RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
Intel's Trust Domain Extensions (Intel TDX) refers to an Intel technology
that extends Virtual Machines Extensions (VMX) and Multi-Key Total Memory
Encryption (MKTME) with a new kind of virutal machines guest called a
Trust Domain (TD). A TD is desinged to run in a CPU mode that protects the
confidentiality of TD memory contents and the TD's CPU state from other
software, including the hosting Virtual-Machine Monitor (VMM), unless
explicitly shared by the TD itself.
Note: Intel TDX is only available on X64, so the Tdx related changes are
in X64 path. In IA32 path, there may be null stub to make the build
success.
This patch includes below major changes.
1. Ia32/IntelTdx.asm
IntelTdx.asm includes below routines used in ResetVector
- IsTdx
Check if the running system is Tdx guest.
- InitTdxWorkarea
It initialize the TDX_WORK_AREA. Because it is called by both BSP and
APs and to avoid the race condition, only BSP can initialize the
WORK_AREA. AP will wait until the field of TDX_WORK_AREA_PGTBL_READY
is set.
- ReloadFlat32
After reset all CPUs in TDX are initialized to 32-bit protected mode.
But GDT register is not set. So this routine loads the GDT then jump
to Flat 32 protected mode again.
- InitTdx
This routine wrap above 3 routines together to do Tdx initialization
in ResetVector phase.
- IsTdxEnabled
It is a OneTimeCall to probe if TDX is enabled by checking the
CC_WORK_AREA.
- CheckTdxFeaturesBeforeBuildPagetables
This routine is called to check if it is Non-TDX guest, TDX-Bsp or
TDX-APs. Because in TDX guest all the initialization is done by BSP
(including the page tables). APs should not build the tables.
- TdxPostBuildPageTables
It is called after Page Tables are built by BSP.
byte[TDX_WORK_AREA_PGTBL_READY] is set by BSP to indicate APs can
leave spin and go.
2. Ia32/PageTables64.asm
As described above only the TDX BSP build the page tables. So
PageTables64.asm is updated to make sure only TDX BSP build the
PageTables. TDX APs will skip the page table building and set Cr3
directly.
3. Ia16/ResetVectorVtf0.asm
In Tdx all CPUs "reset" to run on 32-bit protected mode with flat
descriptor (paging disabled). But in Non-Td guest the initial state of
CPUs is 16-bit real mode. To resolve this conflict, BITS 16/32 is used
in the ResetVectorVtf0.asm. It checks the 32-bit protected mode or 16-bit
real mode, then jump to the corresponding entry point.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
Previously WORK_AREA_GUEST_TYPE was cleared in SetCr3ForPageTables64.
This is workable for Legacy guest and SEV guest. But it doesn't work
after Intel TDX is introduced. It is because all TDX CPUs (BSP and APs)
start to run from 0xfffffff0, thus WORK_AREA_GUEST_TYPE will be cleared
multi-times if it is TDX guest. So the clearance of WORK_AREA_GUEST_TYPE
is moved to Main16 entry point in Main.asm.
Note: WORK_AREA_GUEST_TYPE is only defined for ARCH_X64.
For Intel TDX, its corresponding entry point is Main32 (which will be
introduced in next commit in this patch-set). WORK_AREA_GUEST_TYPE will
be cleared there.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
Previously OvmfPkg/ResetVector uses the Main.asm in
UefiCpuPkg/ReseteVector/Vtf0. In this Main.asm there is only Main16
entry point.
This patch-set is to introduce Intel TDX into Ovmf. Main32 entry point
is needed in Main.asm by Intel TDX. To reduce the complexity of Main.asm
in UefiCpuPkg, OvmfPkg create its own Main.asm to meet the requirement
of Intel TDX. This Main.asm is an unmodified copy (so no functional
change) and the actual changes for tdx come as incremental patches.
UefiCpuPkg/ResetVector/Vtf0/main.asm -> OvmfPkg/ResetVector/Main.asm
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Previously it was:
ESI/RSI - SEC Core entry point
EDI/RDI - PEI Core entry point
EBP/RBP - Start of BFV
Now it is:
RAX/EAX Initial value of the EAX register
(BIST: Built-in Self Test)
DI 'BP': boot-strap processor, or
'AP': application processor
RBP/EBP Address of Boot Firmware Volume (BFV)
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9571 6f19259b-4bc3-4df7-8a09-765794883524
Min Xu
geekboy15a
jljusten