RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
There are below changes in PlatformInitLib for Tdx guest:
1. Publish ram regions
In Tdx guest, the system memory is passed in TdHob by host VMM. So
the major task of PlatformTdxPublishRamRegions is to walk thru the
TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
to the hobs in DXE phase.
2. Build MemoryAllocationHob for Tdx Mailbox and Ovmf work area.
3. Update of PlatformAddressWidthInitialization. The physical
address width that Tdx guest supports is either 48 or 52.
4. Update of PlatformMemMapInitialization.
0xA0000 - 0xFFFFF is VGA bios region. Platform initialization marks the
region as MMIO region. Dxe code maps MMIO region as IO region.
As TDX guest, MMIO region is maps as shared. However VGA BIOS doesn't need
to be shared. Guest TDX Linux maps VGA BIOS as private and accesses for
BIOS and stuck on repeating EPT violation. VGA BIOS (more generally ROM
region) should be private. Skip marking VGA BIOA region [0xa000, 0xfffff]
as MMIO in HOB.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
There are below major changes in this commit.
1. SecEntry.nasm
In TDX BSP and APs goes to the same entry point in SecEntry.nasm.
BSP initialize the temporary stack and then jumps to SecMain, just as
legacy Ovmf does.
APs spin in a modified mailbox loop using initial mailbox structure.
Its structure defition is in OvmfPkg/Include/IndustryStandard/IntelTdx.h.
APs wait for command to see if the command is for me. If so execute the
command.
2. Sec/SecMain.c
When host VMM create the Td guest, the system memory informations are
stored in TdHob, which is a memory region described in Tdx metadata.
The system memory region in TdHob should be accepted before it can be
accessed. So the major task of this patch is to process the TdHobList
to accept the memory. After that TDVF follow the standard OVMF flow
and jump to PEI phase.
PcdUse1GPageTable is set to FALSE by default in OvmfPkgX64.dsc. It gives
no chance for Intel TDX to support 1G page table. To support 1G page
table this PCD is set to TRUE in OvmfPkgX64.dsc.
TDX_GUEST_SUPPORTED is defined in OvmfPkgX64.dsc. This macro wraps the
Tdx specific code.
TDX only works on X64, so the code is only valid in X64 arch.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
When host VMM create the Td guest, the system memory informations are
stored in TdHob, which is a memory region described in Tdx metadata.
The system memory region in TdHob should be accepted before it can be
accessed. So the newly added function (ProcessTdxHobList) is to process
the TdHobList to accept the memory. Because TdHobList is provided by
host VMM which is not trusted, so its content should be checked before
it is consumed by TDVF.
Because ProcessTdxHobList is to be called in SEC phase, so
PlatformInitLib.inf is updated to support SEC.
Note: In this patch it is BSP which accepts the pages. So there maybe
boot performance issue. There are some mitigations to this issue, such
as lazy accept, 2M accept page size, etc. We will re-visit here in the
future.
EFI_RESOURCE_MEMORY_UNACCEPTED is a new ResourceType in
EFI_HOB_RESOURCE_DESCRIPTOR. It is defined for the unaccepted memory
passed from Host VMM. This is proposed in microsoft/mu_basecore#66
files#diff-b20a11152d1ce9249c691be5690b4baf52069efadf2e2546cdd2eb663d80c9
e4R237 according to UEFI-Code-First. The proposal was approved in 2021
in UEFI Mantis, and will be added to the new PI.next specification.
Per the MdePkg reviewer's comments, before this new ResourceType is
added in the PI spec, it should not be in MdePkg. So it is now
defined as an internal implementation and will be moved to
MdePkg/Include/Pi/PiHob.h after it is added in PI spec.
See https://edk2.groups.io/g/devel/message/87641
PcdTdxAcceptPageSize is added for page accepting. Currently TDX supports
4K and 2M accept page size. The default value is 2M.
Tdx guest is only supported in X64. So for IA32 ProcessTdxHobList
just returns EFI_UNSUPPORTED.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3863
There are 3 variants of PlatformPei in OvmfPkg:
- OvmfPkg/PlatformPei
- OvmfPkg/XenPlatformPei
- OvmfPkg/Bhyve/PlatformPei/PlatformPei.inf
These PlatformPeis can share many common codes, such as
Cmos / Hob / Memory / Platform related functions. This commit
(and its following several patches) are to create a PlatformInitLib
which wraps the common code called in above PlatformPeis.
In this initial version of PlatformInitLib, below Cmos related functions
are introduced:
- PlatformCmosRead8
- PlatformCmosWrite8
- PlatformDebugDumpCmos
They correspond to the functions in OvmfPkg/PlatformPei:
- CmosRead8
- CmosWrite8
- DebugDumpCmos
Considering this PlatformInitLib will be used in SEC phase, global
variables and dynamic PCDs are avoided. We use PlatformInfoHob
to exchange information between functions.
EFI_HOB_PLATFORM_INFO is the data struct which contains the platform
information, such as HostBridgeDevId, BootMode, S3Supported,
SmmSmramRequire, etc.
After PlatformInitLib is created, OvmfPkg/PlatformPei is refactored
with this library.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Instead of hardcoding the address of the RSDP in the firmware, let's
rely on the PVH structure hvm_start_info to retrieve this information.
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
Many of the integrity guarantees of SEV-SNP are enforced through the
Reverse Map Table (RMP). Each RMP entry contains the GPA at which a
particular page of DRAM should be mapped. The guest can request the
hypervisor to add pages in the RMP table via the Page State Change VMGEXIT
defined in the GHCB specification section 2.5.1 and 4.1.6. Inside each RMP
entry is a Validated flag; this flag is automatically cleared to 0 by the
CPU hardware when a new RMP entry is created for a guest. Each VM page
can be either validated or invalidated, as indicated by the Validated
flag in the RMP entry. Memory access to a private page that is not
validated generates a #VC. A VM can use the PVALIDATE instruction to
validate the private page before using it.
During the guest creation, the boot ROM memory is pre-validated by the
AMD-SEV firmware. The MemEncryptSevSnpValidateSystemRam() can be called
during the SEC and PEI phase to validate the detected system RAM.
One of the fields in the Page State Change NAE is the RMP page size. The
page size input parameter indicates that either a 4KB or 2MB page should
be used while adding the RMP entry. During the validation, when possible,
the MemEncryptSevSnpValidateSystemRam() will use the 2MB entry. A
hypervisor backing the memory may choose to use the different page size
in the RMP entry. In those cases, the PVALIDATE instruction should return
SIZEMISMATCH. If a SIZEMISMATCH is detected, then validate all 512-pages
constituting a 2MB region.
Upon completion, the PVALIDATE instruction sets the rFLAGS.CF to 0 if
instruction changed the RMP entry and to 1 if the instruction did not
change the RMP entry. The rFlags.CF will be 1 only when a memory region
is already validated. We should not double validate a memory
as it could lead to a security compromise. If double validation is
detected, terminate the boot.
Cc: Michael Roth <michael.roth@amd.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
SEC checks in IsSevGuest if the PCD defined WorkAreaHeader size
matches the size of the WorkAreaHeader struct definition. Set a
default value for the PCD to avoid unnecessary DSC/FDF file
changes in all OVMF DSC/FDF files.
Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Add defines for the config space offsets for virtio 1.0 mmio transport.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Add logic in EjectCpu() to do the actual the CPU ejection.
On the BSP, ejection happens by first selecting the CPU via
its QemuSelector and then sending the QEMU "eject" command.
QEMU in-turn signals the remote VCPU thread which context-switches
the CPU out of the SMI handler.
Meanwhile the CPU being ejected, waits around in its holding
area until it is context-switched out. Note that it is possible
that a slow CPU gets ejected before it reaches the wait loop.
However, this would never happen before it has executed the
"AllCpusInSync" loop in SmiRendezvous().
It can mean that an ejected CPU does not execute code after
that point but given that the CPU state will be destroyed by
QEMU, the missed cleanup is no great loss.
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Aaron Young <aaron.young@oracle.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Message-Id: <20210312062656.2477515-10-ankur.a.arora@oracle.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
[lersek@redhat.com: unneeded inner QemuSelector declaration in EjectCpu()
triggers VS warning #4456 (local variable shadowed); remove it]
Extend parameter list of PciHostBridgeUtilityGetRootBridges() with BusMin/
BusMax, so that the utility function could be compatible with ArmVirtPkg
who uses mutable bus range [BusMin, BusMax] insteand of [0, PCI_MAX_BUS].
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3059
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
Message-Id: <20210119011302.10908-10-cenjiahui@huawei.com>
[lersek@redhat.com: fix logging of UINTN values BusMin, BusMax]
[lersek@redhat.com: keep zeroing of (*Count) centralized]
[lersek@redhat.com: fix typos in ExtraRootBridges comment]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
In order to be able to issue messages or make interface calls that cause
another #VC (e.g. GetLocalApicBaseAddress () issues RDMSR), add support
for nested #VCs.
In order to support nested #VCs, GHCB backup pages are required. If a #VC
is received while currently processing a #VC, a backup of the current GHCB
content is made. This allows the #VC handler to continue processing the
new #VC. Upon completion of the new #VC, the GHCB is restored from the
backup page. The #VC recursion level is tracked in the per-vCPU variable
area.
Support is added to handle up to one nested #VC (or two #VCs total). If
a second nested #VC is encountered, an ASSERT will be issued and the vCPU
will enter CpuDeadLoop ().
For SEC, the GHCB backup pages are reserved in the OvmfPkgX64.fdf memory
layout, with two new fixed PCDs to provide the address and size of the
backup area.
For PEI/DXE, the GHCB backup pages are allocated as boot services pages
using the memory allocation library.
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>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <ac2e8203fc41a351b43f60d68bdad6b57c4fb106.1610045305.git.thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
To help mitigate against ROP attacks, add some checks to validate the
encryption bit position that is reported by the hypervisor.
The first check is to ensure that the hypervisor reports a bit position
above bit 31. After extracting the encryption bit position from the CPUID
information, the code checks that the value is above 31. If the value is
not above 31, then the bit position is not valid, so the code enters a
HLT loop.
The second check is specific to SEV-ES guests and is a two step process.
The first step will obtain random data using RDRAND and store that data to
memory before paging is enabled. When paging is not enabled, all writes to
memory are encrypted. The random data is maintained in registers, which
are protected. The second step is that, after enabling paging, the random
data in memory is compared to the register contents. If they don't match,
then the reported bit position is not valid, so the code enters a HLT
loop.
The third check is after switching to 64-bit long mode. Use the fact that
instruction fetches are automatically decrypted, while a memory fetch is
decrypted only if the encryption bit is set in the page table. By
comparing the bytes of an instruction fetch against a memory read of that
same instruction, the encryption bit position can be validated. If the
compare is not equal, then SEV/SEV-ES is active but the reported bit
position is not valid, so the code enters a HLT loop.
To keep the changes local to the OvmfPkg, an OvmfPkg version of the
Flat32ToFlat64.asm file has been created based on the UefiCpuPkg file
UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm.
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: <cb9c5ab23ab02096cd964ed64115046cc706ce67.1610045305.git.thomas.lendacky@amd.com>
