[edk2-devel] [PATCH 00/12] SEV-ES security mitigations

[Lendacky, Thomas]

From: Tom Lendacky <thomas.lendacky at amd.com>

This patch series provides security mitigations for SEV-ES to protect
against some attacks identified in the paper titled "Exploiting Interfaces
of Secure Encrypted Virtual Machines" at:
  https://arxiv.org/pdf/2010.07094.pdf

The mitigations include:

- Validating the encryption bit position provided by the hypervisor.
  Additionally, once validated use the validated value throughout the
  code.

- Validating that SEV-ES has been advertised to the guest if a #VC has
  been taken to prevent the hypervisor from pretending that SEV-ES is
  not enabled.

- Validate that MMIO is performed to/from unencrypted memory addresses
  to prevent the hypervisor try to inject data or expose secrets within
  the guest.

And a change separate from the above paper:

- When checking #VC related per-vCPU values, make checks for explicit
  values vs non-zero values so that a hypervisor can't write random data
  to the location to alter guest processing behavior.

Also, as part of creating these mitigations:
- MemEncryptSevLib is updated to now be available during SEC
- #VC now supports a single nested invocation

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108

---

These patches are based on commit:
5c3cdebf95bf ("MdePkg/include: Add DMAR SATC Table Definition")

Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Rebecca Cran <rebecca at bsdio.com>
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Julien Grall <julien at xen.org>
Cc: Peter Grehan <grehan at freebsd.org>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Anthony Perard <anthony.perard at citrix.com>
Cc: Brijesh Singh <brijesh.singh at amd.com>

Tom Lendacky (12):
  Ovmf/ResetVector: Simplify and consolidate the SEV features checks
  OvmfPkg/Sec: Move SEV-ES SEC workarea definition to common header file
  OvmfPkg/ResetVector: Validate the encryption bit position for
    SEV/SEV-ES
  OvmfPkg/ResetVector: Perform a simple SEV-ES sanity check
  OvmfPkg/MemEncryptSevLib: Add an interface to retrieve the encryption
    mask
  OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range
  OvmfPkg/VmgExitLib: Check for an explicit DR7 cached value
  OvmfPkg/MemEncryptSevLib: Make the MemEncryptSevLib available for SEC
  OvmfPkg/MemEncryptSevLib: Address range encryption state interface
  OvmfPkg/VmgExitLib: Support nested #VCs
  OvmfPkg/PlatformPei: Reserve GHCB backup pages if S3 is supported
  OvfmPkg/VmgExitLib: Validate #VC MMIO is to un-encrypted memory

 OvmfPkg/OvmfPkg.dec                           |   2 +
 OvmfPkg/AmdSev/AmdSevX64.dsc                  |   6 +-
 OvmfPkg/Bhyve/BhyveX64.dsc                    |   4 +-
 OvmfPkg/OvmfPkgIa32.dsc                       |   4 +-
 OvmfPkg/OvmfPkgIa32X64.dsc                    |   4 +-
 OvmfPkg/OvmfPkgX64.dsc                        |   6 +-
 OvmfPkg/OvmfXen.dsc                           |   3 +-
 OvmfPkg/AmdSev/AmdSevX64.fdf                  |   3 +
 OvmfPkg/OvmfPkgX64.fdf                        |   3 +
 OvmfPkg/AmdSevDxe/AmdSevDxe.inf               |   8 +-
 ...SevLib.inf => DxeBaseMemEncryptSevLib.inf} |  14 +-
 .../PeiBaseMemEncryptSevLib.inf               |  57 ++
 .../SecBaseMemEncryptSevLib.inf               |  55 +
 OvmfPkg/Library/VmgExitLib/SecVmgExitLib.inf  |  44 +
 OvmfPkg/Library/VmgExitLib/VmgExitLib.inf     |   6 +-
 OvmfPkg/PlatformPei/PlatformPei.inf           |   2 +
 OvmfPkg/Include/Library/MemEncryptSevLib.h    |  90 +-
 .../BaseMemEncryptSevLib/X64/VirtualMemory.h  |  35 +-
 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.h |  53 +
 OvmfPkg/AmdSevDxe/AmdSevDxe.c                 |  20 +-
 OvmfPkg/Bhyve/PlatformPei/AmdSev.c            |  12 +-
 .../DxeMemEncryptSevLibInternal.c             | 145 +++
 .../Ia32/MemEncryptSevLib.c                   |  31 +-
 .../MemEncryptSevLibInternal.c                |  91 +-
 .../PeiMemEncryptSevLibInternal.c             | 159 +++
 .../SecMemEncryptSevLibInternal.c             | 130 +++
 .../X64/MemEncryptSevLib.c                    |  32 +-
 .../X64/PeiDxeVirtualMemory.c                 | 893 ++++++++++++++++
 .../X64/SecVirtualMemory.c                    | 100 ++
 .../BaseMemEncryptSevLib/X64/VirtualMemory.c  | 954 +++---------------
 .../VmgExitLib/PeiDxeVmgExitVcHandler.c       | 103 ++
 .../Library/VmgExitLib/SecVmgExitVcHandler.c  | 109 ++
 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 130 ++-
 OvmfPkg/PlatformPei/AmdSev.c                  |  50 +-
 OvmfPkg/PlatformPei/MemDetect.c               |   5 +
 OvmfPkg/Sec/SecMain.c                         |   6 +-
 OvmfPkg/XenPlatformPei/AmdSev.c               |  12 +-
 OvmfPkg/ResetVector/Ia32/Flat32ToFlat64.asm   | 116 +++
 OvmfPkg/ResetVector/Ia32/PageTables64.asm     | 108 +-
 OvmfPkg/ResetVector/ResetVector.nasmb         |   5 +-
 40 files changed, 2590 insertions(+), 1020 deletions(-)
 rename OvmfPkg/Library/BaseMemEncryptSevLib/{BaseMemEncryptSevLib.inf => DxeBaseMemEncryptSevLib.inf} (66%)
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/PeiBaseMemEncryptSevLib.inf
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/SecBaseMemEncryptSevLib.inf
 create mode 100644 OvmfPkg/Library/VmgExitLib/SecVmgExitLib.inf
 create mode 100644 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.h
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLibInternal.c
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLibInternal.c
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLibInternal.c
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
 create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
 create mode 100644 OvmfPkg/Library/VmgExitLib/PeiDxeVmgExitVcHandler.c
 create mode 100644 OvmfPkg/Library/VmgExitLib/SecVmgExitVcHandler.c
 create mode 100644 OvmfPkg/ResetVector/Ia32/Flat32ToFlat64.asm

-- 
2.28.0



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