Based on gSmmBaseHobGuid:
If gSmmBaseHobGuid found, means SmBase info has been relocated
and recorded in the SmBase array.
So, this patch check smbase relocation is done or not in
SmmCpuFeaturesInitializeProcessor().
With SmmRelocationLib, gSmmBaseHobGuid will be always created.
Here this patch just makes the function/logic correct. The SMM
Relocation logic can be totally cleaned from the
SmmCpuFeaturesLib. But it will happen in the future patch set,
this patch does not target to the cleanup work.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
This patch refines the SmmAccess implementation:
1. SmramMap will be retrieved from the
gEfiSmmSmramMemoryGuid instead of original from
the TSEG Memory Base register.
2. Remove the gEfiAcpiVariableGuid creation, thus
the DESCRIPTOR_INDEX definition can be also cleaned.
3. The gEfiAcpiVariableGuid HOB is moved to the
OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
In the PiSmmCpuDxeSmm driver, SMRAM allocation for SMI
handlers and processor Save State areas was traditionally
performed using the Smst->AllocatePages() function during
the DXE phase. The introduction of SmmRelocationLib
changes this process by moving the allocation to the PEI
phase, where Smst->AllocatePages() is not accessible.
Instead, the allocation is now handled by partitioning
the SMRAM based on the information provided by a GUID HOB
(identified by gEfiSmmSMramMemoryGuid).
This patch is to ensure that OVMF produces the
gEfiSmmSMramMemoryGuid HOB, allowing SmmRelocationLib to
reserve the necessary memory for SMBASE relocation.
More info for the change:
1. The EFI_SMM_SMRAM_MEMORY_GUID HOB, as defined in the PI
specification, vol.3, section 5, which is used to describe
the SMRAM memory regions supported by the platform. This HOB
should be produced during the memory detection phase to
align with the PI spec.
2. In addition to the memory reserved for ACPI S3 resume,
an increasing number of features require reserving SMRAM
for specific purposes, such as SmmRelocation. Other
advanced features in Intel platforms also necessitate
this. The implementation of these features varies and is
entirely dependent on the platform. This is why an
increasing number of platforms are adopting the
EFI_SMM_SMRAM_MEMORY_GUID HOB for SMRAM description.
3. It is crucial that the SMRAM information remains
consistent when retrieved from the platform, whether
through the SMM ACCESS PPI/Protocol or the
EFI_SMM_SMRAM_MEMORY_GUID HOB. Inconsistencies can lead
to unexpected issues, most commonly memory region conflicts.
4. The SMM ACCESS PPI/Protocol can be naturally
implemented for general use. The common approach is to
utilize the EFI_SMM_SMRAM_MEMORY_GUID HOB. For reference,
see the existing implementation in the EDK2 repository at
edk2/UefiPayloadPkg/SmmAccessDxe/SmmAccessDxe.inf and
edk2-platforms/Silicon/Intel/IntelSiliconPkg/Feature/
SmmAccess/Library/PeiSmmAccessLib/PeiSmmAccessLib.inf.
Next patch will refine the OVMF SMM Access to consume
the EFI_SMM_SMRAM_MEMORY_GUID HOB.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
There are below 2 differences between AMD & OVMF according
existing implementation:
1.The mode of the CPU check is different between the AMD & OVMF.
OVMF:
CpuSaveState->x86.SMMRevId & 0Xffff
AMD:
LMAValue = (UINT32)AsmReadMsr64 (EFER_ADDRESS) & LMA
2.Existing SmBase configuration is different between the
AMD & OVMF.
OVMF:
if ((CpuSaveState->x86.SMMRevId & 0xFFFF) == 0) {
CpuSaveState->x86.SMBASE = mSmBaseForAllCpus[CpuIndex];
} else {
CpuSaveState->x64.SMBASE = mSmBaseForAllCpus[CpuIndex];
}
AMD:
AmdCpuState->x64.SMBASE = mSmBaseForAllCpus[CpuIndex];
This patch provides the SmmRelocationLib library instance
for OVMF to handle the logic difference, and it won't change
the existing implementation code logic.
Cc: Ray Ni <ray.ni@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
The current #VC handler guards against MMIO to addresses that are mapped
with the encryption bit set, but has an special exception for MMIO
accesses to the APIC base address so allow for early access during SEC.
Now that the SEC page table has the encryption bit cleared for the APIC
base address range, there is no longer any need for this special
handling. Go ahead and remove it.
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
The VirtHstiDxe does not work in confidential guests. There also isn't
anything we can reasonably test, neither flash storage nor SMM mode will
be used in that case. So just skip driver load when running in a
confidential guest.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Fixes: 506740982b ("OvmfPkg/VirtHstiDxe: add code flash check")
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Ensure that when a #VC exception happens, the instruction at the
instruction pointer matches the instruction that is expected given the
error code. This is to mitigate the ahoi WeSee attack [1] that could
allow hypervisors to breach integrity and confidentiality of the
firmware by maliciously injecting interrupts. This change is a
translated version of a linux patch e3ef461af35a ("x86/sev: Harden #VC
instruction emulation somewhat")
[1] https://ahoi-attacks.github.io/wesee/
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Adam Dunlap <acdunlap@google.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
The driver supports qemu machine types 'pc' and 'q35'.
This patch adds some helper functions to manage the bitmasks.
The implemented features depend on both OVMF build configuration
and qemu VM configuration.
For q35 a single security feature is supported and checked: In
SMM-enabled builds the driver will verify smram is properly locked.
That test should never fail.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Konstantin Kostiuk <kkostiuk@redhat.com>
Initial-patch-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
The SVSM specification documents an alternative method of discovery for
the SVSM using a reserved CPUID bit and a reserved MSR.
For the CPUID support, the #VC handler of an SEV-SNP guest should modify
the returned value in the EAX register for the 0x8000001f CPUID function
by setting bit 28 when an SVSM is present.
For the MSR support, new reserved MSR 0xc001f000 has been defined. A #VC
should be generated when accessing this MSR. The #VC handler is expected
to ignore writes to this MSR and return the physical calling area address
(CAA) on reads of this MSR.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
The RMPADJUST instruction is used to alter the VMSA attribute of a page,
but the VMSA attribute can only be changed when running at VMPL0. When
an SVSM is present, use the SVSM_CORE_CREATE_VCPU and SVSM_CORE_DELTE_VCPU
calls to add or remove the VMSA attribute on a page instead of issuing
the RMPADJUST instruction directly.
Implement the AmdSvsmSnpVmsaRmpAdjust() API to perform the proper operation
to update the VMSA attribute.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
Add initial support for the new AmdSvsmLib library to OvmfPkg. The initial
implementation fully implements the library interfaces.
The SVSM presence check, AmdSvsmIsSvsmPresent(), determines the presence
of an SVSM by checking if an SVSM has been advertised in the SEV-SNP
Secrets Page.
The VMPL API, AmdSvsmSnpGetVmpl(), returns the VMPL level at which OVMF is
currently running.
The CAA API, AmdSvsmSnpGetCaa(), returns the Calling Area Address when an
SVSM is present, 0 otherwise.
The PVALIDATE API, AmdSvsmSnpPvalidate(), copies the PVALIDATE logic from
the BaseMemEncryptSevLib library for the initial implementation. The
BaseMemEncryptSevLib library will be changed to use this new API so that
the decision as to whether the SVSM is needed to perform the operation
can be isolated to this library.
The VMSA API, AmdSvsmSnpVmsaRmpAdjust(), copies the RMPUPDATE logic from
the MpInitLib library for the initial implementation. The MpInitLib
library will be changed to use this new API so that the decision as to
whether the SVSM is needed to perform the operation can be isolated to
this library.
Cc: Anatol Belski <anbelski@linux.microsoft.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jianyong Wu <jianyong.wu@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
When building the Page State Change entries for a range of memory, it can
happen that multiple calls to BuildPageStateBuffer() need to be made. If
the size of the input work area passed to BuildPageStateBuffer() exceeds
the number of entries that can be passed to the hypervisor using the GHCB
shared buffer, the Page State Change VMGEXIT support will issue multiple
VMGEXITs to process all entries in the buffer.
However, it could be that the final VMGEXIT for each round of Page State
Changes is only for a small number of entries and subsequent VMGEXITs may
still be issued to handle the full range of memory requested. To maximize
the number of entries processed during the Page State Change VMGEXIT,
limit BuildPageStateBuffer() to not build entries that exceed the maximum
number of entries that can be handled in a single Page State Change
VMGEXIT.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
In preparation for running under an SVSM at VMPL1 or higher (higher
numerically, lower privilege), re-organize the way a page state change
is performed in order to free up the GHCB for use by the SVSM support.
Currently, the page state change logic directly uses the GHCB shared
buffer to build the page state change structures. However, this will be
in conflict with the use of the GHCB should an SVSM call be required.
Instead, use a separate buffer (an area in the workarea during SEC and
an allocated page during PEI/DXE) to hold the page state change request
and only update the GHCB shared buffer as needed.
Since the information is copied to, and operated on, in the GHCB shared
buffer this has the added benefit of not requiring to save the start and
end entries for use when validating the memory during the page state
change sequence.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
