On Mon, Jan 11, 2010 at 06:24:32PM +0900, Ryota Ozaki wrote: > 2010/1/10 Gleb Natapov <gleb@xxxxxxxxxx>: > > On Sun, Jan 10, 2010 at 05:33:02PM +0900, Ryota Ozaki wrote: > [...] > >> I see. Anyway I think we need some workaround to avoid segfault. > >> > > Disabling cpu_set command for qemu-kvm-0.12 is good enough workaround. > > Agree. I'll send a patch. > Thanks. > > > >> > but ACPI code that handles CPU host-plug was not ported to > >> > SeaBIOS when it replaces BOCH BIOS. > >> > >> Yeah, I confirmed it during memory hotplug work... > >> > >> So I'd like to know when cpu hotplug comes back? I didn't see > >> it in qemu-0.13 feature requests. > >> > > May I ask what do you need it for? > > Oh sorry, actually I have not so strong desire on cpu hotplug but > I have on memory hotplug and just want to learn stuffs to implement > it from cpu's one. Honestly said I'm not sure someone want it. Hmm, everybody want it, but nobody can't say why. Looks like it just sounds cool :) > > > The problem is that there is no standard > > way to hotplug CPUs in a PC. Linux implements the way UNISYS happen to do > > it, but no other system do it like that. Windows implements it > > differently and in the way that conflicts with Linux, so you can't > > have working Linux implementation and pass Microsoft SVVP test at the > > same time for instance. > > Could I ask you what's the difference between the two implementations? I have no idea how it works in Windows. It seems that some kind of driver is required for hot-plugging cpu there. > Don't we have a possibility to have different implementations in qemu-kvm > (and SeaBIOS)? What do you mean by different implementation? Different one for Windows and Linux and have a switch to choose one? Possible, but not desirable. Different from what we had in BOCHS BIOS? Also possible, but will require changes to Linux kernel and older Kernel will not work. > And also I want to ask that the problem can be applied > to memory hotplug case? > AFAIK memory hotplug is part of ACPI spec and if implemented correctly should not cause any problems. -- 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
