OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check

[mirror_edk2.git] / OvmfPkg / ResetVector / Ia32 / PageTables64.asm

diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index ccc95ad4715d3770e53fa6f9680c9ce28279a7c2..a1771dfdec23766f8f4127c3111b59330c8ca46c 100644 (file)
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -154,6 +154,22 @@ SevEncBitLowHlt:
     jmp       SevEncBitLowHlt\r
 \r
 NoSev:\r
+    ;\r
+    ; Perform an SEV-ES sanity check by seeing if a #VC exception occurred.\r
+    ;\r
+    cmp       byte[SEV_ES_WORK_AREA], 0\r
+    jz        NoSevPass\r
+\r
+    ;\r
+    ; A #VC was received, yet CPUID indicates no SEV-ES support, something\r
+    ; isn't right.\r
+    ;\r
+NoSevEsVcHlt:\r
+    cli\r
+    hlt\r
+    jmp       NoSevEsVcHlt\r
+\r
+NoSevPass:\r
     xor       eax, eax\r
 \r
 SevExit:\r