On 07/22/20 02:55, Liu, Zhiguang wrote: > Hi Tom, > Nasm is a cross-OS assembly code and can be used in Linux. > So I think we don't need implement the same function in GccInline.c, we can > just use the nasm file in Linux.
I could agree, but this would create an inconsistency with the existent functions (where both gcc inline assembly and NASM exists). For example, consider AsmReadEflags(): - inline assembly for MSFT IA32 ("Ia32/ReadEflags.c") - NASM for MSFT X64 ("X64/ReadEflags.nasm") - inline assembly for GCC IA32 ("Ia32/GccInline.c") - inline assembly for GCC X64 ("X64/GccInline.c") The source file "X64/ReadEflags.nasm" could be used with GCC X64 too, not just with MSFT X64. So why do we have the gcc inline implementation for AsmReadEflags() in "X64/GccInline.c", in the first place? The pattern that a contributor is supposed to follow is not clear to me. Thanks, Laszlo >> -----Original Message----- >> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of >> Lendacky, Thomas >> Sent: Wednesday, July 22, 2020 5:19 AM >> 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: [edk2-devel] [PATCH v11 06/46] MdePkg/BaseLib: Add support for >> the XGETBV instruction >> >> From: Tom Lendacky <thomas.lenda...@amd.com> >> >> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198 >> >> Under SEV-ES, a CPUID instruction requires the current value of the XCR0 >> register. In order to retrieve that value, the XGETBV instruction needs >> to be executed. >> >> Provide the necessary support to execute the XGETBV instruction. >> >> 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 | 17 +++++++++++++ >> MdePkg/Library/BaseLib/Ia32/GccInline.c | 28 ++++++++++++++++++++ >> MdePkg/Library/BaseLib/X64/GccInline.c | 30 ++++++++++++++++++++++ >> MdePkg/Library/BaseLib/Ia32/XGetBv.nasm | 31 >> ++++++++++++++++++++++ >> MdePkg/Library/BaseLib/X64/XGetBv.nasm | 34 >> +++++++++++++++++++++++++ >> 6 files changed, 142 insertions(+) >> create mode 100644 MdePkg/Library/BaseLib/Ia32/XGetBv.nasm >> create mode 100644 MdePkg/Library/BaseLib/X64/XGetBv.nasm >> >> diff --git a/MdePkg/Library/BaseLib/BaseLib.inf >> b/MdePkg/Library/BaseLib/BaseLib.inf >> index c740a819cacf..e26c0d8cb0ac 100644 >> --- a/MdePkg/Library/BaseLib/BaseLib.inf >> +++ b/MdePkg/Library/BaseLib/BaseLib.inf >> @@ -153,6 +153,7 @@ [Sources.Ia32] >> Ia32/ARShiftU64.c | MSFT >> Ia32/EnableCache.c | MSFT >> Ia32/DisableCache.c | MSFT >> + Ia32/XGetBv.nasm | MSFT >> >> >> Ia32/GccInline.c | GCC >> @@ -288,6 +289,7 @@ [Sources.X64] >> X64/ReadCr2.nasm| MSFT >> X64/ReadCr0.nasm| MSFT >> X64/ReadEflags.nasm| MSFT >> + X64/XGetBv.nasm | MSFT >> >> >> X64/Non-existing.c >> diff --git a/MdePkg/Include/Library/BaseLib.h >> b/MdePkg/Include/Library/BaseLib.h >> index 8e7b87cbda4e..7edf0051a0a0 100644 >> --- a/MdePkg/Include/Library/BaseLib.h >> +++ b/MdePkg/Include/Library/BaseLib.h >> @@ -7831,6 +7831,23 @@ AsmLfence ( >> VOID >> ); >> >> +/** >> + Executes a XGETBV instruction >> + >> + Executes a XGETBV instruction. This function is only available on IA-32 >> and >> + x64. >> + >> + @param[in] Index Extended control register index >> + >> + @return The current value of the extended control register >> +**/ >> +UINT64 >> +EFIAPI >> +AsmXGetBv ( >> + IN UINT32 Index >> + ); >> + >> + >> /** >> 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/GccInline.c >> b/MdePkg/Library/BaseLib/Ia32/GccInline.c >> index 6ed938187a08..c2565ab9a183 100644 >> --- a/MdePkg/Library/BaseLib/Ia32/GccInline.c >> +++ b/MdePkg/Library/BaseLib/Ia32/GccInline.c >> @@ -584,3 +584,31 @@ AsmReadTsc ( >> >> return Data; >> } >> + >> + >> +/** >> + Executes a XGETBV instruction >> + >> + Executes a XGETBV instruction. This function is only available on IA-32 >> and >> + x64. >> + >> + @param[in] Index Extended control register index >> + >> + @return The current value of the extended control register >> +**/ >> +UINT64 >> +EFIAPI >> +AsmXGetBv ( >> + IN UINT32 Index >> + ) >> +{ >> + UINT64 Data; >> + >> + __asm__ __volatile__ ( >> + "xgetbv" >> + : "=A" (Data) >> + : "c" (Index) >> + ); >> + >> + return Data; >> +} >> diff --git a/MdePkg/Library/BaseLib/X64/GccInline.c >> b/MdePkg/Library/BaseLib/X64/GccInline.c >> index 40a208f1985f..65f864e35922 100644 >> --- a/MdePkg/Library/BaseLib/X64/GccInline.c >> +++ b/MdePkg/Library/BaseLib/X64/GccInline.c >> @@ -560,3 +560,33 @@ AsmReadTsc ( >> >> return (((UINT64)HiData) << 32) | LowData; >> } >> + >> + >> +/** >> + Executes a XGETBV instruction >> + >> + Executes a XGETBV instruction. This function is only available on IA-32 >> and >> + x64. >> + >> + @param[in] Index Extended control register index >> + >> + @return The current value of the extended control register >> +**/ >> +UINT64 >> +EFIAPI >> +AsmXGetBv ( >> + IN UINT32 Index >> + ) >> +{ >> + UINT32 LowData; >> + UINT32 HighData; >> + >> + __asm__ __volatile__ ( >> + "xgetbv" >> + : "=a" (LowData), >> + "=d" (HighData) >> + : "c" (Index) >> + ); >> + >> + return (((UINT64)HighData) << 32) | LowData; >> +} >> diff --git a/MdePkg/Library/BaseLib/Ia32/XGetBv.nasm >> b/MdePkg/Library/BaseLib/Ia32/XGetBv.nasm >> new file mode 100644 >> index 000000000000..9f7b03bbff35 >> --- /dev/null >> +++ b/MdePkg/Library/BaseLib/Ia32/XGetBv.nasm >> @@ -0,0 +1,31 @@ >> +;------------------------------------------------------------------------------ >> +; >> +; Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR> >> +; SPDX-License-Identifier: BSD-2-Clause-Patent >> +; >> +; Module Name: >> +; >> +; XGetBv.Asm >> +; >> +; Abstract: >> +; >> +; AsmXgetBv function >> +; >> +; Notes: >> +; >> +;------------------------------------------------------------------------------ >> + >> + SECTION .text >> + >> +;------------------------------------------------------------------------------ >> +; UINT64 >> +; EFIAPI >> +; AsmXGetBv ( >> +; IN UINT32 Index >> +; ); >> +;------------------------------------------------------------------------------ >> +global ASM_PFX(AsmXGetBv) >> +ASM_PFX(AsmXGetBv): >> + mov ecx, [esp + 4] >> + xgetbv >> + ret >> diff --git a/MdePkg/Library/BaseLib/X64/XGetBv.nasm >> b/MdePkg/Library/BaseLib/X64/XGetBv.nasm >> new file mode 100644 >> index 000000000000..09f3be8ae0a8 >> --- /dev/null >> +++ b/MdePkg/Library/BaseLib/X64/XGetBv.nasm >> @@ -0,0 +1,34 @@ >> +;------------------------------------------------------------------------------ >> +; >> +; Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR> >> +; SPDX-License-Identifier: BSD-2-Clause-Patent >> +; >> +; Module Name: >> +; >> +; XGetBv.Asm >> +; >> +; Abstract: >> +; >> +; AsmXgetBv function >> +; >> +; Notes: >> +; >> +;------------------------------------------------------------------------------ >> + >> + DEFAULT REL >> + SECTION .text >> + >> +;------------------------------------------------------------------------------ >> +; UINT64 >> +; EFIAPI >> +; AsmXGetBv ( >> +; IN UINT32 Index >> +; ); >> +;------------------------------------------------------------------------------ >> +global ASM_PFX(AsmXGetBv) >> +ASM_PFX(AsmXGetBv): >> + xgetbv >> + shl rdx, 32 >> + or rax, rdx >> + ret >> + >> -- >> 2.27.0 >> >> >> > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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