[edk2-devel] [PATCH RFC v2 11/28] OvmfPkg: Reserve Secrets page in MEMFD
Brijesh Singh
brijesh.singh at amd.com
Wed May 5 13:11:34 UTC 2021
On 5/5/21 1:42 AM, Dov Murik wrote:
> [+cc: Tobin]
>
> Hi Brijesh,
>
> On 30/04/2021 14:51, Brijesh Singh wrote:
>> BZ: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D3275&data=04%7C01%7Cbrijesh.singh%40amd.com%7C93168c94eb6d44ed08e608d90f910426%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637557937779907471%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=nLpmk3G%2BmXcZrzXxCmO3M9EDPiLRnP1IUmPqRQNbBuU%3D&reserved=0
>>
>> When AMD SEV is enabled in the guest VM, a hypervisor need to insert a
>> secrets page.
>>
>> When SEV-SNP is enabled, the secrets page contains the VM platform
>> communication keys. The guest BIOS and OS can use this key to communicate
>> with the SEV firmware to get attesation report. See the SEV-SNP firmware
>> spec for more details for the content of the secrets page.
>>
>> When SEV and SEV-ES is enabled, the secrets page contains the information
>> provided by the guest owner after the attestation. See the SEV
>> LAUNCH_SECRET command for more details.
>>
>> Cc: James Bottomley <jejb at linux.ibm.com>
>> Cc: Min Xu <min.m.xu at intel.com>
>> Cc: Jiewen Yao <jiewen.yao at intel.com>
>> Cc: Tom Lendacky <thomas.lendacky at amd.com>
>> Cc: Jordan Justen <jordan.l.justen at intel.com>
>> Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
>> Cc: Laszlo Ersek <lersek at redhat.com>
>> Cc: Erdem Aktas <erdemaktas at google.com>
>> Signed-off-by: Brijesh Singh <brijesh.singh at amd.com>
>> ---
>> OvmfPkg/AmdSev/SecretPei/SecretPei.c | 16 +++++++++++++++-
>> OvmfPkg/AmdSev/SecretPei/SecretPei.inf | 1 +
>> OvmfPkg/OvmfPkgX64.dsc | 2 ++
>> OvmfPkg/OvmfPkgX64.fdf | 5 +++++
>> 4 files changed, 23 insertions(+), 1 deletion(-)
>>
>> diff --git a/OvmfPkg/AmdSev/SecretPei/SecretPei.c b/OvmfPkg/AmdSev/SecretPei/SecretPei.c
>> index ad491515dd..92836c562c 100644
>> --- a/OvmfPkg/AmdSev/SecretPei/SecretPei.c
>> +++ b/OvmfPkg/AmdSev/SecretPei/SecretPei.c
>> @@ -7,6 +7,7 @@
>> #include <PiPei.h>
>> #include <Library/HobLib.h>
>> #include <Library/PcdLib.h>
>> +#include <Library/MemEncryptSevLib.h>
>>
>> EFI_STATUS
>> EFIAPI
>> @@ -15,10 +16,23 @@ InitializeSecretPei (
>> IN CONST EFI_PEI_SERVICES **PeiServices
>> )
>> {
>> + UINTN Type;
>> +
>> + //
>> + // The secret page should be mapped encrypted by the guest OS and must not
>> + // be treated as a system RAM. Mark it as ACPI NVS so that guest OS maps it
>> + // encrypted.
>> + //
>> + if (MemEncryptSevSnpIsEnabled ()) {
>> + Type = EfiACPIMemoryNVS;
>> + } else {
>> + Type = EfiBootServicesData;
>> + }
>> +
> Would it make sense to always use EfiACPIMemoryNVS for the injected secret area, even for regular SEV (non-SNP)?
Ideally yes. Maybe James had some reasons for choosing the
EfiBootServicesData. If I had to guess, it was mainly because there no
guest kernel support which consumes the SEV secrets page. Since the
memory is not marked ACPI NVS, so it can be used as a system RAM after
the ExitBootServices is called in the kernel.
I am fine with using ACPI NVS for both SEV and SEV-SNP. I was not able
to build and run AmdSev package in my setup, can you submit a prepatch
to change the memory type and verify that it works ?
>
> -Dov
>
>
>
>> BuildMemoryAllocationHob (
>> PcdGet32 (PcdSevLaunchSecretBase),
>> PcdGet32 (PcdSevLaunchSecretSize),
>> - EfiBootServicesData
>> + Type
>> );
>>
>> return EFI_SUCCESS;
>> diff --git a/OvmfPkg/AmdSev/SecretPei/SecretPei.inf b/OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>> index 08be156c4b..9265f8adee 100644
>> --- a/OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>> +++ b/OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>> @@ -26,6 +26,7 @@
>> HobLib
>> PeimEntryPoint
>> PcdLib
>> + MemEncryptSevLib
>>
>> [FixedPcd]
>> gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase
>> diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
>> index a7d747f6b4..593c0e69f6 100644
>> --- a/OvmfPkg/OvmfPkgX64.dsc
>> +++ b/OvmfPkg/OvmfPkgX64.dsc
>> @@ -716,6 +716,7 @@
>> OvmfPkg/SmmAccess/SmmAccessPei.inf
>> !endif
>> UefiCpuPkg/CpuMpPei/CpuMpPei.inf
>> + OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>>
>> !if $(TPM_ENABLE) == TRUE
>> OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
>> @@ -965,6 +966,7 @@
>> OvmfPkg/PlatformDxe/Platform.inf
>> OvmfPkg/AmdSevDxe/AmdSevDxe.inf
>> OvmfPkg/IoMmuDxe/IoMmuDxe.inf
>> + OvmfPkg/AmdSev/SecretDxe/SecretDxe.inf
>>
>> !if $(SMM_REQUIRE) == TRUE
>> OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
>> diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
>> index d519f85328..b04175f77c 100644
>> --- a/OvmfPkg/OvmfPkgX64.fdf
>> +++ b/OvmfPkg/OvmfPkgX64.fdf
>> @@ -88,6 +88,9 @@ gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase|gUefiCpuPkgTokenSpaceGuid.PcdSevE
>> 0x00C000|0x001000
>> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize
>>
>> +0x00D000|0x001000
>> +gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase|gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
>> +
>> 0x010000|0x010000
>> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
>>
>> @@ -178,6 +181,7 @@ INF OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
>> INF SecurityPkg/Tcg/TcgPei/TcgPei.inf
>> INF SecurityPkg/Tcg/Tcg2Pei/Tcg2Pei.inf
>> !endif
>> +INF OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>>
>> ################################################################################
>>
>> @@ -313,6 +317,7 @@ INF OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
>> INF ShellPkg/Application/Shell/Shell.inf
>>
>> INF MdeModulePkg/Logo/LogoDxe.inf
>> +INF OvmfPkg/AmdSev/SecretDxe/SecretDxe.inf
>>
>> #
>> # Network modules
>>
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