On Thu, 2017-03-30 at 13:10 +0300, Stas Sergeev wrote: > 30.03.2017 08:14, Ricardo Neri пишет: > >>>> But at least dosemu implements it, so probably it is needed. > >>> Right. > >>> > >>>> Of course if it is used by one of 100 DOS progs, then there > >>>> is an option to just add its support to dosemu2 and pretend > >>>> the compatibility problems did not exist. :) > >>> Do you mean relaying the GP fault to dosemu instead of trapping it and > >>> emulating it in the kernel? > >> Yes, that would be optimal if this does not severely break > >> the current setups. If we can find out that smsw is not in > >> the real use, we can probably do exactly that. > >> But other > >> instructions are not in real use in v86 for sure, so I > >> wouldn't be adding the explicit test-cases to the kernel > >> that will make you depend on some particular behaviour > >> that no one may need. > >> My objection was that we shouldn't > >> write tests before we know exactly how we want this to work. > > OK, if only SMSW is used then I'll keep the emulation for SMSW only. > In fact, smsw has an interesting property, which is that > no one will ever want to disable its in-kernel emulation > to provide its own. > So while I'll try to estimate its usage, emulating it in kernel > will not be that problematic in either case. Ah good to know! > As for protected mode, if wine only needs sgdt/sidt, then > again, no one will want to disable its emulation. Not the > case with sldt, but AFAICS wine doesn't need sldt, and so > we can leave sldt without a fixups. Is my understanding > correct? This is my understanding as well. I could not find any use of sldt in wine. Alexandre, would you mind confirming? > In this case, I suppose, we are very well on a way to avoid > the extra syscalls to toggle the emulation features. Great! Then I will keep the emulation for sgdt, sidt, and smsw but not for str and sldt; for both vm86 and protected mode. This seems to be the agreement. Thanks and BR, Ricardo -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
