On Sun, Jan 8, 2012 at 3:26 AM, Takuya Yoshikawa <takuya.yoshikawa@xxxxxxxxx> wrote: > Hi, > > Nadav Amit <nadav.amit@xxxxxxxxx> wrote: >> On Jan 7, 2012, at 10:25 PM, H. Peter Anvin wrote: >> >> > On 01/07/2012 12:21 PM, Nadav Amit wrote: >> >> MOV immediate instruction (opcodes 0xB8-0xBF) may take 64-bit operand. >> >> The previous emulation implementation assumes the operand is no longer than 32. >> >> >> >> Signed-off-by: Nadav Amit <nadav.amit@xxxxxxxxx> >> > >> > There are exactly two such instructions: MOV immediate (B8-BF) and MOV >> > moff (A0-A3); you may want to check the latter too. >> > >> > -hpa >> > >> >> These instructions (A0-A3) seem to be already covered by the decode_abs function. > > Like these how about introducing a new flag and change the following entries in the > decode table to indicate possible 64bit immediate: > > /* 0xB8 - 0xBF */ > X8(I(DstReg | SrcImm | Mov, em_mov)), > > Checking the opcode byte at the operand decoding stage, like below, does not look nice: > (IMO so better ask Avi) > > + if (size == 8 && ((ctxt->b & 0xF8) != 0xB8 || ctxt->twobyte)) > size = 4; > I agree. I remembered these flags are expensive (from the time flags were set in u32). I guess I can add OpImm64. Another less preferable alternative is to add a misc. flag or reuse another flag. Avi, please acknowledge adding OpImm64. Regards, Nadav -- 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
