Re: [PATCH 0/3] Add safe unaccepted memory behavior

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

On 9/23/22 14:34, Dionna Amalie Glaze wrote:
> Ah yes, I did forget to include that patch. Will add to v2. I was just 
> setting the ResourceType to unaccepted and skipping the Prevalidate call 
> in PlatformPei if the start address is greater or equal to SIZE_4GB. That 
> seemed more self-contained than messing with PlatformInitLib. Would you 
> prefer that I add SevSnp logic to PlatformInitLib?

No, if it works and is easier / more concise, then please keep it the way 
you have it.

Thanks,
Tom

> 
> On Fri, Sep 23, 2022 at 10:19 AM Tom Lendacky <thomas.lendacky@amd.com 
> <mailto:thomas.lendacky@amd.com>> wrote:
> 
>     On 9/22/22 15:50, Dionna Glaze wrote:
>      > These three patches build on the lazy-accept patch series
>      >
>      > "Introduce Lazy-accept for Tdx guest"
>      >
>      > by adding SEV-SNP support for the MemoryAccept protocol, and
>      > importantly making eager memory acceptance the default behavior.
>      >
>      > For unaccepted memory to be enabled, we must know that the booted image
>      > supports the unaccepted memory type. We add a trivial protocol that
>     sets
>      > a dynamic Pcd to true when called in order for the booted image to
>      > signal its support for unaccepted memory. This does not need to be an
>      > OsIndications bit because it does not need to be persisted.
>      >
>      > We use the Pcd to disable a new ExitBootServices notification that
>      > accepts all unaccepted memory, removes the unaccepted memory entries in
>      > the memory space map, and then add the same memory ranges back as
>      > conventional memory.
>      >
>      > All images that support unaccepted memory must now locate and call this
>      > new ENABLE_UNACCEPTED_MEMORY_PROTOCOL.
> 
>     This seems to be missing the creation of unaccepted memory under SEV-SNP.
>     Is that going to be part of a separate patch (to update
>     PlatformAddMemoryBaseSizeHob () and mark anything above 4GB as
>     unaccepted)?
> 
>     Thanks,
>     Tom
> 
>      >
>      > Cc: Ard Biescheuvel <ardb@kernel.org <mailto:ardb@kernel.org>>
>      > Cc: "Min M. Xu" <min.m.xu@intel.org <mailto:min.m.xu@intel.org>>
>      > Cc: Gerd Hoffmann <kraxel@redhat.com <mailto:kraxel@redhat.com>>
>      > Cc: James Bottomley <jejb@linux.ibm.com <mailto:jejb@linux.ibm.com>>
>      > Cc: Tom Lendacky <Thomas.Lendacky@amd.com
>     <mailto:Thomas.Lendacky@amd.com>>
>      > Cc: Jiewen Yao <jiewen.yao@intel.com <mailto:jiewen.yao@intel.com>>
>      > Cc: Erdem Aktas <erdemaktas@google.com <mailto:erdemaktas@google.com>>
>      >
>      > Signed-off-by: Dionna Glaze <dionnaglaze@google.com
>     <mailto:dionnaglaze@google.com>>
>      >
>      > Dionna Glaze (3):
>      >    OvmfPkg: Realize EfiMemoryAcceptProtocol in AmdSevDxe
>      >    DxeMain accepts all memory at EBS if needed
>      >    MdeModulePkg: add EnableUnacceptedMemoryProtocol
>      >
>      >   MdeModulePkg/Core/Dxe/DxeMain.h               |  32 +++++
>      >   MdeModulePkg/Core/Dxe/DxeMain.inf             |   3 +
>      >   MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c       |  19 ++-
>      >   MdeModulePkg/Core/Dxe/Mem/Page.c              | 122
>     ++++++++++++++++++
>      >   MdeModulePkg/MdeModulePkg.dec                 |   9 ++
>      >   MdeModulePkg/MdeModulePkg.uni                 |   6 +
>      >   OvmfPkg/AmdSev/AmdSevX64.dsc                  |   1 +
>      >   OvmfPkg/AmdSevDxe/AmdSevDxe.c                 |  27 ++++
>      >   OvmfPkg/AmdSevDxe/AmdSevDxe.inf               |   3 +
>      >   OvmfPkg/Bhyve/BhyveX64.dsc                    |   2 +
>      >   OvmfPkg/CloudHv/CloudHvX64.dsc                |   2 +
>      >   OvmfPkg/Include/Library/MemEncryptSevLib.h    |  14 ++
>      >   OvmfPkg/IntelTdx/IntelTdxX64.dsc              |   2 +
>      >   .../Ia32/MemEncryptSevLib.c                   |  17 +++
>      >   .../X64/DxeSnpSystemRamValidate.c             |  35 +++++
>      >   .../X64/PeiSnpSystemRamValidate.c             |  17 +++
>      >   .../X64/SecSnpSystemRamValidate.c             |  18 +++
>      >   OvmfPkg/OvmfPkgIa32X64.dsc                    |   2 +
>      >   OvmfPkg/OvmfPkgX64.dsc                        |   2 +
>      >   OvmfPkg/OvmfXen.dsc                           |   2 +
>      >   20 files changed, 334 insertions(+), 1 deletion(-)
>      >
> 
> 
> 
> -- 
> -Dionna Glaze, PhD (she/her)