[PATCH] x86: ignore high register select bit(s) in 32- and 16-bit modes

[Jan Beulich]

>>> On 24.02.17 at 17:57, <hjl.tools@gmail.com> wrote:
> On Tue, Feb 21, 2017 at 8:27 AM, Jan Beulich <JBeulich@suse.com> wrote:
>> While commits 9889cbb14e ("Check invalid mask registers") and
>> abfcb414b9 ("X86: Ignore REX_B bit for 32-bit XOP instructions") went a
>> bit into the right direction, this wasn't quite enough:
>> - VEX.vvvv has its high bit ignored
>> - EVEX.vvvv has its high bit ignored together with EVEX.v'
>> - the high bits of {,E}VEX.vvvv should not be prematurely zapped, to
>>   allow proper checking of them when the fields has to hold al ones
>> - when the high bits of an immediate specify a register, bit 7 is
>>   ignored
>> - GPR names should be determined base on REX_W rather than vex.w
>>
> 
> There are several issues.  Please send individual patches to address
> them separately. Remove VEXI4_Fixup should be in a separate patch.

I disagree (there's just one fundamental issue, requiring fixes in
multiple places). At best the 3rd of the five items above could be
viewed as a separate issue imo. But anyway, it may be several
months until I may find time to split this up.

Jan