[edk2-devel] [PATCH 05/10] OvmfPkg/ResetVector: split SEV and non-CoCo workflows

["Gerd Hoffmann" <kraxel@redhat.com>]

Use separate control flows for SEV and non-CoCo cases.

SevClearPageEncMaskForGhcbPage and GetSevCBitMaskAbove31 will now only
be called when running in SEV mode, so the SEV check in these functions
is not needed any more.

No functional change.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 OvmfPkg/ResetVector/Ia32/AmdSev.asm       | 16 ++--------------
 OvmfPkg/ResetVector/Ia32/PageTables64.asm | 17 ++++++++++++++---
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/OvmfPkg/ResetVector/Ia32/AmdSev.asm b/OvmfPkg/ResetVector/Ia32/AmdSev.asm
index 043c88a7abbe..ed94f1dc668f 100644
--- a/OvmfPkg/ResetVector/Ia32/AmdSev.asm
+++ b/OvmfPkg/ResetVector/Ia32/AmdSev.asm
@@ -152,12 +152,8 @@ SevEsUnexpectedRespTerminate:
 
 %ifdef ARCH_X64
 
-; If SEV-ES is enabled then initialize and make the GHCB page shared
+; initialize and make the GHCB page shared
 SevClearPageEncMaskForGhcbPage:
-    ; Check if SEV is enabled
-    cmp       byte[WORK_AREA_GUEST_TYPE], 1
-    jnz       SevClearPageEncMaskForGhcbPageExit
-
     ; Check if SEV-ES is enabled
     mov       ecx, 1
     bt        [SEV_ES_WORK_AREA_STATUS_MSR], ecx
@@ -195,20 +191,12 @@ pageTableEntries4kLoop:
 SevClearPageEncMaskForGhcbPageExit:
     OneTimeCallRet SevClearPageEncMaskForGhcbPage
 
-; Check if SEV is enabled, and get the C-bit mask above 31.
+; Get the C-bit mask above 31.
 ; Modified: EDX
 ;
 ; The value is returned in the EDX
 GetSevCBitMaskAbove31:
-    xor       edx, edx
-
-    ; Check if SEV is enabled
-    cmp       byte[WORK_AREA_GUEST_TYPE], 1
-    jnz       GetSevCBitMaskAbove31Exit
-
     mov       edx, dword[SEV_ES_WORK_AREA_ENC_MASK + 4]
-
-GetSevCBitMaskAbove31Exit:
     OneTimeCallRet GetSevCBitMaskAbove31
 
 %endif
diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index 166e80293c89..84a7b4efc019 100644
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -118,15 +118,26 @@ SetCr3ForPageTables64:
 
     ; Check whether the SEV is active and populate the SevEsWorkArea
     OneTimeCall   CheckSevFeatures
+    cmp       byte[WORK_AREA_GUEST_TYPE], 1
+    jz        SevInit
 
+    ;
+    ; normal (non-CoCo) workflow
+    ;
+    ClearOvmfPageTables
+    CreatePageTables4Level 0
+    jmp SetCr3
+
+SevInit:
+    ;
+    ; SEV workflow
+    ;
+    ClearOvmfPageTables
     ; If SEV is enabled, the C-bit position is always above 31.
     ; The mask will be saved in the EDX and applied during the
     ; the page table build below.
     OneTimeCall   GetSevCBitMaskAbove31
-
-    ClearOvmfPageTables
     CreatePageTables4Level edx
-
     ; Clear the C-bit from the GHCB page if the SEV-ES is enabled.
     OneTimeCall   SevClearPageEncMaskForGhcbPage
     jmp SetCr3
-- 
2.43.2



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