+ return Available;
+}
+
+/**
+ Check if Execute Disable Bit (IA32_EFER.NXE) should be enabled or not.
+
+ @retval TRUE IA32_EFER.NXE should be enabled.
+ @retval FALSE IA32_EFER.NXE should not be enabled.
+
+**/
+BOOLEAN
+IsEnableNonExecNeeded (
+ VOID
+ )
+{
+ if (!IsExecuteDisableBitAvailable ()) {
+ return FALSE;
+ }
+
+ //
+ // XD flag (BIT63) in page table entry is only valid if IA32_EFER.NXE is set.
+ // Features controlled by Following PCDs need this feature to be enabled.
+ //
+ return (PcdGetBool (PcdSetNxForStack) ||
+ PcdGet64 (PcdDxeNxMemoryProtectionPolicy) != 0 ||
+ PcdGet32 (PcdImageProtectionPolicy) != 0);
+}
+
+/**
+ Enable Execute Disable Bit.
+
+**/
+VOID
+EnableExecuteDisableBit (
+ VOID
+ )
+{
+ UINT64 MsrRegisters;
+
+ MsrRegisters = AsmReadMsr64 (0xC0000080);
+ MsrRegisters |= BIT11;
+ AsmWriteMsr64 (0xC0000080, MsrRegisters);
+}
+
+/**
+ 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.
+
+ To reduce the potential split operation on page table, the pages reserved for
+ page table should be allocated in the times of PAGE_TABLE_POOL_UNIT_PAGES and
+ at the boundary of PAGE_TABLE_POOL_ALIGNMENT. So the page pool is always
+ initialized with number of pages greater than or equal to the given PoolPages.
+
+ Once the pages in the pool are used up, this method should be called again to
+ reserve at least another PAGE_TABLE_POOL_UNIT_PAGES. But usually this won't
+ happen in practice.
+
+ @param PoolPages The least page number of the pool to be created.
+
+ @retval TRUE The pool is initialized successfully.
+ @retval FALSE The memory is out of resource.
+**/
+BOOLEAN
+InitializePageTablePool (
+ IN UINTN PoolPages
+ )
+{
+ VOID *Buffer;
+
+ //
+ // Always reserve at least PAGE_TABLE_POOL_UNIT_PAGES, including one page for
+ // header.
+ //
+ PoolPages += 1; // Add one page for header.
+ PoolPages = ((PoolPages - 1) / PAGE_TABLE_POOL_UNIT_PAGES + 1) *
+ PAGE_TABLE_POOL_UNIT_PAGES;
+ Buffer = AllocateAlignedPages (PoolPages, PAGE_TABLE_POOL_ALIGNMENT);
+ if (Buffer == NULL) {
+ DEBUG ((DEBUG_ERROR, "ERROR: Out of aligned pages\r\n"));
+ return FALSE;
+ }
+
+ //
+ // Link all pools into a list for easier track later.
+ //
+ if (mPageTablePool == NULL) {
+ mPageTablePool = Buffer;
+ mPageTablePool->NextPool = mPageTablePool;
+ } else {
+ ((PAGE_TABLE_POOL *)Buffer)->NextPool = mPageTablePool->NextPool;
+ mPageTablePool->NextPool = Buffer;
+ mPageTablePool = Buffer;
+ }
+
+ //
+ // Reserve one page for pool header.
+ //
+ mPageTablePool->FreePages = PoolPages - 1;
+ mPageTablePool->Offset = EFI_PAGES_TO_SIZE (1);
+
+ return TRUE;
+}
+
+/**
+ 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
+ )
+{
+ VOID *Buffer;
+
+ if (Pages == 0) {
+ return NULL;
+ }
+
+ //
+ // Renew the pool if necessary.
+ //
+ if (mPageTablePool == NULL ||
+ Pages > mPageTablePool->FreePages) {
+ if (!InitializePageTablePool (Pages)) {
+ return NULL;
+ }
+ }
+
+ Buffer = (UINT8 *)mPageTablePool + mPageTablePool->Offset;
+
+ mPageTablePool->Offset += EFI_PAGES_TO_SIZE (Pages);
+ mPageTablePool->FreePages -= Pages;
+
+ return Buffer;
+}
+
+/**
+ 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
+ )
+{
+ 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;
+ }
+ }
+}
+
+/**
+ 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;
+ }
+ }
+}
+
+/**
+ Set one page of page table pool memory to be read-only.
+
+ @param[in] PageTableBase Base address of page table (CR3).
+ @param[in] Address Start address of a page to be set as read-only.
+ @param[in] Level4Paging Level 4 paging flag.
+
+**/
+VOID
+SetPageTablePoolReadOnly (
+ IN UINTN PageTableBase,
+ IN EFI_PHYSICAL_ADDRESS Address,
+ IN BOOLEAN Level4Paging
+ )
+{
+ UINTN Index;
+ UINTN EntryIndex;
+ UINT64 AddressEncMask;
+ EFI_PHYSICAL_ADDRESS PhysicalAddress;
+ UINT64 *PageTable;
+ UINT64 *NewPageTable;
+ UINT64 PageAttr;
+ UINT64 LevelSize[5];
+ UINT64 LevelMask[5];
+ UINTN LevelShift[5];
+ UINTN Level;
+ UINT64 PoolUnitSize;
+
+ ASSERT (PageTableBase != 0);
+
+ //
+ // Since the page table is always from page table pool, which is always
+ // located at the boundary of PcdPageTablePoolAlignment, we just need to
+ // set the whole pool unit to be read-only.
+ //
+ Address = Address & PAGE_TABLE_POOL_ALIGN_MASK;
+
+ LevelShift[1] = PAGING_L1_ADDRESS_SHIFT;
+ LevelShift[2] = PAGING_L2_ADDRESS_SHIFT;
+ LevelShift[3] = PAGING_L3_ADDRESS_SHIFT;
+ LevelShift[4] = PAGING_L4_ADDRESS_SHIFT;
+
+ LevelMask[1] = PAGING_4K_ADDRESS_MASK_64;
+ LevelMask[2] = PAGING_2M_ADDRESS_MASK_64;
+ LevelMask[3] = PAGING_1G_ADDRESS_MASK_64;
+ LevelMask[4] = PAGING_1G_ADDRESS_MASK_64;
+
+ LevelSize[1] = SIZE_4KB;
+ LevelSize[2] = SIZE_2MB;
+ LevelSize[3] = SIZE_1GB;
+ LevelSize[4] = SIZE_512GB;
+
+ AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) &
+ PAGING_1G_ADDRESS_MASK_64;
+ PageTable = (UINT64 *)(UINTN)PageTableBase;
+ PoolUnitSize = PAGE_TABLE_POOL_UNIT_SIZE;
+
+ for (Level = (Level4Paging) ? 4 : 3; Level > 0; --Level) {
+ Index = ((UINTN)RShiftU64 (Address, LevelShift[Level]));
+ Index &= PAGING_PAE_INDEX_MASK;
+
+ PageAttr = PageTable[Index];
+ if ((PageAttr & IA32_PG_PS) == 0) {
+ //
+ // Go to next level of table.
+ //
+ PageTable = (UINT64 *)(UINTN)(PageAttr & ~AddressEncMask &
+ PAGING_4K_ADDRESS_MASK_64);
+ continue;
+ }
+
+ if (PoolUnitSize >= LevelSize[Level]) {
+ //
+ // Clear R/W bit if current page granularity is not larger than pool unit
+ // size.
+ //
+ if ((PageAttr & IA32_PG_RW) != 0) {
+ while (PoolUnitSize > 0) {
+ //
+ // PAGE_TABLE_POOL_UNIT_SIZE and PAGE_TABLE_POOL_ALIGNMENT are fit in
+ // one page (2MB). Then we don't need to update attributes for pages
+ // crossing page directory. ASSERT below is for that purpose.
+ //
+ ASSERT (Index < EFI_PAGE_SIZE/sizeof (UINT64));
+
+ PageTable[Index] &= ~(UINT64)IA32_PG_RW;
+ PoolUnitSize -= LevelSize[Level];
+
+ ++Index;
+ }
+ }
+
+ break;
+
+ } else {
+ //
+ // The smaller granularity of page must be needed.
+ //
+ ASSERT (Level > 1);
+
+ NewPageTable = AllocatePageTableMemory (1);
+ ASSERT (NewPageTable != NULL);
+
+ PhysicalAddress = PageAttr & LevelMask[Level];
+ for (EntryIndex = 0;
+ EntryIndex < EFI_PAGE_SIZE/sizeof (UINT64);
+ ++EntryIndex) {
+ NewPageTable[EntryIndex] = PhysicalAddress | AddressEncMask |
+ IA32_PG_P | IA32_PG_RW;
+ if (Level > 2) {
+ NewPageTable[EntryIndex] |= IA32_PG_PS;
+ }
+ PhysicalAddress += LevelSize[Level - 1];
+ }
+
+ PageTable[Index] = (UINT64)(UINTN)NewPageTable | AddressEncMask |
+ IA32_PG_P | IA32_PG_RW;
+ PageTable = NewPageTable;
+ }
+ }
+}
+
+/**
+ 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
+ )
+{
+ PAGE_TABLE_POOL *HeadPool;
+ PAGE_TABLE_POOL *Pool;
+ UINT64 PoolSize;
+ EFI_PHYSICAL_ADDRESS Address;
+
+ if (mPageTablePool == NULL) {
+ return;
+ }
+
+ //
+ // Disable write protection, because we need to mark page table to be write
+ // protected.
+ //
+ AsmWriteCr0 (AsmReadCr0() & ~CR0_WP);
+
+ //
+ // SetPageTablePoolReadOnly might update mPageTablePool. It's safer to
+ // remember original one in advance.
+ //
+ HeadPool = mPageTablePool;
+ Pool = HeadPool;
+ do {
+ Address = (EFI_PHYSICAL_ADDRESS)(UINTN)Pool;
+ PoolSize = Pool->Offset + EFI_PAGES_TO_SIZE (Pool->FreePages);
+
+ //
+ // The size of one pool must be multiple of PAGE_TABLE_POOL_UNIT_SIZE, which
+ // is one of page size of the processor (2MB by default). Let's apply the
+ // protection to them one by one.
+ //
+ while (PoolSize > 0) {
+ SetPageTablePoolReadOnly(PageTableBase, Address, Level4Paging);
+ Address += PAGE_TABLE_POOL_UNIT_SIZE;
+ PoolSize -= PAGE_TABLE_POOL_UNIT_SIZE;
+ }
+
+ Pool = Pool->NextPool;
+ } while (Pool != HeadPool);
+
+ //
+ // Enable write protection, after page table attribute updated.
+ //
+ AsmWriteCr0 (AsmReadCr0() | CR0_WP);
+}
+
+/**
+ Allocates and fills in the Page Directory and Page Table Entries 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.
+
+**/
+UINTN
+CreateIdentityMappingPageTables (
+ IN EFI_PHYSICAL_ADDRESS StackBase,
+ IN UINTN StackSize,
+ IN EFI_PHYSICAL_ADDRESS GhcbBase,
+ IN UINTN GhcbSize
+ )
+{
+ UINT32 RegEax;
+ 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;
+
+ //
+ // 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;
+ }
+ }
+ }
+
+ //
+ // 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;
+ } else {
+ PhysicalAddressBits = 36;
+ }
+ }
+
+ Page5LevelSupport = FALSE;
+ if (PcdGetBool (PcdUse5LevelPageTable)) {
+ AsmCpuidEx (
+ CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, NULL,
+ &EcxFlags.Uint32, NULL, 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;
+ }
+
+ NumberOfPml4EntriesNeeded = 1;
+ if (PhysicalAddressBits > 39) {
+ NumberOfPml4EntriesNeeded = (UINT32) LShiftU64 (1, PhysicalAddressBits - 39);
+ PhysicalAddressBits = 39;
+ }
+
+ NumberOfPdpEntriesNeeded = 1;
+ ASSERT (PhysicalAddressBits > 30);
+ NumberOfPdpEntriesNeeded = (UINT32) LShiftU64 (1, PhysicalAddressBits - 30);
+
+ //
+ // 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--;
+ }
+
+ 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) {
+ //
+ // By architecture only one PageMapLevel5 exists - so lets allocate storage for it.
+ //
+ PageMapLevel5Entry = PageMap;
+ BigPageAddress += SIZE_4KB;
+ }
+ PageAddress = 0;
+
+ for ( IndexOfPml5Entries = 0
+ ; IndexOfPml5Entries < NumberOfPml5EntriesNeeded
+ ; IndexOfPml5Entries++) {
+ //
+ // 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.
+ //
+ 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));
+ }
+ }
+
+ //
+ // For the PML4 entries we are not using fill in a null entry.
+ //
+ ZeroMem (PageMapLevel4Entry, (512 - IndexOfPml4Entries) * sizeof (PAGE_MAP_AND_DIRECTORY_POINTER));
+ }
+
+ 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);
+
+ //
+ // Set IA32_EFER.NXE if necessary.
+ //
+ if (IsEnableNonExecNeeded ()) {
+ EnableExecuteDisableBit ();
+ }
+
+ return (UINTN)PageMap;
+}
+
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