Re: vm86

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 10/08/2017 à 17:14, Kamil Rytarowski a écrit :
> On 10.08.2017 12:38, Maxime Villard wrote:
> > Hi,
> > does someone use vm86?
> >
> > Maxime
>
> vm86 was used by VGA software like s3switch, atitvout, zhcon... but
> presumably there are no users now other than DOSBOX ones.

It seems to me vm86 programs can easily be emulated in userland entirely: the
instruction set is small, and these binaries do not perform syscalls. I am
quite unhappy with having support for vm86 in the kernel, it makes the
introduction of new features (like smap) painful, and I've already seen that
several of the assumptions in the code are not respected. Besides, it is bug
friendly, given that it has a special handling of the trap frame (in which
some of the segment registers have different meanings too).

vm86 has received zero maintenance. I would like to remove it, and let
potential users use a complete userland emulator, which will produce better
results than our flimsy implementation.

Maxime