On 7/27/20 8:34 PM, Gao, Liming wrote:
Tom:
Hi Liming,
I meet with GCC failure on this patch. Can you help check it? If nasm
doesn't support the vmmcall instruction in 32-bit mode, you have to use inline
assembly to support it.
What version of GCC are you using. I was able to successfully build the
Ia32 version with my GCC level. The Ia32 version uses a trick to do switch
to 64-bit just to encode the instruction. Looks like that doesn't work
with your version of GCC.
I can probably switch to defining the instruction as bytes. Let me look
into that and possibly send you a patch to test.
Thanks,
Tom
Edk2/Build/IntelFsp2Pkg/DEBUG_GCC5/IA32/MdePkg/Library/BaseLib/BaseLib/OUTPUT/Ia32/VmgExit.iii:33:
error: elf32 output format does not support 64-bit code
GNUmakefile:741: recipe for target
Thanks
Liming
-----Original Message-----
From: Tom Lendacky <thomas.lenda...@amd.com>
Sent: 2020年7月27日 23:26
To: devel@edk2.groups.io
Cc: Brijesh Singh <brijesh.si...@amd.com>; Ard Biesheuvel <ard.biesheu...@arm.com>; Dong, Eric
<eric.d...@intel.com>; Justen, Jordan L <jordan.l.jus...@intel.com>; Laszlo Ersek <ler...@redhat.com>; Gao,
Liming <liming....@intel.com>; Kinney, Michael D <michael.d.kin...@intel.com>; Ni, Ray <ray...@intel.com>
Subject: [PATCH v12 07/46] MdePkg/BaseLib: Add support for the VMGEXIT
instruction
From: Tom Lendacky <thomas.lenda...@amd.com>
BZ:
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2198&data=02%7C01%7Cthomas.lendacky%40amd.com%7C77c8250cd9e14f2929a008d832965726%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637314968570901400&sdata=6zqseI3tVmaw351w9mfEymMnDcjDzjvcBrhARU6r3Ho%3D&reserved=0
VMGEXIT is a new instruction used for Hypervisor/Guest communication when
running as an SEV-ES guest. A VMGEXIT will cause an automatic exit (AE) to
occur, resulting in a #VMEXIT with an exit code value of 0x403.
Provide the necessary support to execute the VMGEXIT instruction, which is "rep;
vmmcall".
Cc: Michael D Kinney <michael.d.kin...@intel.com>
Cc: Liming Gao <liming....@intel.com>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
MdePkg/Library/BaseLib/BaseLib.inf | 2 ++
MdePkg/Include/Library/BaseLib.h | 14 +++++++++
MdePkg/Library/BaseLib/Ia32/VmgExit.nasm | 37 ++++++++++++++++++++++++
MdePkg/Library/BaseLib/X64/VmgExit.nasm | 32 ++++++++++++++++++++
4 files changed, 85 insertions(+)
create mode 100644 MdePkg/Library/BaseLib/Ia32/VmgExit.nasm
create mode 100644 MdePkg/Library/BaseLib/X64/VmgExit.nasm
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf
b/MdePkg/Library/BaseLib/BaseLib.inf
index 3b93b5db8d24..3b85c56c3c03 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -184,6 +184,7 @@ [Sources.Ia32]
Ia32/DisableCache.nasm| GCC
Ia32/RdRand.nasm
Ia32/XGetBv.nasm
+ Ia32/VmgExit.nasm
Ia32/DivS64x64Remainder.c
Ia32/InternalSwitchStack.c | MSFT
@@ -317,6 +318,7 @@ [Sources.X64]
X64/DisablePaging64.nasm
X64/RdRand.nasm
X64/XGetBv.nasm
+ X64/VmgExit.nasm
ChkStkGcc.c | GCC
[Sources.EBC]
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 7edf0051a0a0..04fb329eaabb 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -7848,6 +7848,20 @@ AsmXGetBv (
);
+/**
+ Executes a VMGEXIT instruction (VMMCALL with a REP prefix)
+
+ Executes a VMGEXIT instruction. This function is only available on
+ IA-32 and x64.
+
+**/
+VOID
+EFIAPI
+AsmVmgExit (
+ VOID
+ );
+
+
/**
Patch the immediate operand of an IA32 or X64 instruction such that the
byte,
word, dword or qword operand is encoded at the end of the instruction's
diff --git a/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm
b/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm
new file mode 100644
index 000000000000..a4b37385cc7a
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm
@@ -0,0 +1,37 @@
+;----------------------------------------------------------------------
+--------
+;
+; Copyright (C) 2020, Advanced Micro Devices, Inc. All rights
+reserved.<BR> ; SPDX-License-Identifier: BSD-2-Clause-Patent ; ; Module
+Name:
+;
+; VmgExit.Asm
+;
+; Abstract:
+;
+; AsmVmgExit function
+;
+; Notes:
+;
+;----------------------------------------------------------------------
+--------
+
+ SECTION .text
+
+;----------------------------------------------------------------------
+--------
+; VOID
+; EFIAPI
+; AsmVmgExit (
+; VOID
+; );
+;----------------------------------------------------------------------
+--------
+global ASM_PFX(AsmVmgExit)
+ASM_PFX(AsmVmgExit):
+;
+; NASM doesn't support the vmmcall instruction in 32-bit mode, so work
+around ; this by temporarily switching to 64-bit mode.
+;
+BITS 64
+ rep vmmcall
+BITS 32
+ ret
+
diff --git a/MdePkg/Library/BaseLib/X64/VmgExit.nasm
b/MdePkg/Library/BaseLib/X64/VmgExit.nasm
new file mode 100644
index 000000000000..26f034593c67
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/VmgExit.nasm
@@ -0,0 +1,32 @@
+;----------------------------------------------------------------------
+--------
+;
+; Copyright (C) 2020, Advanced Micro Devices, Inc. All rights
+reserved.<BR> ; SPDX-License-Identifier: BSD-2-Clause-Patent ; ; Module
+Name:
+;
+; VmgExit.Asm
+;
+; Abstract:
+;
+; AsmVmgExit function
+;
+; Notes:
+;
+;----------------------------------------------------------------------
+--------
+
+ DEFAULT REL
+ SECTION .text
+
+;----------------------------------------------------------------------
+--------
+; VOID
+; EFIAPI
+; AsmVmgExit (
+; VOID
+; );
+;----------------------------------------------------------------------
+--------
+global ASM_PFX(AsmVmgExit)
+ASM_PFX(AsmVmgExit):
+ rep vmmcall
+ ret
+
--
2.27.0
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#63384): https://edk2.groups.io/g/devel/message/63384
Mute This Topic: https://groups.io/mt/75824947/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
