On 07/30/20 20:43, Lendacky, Thomas wrote: > From: Tom Lendacky <thomas.lenda...@amd.com> > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198 > > 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. > > Since SEV-ES is only supported in X64, provide the necessary X64 support > to execute the VMGEXIT instruction, which is coded as "rep vmmcall". For > IA32, since "vmmcall" is not supported in NASM 32-bit mode and VMGEXIT > should never be called, provide a stub implementation that is identical > to CpuBreakpoint(). > > 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 | 38 ++++++++++++++++++++++++ > MdePkg/Library/BaseLib/X64/VmgExit.nasm | 32 ++++++++++++++++++++ > 4 files changed, 86 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..69f7fbf3506a > --- /dev/null > +++ b/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm > @@ -0,0 +1,38 @@ > +;------------------------------------------------------------------------------ > +; > +; 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 and NASM > versions > +; before 2.12 cannot translate the 64-bit "rep vmmcall" instruction into > elf32 > +; format. Given that VMGEXIT does not make sense on IA32, provide a stub > +; implementation that is identical to CpuBreakpoint(). In practice, > AsmVmgExit() > +; should never be called on IA32. > +; > + int 3 > + 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 > + >
FWIW: Reviewed-by: Laszlo Ersek <ler...@redhat.com> -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#63568): https://edk2.groups.io/g/devel/message/63568 Mute This Topic: https://groups.io/mt/75892696/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
