Hi Tom,
On 12/15/20 21:50, Tom Lendacky wrote:
> From: Tom Lendacky <thomas.lendacky@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")
I plan to review this series next year (and then after the VCPU
hot-unplug stuff that's already been in my review queue for a bit...)
Thanks,
Laszlo
>
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
> Cc: Rebecca Cran <rebecca@bsdio.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Julien Grall <julien@xen.org>
> Cc: Peter Grehan <grehan@freebsd.org>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Anthony Perard <anthony.perard@citrix.com>
> Cc: Brijesh Singh <brijesh.singh@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
>
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