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* [PATCH] UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page
@ 2022-05-13 13:22 Michael Roth
  2022-05-13 13:56 ` Lendacky, Thomas
  0 siblings, 1 reply; 3+ messages in thread
From: Michael Roth @ 2022-05-13 13:22 UTC (permalink / raw)
  To: devel; +Cc: Tom Lendacky

A full-featured SEV-SNP guest will not rely on the AP jump table, and
will instead use the AP Creation interface defined by the GHCB. However,
a guest is still allowed to use the AP jump table if desired.

However, unlike with SEV-ES guests, SEV-SNP guests should not
store/retrieve the jump table address via GHCB requests to the
hypervisor, they should instead store/retrieve it via the SEV-SNP
secrets page. Implement the store side of this for OVMF.

Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
 MdePkg/Include/AmdSevSnpSecretsPage.h         | 51 +++++++++++++++++++
 MdePkg/MdePkg.dec                             |  4 ++
 OvmfPkg/AmdSev/AmdSevX64.dsc                  |  3 ++
 OvmfPkg/CloudHv/CloudHvX64.dsc                |  3 ++
 OvmfPkg/IntelTdx/IntelTdxX64.dsc              |  3 ++
 OvmfPkg/Microvm/MicrovmX64.dsc                |  3 ++
 OvmfPkg/OvmfPkgIa32.dsc                       |  3 ++
 OvmfPkg/OvmfPkgIa32X64.dsc                    |  3 ++
 OvmfPkg/OvmfPkgX64.dsc                        |  3 ++
 OvmfPkg/PlatformPei/AmdSev.c                  |  5 ++
 OvmfPkg/PlatformPei/PlatformPei.inf           |  1 +
 UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |  1 +
 UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       |  9 ++++
 13 files changed, 92 insertions(+)
 create mode 100644 MdePkg/Include/AmdSevSnpSecretsPage.h

diff --git a/MdePkg/Include/AmdSevSnpSecretsPage.h b/MdePkg/Include/AmdSevSnpSecretsPage.h
new file mode 100644
index 0000000000..55c7475ff0
--- /dev/null
+++ b/MdePkg/Include/AmdSevSnpSecretsPage.h
@@ -0,0 +1,51 @@
+/** @file
+Definitions for AMD SEV-SNP Secrets Page
+
+Copyright (c) 2022 AMD Inc. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef AMD_SEV_SNP_SECRETS_PAGE_H_
+#define AMD_SEV_SNP_SECRETS_PAGE_H_
+
+//
+// OS-defined area of secrets page
+//
+// As defined by "SEV-ES Guest-Hypervisor Communication Block Standardization",
+// revision 1.50, section 2.7, "SEV-SNP Secrets Page".
+//
+typedef PACKED struct _SNP_SECRETS_OS_AREA {
+  UINT32    MsgSeqNum0;
+  UINT32    MsgSeqNum1;
+  UINT32    MsgSeqNum2;
+  UINT32    MsgSeqNum3;
+  UINT64    ApJumpTablePa;
+  UINT8     Reserved[40];
+  UINT8     GuestUsage[32];
+} SNP_SECRETS_OS_AREA;
+
+#define VMPCK_KEY_LEN  32
+
+//
+// SEV-SNP Secrets page
+//
+// As defined by "SEV-SNP Firmware ABI", revision 1.51, section 8.17.2.5,
+// "PAGE_TYPE_SECRETS".
+//
+typedef PACKED struct _SNP_SECRETS_PAGE {
+  UINT32                 Version;
+  UINT32                 ImiEn    : 1,
+                         Reserved : 31;
+  UINT32                 Fms;
+  UINT32                 Reserved2;
+  UINT8                  Gosvw[16];
+  UINT8                  Vmpck0[VMPCK_KEY_LEN];
+  UINT8                  Vmpck1[VMPCK_KEY_LEN];
+  UINT8                  Vmpck2[VMPCK_KEY_LEN];
+  UINT8                  Vmpck3[VMPCK_KEY_LEN];
+  SNP_SECRETS_OS_AREA    OsArea;
+  UINT8                  Reserved3[3840];
+} SNP_SECRETS_PAGE;
+
+#endif
diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index f1ebf9e251..a365bfcfe8 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -2417,5 +2417,9 @@
   # @Prompt Memory encryption attribute
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0|UINT64|0x0000002e
 
+  ## This dynamic PCD indicates the location of the SEV-SNP secrets page.
+  # @Prompt SEV-SNP secrets page address
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0|UINT64|0x0000002f
+
 [UserExtensions.TianoCore."ExtraFiles"]
   MdePkgExtra.uni
diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
index f0700035c1..02306945fd 100644
--- a/OvmfPkg/AmdSev/AmdSevX64.dsc
+++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
@@ -575,6 +575,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 !include OvmfPkg/OvmfTpmPcds.dsc.inc
 
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
diff --git a/OvmfPkg/CloudHv/CloudHvX64.dsc b/OvmfPkg/CloudHv/CloudHvX64.dsc
index d1c85f60c7..7143698253 100644
--- a/OvmfPkg/CloudHv/CloudHvX64.dsc
+++ b/OvmfPkg/CloudHv/CloudHvX64.dsc
@@ -630,6 +630,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 [PcdsDynamicHii]
 !include OvmfPkg/OvmfTpmPcdsHii.dsc.inc
 
diff --git a/OvmfPkg/IntelTdx/IntelTdxX64.dsc b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
index 80c331ea23..b19718c572 100644
--- a/OvmfPkg/IntelTdx/IntelTdxX64.dsc
+++ b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
@@ -512,6 +512,9 @@
 
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform.
diff --git a/OvmfPkg/Microvm/MicrovmX64.dsc b/OvmfPkg/Microvm/MicrovmX64.dsc
index 20c3c9c4d8..42673c29ee 100644
--- a/OvmfPkg/Microvm/MicrovmX64.dsc
+++ b/OvmfPkg/Microvm/MicrovmX64.dsc
@@ -613,6 +613,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform.
diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 533bbdb435..8ffef069a3 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -649,6 +649,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 !if $(CSM_ENABLE) == FALSE
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
 !endif
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index cb68e612bd..0b4d5001b2 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -657,6 +657,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 !if $(CSM_ENABLE) == FALSE
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
 !endif
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 71526bba31..3a3223be6b 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -680,6 +680,9 @@
   # Set ConfidentialComputing defaults
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
 
+  # Set SEV-SNP Secrets page address default
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
+
 !if $(CSM_ENABLE) == FALSE
   gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
 !endif
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index 385562b44c..70352ca43b 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -408,6 +408,11 @@ AmdSevInitialize (
   //
   if (MemEncryptSevSnpIsEnabled ()) {
     PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevSnp);
+    ASSERT_RETURN_ERROR (PcdStatus);
+    PcdStatus = PcdSet64S (
+                  PcdSevSnpSecretsAddress,
+                  (UINT64)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase)
+                  );
   } else if (MemEncryptSevEsIsEnabled ()) {
     PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevEs);
   } else {
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf
index 00372fa0eb..c688e4ee24 100644
--- a/OvmfPkg/PlatformPei/PlatformPei.inf
+++ b/OvmfPkg/PlatformPei/PlatformPei.inf
@@ -114,6 +114,7 @@
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr
   gUefiCpuPkgTokenSpaceGuid.PcdGhcbHypervisorFeatures
   gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress
 
 [FixedPcd]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
index e1cd0b3500..d8cfddcd82 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
@@ -80,3 +80,4 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                      ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase                           ## CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr           ## CONSUMES
+  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress                     ## CONSUMES
diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index 60d14a5a0e..6014dce136 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -15,6 +15,7 @@
 #include <Library/VmgExitLib.h>
 #include <Register/Amd/Fam17Msr.h>
 #include <Register/Amd/Ghcb.h>
+#include <AmdSevSnpSecretsPage.h>
 
 #include <Protocol/Timer.h>
 
@@ -216,6 +217,14 @@ GetSevEsAPMemory (
 
   DEBUG ((DEBUG_INFO, "Dxe: SevEsAPMemory = %lx\n", (UINTN)StartAddress));
 
+  if (ConfidentialComputingGuestHas (CCAttrAmdSevSnp)) {
+    SNP_SECRETS_PAGE  *Secrets = (SNP_SECRETS_PAGE *)(INTN)PcdGet64 (PcdSevSnpSecretsAddress);
+
+    Secrets->OsArea.ApJumpTablePa = (UINT64)(UINTN)StartAddress;
+
+    return (UINTN)StartAddress;
+  }
+
   //
   // Save the SevEsAPMemory as the AP jump table.
   //
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page
  2022-05-13 13:22 [PATCH] UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page Michael Roth
@ 2022-05-13 13:56 ` Lendacky, Thomas
  2022-05-13 14:20   ` Michael Roth
  0 siblings, 1 reply; 3+ messages in thread
From: Lendacky, Thomas @ 2022-05-13 13:56 UTC (permalink / raw)
  To: Michael Roth, devel

On 5/13/22 08:22, Michael Roth wrote:
> A full-featured SEV-SNP guest will not rely on the AP jump table, and
> will instead use the AP Creation interface defined by the GHCB. However,
> a guest is still allowed to use the AP jump table if desired.
> 
> However, unlike with SEV-ES guests, SEV-SNP guests should not
> store/retrieve the jump table address via GHCB requests to the
> hypervisor, they should instead store/retrieve it via the SEV-SNP
> secrets page. Implement the store side of this for OVMF.
> 
> Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
> ---
>   MdePkg/Include/AmdSevSnpSecretsPage.h         | 51 +++++++++++++++++++
>   MdePkg/MdePkg.dec                             |  4 ++
>   OvmfPkg/AmdSev/AmdSevX64.dsc                  |  3 ++
>   OvmfPkg/CloudHv/CloudHvX64.dsc                |  3 ++
>   OvmfPkg/IntelTdx/IntelTdxX64.dsc              |  3 ++
>   OvmfPkg/Microvm/MicrovmX64.dsc                |  3 ++
>   OvmfPkg/OvmfPkgIa32.dsc                       |  3 ++
>   OvmfPkg/OvmfPkgIa32X64.dsc                    |  3 ++
>   OvmfPkg/OvmfPkgX64.dsc                        |  3 ++
>   OvmfPkg/PlatformPei/AmdSev.c                  |  5 ++
>   OvmfPkg/PlatformPei/PlatformPei.inf           |  1 +
>   UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |  1 +
>   UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       |  9 ++++
>   13 files changed, 92 insertions(+)
>   create mode 100644 MdePkg/Include/AmdSevSnpSecretsPage.h
> 
> diff --git a/MdePkg/Include/AmdSevSnpSecretsPage.h b/MdePkg/Include/AmdSevSnpSecretsPage.h
> new file mode 100644
> index 0000000000..55c7475ff0
> --- /dev/null
> +++ b/MdePkg/Include/AmdSevSnpSecretsPage.h

Just wondering if this should be in the MdePkg/Include/Register/Amd directory?

> @@ -0,0 +1,51 @@
> +/** @file
> +Definitions for AMD SEV-SNP Secrets Page
> +
> +Copyright (c) 2022 AMD Inc. All rights reserved.<BR>
> +SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#ifndef AMD_SEV_SNP_SECRETS_PAGE_H_
> +#define AMD_SEV_SNP_SECRETS_PAGE_H_
> +
> +//
> +// OS-defined area of secrets page
> +//
> +// As defined by "SEV-ES Guest-Hypervisor Communication Block Standardization",
> +// revision 1.50, section 2.7, "SEV-SNP Secrets Page".

This should be using at least revision 2.00 (if not 2.01 which is in the 
process of being published). 2.01 uses some of the 40-byte reserved area 
to hold the high 32-bits of the message sequence numbers (since the SNP 
API changed after the GHCB spec was published to convert the sequence 
numbers from 32-bit to 64-bit). The changes are backwards compatible, so 
not a big deal as to whether to implement since OVMF doesn't make any 
guest request API calls.

Thanks,
Tom

> +//
> +typedef PACKED struct _SNP_SECRETS_OS_AREA {
> +  UINT32    MsgSeqNum0;
> +  UINT32    MsgSeqNum1;
> +  UINT32    MsgSeqNum2;
> +  UINT32    MsgSeqNum3;
> +  UINT64    ApJumpTablePa;
> +  UINT8     Reserved[40];
> +  UINT8     GuestUsage[32];
> +} SNP_SECRETS_OS_AREA;
> +
> +#define VMPCK_KEY_LEN  32
> +
> +//
> +// SEV-SNP Secrets page
> +//
> +// As defined by "SEV-SNP Firmware ABI", revision 1.51, section 8.17.2.5,
> +// "PAGE_TYPE_SECRETS".
> +//
> +typedef PACKED struct _SNP_SECRETS_PAGE {
> +  UINT32                 Version;
> +  UINT32                 ImiEn    : 1,
> +                         Reserved : 31;
> +  UINT32                 Fms;
> +  UINT32                 Reserved2;
> +  UINT8                  Gosvw[16];
> +  UINT8                  Vmpck0[VMPCK_KEY_LEN];
> +  UINT8                  Vmpck1[VMPCK_KEY_LEN];
> +  UINT8                  Vmpck2[VMPCK_KEY_LEN];
> +  UINT8                  Vmpck3[VMPCK_KEY_LEN];
> +  SNP_SECRETS_OS_AREA    OsArea;
> +  UINT8                  Reserved3[3840];
> +} SNP_SECRETS_PAGE;
> +
> +#endif
> diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
> index f1ebf9e251..a365bfcfe8 100644
> --- a/MdePkg/MdePkg.dec
> +++ b/MdePkg/MdePkg.dec
> @@ -2417,5 +2417,9 @@
>     # @Prompt Memory encryption attribute
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0|UINT64|0x0000002e
>   
> +  ## This dynamic PCD indicates the location of the SEV-SNP secrets page.
> +  # @Prompt SEV-SNP secrets page address
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0|UINT64|0x0000002f
> +
>   [UserExtensions.TianoCore."ExtraFiles"]
>     MdePkgExtra.uni
> diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
> index f0700035c1..02306945fd 100644
> --- a/OvmfPkg/AmdSev/AmdSevX64.dsc
> +++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
> @@ -575,6 +575,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   !include OvmfPkg/OvmfTpmPcds.dsc.inc
>   
>     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> diff --git a/OvmfPkg/CloudHv/CloudHvX64.dsc b/OvmfPkg/CloudHv/CloudHvX64.dsc
> index d1c85f60c7..7143698253 100644
> --- a/OvmfPkg/CloudHv/CloudHvX64.dsc
> +++ b/OvmfPkg/CloudHv/CloudHvX64.dsc
> @@ -630,6 +630,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   [PcdsDynamicHii]
>   !include OvmfPkg/OvmfTpmPcdsHii.dsc.inc
>   
> diff --git a/OvmfPkg/IntelTdx/IntelTdxX64.dsc b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> index 80c331ea23..b19718c572 100644
> --- a/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> +++ b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> @@ -512,6 +512,9 @@
>   
>     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   ################################################################################
>   #
>   # Components Section - list of all EDK II Modules needed by this Platform.
> diff --git a/OvmfPkg/Microvm/MicrovmX64.dsc b/OvmfPkg/Microvm/MicrovmX64.dsc
> index 20c3c9c4d8..42673c29ee 100644
> --- a/OvmfPkg/Microvm/MicrovmX64.dsc
> +++ b/OvmfPkg/Microvm/MicrovmX64.dsc
> @@ -613,6 +613,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   ################################################################################
>   #
>   # Components Section - list of all EDK II Modules needed by this Platform.
> diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
> index 533bbdb435..8ffef069a3 100644
> --- a/OvmfPkg/OvmfPkgIa32.dsc
> +++ b/OvmfPkg/OvmfPkgIa32.dsc
> @@ -649,6 +649,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   !if $(CSM_ENABLE) == FALSE
>     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
>   !endif
> diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
> index cb68e612bd..0b4d5001b2 100644
> --- a/OvmfPkg/OvmfPkgIa32X64.dsc
> +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
> @@ -657,6 +657,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   !if $(CSM_ENABLE) == FALSE
>     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
>   !endif
> diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
> index 71526bba31..3a3223be6b 100644
> --- a/OvmfPkg/OvmfPkgX64.dsc
> +++ b/OvmfPkg/OvmfPkgX64.dsc
> @@ -680,6 +680,9 @@
>     # Set ConfidentialComputing defaults
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
>   
> +  # Set SEV-SNP Secrets page address default
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> +
>   !if $(CSM_ENABLE) == FALSE
>     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
>   !endif
> diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
> index 385562b44c..70352ca43b 100644
> --- a/OvmfPkg/PlatformPei/AmdSev.c
> +++ b/OvmfPkg/PlatformPei/AmdSev.c
> @@ -408,6 +408,11 @@ AmdSevInitialize (
>     //
>     if (MemEncryptSevSnpIsEnabled ()) {
>       PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevSnp);
> +    ASSERT_RETURN_ERROR (PcdStatus);
> +    PcdStatus = PcdSet64S (
> +                  PcdSevSnpSecretsAddress,
> +                  (UINT64)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase)
> +                  );
>     } else if (MemEncryptSevEsIsEnabled ()) {
>       PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevEs);
>     } else {
> diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf
> index 00372fa0eb..c688e4ee24 100644
> --- a/OvmfPkg/PlatformPei/PlatformPei.inf
> +++ b/OvmfPkg/PlatformPei/PlatformPei.inf
> @@ -114,6 +114,7 @@
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr
>     gUefiCpuPkgTokenSpaceGuid.PcdGhcbHypervisorFeatures
>     gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress
>   
>   [FixedPcd]
>     gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
> diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> index e1cd0b3500..d8cfddcd82 100644
> --- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> @@ -80,3 +80,4 @@
>     gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                      ## CONSUMES
>     gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase                           ## CONSUMES
>     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr           ## CONSUMES
> +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress                     ## CONSUMES
> diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> index 60d14a5a0e..6014dce136 100644
> --- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> @@ -15,6 +15,7 @@
>   #include <Library/VmgExitLib.h>
>   #include <Register/Amd/Fam17Msr.h>
>   #include <Register/Amd/Ghcb.h>
> +#include <AmdSevSnpSecretsPage.h>
>   
>   #include <Protocol/Timer.h>
>   
> @@ -216,6 +217,14 @@ GetSevEsAPMemory (
>   
>     DEBUG ((DEBUG_INFO, "Dxe: SevEsAPMemory = %lx\n", (UINTN)StartAddress));
>   
> +  if (ConfidentialComputingGuestHas (CCAttrAmdSevSnp)) {
> +    SNP_SECRETS_PAGE  *Secrets = (SNP_SECRETS_PAGE *)(INTN)PcdGet64 (PcdSevSnpSecretsAddress);
> +
> +    Secrets->OsArea.ApJumpTablePa = (UINT64)(UINTN)StartAddress;
> +
> +    return (UINTN)StartAddress;
> +  }
> +
>     //
>     // Save the SevEsAPMemory as the AP jump table.
>     //

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page
  2022-05-13 13:56 ` Lendacky, Thomas
@ 2022-05-13 14:20   ` Michael Roth
  0 siblings, 0 replies; 3+ messages in thread
From: Michael Roth @ 2022-05-13 14:20 UTC (permalink / raw)
  To: Tom Lendacky; +Cc: devel

On Fri, May 13, 2022 at 08:56:06AM -0500, Tom Lendacky wrote:
> On 5/13/22 08:22, Michael Roth wrote:
> > A full-featured SEV-SNP guest will not rely on the AP jump table, and
> > will instead use the AP Creation interface defined by the GHCB. However,
> > a guest is still allowed to use the AP jump table if desired.
> > 
> > However, unlike with SEV-ES guests, SEV-SNP guests should not
> > store/retrieve the jump table address via GHCB requests to the
> > hypervisor, they should instead store/retrieve it via the SEV-SNP
> > secrets page. Implement the store side of this for OVMF.
> > 
> > Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
> > Signed-off-by: Michael Roth <michael.roth@amd.com>
> > ---
> >   MdePkg/Include/AmdSevSnpSecretsPage.h         | 51 +++++++++++++++++++
> >   MdePkg/MdePkg.dec                             |  4 ++
> >   OvmfPkg/AmdSev/AmdSevX64.dsc                  |  3 ++
> >   OvmfPkg/CloudHv/CloudHvX64.dsc                |  3 ++
> >   OvmfPkg/IntelTdx/IntelTdxX64.dsc              |  3 ++
> >   OvmfPkg/Microvm/MicrovmX64.dsc                |  3 ++
> >   OvmfPkg/OvmfPkgIa32.dsc                       |  3 ++
> >   OvmfPkg/OvmfPkgIa32X64.dsc                    |  3 ++
> >   OvmfPkg/OvmfPkgX64.dsc                        |  3 ++
> >   OvmfPkg/PlatformPei/AmdSev.c                  |  5 ++
> >   OvmfPkg/PlatformPei/PlatformPei.inf           |  1 +
> >   UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |  1 +
> >   UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       |  9 ++++
> >   13 files changed, 92 insertions(+)
> >   create mode 100644 MdePkg/Include/AmdSevSnpSecretsPage.h
> > 
> > diff --git a/MdePkg/Include/AmdSevSnpSecretsPage.h b/MdePkg/Include/AmdSevSnpSecretsPage.h
> > new file mode 100644
> > index 0000000000..55c7475ff0
> > --- /dev/null
> > +++ b/MdePkg/Include/AmdSevSnpSecretsPage.h
> 
> Just wondering if this should be in the MdePkg/Include/Register/Amd directory?

That might be the better spot. I was thinking that was reserved for
definitions related to specific registers, but I somehow missed that it's
also where the GHCB struct is defined. So probably makes sense to put
the secrets page definition there as well.

> 
> > @@ -0,0 +1,51 @@
> > +/** @file
> > +Definitions for AMD SEV-SNP Secrets Page
> > +
> > +Copyright (c) 2022 AMD Inc. All rights reserved.<BR>
> > +SPDX-License-Identifier: BSD-2-Clause-Patent
> > +
> > +**/
> > +
> > +#ifndef AMD_SEV_SNP_SECRETS_PAGE_H_
> > +#define AMD_SEV_SNP_SECRETS_PAGE_H_
> > +
> > +//
> > +// OS-defined area of secrets page
> > +//
> > +// As defined by "SEV-ES Guest-Hypervisor Communication Block Standardization",
> > +// revision 1.50, section 2.7, "SEV-SNP Secrets Page".
> 
> This should be using at least revision 2.00 (if not 2.01 which is in the
> process of being published). 2.01 uses some of the 40-byte reserved area to
> hold the high 32-bits of the message sequence numbers (since the SNP API
> changed after the GHCB spec was published to convert the sequence numbers
> from 32-bit to 64-bit). The changes are backwards compatible, so not a big
> deal as to whether to implement since OVMF doesn't make any guest request
> API calls.

Okay, will go ahead and update these while I'm at it and send a v2.

Thanks!

-Mike

> 
> Thanks,
> Tom
> 
> > +//
> > +typedef PACKED struct _SNP_SECRETS_OS_AREA {
> > +  UINT32    MsgSeqNum0;
> > +  UINT32    MsgSeqNum1;
> > +  UINT32    MsgSeqNum2;
> > +  UINT32    MsgSeqNum3;
> > +  UINT64    ApJumpTablePa;
> > +  UINT8     Reserved[40];
> > +  UINT8     GuestUsage[32];
> > +} SNP_SECRETS_OS_AREA;
> > +
> > +#define VMPCK_KEY_LEN  32
> > +
> > +//
> > +// SEV-SNP Secrets page
> > +//
> > +// As defined by "SEV-SNP Firmware ABI", revision 1.51, section 8.17.2.5,
> > +// "PAGE_TYPE_SECRETS".
> > +//
> > +typedef PACKED struct _SNP_SECRETS_PAGE {
> > +  UINT32                 Version;
> > +  UINT32                 ImiEn    : 1,
> > +                         Reserved : 31;
> > +  UINT32                 Fms;
> > +  UINT32                 Reserved2;
> > +  UINT8                  Gosvw[16];
> > +  UINT8                  Vmpck0[VMPCK_KEY_LEN];
> > +  UINT8                  Vmpck1[VMPCK_KEY_LEN];
> > +  UINT8                  Vmpck2[VMPCK_KEY_LEN];
> > +  UINT8                  Vmpck3[VMPCK_KEY_LEN];
> > +  SNP_SECRETS_OS_AREA    OsArea;
> > +  UINT8                  Reserved3[3840];
> > +} SNP_SECRETS_PAGE;
> > +
> > +#endif
> > diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
> > index f1ebf9e251..a365bfcfe8 100644
> > --- a/MdePkg/MdePkg.dec
> > +++ b/MdePkg/MdePkg.dec
> > @@ -2417,5 +2417,9 @@
> >     # @Prompt Memory encryption attribute
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0|UINT64|0x0000002e
> > +  ## This dynamic PCD indicates the location of the SEV-SNP secrets page.
> > +  # @Prompt SEV-SNP secrets page address
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0|UINT64|0x0000002f
> > +
> >   [UserExtensions.TianoCore."ExtraFiles"]
> >     MdePkgExtra.uni
> > diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
> > index f0700035c1..02306945fd 100644
> > --- a/OvmfPkg/AmdSev/AmdSevX64.dsc
> > +++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
> > @@ -575,6 +575,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   !include OvmfPkg/OvmfTpmPcds.dsc.inc
> >     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> > diff --git a/OvmfPkg/CloudHv/CloudHvX64.dsc b/OvmfPkg/CloudHv/CloudHvX64.dsc
> > index d1c85f60c7..7143698253 100644
> > --- a/OvmfPkg/CloudHv/CloudHvX64.dsc
> > +++ b/OvmfPkg/CloudHv/CloudHvX64.dsc
> > @@ -630,6 +630,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   [PcdsDynamicHii]
> >   !include OvmfPkg/OvmfTpmPcdsHii.dsc.inc
> > diff --git a/OvmfPkg/IntelTdx/IntelTdxX64.dsc b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> > index 80c331ea23..b19718c572 100644
> > --- a/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> > +++ b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
> > @@ -512,6 +512,9 @@
> >     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   ################################################################################
> >   #
> >   # Components Section - list of all EDK II Modules needed by this Platform.
> > diff --git a/OvmfPkg/Microvm/MicrovmX64.dsc b/OvmfPkg/Microvm/MicrovmX64.dsc
> > index 20c3c9c4d8..42673c29ee 100644
> > --- a/OvmfPkg/Microvm/MicrovmX64.dsc
> > +++ b/OvmfPkg/Microvm/MicrovmX64.dsc
> > @@ -613,6 +613,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   ################################################################################
> >   #
> >   # Components Section - list of all EDK II Modules needed by this Platform.
> > diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
> > index 533bbdb435..8ffef069a3 100644
> > --- a/OvmfPkg/OvmfPkgIa32.dsc
> > +++ b/OvmfPkg/OvmfPkgIa32.dsc
> > @@ -649,6 +649,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   !if $(CSM_ENABLE) == FALSE
> >     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> >   !endif
> > diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
> > index cb68e612bd..0b4d5001b2 100644
> > --- a/OvmfPkg/OvmfPkgIa32X64.dsc
> > +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
> > @@ -657,6 +657,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   !if $(CSM_ENABLE) == FALSE
> >     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> >   !endif
> > diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
> > index 71526bba31..3a3223be6b 100644
> > --- a/OvmfPkg/OvmfPkgX64.dsc
> > +++ b/OvmfPkg/OvmfPkgX64.dsc
> > @@ -680,6 +680,9 @@
> >     # Set ConfidentialComputing defaults
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr|0
> > +  # Set SEV-SNP Secrets page address default
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress|0
> > +
> >   !if $(CSM_ENABLE) == FALSE
> >     gEfiMdePkgTokenSpaceGuid.PcdFSBClock|100000000
> >   !endif
> > diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
> > index 385562b44c..70352ca43b 100644
> > --- a/OvmfPkg/PlatformPei/AmdSev.c
> > +++ b/OvmfPkg/PlatformPei/AmdSev.c
> > @@ -408,6 +408,11 @@ AmdSevInitialize (
> >     //
> >     if (MemEncryptSevSnpIsEnabled ()) {
> >       PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevSnp);
> > +    ASSERT_RETURN_ERROR (PcdStatus);
> > +    PcdStatus = PcdSet64S (
> > +                  PcdSevSnpSecretsAddress,
> > +                  (UINT64)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase)
> > +                  );
> >     } else if (MemEncryptSevEsIsEnabled ()) {
> >       PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, CCAttrAmdSevEs);
> >     } else {
> > diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf
> > index 00372fa0eb..c688e4ee24 100644
> > --- a/OvmfPkg/PlatformPei/PlatformPei.inf
> > +++ b/OvmfPkg/PlatformPei/PlatformPei.inf
> > @@ -114,6 +114,7 @@
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr
> >     gUefiCpuPkgTokenSpaceGuid.PcdGhcbHypervisorFeatures
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress
> >   [FixedPcd]
> >     gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
> > diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> > index e1cd0b3500..d8cfddcd82 100644
> > --- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> > +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> > @@ -80,3 +80,4 @@
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                      ## CONSUMES
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase                           ## CONSUMES
> >     gEfiMdePkgTokenSpaceGuid.PcdConfidentialComputingGuestAttr           ## CONSUMES
> > +  gEfiMdePkgTokenSpaceGuid.PcdSevSnpSecretsAddress                     ## CONSUMES
> > diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> > index 60d14a5a0e..6014dce136 100644
> > --- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> > +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> > @@ -15,6 +15,7 @@
> >   #include <Library/VmgExitLib.h>
> >   #include <Register/Amd/Fam17Msr.h>
> >   #include <Register/Amd/Ghcb.h>
> > +#include <AmdSevSnpSecretsPage.h>
> >   #include <Protocol/Timer.h>
> > @@ -216,6 +217,14 @@ GetSevEsAPMemory (
> >     DEBUG ((DEBUG_INFO, "Dxe: SevEsAPMemory = %lx\n", (UINTN)StartAddress));
> > +  if (ConfidentialComputingGuestHas (CCAttrAmdSevSnp)) {
> > +    SNP_SECRETS_PAGE  *Secrets = (SNP_SECRETS_PAGE *)(INTN)PcdGet64 (PcdSevSnpSecretsAddress);
> > +
> > +    Secrets->OsArea.ApJumpTablePa = (UINT64)(UINTN)StartAddress;
> > +
> > +    return (UINTN)StartAddress;
> > +  }
> > +
> >     //
> >     // Save the SevEsAPMemory as the AP jump table.
> >     //

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-05-13 14:20 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2022-05-13 13:22 [PATCH] UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page Michael Roth
2022-05-13 13:56 ` Lendacky, Thomas
2022-05-13 14:20   ` Michael Roth

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