Re: [Qemu-devel] [RFC qom-cpu v4 00/10] i386: add cpu hot remove support

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 9 Oct 2013 17:43:08 +0800
Chen Fan <chen.fan.fnst@cn.fujitsu.com> wrote:

> Via implementing ACPI standard methods _EJ0 in bios, after Guest OS hot remove
> one vCPU, it is able to send a signal to QEMU, then QEMU could notify
> the assigned vCPU of exiting. meanwhile, and intruduce the QOM command 'cpu-del' to remove
> vCPU from QEMU itself.

have you tried following sequence:
cpu-add 1
cpu-add 2
cpu-del 1
and then do migration?

> 
> this work is based on Andreas Färber's qom-cpu branch tree.
>     git://github.com/afaerber/qemu-cpu.git
> 
> this series patches must be used with seabios patch and KVM patch together.
> 
> for KVM patches:
>     http://comments.gmane.org/gmane.comp.emulators.kvm.devel/114347
> 
> for seabios patches:
>     http://comments.gmane.org/gmane.comp.emulators.qemu/230460
> 
> Chen Fan (10):
>   x86: move apic_state field from CPUX86State to X86CPU
>   apic: remove redundant variable 'apic_no' from apic_init_common()
>   apic: remove local_apics array and using CPU_FOREACH instead
>   x86: add x86_cpu_unrealizefn() for cpu apic remove
>   qmp: add 'cpu-del' command support
>   qom cpu: rename variable 'cpu_added_notifier' to
>     'cpu_hotplug_notifier'
>   qom cpu: add UNPLUG cpu notifier support
>   i386: implement pc interface pc_hot_del_cpu()
>   piix4: implement function cpu_status_write() for vcpu ejection
>   cpus: reclaim allocated vCPU objects
> 
>  cpu-exec.c                      |  2 +-
>  cpus.c                          | 51 +++++++++++++++++++++--
>  hw/acpi/piix4.c                 | 66 ++++++++++++++++++++++++------
>  hw/i386/kvm/apic.c              | 18 +++++++-
>  hw/i386/kvmvapic.c              |  8 ++--
>  hw/i386/pc.c                    | 51 ++++++++++++++++++-----
>  hw/i386/pc_piix.c               |  3 +-
>  hw/intc/apic.c                  | 91 ++++++++++++++++++++++-------------------
>  hw/intc/apic_common.c           | 17 ++------
>  include/hw/boards.h             |  2 +
>  include/hw/i386/apic_internal.h |  6 +--
>  include/hw/i386/pc.h            |  1 +
>  include/qom/cpu.h               | 20 +++++++++
>  include/sysemu/kvm.h            |  1 +
>  include/sysemu/sysemu.h         |  2 +-
>  kvm-all.c                       | 25 +++++++++++
>  qapi-schema.json                | 12 ++++++
>  qmp-commands.hx                 | 23 +++++++++++
>  qmp.c                           |  9 ++++
>  qom/cpu.c                       | 26 +++++++++---
>  target-i386/cpu-qom.h           |  5 +++
>  target-i386/cpu.c               | 57 ++++++++++++++++++++------
>  target-i386/cpu.h               |  4 --
>  target-i386/helper.c            |  9 ++--
>  target-i386/kvm.c               | 23 +++++------
>  target-i386/misc_helper.c       |  8 ++--
>  26 files changed, 403 insertions(+), 137 deletions(-)
>