From 0bc5eedb82a54ccd9cbf79825226dd068427a94a Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 29 Oct 2013 12:54:10 +0100 Subject: [PATCH] kvm, emulator: Add initial three-byte insns support Add initial support for handling three-byte instructions in the emulator. Signed-off-by: Borislav Petkov Signed-off-by: Paolo Bonzini --- 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 5418015..6c5cfe9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3892,6 +3892,25 @@ 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 three_byte_0f_38_f0 = { + N, N, N, N +}; + +static const struct gprefix three_byte_0f_38_f1 = { + 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 @@ -4212,6 +4231,13 @@ 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; @@ -4543,6 +4569,8 @@ 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 */ @@ -4727,6 +4755,8 @@ twobyte_insn: goto cannot_emulate; } +threebyte_insn: + if (rc != X86EMUL_CONTINUE) goto done; -- 2.7.4