RE: [PATCH v4 1/7] x86/kexec: Consolidate relocate_kernel() function parameters

[Huang, Kai]

> On July 21, 2025 2:36:48 PM PDT, "Huang, Kai" <kai.huang@xxxxxxxxx> wrote:
> >On Mon, 2025-07-21 at 16:27 -0500, Tom Lendacky wrote:
> >> > > > @@ -204,7 +202,7 @@
> SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
> >> > > >   	 * entries that will conflict with the now unencrypted memory
> >> > > >   	 * used by kexec. Flush the caches before copying the kernel.
> >> > > >   	 */
> >> > > > -	testq	%r8, %r8
> >> > > > +	testq	$RELOC_KERNEL_HOST_MEM_ACTIVE, %r11
> >> > >
> >> > > Hmmm... can't both bits be set at the same time? If so, then this
> >> > > will fail. This should be doing bit tests now.
> >> >
> >> > TEST instruction performs logical AND of the two operands,
> >> > therefore the above equals to:
> >> >
> >> >  	set ZF if "R11 AND BIT(1) == 0".
> >> >
> >> > Whether there's any other bits set in R11 doesn't impact the above, right?
> >> >
> >>
> >> Doh! My bad, yes, not sure what I was thinking there.
> >>
> >
> >Np and thanks! I'll address your other comments but I'll see whether
> >Boris has any other comments first.
> >
> 
> You can use testb in this case to save 3 bytes, too.

Yeah I can do that, thanks for the info!