There could be scenarios where the HOB producer does not create any HOBs.
In such cases, the buffer intended to be freed will have zero pages.

This update addresses the issue that could cause assertions during
runtime by ensuring that buffers with zero pages are not freed.

Signed-off-by: Kun Qin <[email protected]>

Current MM IPL in PEI phase does not open the MMRAM regions through MM
access PPI. This is causing some platforms like OVMF reading all `0xFF`s
when trying to relocate the Standalone MM core.

This change opens all the MMRAM regions provided by MM access PPI and
closes + locks the regions after initial MM foundation setup, when MM
Access PPI is available.

Platforms that require MM access PPI can inject depex through libraries.

Signed-off-by: Kun Qin <[email protected]>

This change extends the supported types to Standalone MM and Standalone
MM Core module types to support potential MM usage.

Signed-off-by: Kun Qin <[email protected]>

This change extends the library to support MM_CORE_STANDALONE and
MM_STANDALONE for usage in MM standalone environment.

Signed-off-by: Kun Qin <[email protected]>

This change extends the library to support MM_CORE_STANDALONE and
MM_STANDALONE for usage in MM standalone environment.

Signed-off-by: Kun Qin <[email protected]>

This change extends the library to support MM_CORE_STANDALONE and
MM_STANDALONE for usage in MM standalone environment.

Signed-off-by: Kun Qin <[email protected]>

This update refactors the existing SmmCpuFeaturesLib to eliminate direct
calls to SMM-specific functions.

In particular, the constructor has been relocated to traditional MM-
specific C files, utilizing a common entry point.

Furthermore, several implementation-specific functions have been
modularized into its respective C files.

These changes lay the groundwork for supporting a Standalone MM-based
solution in the future.

Signed-off-by: Kun Qin <[email protected]>

…Ovmf

This change adds the implementation of SmmCpuFeaturesLib for Ovmf to
operate with Standalone MM supported platforms.

Signed-off-by: Kun Qin <[email protected]>

This change adds a PEIM that produces gEfiPeiMmControlPpiGuid to be used
in PEI phase, i.e. boot strap MM foundation.

This flow is largely in assemblence of MM control DXE driver and used the
`SmiFeatures.*` files from the DXE drivers as the common resources.

Signed-off-by: Kun Qin <[email protected]>

This change adds a build time PCD to prevent the SmmControl2Dxe driver
from re-initialization the MM related registers.

This register is to be used when MmControlPei is already executed in PEI
phase and completed setting up the MM control registers.

Signed-off-by: Kun Qin <[email protected]>

This update refactors QemuFlashFvbServicesRuntimeDxe to abstract out
direct calls to SMM and DXE specific functions.

Specifically, dynamic PCD usage and gBS references have been moved to SMM
specific files.

The constructor functionality has been relocated to a common
implementation and is invoked from their respective entry points.

These changes lay the groundwork for supporting a Standalone MM-based
solution in the future.

Signed-off-by: Kun Qin <[email protected]>

This update introduces the implementation of QemuFlashFvbServices to
support operation with Standalone MM backed platforms.

Signed-off-by: Kun Qin <[email protected]>

This change introduces a Null instance of MemEncryptSevLib to enable
platforms that do not have confidential compute support.

Signed-off-by: Kun Qin <[email protected]>

… Stmm

This change introduces a platform specific HOB producor library to meet
the expectation of Standalone MM core.

Signed-off-by: Kun Qin <[email protected]>

This change adds a build flag in the platform DSC file to support
standalone MM build on OVMF platform.

The new standalone MM platform will not support S3 boot and thus no SMM
lock box related components are included.

Signed-off-by: Kun Qin <[email protected]>

This change expands the CI pipeline build to a new platform type with
Standalone MM support to ensure the incoming change works with Standalone
MM environment on x64 platforms.

Signed-off-by: Kun Qin <[email protected]>

This update introduces a new section in the README file, detailing the
design considerations of the recently onboarded Standalone MM platform in
OVMF.

The section is intended for future reference and should be revised
accordingly if updates to the Standalone MM framework render these
limitations obsolete.

Signed-off-by: Kun Qin <[email protected]>