Explorar el Código

OvmfPkg/ResetVector: Removing SEV-ES CPUID bit check

The SEV-ES bit of Fn800-001F[EAX] - Bit 3 is used for a host to
determine support for running SEV-ES guests. It should not be checked by
a guest to determine if it is running under SEV-ES. The guest should use
the SEV_STATUS MSR Bit 1 to determine if SEV-ES is enabled. This check
was not part of the original SEV-ES support and was added in
a91b700e38. Removing the check makes this code consistent with the
Linux kernel

Fixes: a91b700e38 ("Ovmf/ResetVector: Simplify and consolidate the SEV features checks")
Signed-off-by: Peter Gonda <pgonda@google.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Peter Gonda hace 1 año
padre
commit
62044aa99b
Se han modificado 1 ficheros con 0 adiciones y 8 borrados
  1. 0 8
      OvmfPkg/ResetVector/Ia32/AmdSev.asm

+ 0 - 8
OvmfPkg/ResetVector/Ia32/AmdSev.asm

@@ -278,14 +278,6 @@ ClearSevEsWorkArea:
     mov     [SEV_ES_WORK_AREA_STATUS_MSR], eax
     mov     [SEV_ES_WORK_AREA_STATUS_MSR + 4], edx
 
-    ; Check for SEV-ES memory encryption feature:
-    ; CPUID  Fn8000_001F[EAX] - Bit 3
-    ;   CPUID raises a #VC exception if running as an SEV-ES guest
-    mov       eax, 0x8000001f
-    cpuid
-    bt        eax, 3
-    jnc       GetSevEncBit
-
     ; Check if SEV-ES is enabled
     ;  MSR_0xC0010131 - Bit 1 (SEV-ES enabled)
     mov       ecx, SEV_STATUS_MSR