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>
39 lines
1.0 KiB
NASM
39 lines
1.0 KiB
NASM
;------------------------------------------------------------------------------
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;
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; Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
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; SPDX-License-Identifier: BSD-2-Clause-Patent
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;
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; Module Name:
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;
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; VmgExit.Asm
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;
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; Abstract:
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;
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; AsmVmgExit function
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;
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; Notes:
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;
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;------------------------------------------------------------------------------
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SECTION .text
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;------------------------------------------------------------------------------
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; VOID
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; EFIAPI
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; AsmVmgExit (
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; VOID
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; );
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;------------------------------------------------------------------------------
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global ASM_PFX(AsmVmgExit)
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ASM_PFX(AsmVmgExit):
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;
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; NASM doesn't support the vmmcall instruction in 32-bit mode and NASM versions
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; before 2.12 cannot translate the 64-bit "rep vmmcall" instruction into elf32
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; format. Given that VMGEXIT does not make sense on IA32, provide a stub
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; implementation that is identical to CpuBreakpoint(). In practice, AsmVmgExit()
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; should never be called on IA32.
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;
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int 3
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ret
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