[edk2-devel] [PATCH V3 03/10] OvmfPkg: Set TdMailbox initial value and macros

[Min Xu]

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

In Tdx the memory region defined by PcdOvmfSecGhcbBackupBase is used as
TdMailbox. It is initialized to all-0 by host VMM. Piece of the memory
region TdMailbox[0x10, 0x20] is used as TDX_WORK_AREA. In this area a
flag 'TDXG' is set so that the following code can check if it is
Tdx guest.

So in Non-Tdx guest, this memory region should be initialized to all-0 in
the definition of MEMFD.

Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Brijesh Singh <brijesh.singh at amd.com>
Cc: Erdem Aktas <erdemaktas at google.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
 OvmfPkg/OvmfPkgX64.fdf                |  6 ++++++
 OvmfPkg/ResetVector/ResetVector.nasmb | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
index 5fa8c0895808..c587d1412803 100644
--- a/OvmfPkg/OvmfPkgX64.fdf
+++ b/OvmfPkg/OvmfPkgX64.fdf
@@ -87,6 +87,12 @@ gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase|gUefiCpuPkgTokenSpaceGuid.PcdSevE
 
 0x00C000|0x001000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize
+DATA = {
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+}
 
 0x010000|0x010000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
diff --git a/OvmfPkg/ResetVector/ResetVector.nasmb b/OvmfPkg/ResetVector/ResetVector.nasmb
index b653fe87abd6..42b4a3791d29 100644
--- a/OvmfPkg/ResetVector/ResetVector.nasmb
+++ b/OvmfPkg/ResetVector/ResetVector.nasmb
@@ -106,6 +106,18 @@
   %define TDX_EXTRA_PAGE_TABLE_BASE FixedPcdGet32 (PcdOvmfSecGhcbPageTableBase)
   %define TDX_EXTRA_PAGE_TABLE_SIZE FixedPcdGet32 (PcdOvmfSecGhcbPageTableSize)
 
+  ;
+  ; TdMailboxBase [0x10, 0x800] is reserved for OS.
+  ; Td guest initialize piece of this area (TdMailboxBase [0x10,0x20]) to
+  ; record the Td guest info so that this information can be used in the
+  ; following ResetVector flow.
+  ;
+  %define TD_MAILBOX_WORKAREA_OFFSET    0x10
+  %define TDX_WORK_AREA                 (TDX_MAILBOX_MEMORY_BASE + TD_MAILBOX_WORKAREA_OFFSET)
+  %define TDX_WORK_AREA_PAGELEVEL5      (TDX_WORK_AREA + 4)
+  %define TDX_WORK_AREA_PGTBL_READY     (TDX_WORK_AREA + 5)
+  %define TDX_WORK_AREA_INITVP          (TDX_WORK_AREA + 8)
+  %define TDX_WORK_AREA_INFO            (TDX_WORK_AREA + 8 + 4)
   %define PT_ADDR(Offset) (FixedPcdGet32 (PcdOvmfSecPageTablesBase) + (Offset))
 
   %define GHCB_PT_ADDR (FixedPcdGet32 (PcdOvmfSecGhcbPageTableBase))
-- 
2.29.2.windows.2



-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#78193): https://edk2.groups.io/g/devel/message/78193
Mute This Topic: https://groups.io/mt/84476061/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-