On 10.08.2022 21:09, Andrew Cooper wrote: > On 15/06/2022 11:31, Jan Beulich wrote: >> Signed-off-by: Jan Beulich <[email protected]> >> >> --- a/xen/arch/x86/x86_emulate/decode.c >> +++ b/xen/arch/x86/x86_emulate/decode.c >> @@ -1489,12 +1489,25 @@ int x86emul_decode(struct x86_emulate_st >> s->simd_size = simd_scalar_vexw; >> break; >> >> + case 0x2a: /* vcvtsi2sh */ >> + break; >> + >> + case 0x2c: case 0x2d: /* vcvt{,t}sh2si */ >> + if ( s->evex.pfx == vex_f3 ) >> + s->fp16 = true; >> + break; >> + >> case 0x2e: case 0x2f: /* v{,u}comish */ >> if ( !s->evex.pfx ) >> s->fp16 = true; >> s->simd_size = simd_none; >> break; >> >> + case 0x5b: /* vcvt{d,q}q2ph, vcvt{,t}ph2dq */ >> + if ( s->evex.pfx && s->evex.pfx != vex_f2 ) >> + s->fp16 = true; >> + break; >> + >> case 0x6e: /* vmovw r/m16, xmm */ >> d = (d & ~SrcMask) | SrcMem16; >> /* fall through */ >> @@ -1504,6 +1517,17 @@ int x86emul_decode(struct x86_emulate_st >> s->simd_size = simd_none; >> break; >> >> + case 0x78: case 0x79: /* vcvt{,t}ph2u{d,q}q, vcvt{,t}sh2usi */ >> + if ( s->evex.pfx != vex_f2 ) >> + s->fp16 = true; >> + break; >> + >> + case 0x7a: /* vcvttph2qq, vcvtu{d,q}q2ph */ >> + case 0x7b: /* vcvtph2qq, vcvtusi2sh */ >> + if ( s->evex.pfx == vex_66 ) >> + s->fp16 = true; >> + break; >> + >> case 0x7c: /* vcvttph2{,u}w */ >> case 0x7d: /* vcvtph2{,u}w / vcvt{,u}w2ph */ >> d = DstReg | SrcMem | TwoOp; >> @@ -1515,10 +1539,34 @@ int x86emul_decode(struct x86_emulate_st >> >> switch ( b ) >> { >> + case 0x78: >> + case 0x79: >> + /* vcvt{,t}ph2u{d,q}q need special casing */ >> + if ( s->evex.pfx <= vex_66 ) >> + { >> + if ( !s->evex.brs ) >> + disp8scale -= 1 + (s->evex.pfx == vex_66); >> + break; >> + } >> + /* vcvt{,t}sh2usi needs special casing: fall through */ >> + case 0x2c: case 0x2d: /* vcvt{,t}sh2si need special casing */ >> + disp8scale = 1; >> + break; >> + >> case 0x5a: /* vcvtph2pd needs special casing */ >> if ( !s->evex.pfx && !s->evex.brs ) >> disp8scale -= 2; >> break; >> + >> + case 0x5b: /* vcvt{,t}ph2dq need special casing */ >> + if ( s->evex.pfx && !s->evex.brs ) >> + --disp8scale; >> + break; >> + >> + case 0x7a: case 0x7b: /* vcvt{,t}ph2qq need special casing */ >> + if ( s->evex.pfx == vex_66 && !s->evex.brs ) >> + disp8scale = s->evex.brs ? 1 : 2 + s->evex.lr; >> + break; >> } >> >> break; > > Perhaps here, in terms of overriding...
>From all I can tell, the s->fp16 setting would better remain here, as it's (embedded) prefix dependent. As are the disp8scale adjustments (if you go look, you'll find similar pre-existing code a little higher up in the file.) Jan
