From: "Lendacky, Thomas" <thomas.lendacky@amd.com>
To: Laszlo Ersek <lersek@redhat.com>, devel@edk2.groups.io
Cc: Brijesh Singh <brijesh.singh@amd.com>,
James Bottomley <jejb@linux.ibm.com>,
Jordan Justen <jordan.l.justen@intel.com>,
Ard Biesheuvel <ard.biesheuvel@arm.com>
Subject: Re: [edk2-devel] [PATCH 04/12] OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check
Date: Mon, 4 Jan 2021 14:48:16 -0600 [thread overview]
Message-ID: <c1a2618b-7153-8736-22b5-d73672a926ff@amd.com> (raw)
In-Reply-To: <cd9647a9-04ef-7754-814a-e345a79c40b3@redhat.com>
On 1/4/21 2:00 PM, Laszlo Ersek wrote:
> On 12/15/20 21:51, Lendacky, Thomas wrote:
>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>
>> BZ: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D3108&data=04%7C01%7Cthomas.lendacky%40amd.com%7C653d18caa3484d3cd37608d8b0eb6075%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637453872278185152%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=K8Tcu8N5gC3IxFtz2ZxNxa4hCJIAI72Gr8adBt6vaBU%3D&reserved=0
>>
>> 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>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>> OvmfPkg/ResetVector/Ia32/PageTables64.asm | 15 +++++++++++++++
>> 1 file changed, 15 insertions(+)
>>
>> diff --git a/OvmfPkg/ResetVector/Ia32/PageTables64.asm b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
>> index 3cd909df4f09..b08f31157cbf 100644
>> --- a/OvmfPkg/ResetVector/Ia32/PageTables64.asm
>> +++ b/OvmfPkg/ResetVector/Ia32/PageTables64.asm
>> @@ -153,6 +153,21 @@ 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:
>> + hlt
>> + jmp NoSevEsVcHlt
>> +
>> +NoSevPass:
>> xor eax, eax
>>
>> SevExit:
>>
>
> (Please consider the CLI question for this patch as well.)
Yup, I'll add a CLI.
Thanks,
Tom
>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>
> Thanks
> Laszlo
>
next prev parent reply other threads:[~2021-01-04 20:48 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 20:50 [PATCH 00/12] SEV-ES security mitigations Lendacky, Thomas
2020-12-15 20:51 ` [PATCH 01/12] Ovmf/ResetVector: Simplify and consolidate the SEV features checks Lendacky, Thomas
2021-01-04 18:58 ` [edk2-devel] " Laszlo Ersek
2020-12-15 20:51 ` [PATCH 02/12] OvmfPkg/Sec: Move SEV-ES SEC workarea definition to common header file Lendacky, Thomas
2021-01-04 19:02 ` [edk2-devel] " Laszlo Ersek
2020-12-15 20:51 ` [PATCH 03/12] OvmfPkg/ResetVector: Validate the encryption bit position for SEV/SEV-ES Lendacky, Thomas
2021-01-04 19:59 ` [edk2-devel] " Laszlo Ersek
2021-01-04 20:45 ` Lendacky, Thomas
2020-12-15 20:51 ` [PATCH 04/12] OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check Lendacky, Thomas
2021-01-04 20:00 ` [edk2-devel] " Laszlo Ersek
2021-01-04 20:48 ` Lendacky, Thomas [this message]
2020-12-15 20:51 ` [PATCH 05/12] OvmfPkg/MemEncryptSevLib: Add an interface to retrieve the encryption mask Lendacky, Thomas
2021-01-04 20:34 ` [edk2-devel] " Laszlo Ersek
2021-01-04 21:09 ` Lendacky, Thomas
2020-12-15 20:51 ` [PATCH 06/12] OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range Lendacky, Thomas
2021-01-04 21:04 ` [edk2-devel] " Laszlo Ersek
2021-01-05 22:48 ` Lendacky, Thomas
2021-01-06 15:38 ` Laszlo Ersek
2020-12-15 20:51 ` [PATCH 07/12] OvmfPkg/VmgExitLib: Check for an explicit DR7 cached value Lendacky, Thomas
2021-01-04 21:05 ` [edk2-devel] " Laszlo Ersek
2020-12-15 20:51 ` [PATCH 08/12] OvmfPkg/MemEncryptSevLib: Make the MemEncryptSevLib available for SEC Lendacky, Thomas
2021-01-05 9:40 ` [edk2-devel] " Laszlo Ersek
2021-01-05 14:34 ` Lendacky, Thomas
2021-01-05 15:38 ` Lendacky, Thomas
2021-01-06 14:22 ` Laszlo Ersek
2021-01-06 14:21 ` Laszlo Ersek
2020-12-15 20:51 ` [PATCH 09/12] OvmfPkg/MemEncryptSevLib: Address range encryption state interface Lendacky, Thomas
2021-01-05 9:48 ` [edk2-devel] " Laszlo Ersek
2020-12-15 20:51 ` [PATCH 10/12] OvmfPkg/VmgExitLib: Support nested #VCs Lendacky, Thomas
2021-01-05 10:08 ` [edk2-devel] " Laszlo Ersek
2020-12-15 20:51 ` [PATCH 11/12] OvmfPkg/PlatformPei: Reserve GHCB backup pages if S3 is supported Lendacky, Thomas
2021-01-05 10:13 ` [edk2-devel] " Laszlo Ersek
2021-01-05 14:40 ` Lendacky, Thomas
2020-12-15 20:51 ` [PATCH 12/12] OvfmPkg/VmgExitLib: Validate #VC MMIO is to un-encrypted memory Lendacky, Thomas
2021-01-05 10:28 ` [edk2-devel] " Laszlo Ersek
2021-01-05 14:45 ` Lendacky, Thomas
2020-12-17 14:23 ` [PATCH 00/12] SEV-ES security mitigations Laszlo Ersek
2020-12-21 15:02 ` [edk2-devel] " Laszlo Ersek
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