diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-08-12 15:21:35 -0500 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2020-08-16 16:45:42 +0000 |
| commit | f8422f1e0be2654ca253630e0a9996ad87f89c9e (patch) | |
| tree | dfe07320acce57ce75de13cf4c148d0e66af5f42 /MdePkg | |
| parent | 9b3ca509abd4e45439bbdfe2c2fa8780c950320a (diff) | |
| download | edk2-f8422f1e0be2654ca253630e0a9996ad87f89c9e.tar.gz | |
MdePkg/BaseLib: Add support for the VMGEXIT instruction
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.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'MdePkg')
| -rw-r--r-- | MdePkg/Include/Library/BaseLib.h | 14 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/BaseLib.inf | 2 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ia32/VmgExit.nasm | 38 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/VmgExit.nasm | 32 |
4 files changed, 86 insertions, 0 deletions
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h index 7edf0051a0..04fb329eaa 100644 --- a/MdePkg/Include/Library/BaseLib.h +++ b/MdePkg/Include/Library/BaseLib.h @@ -7849,6 +7849,20 @@ 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
binary representation.
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf index 3b93b5db8d..3b85c56c3c 100644 --- a/MdePkg/Library/BaseLib/BaseLib.inf +++ b/MdePkg/Library/BaseLib/BaseLib.inf @@ -184,6 +184,7 @@ Ia32/DisableCache.nasm| GCC
Ia32/RdRand.nasm
Ia32/XGetBv.nasm
+ Ia32/VmgExit.nasm
Ia32/DivS64x64Remainder.c
Ia32/InternalSwitchStack.c | MSFT
@@ -317,6 +318,7 @@ X64/DisablePaging64.nasm
X64/RdRand.nasm
X64/XGetBv.nasm
+ X64/VmgExit.nasm
ChkStkGcc.c | GCC
[Sources.EBC]
diff --git a/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm b/MdePkg/Library/BaseLib/Ia32/VmgExit.nasm new file mode 100644 index 0000000000..69f7fbf350 --- /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 0000000000..26f034593c --- /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
+
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