From: "Lendacky, Thomas" <thomas.lendacky@amd.com>
To: devel@edk2.groups.io
Cc: Brijesh Singh <brijesh.singh@amd.com>,
James Bottomley <jejb@linux.ibm.com>,
Jordan Justen <jordan.l.justen@intel.com>,
Laszlo Ersek <lersek@redhat.com>,
Ard Biesheuvel <ard.biesheuvel@arm.com>
Subject: [PATCH v2 04/15] OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check
Date: Wed, 6 Jan 2021 15:21:30 -0600 [thread overview]
Message-ID: <1c6e5ce7612f64fb1e4aea5f642d01572c063850.1609968101.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1609968101.git.thomas.lendacky@amd.com>
From: Tom Lendacky <thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
If a hypervisor incorrectly reports through CPUID that SEV-ES is not
active, ensure that a #VC exception was not taken. If it is found that
a #VC was taken, then the code enters a HLT loop.
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
OvmfPkg/ResetVector/Ia32/PageTables64.asm | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
index ccc95ad4715d..a1771dfdec23 100644
--- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
+++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
@@ -154,6 +154,22 @@ SevEncBitLowHlt:
jmp SevEncBitLowHlt
NoSev:
+ ;
+ ; Perform an SEV-ES sanity check by seeing if a #VC exception occurred.
+ ;
+ cmp byte[SEV_ES_WORK_AREA], 0
+ jz NoSevPass
+
+ ;
+ ; A #VC was received, yet CPUID indicates no SEV-ES support, something
+ ; isn't right.
+ ;
+NoSevEsVcHlt:
+ cli
+ hlt
+ jmp NoSevEsVcHlt
+
+NoSevPass:
xor eax, eax
SevExit:
--
2.30.0
next prev parent reply other threads:[~2021-01-06 21:22 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 21:21 [PATCH v2 00/15] SEV-ES security mitigations Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 01/15] Ovmf/ResetVector: Simplify and consolidate the SEV features checks Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 02/15] OvmfPkg/Sec: Move SEV-ES SEC workarea definition to common header file Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 03/15] OvmfPkg/ResetVector: Validate the encryption bit position for SEV/SEV-ES Lendacky, Thomas
2021-01-07 14:43 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` Lendacky, Thomas [this message]
2021-01-07 14:44 ` [edk2-devel] [PATCH v2 04/15] OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 05/15] OvmfPkg/MemEncryptSevLib: Save the encryption mask at boot time Lendacky, Thomas
2021-01-07 14:52 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 06/15] OvmfPkg/MemEncryptSevLib: Add an interface to retrieve the encryption mask Lendacky, Thomas
2021-01-07 15:50 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 07/15] OvmfPkg/MemEncryptSevLib: Obtain encryption mask using the new interface Lendacky, Thomas
2021-01-07 15:56 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 08/15] OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range Lendacky, Thomas
2021-01-07 17:11 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 09/15] OvmfPkg/VmgExitLib: Check for an explicit DR7 cached value Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 10/15] OvmfPkg/MemEncryptSevLib: Coding style fixes in prep for SEC library Lendacky, Thomas
2021-01-07 17:12 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 11/15] OvmfPkg/MemEncryptSevLib: Make the MemEncryptSevLib available for SEC Lendacky, Thomas
2021-01-07 17:22 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 12/15] OvmfPkg/MemEncryptSevLib: Address range encryption state interface Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 13/15] OvmfPkg/VmgExitLib: Support nested #VCs Lendacky, Thomas
2021-01-06 21:21 ` [PATCH v2 14/15] OvmfPkg/PlatformPei: Reserve GHCB backup pages if S3 is supported Lendacky, Thomas
2021-01-07 17:25 ` [edk2-devel] " Laszlo Ersek
2021-01-06 21:21 ` [PATCH v2 15/15] OvfmPkg/VmgExitLib: Validate #VC MMIO is to un-encrypted memory Lendacky, Thomas
2021-01-07 17:27 ` [edk2-devel] " Laszlo Ersek
2021-01-07 17:33 ` Lendacky, Thomas
2021-01-07 17:48 ` Laszlo Ersek
2021-01-07 18:37 ` Lendacky, Thomas
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