Re: [libvirt] RFC: add <currentVcpu> element
On 09/27/2010 11:20 AM, Eric Blake wrote:
>
> Another question I had, is there a way in QEmu to specifiy a different
> cpu count from the -smp indicating the startup count ?
I wish I knew off-hand, as it would make it easier for me to implement
when I get to that part of the patch series :) But even if there isn't,
I think that starting with the maximum via -smp and immediately after
hot-unplugging to the current count is better than nothing.
Answering my own question: with qemu 0.12.5, 'qemu -help' lists:
-smp n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]
set the number of CPUs to 'n' [default=1]
maxcpus= maximum number of total cpus, including
offline CPUs for hotplug etc.
So it looks like '-smp 1,maxcpus=2' maps nicely to <vcpu
current='1'>2</vcpu>.
But per tests/qemuhelpdata, qemu 0.11.0 lacks this, so I also have to
code up a qemu feature test.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org