Commit e70316d1 authored by Tom Lendacky's avatar Tom Lendacky Committed by Borislav Petkov (AMD)
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x86/sev: Check for MWAITX and MONITORX opcodes in the #VC handler 



The MWAITX and MONITORX instructions generate the same #VC error code as
the MWAIT and MONITOR instructions, respectively. Update the #VC handler
opcode checking to also support the MWAITX and MONITORX opcodes.

Fixes: e3ef461a ("x86/sev: Harden #VC instruction emulation somewhat")
Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/453d5a7cfb4b9fe818b6fb67f93ae25468bc9e23.1713793161.git.thomas.lendacky@amd.com
parent ed30a4a5

arch/x86/kernel/sev-shared.c

+4 −2
Original line number Diff line number Diff line
@@ -1203,12 +1203,14 @@ static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt, 
		break;



	case SVM_EXIT_MONITOR:

		if (opcode == 0x010f && modrm == 0xc8)

		/* MONITOR and MONITORX instructions generate the same error code */

		if (opcode == 0x010f && (modrm == 0xc8 || modrm == 0xfa))

			return ES_OK;

		break;



	case SVM_EXIT_MWAIT:

		if (opcode == 0x010f && modrm == 0xc9)

		/* MWAIT and MWAITX instructions generate the same error code */

		if (opcode == 0x010f && (modrm == 0xc9 || modrm == 0xfb))

			return ES_OK;

		break;