diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm index 378ba2feeb..14cc2c33aa 100644 --- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm +++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm @@ -63,6 +63,44 @@ BITS 32 loop .clearPageTablesMemoryLoop %endmacro +; +; Create page tables for 4-level paging +; +; Argument: upper 32 bits of the page table entries +; +%macro CreatePageTables4Level 1 + ; + ; Top level Page Directory Pointers (1 * 512GB entry) + ; + mov dword[PT_ADDR (0)], PT_ADDR (0x1000) + PAGE_PDE_DIRECTORY_ATTR + mov dword[PT_ADDR (4)], %1 + + ; + ; Next level Page Directory Pointers (4 * 1GB entries => 4GB) + ; + mov dword[PT_ADDR (0x1000)], PT_ADDR (0x2000) + PAGE_PDE_DIRECTORY_ATTR + mov dword[PT_ADDR (0x1004)], %1 + mov dword[PT_ADDR (0x1008)], PT_ADDR (0x3000) + PAGE_PDE_DIRECTORY_ATTR + mov dword[PT_ADDR (0x100C)], %1 + mov dword[PT_ADDR (0x1010)], PT_ADDR (0x4000) + PAGE_PDE_DIRECTORY_ATTR + mov dword[PT_ADDR (0x1014)], %1 + mov dword[PT_ADDR (0x1018)], PT_ADDR (0x5000) + PAGE_PDE_DIRECTORY_ATTR + mov dword[PT_ADDR (0x101C)], %1 + + ; + ; Page Table Entries (2048 * 2MB entries => 4GB) + ; + mov ecx, 0x800 +.pageTableEntriesLoop4Level: + mov eax, ecx + dec eax + shl eax, 21 + add eax, PAGE_PDE_LARGEPAGE_ATTR + mov dword[ecx * 8 + PT_ADDR (0x2000 - 8)], eax + mov dword[(ecx * 8 + PT_ADDR (0x2000 - 8)) + 4], %1 + loop .pageTableEntriesLoop4Level +%endmacro + ; ; Modified: EAX, EBX, ECX, EDX ; @@ -88,37 +126,7 @@ SetCr3ForPageTables64: ClearOvmfPageTables: ClearOvmfPageTables - - ; - ; Top level Page Directory Pointers (1 * 512GB entry) - ; - mov dword[PT_ADDR (0)], PT_ADDR (0x1000) + PAGE_PDE_DIRECTORY_ATTR - mov dword[PT_ADDR (4)], edx - - ; - ; Next level Page Directory Pointers (4 * 1GB entries => 4GB) - ; - mov dword[PT_ADDR (0x1000)], PT_ADDR (0x2000) + PAGE_PDE_DIRECTORY_ATTR - mov dword[PT_ADDR (0x1004)], edx - mov dword[PT_ADDR (0x1008)], PT_ADDR (0x3000) + PAGE_PDE_DIRECTORY_ATTR - mov dword[PT_ADDR (0x100C)], edx - mov dword[PT_ADDR (0x1010)], PT_ADDR (0x4000) + PAGE_PDE_DIRECTORY_ATTR - mov dword[PT_ADDR (0x1014)], edx - mov dword[PT_ADDR (0x1018)], PT_ADDR (0x5000) + PAGE_PDE_DIRECTORY_ATTR - mov dword[PT_ADDR (0x101C)], edx - - ; - ; Page Table Entries (2048 * 2MB entries => 4GB) - ; - mov ecx, 0x800 -pageTableEntriesLoop: - mov eax, ecx - dec eax - shl eax, 21 - add eax, PAGE_PDE_LARGEPAGE_ATTR - mov [ecx * 8 + PT_ADDR (0x2000 - 8)], eax - mov [(ecx * 8 + PT_ADDR (0x2000 - 8)) + 4], edx - loop pageTableEntriesLoop + CreatePageTables4Level edx ; Clear the C-bit from the GHCB page if the SEV-ES is enabled. OneTimeCall SevClearPageEncMaskForGhcbPage