On Sun, Jan 10, 2010 at 05:33:02PM +0900, Ryota Ozaki wrote: > On Sun, Jan 10, 2010 at 3:39 PM, Gleb Natapov <gleb@xxxxxxxxxx> wrote: > > On Sat, Jan 09, 2010 at 04:30:11PM -0300, Daniel Bareiro wrote: > >> On Friday, 08 January 2010 19:35:04 +0900, > >> Ryota Ozaki wrote: > >> > >> > Hi all, > >> > >> Hi, Ryota. > >> > >> > I've tried CPU hotplug with latest qemu-kvm.git code, > >> > and got segmentation fault. > >> > >> I'm also having this problem but with Linux 2.6.32.2 + qemu-kvm-0.12.1.1 > >> in the host: > >> > >> Jan 9 16:11:11 ubuntu kernel: [758479.480219] qemu-system-x86[29330]: > >> segfault at 90 ip 00007f5816bf3990 sp 00007fff9258fc88 error 4 in > >> libpthread-2.7.so[7f5816be8000+16000] > >> > >> I've guest with one cpu in which I try to add one more. For this I > >> execute the following in qemu monitor and here it is where I got > >> segmentation fault: > >> > >> (qemu) cpu_set 1 online > >> Connection closed by foreign host. > >> > >> > >> I'm not sure if the procedure that I'm following is the correct one. I > >> tried as much without using additional parameters when boots guest like > >> using -smp 1,maxcpus=2, but I reach the same result. > >> > >> The Kernel of guest has checked the "Support for hot-pluggable CPUs" > >> option, in case it is necessary. > >> > > CPU host-plug is not supported on qemu-kvm-0.12. It shouldn't segfault > > obviously, > > 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. > > 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? 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. -- 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
