On Mon, Dec 27, 2010 at 04:55:08PM +0200, Avi Kivity wrote: > On 12/27/2010 04:37 PM, Gleb Natapov wrote: > >> What's the scenario here? And what segment is involved? if it's fs > >> or gs, or maybe ss, I can see it working out, but hardly otherwise. > >> > >The scenario is older Seabios that lefts DS segment unaligned during > >switch to real mode in int1587 function (copy extended memory). > > > > Did it not use %ds then? > It restores %ds before first use. There can be other guests of course that try to use %ds in protected mode. We can distinguish one from the other. > What about switching back to protected mode? I see we do restore the > base, so it can continue to use the segment. I guess this isn't an > issue for 1587. > Correct. 1587 does not return to protected mode again. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
