The following patchset enables hotplug of s390 CPUs.
The standard interface is used -- to configure a guest with 2 CPUs online at
boot and 4 maximum:
qemu -smp 2,maxcpus=4
Or, when using libvirt:
<domain>
...
<vcpu current="2">4</vcpu>
...
</domain>
To subsequently hotplug a CPU:
Issue 'cpu-add <id>' from qemu monitor, or use virsh setvcpus --count <n>
<domain>, where <n> is the total number of desired guest CPUs.
At this point, the guest must bring the CPU online for use -- This can be
achieved via "echo 1 > /sys/devices/system/cpu/cpuX/online" or via a management
tool like cpuplugd.
This patch set is based on work previously done by Jason Herne.
Matthew Rosato (4):
s390x/cpu: Cleanup init in preparation for hotplug
s390x/cpu: Set initial CPU state in common routine
s390x/cpu: Add function to set CPU state
s390x/cpu: Allow hotplug of CPUs
hw/s390x/s390-virtio-ccw.c | 3 ++-
hw/s390x/s390-virtio.c | 41 +++++++++++++++++++++++----------------
hw/s390x/s390-virtio.h | 2 +-
target-s390x/cpu.c | 48 ++++++++++++++++++++++++++++++++++++++++++++--
target-s390x/cpu.h | 2 ++
5 files changed, 75 insertions(+), 21 deletions(-)
--
1.9.1
