On 13/12/2019 12:54, Jan Beulich wrote: > AMD and friends explicitly specify that 64-bit operands aren't possible > for these insns. Nevertheless REX.W isn't fully ignored: It still > cancels a possible operand size override (0x66). Intel otoh explicitly > provides for 64-bit operands on the respective insn page of the SDM. > > Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> > > --- a/xen/arch/x86/x86_emulate/x86_emulate.c > +++ b/xen/arch/x86/x86_emulate/x86_emulate.c > @@ -2519,9 +2519,16 @@ x86_decode_onebyte( > case 6: /* push */ > if ( mode_64bit() && op_bytes == 4 ) > op_bytes = 8; > - /* fall through */ > + state->desc = DstNone | SrcMem | Mov; > + break; > + > case 3: /* call (far, absolute indirect) */ > case 5: /* jmp (far, absolute indirect) */ > + /* REX.W ignored on a vendor-dependent basis. */ > + if ( op_bytes == 8 && > + (ctxt->cpuid->x86_vendor & > + (X86_VENDOR_AMD | X86_VENDOR_HYGON)) ) I'm wondering whether in general we want some amd_like() and intel_like() predicates. It is how almost all of the boundaries end up falling. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
