The Confidential Computing blob defined here is intended to match the
definition defined by linux guest kernel. Previously, both definitions
relied on natural alignment, but that relies on both OVMF and kernel
being compiled as 64-bit. While there aren't currently any plans to
enable SNP support for 32-bit compilations, the kernel definition has
since been updated to use explicit padding/reserved fields to avoid
this dependency. Update OVMF to match that definition.
While at it, also fix up the Reserved fields to match the numbering
used in the kernel.
No functional changes (for currently-supported environments, at least).
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
The SEV-SNP Confidential Computing blob contains metadata that should
remain accessible for the life of the guest. Allocate it as
EfiACPIReclaimMemory to ensure the memory isn't overwritten by the guest
operating system later.
Reported-by: Dov Murik <dovmurik@linux.ibm.com>
Suggested-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
__FUNCTION__ is a pre-standard extension that gcc and Visual C++ among
others support, while __func__ was standardized in C99.
Since it's more standard, replace __FUNCTION__ with __func__ throughout
OvmfPkg.
Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
This patch is a preparation for the patches that follow. The
subsequent patches will introduce and integrate new alignment-related
macros, which collide with existing definitions in OvmfPkg.
Temporarily rename them to avoid build failure, till they can be
substituted with the new, shared definitions.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
The hard-coded attributes for the re-added memory space should instead
forward the replaced descriptor's capabilities.
Tested on Linux with efi=debug. Prior to this change, an 8GiB VM running
a kernel without unaccepted memory support shows this entry
efi: mem94: [Conventional| | |CC| | | | | | | | | | | ]
range=[0x0000000100000000-0x000000023fffffff] (5120MB)
This does not have the cache capabilities one would expect for system
memory, UC|WC|WT|WB.
After this change, the same entry becomes
efi: mem94: [Conventional| | |CC| | | | | | | |WB|WT|WC|UC]
range=[0x0000000100000000-0x000000023fffffff] (5120MB)
This has all the expected attributes.
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
[ardb: drop the EFI_MEMORY_CPU_CRYPTO flag - it isn't used anywhere else
in EDK2 or Linux so it doesn't actually do anything, and it is
unclear whether it is intended for use by the guest in the first
place]
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
The PCIe MMCONFIG range should be treated as an MMIO range. However,
there is a comment in the code explaining why AddIoMemoryBaseSizeHob()
is not called. The AmdSevDxe walks the GCD map looking for MemoryMappedIo
or NonExistent type memory and will clear the encryption bit for these
ranges.
Since the MMCONFIG range does not have one of these types, the encryption
bit is not cleared for this range. Add support to detect the presence of
the MMCONFIG range and clear the encryption bit. This will be needed for
follow-on support that will validate that MMIO is not being performed to
an encrypted address range under SEV-ES.
Even though the encryption bit was set for this range, this still worked
under both SEV and SEV-ES because the address range is marked by the
hypervisor as MMIO in the nested page tables:
- For SEV, access to this address range triggers a nested page fault (NPF)
and the hardware supplies the guest physical address (GPA) in the VMCB's
EXITINFO2 field as part of the exit information. However, the encryption
bit is not set in the GPA, so the hypervisor can process the request
without any issues.
- For SEV-ES, access to this address range triggers a #VC. Since OVMF runs
identity mapped (VA == PA), the virtual address is used to avoid the
lookup of the physical address. The virtual address does not have the
encryption bit set, so the hypervisor can process the request without
any issues.
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>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <711ae2dcb6cb29e4c60862c18330cff627269b81.1610045305.git.thomas.lendacky@amd.com>
Based on the following patch from Brijesh Singh <brijesh.singh@amd.com>:
[PATCH v2 1/2] OvmfPkg/AmdSevDxe: Clear the C-bit from SMM Saved State
http://mid.mail-archive.com/20180228161415.28723-2-brijesh.singh@amd.comhttps://lists.01.org/pipermail/edk2-devel/2018-February/022016.html
Original commit message from Brijesh:
> When OVMF is built with SMM, SMMSaved State area (SMM_DEFAULT_SMBASE +
> SMRAM_SAVE_STATE_MAP_OFFSET) contains data which need to be accessed by
> both guest and hypervisor. Since the data need to be accessed by both
> hence we must map the SMMSaved State area as unencrypted (i.e C-bit
> cleared).
>
> This patch clears the SavedStateArea address before SMBASE relocation.
> Currently, we do not clear the SavedStateArea address after SMBASE is
> relocated due to the following reasons:
>
> 1) Guest BIOS never access the relocated SavedStateArea.
>
> 2) The C-bit works on page-aligned address, but the SavedStateArea
> address is not a page-aligned. Theoretically, we could roundup the
> address and clear the C-bit of aligned address but looking carefully we
> found that some portion of the page contains code -- which will causes a
> bigger issue for the SEV guest. When SEV is enabled, all the code must
> be encrypted otherwise hardware will cause trap.
Changes by Laszlo:
- separate AmdSevDxe bits from SmmCpuFeaturesLib bits;
- spell out PcdLib dependency with #include and in LibraryClasses;
- replace (SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET) calculation
with call to new MemEncryptSevLocateInitialSmramSaveStateMapPages()
function;
- consequently, pass page-aligned BaseAddress to
MemEncryptSevClearPageEncMask();
- zero the pages before clearing the C-bit;
- pass Flush=TRUE to MemEncryptSevClearPageEncMask();
- harden the treatment of MemEncryptSevClearPageEncMask() failure.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
When SEV is enabled, the MMIO memory range must be mapped as unencrypted
(i.e C-bit cleared).
We need to clear the C-bit for MMIO GCD entries in order to cover the
ranges that were added during the PEI phase (through memory resource
descriptor HOBs). Additionally, the NonExistent ranges are processed
in order to cover, in advance, MMIO ranges added later in the DXE phase
by various device drivers, via the appropriate DXE memory space services.
The approach is not transparent for later addition of system memory ranges
to the GCD memory space map. (Such ranges should be encrypted.) OVMF does
not do such a thing at the moment, so this approach should be OK.
The driver is being added to the APRIORI DXE file so that, we clear the
C-bit from MMIO regions before any driver accesses it.
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Leo Duran <leo.duran@amd.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Suggested-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
