Re: [PATCH v3 01/22] x86/include/asm/intel-txt.h: constants and accessors for TXT registers and heap

[Sergii Dmytruk <sergii.dmytruk@xxxxxxxxx>]

On Mon, Jul 07, 2025 at 10:24:37AM +0200, Jan Beulich wrote:
> On 06.07.2025 17:57, Sergii Dmytruk wrote:
> > On Wed, Jul 02, 2025 at 04:29:18PM +0200, Jan Beulich wrote:
> >> Btw, a brief rev log would be nice here. I saw you have something in the
> >> cover letter, but having to look in two places isn't very helpful.
> >
> > I don't really know how to effectively maintain 23 logs at the same time
> > given that changing one patch has cascading effects on the rest.  I'd
> > suggest using `git diff-range` instead, commands for which I can include
> > in cover letters for convenience.
>
> Well, no, doing this per patch is possible and relevant. For cascading
> effects their mentioning in a revlog can be pretty brief.

OK, will give it a try.

> >>> +    (void)txt_read(TXTCR_ESTS);
> >>
> >> I don't think the cast is needed.
> >
> > It's not needed, but I think that explicitly discarding unused return
> > value is a generally good practice even when there is a comment.
>
> In the context of Misra there has been discussion about doing so. But in our
> present code base you will find such as the exception, not the rule.

Will state the result is discarded in a comment instead.

> >>> +    txt_write(TXTCR_CMD_RESET, 1);
> >>> +    unreachable();
> >>
> >> What guarantees the write to take immediate effect? That is, shouldn't 
> >> there
> >> be e.g. an infinite loop here, just in case?
> >
> > I'll return infinite loop from v2.  Tried adding `halt()` as Ross
> > suggests, but including <asm/system.h> doesn't work in the early code
> > (something about compat headers and missing expansion of things like
> > __DeFiNe__).
>
> Yeah, untangling that may be a little involved. Open-coding halt() is an
> option, as long as you clearly indicate it as such (for e.g. grep to still
> find that instance).
>
> Jan

Will do that.

Regards