Re: [Qemu-devel] [PATCH] target-i386: Use struct X86XSaveArea in fpu_helper.c

[Richard Henderson]

On 07/02/2016 01:02 PM, Eduardo Habkost wrote:
> On Sat, Jul 02, 2016 at 09:44:31AM -0700, Richard Henderson wrote:
> [...]
> > @@ -1402,9 +1409,8 @@ void helper_xrstor(CPUX86State *env, target_ulong ptr, 
> > uint64_t rfbm)
> >      }
> >
> >      /* The XCOMP field must be zero.  */
> > -    xcomp_bv0 = cpu_ldq_data_ra(env, ptr + 520, ra);
> > -    xcomp_bv1 = cpu_ldq_data_ra(env, ptr + 528, ra);
> > -    if (xcomp_bv0 || xcomp_bv1) {
> > +    xcomp_bv = cpu_ldq_data_ra(env, ptr + XO(header.xcomp_bv), ra);
> > +    if (xcomp_bv) {
> >          raise_exception_ra(env, EXCP0D_GPF, ra);
>
> You are changing the code to not check bytes 528-535 (bytes 16:23
> of the XSAVE header) anymore, but Intel SDM says XRSTOR raises
> #GP "If the standard form is executed and bytes 23:8 of the XSAVE
> header are not all zero."

Hmm.  I must have an out-of-date version here, since mine just mentions the 
first 8 bytes, and I thought the current definition of X86XSaveHeader backed 
that up.

I can certainly modify the structure...


r~