From: Borislav Petkov <bp@xxxxxxx> Add initial support for handling three-byte instructions in the emulator. Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- arch/x86/kvm/emulate.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 67277bcb377a..72093d76c769 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3880,6 +3880,25 @@ static const struct opcode twobyte_table[256] = { N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N }; +static const struct gprefix third_opcode_byte_0xf0 = { + N, N, N, N +}; + +static const struct gprefix third_opcode_byte_0xf1 = { + N, N, N, N +}; + +/* + * Insns below are selected by the prefix which indexed by the third opcode + * byte. + */ +static const struct opcode opcode_map_0f_38[256] = { + /* 0x00 - 0x7f */ + X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), + /* 0x80 - 0xff */ + X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N) +}; + #undef D #undef N #undef G @@ -4200,6 +4219,13 @@ done_prefixes: ctxt->opcode_len = 2; ctxt->b = insn_fetch(u8, ctxt); opcode = twobyte_table[ctxt->b]; + + /* 0F_38 opcode map */ + if (ctxt->b == 0x38) { + ctxt->opcode_len = 3; + ctxt->b = insn_fetch(u8, ctxt); + opcode = opcode_map_0f_38[ctxt->b]; + } } ctxt->d = opcode.flags; @@ -4531,6 +4557,8 @@ special_insn: if (ctxt->opcode_len == 2) goto twobyte_insn; + else if (ctxt->opcode_len == 3) + goto threebyte_insn; switch (ctxt->b) { case 0x63: /* movsxd */ @@ -4715,6 +4743,8 @@ twobyte_insn: goto cannot_emulate; } +threebyte_insn: + if (rc != X86EMUL_CONTINUE) goto done; -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html