[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v3 2/2] x86/fpu: Split fpu_setup_fpu() in three
Hi, On Tue Aug 13, 2024 at 5:33 PM BST, Alejandro Vallejo wrote: > On Tue Aug 13, 2024 at 3:32 PM BST, Jan Beulich wrote: > > On 13.08.2024 16:21, Alejandro Vallejo wrote: > > > It was trying to do too many things at once and there was no clear way of > > > defining what it was meant to do. This commit splits the function in > > > three. > > > > > > 1. A function to return the FPU to power-on reset values. > > > 2. A function to return the FPU to default values. > > > 3. A x87/SSE state loader (equivalent to the old function when it took > > > a data > > > pointer). > > > > > > While at it, make sure the abridged tag is consistent with the manuals and > > > start as 0xFF. > > > > > > Signed-off-by: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx> > > > > Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> > > > > > --- > > > v3: > > > * Adjust commit message, as the split is now in 3. > > > * Remove bulky comment, as the rationale for it turned out to be > > > unsubstantiated. I can't find proof in xen-devel of the stream > > > operating the way I claimed, and at that point having the comment > > > at all is pointless > > > > So you deliberately removed the comment altogether, not just point 3 of it? > > > > Jan > > Yes. The other two cases can be deduced pretty trivially from the conditional, > I reckon. I commented them more heavily in order to properly introduce (3), > but > seeing how it was all a midsummer dream might as well reduce clutter. > > I got as far as the original implementation of XSAVE in Xen and it seems to > have been tested against many combinations of src and dst, none of which was > that ficticious "xsave enabled + xsave context missing". I suspect the > xsave_enabled(v) was merely avoiding writing to the XSAVE buffer just for > efficiency (however minor effect it might have had). I just reverse > engineering > it wrong. > > Which reminds me. Thanks for mentioning that, because it was really just > guesswork on my part. > > Cheers, > Alejandro Playing around with the FPU I noticed this patch wasn't committed, did it fall under the cracks or is there a specific reason? Cheers, Alejandro
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |