[edk2-devel] [PATCH V1 0/2] OvmfPkg/BaseMemEncryptTdxLib: Handle retry result of MapGPA

["sunceping" <cepingx.sun@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4572

According to section 3.2 of the [GHCI] documentation, if the result is
"TDG.VP.VMCALL_RETRY" for TDG.VP.VMCALL, TD must retry the mapping for
the pages in the region starting at the GPA specified in r11.

Currently, TDVF does not properly handle the retry results of MapGPA.
For this, TDVF should add the API to return the value in R11 and must 
retry the mapping for the pages by the value.

How to verify the retry for MapGPA in TDVF:
Note: Since the range size of MapGPA in QEMU is limited to 64MB and 
TDVF always maps 1.5GB( 2GB~3.5GB) MMIO to shared-memory for TD guest, 
the retry action is triggered always.
Pre-Config:
QEMU:
https://github.com/intel/qemu-tdx/tree/tdx-qemu-upstream | tag: tdx-qemu-upstream-2023.10.20-v8.1.0
KERNEL:
https://github.com/intel/tdx/tree/kvm-upstream-2023.10.16-v6.6-rc2

Step:
Boot with TD guest and check the log with TdVmcall(MAPGPA). Would See the line as below:
TdxDxe:SetMemorySharedOrPrivate: Cr3Base=0x0 Physical=0x80000000 Length=0x60000000 Mode=Shared
SetOrClearSharedBit: TdVmcall(MAPGPA) Retry PhysicalAddress is 8000080000000, MapGpaRetryaddr is 8000084000000

Reference:
[GHCI]: TDX Guest-Host-Communication Interface v1.0
https://cdrdv2.intel.com/v1/dl/getContent/726790

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>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Ceping Sun <cepingx.sun@intel.com>

Ceping Sun (2):
  OvmfPkg/BaseMemEncryptTdxLib: Add TdVmCallMapGPA
  OvmfPkg/BaseMemEncryptTdxLib: Handle retry result of MapGPA

 .../BaseMemEncryptTdxLib.inf                  |   1 +
 .../BaseMemEncryptTdxLib/MemoryEncryption.c   |  55 +++++++-
 .../X64/TdVmCallMapGPA.nasm                   | 130 ++++++++++++++++++
 3 files changed, 185 insertions(+), 1 deletion(-)
 create mode 100644 OvmfPkg/Library/BaseMemEncryptTdxLib/X64/TdVmCallMapGPA.nasm

-- 
2.34.1



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