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) Cc: James Bottomley <[email protected]> Cc: Min Xu <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Jordan Justen <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Laszlo Ersek <[email protected]> Cc: Erdem Aktas <[email protected]> Cc: Brijesh Singh <[email protected]> Cc: Erdem Aktas <[email protected]> Cc: Marc Orr <[email protected]> Signed-off-by: Peter Gonda <[email protected]> --- OvmfPkg/ResetVector/Ia32/AmdSev.asm | 8 -------- 1 file changed, 8 deletions(-) diff --git a/OvmfPkg/ResetVector/Ia32/AmdSev.asm b/OvmfPkg/ResetVector/Ia32/AmdSev.asm index 1f827da3b9..77692db27e 100644 --- a/OvmfPkg/ResetVector/Ia32/AmdSev.asm +++ b/OvmfPkg/ResetVector/Ia32/AmdSev.asm @@ -265,14 +265,6 @@ CheckSevFeatures: ; Set the work area header to indicate that the SEV is enabled mov byte[WORK_AREA_GUEST_TYPE], 1 - ; 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 -- 2.34.1.575.g55b058a8bb-goog -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#85664): https://edk2.groups.io/g/devel/message/85664 Mute This Topic: https://groups.io/mt/88400388/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
