OvmfPkg/ResetVector: add ClearOvmfPageTables macro

Move code to clear the page tables to a nasm macro.
No functional change.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20240301074402.98625-3-kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Oliver Steffen <osteffen@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
[lersek@redhat.com: turn the "Cc:" message headers from Gerd's on-list
 posting into "Cc:" tags in the commit message, in order to pacify
 "PatchCheck.py"]

1 files changed, 19 insertions, 16 deletions

diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index 6fec6f2bee..378ba2feeb 100644
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -46,6 +46,24 @@ BITS    32
 %define TDX_AP          2

 

 ;

+; For OVMF, build some initial page tables at

+; PcdOvmfSecPageTablesBase - (PcdOvmfSecPageTablesBase + 0x6000).

+;

+; This range should match with PcdOvmfSecPageTablesSize which is

+; declared in the FDF files.

+;

+; At the end of PEI, the pages tables will be rebuilt into a

+; more permanent location by DxeIpl.

+;

+%macro ClearOvmfPageTables 0

+    mov     ecx, 6 * 0x1000 / 4

+    xor     eax, eax

+.clearPageTablesMemoryLoop:

+    mov     dword[ecx * 4 + PT_ADDR (0) - 4], eax

+    loop    .clearPageTablesMemoryLoop

+%endmacro

+

+;

 ; Modified:  EAX, EBX, ECX, EDX

 ;

 SetCr3ForPageTables64:

@@ -69,22 +87,7 @@ SetCr3ForPageTables64:
     OneTimeCall   GetSevCBitMaskAbove31

 

 ClearOvmfPageTables:

-    ;

-    ; For OVMF, build some initial page tables at

-    ; PcdOvmfSecPageTablesBase - (PcdOvmfSecPageTablesBase + 0x6000).

-    ;

-    ; This range should match with PcdOvmfSecPageTablesSize which is

-    ; declared in the FDF files.

-    ;

-    ; At the end of PEI, the pages tables will be rebuilt into a

-    ; more permanent location by DxeIpl.

-    ;

-

-    mov     ecx, 6 * 0x1000 / 4

-    xor     eax, eax

-clearPageTablesMemoryLoop:

-    mov     dword[ecx * 4 + PT_ADDR (0) - 4], eax

-    loop    clearPageTablesMemoryLoop

+    ClearOvmfPageTables

 

     ;

     ; Top level Page Directory Pointers (1 * 512GB entry)