[Qemu-devel] [PATCH 00/16 v4] target-i386: CPU hot-add with cpu-add QMP command

[Igor Mammedov <imammedo@redhat.com>]

Implements alternative way for hot-adding CPU using cpu-add QMP command,
wich could be useful until it would be possible to add CPUs via device_add.

All patches except the last are also applicable to device_add aprroach.

To hot-add CPU use following command from qmp-shell:
 cpu-add id=[0..max-cpus - 1)

git tree for testing: https://github.com/imammedo/qemu/tree/cpu_add.v4

based on qom-cpu tree

v4->v3:
  * 'id' in cpu-add command will be a thread number instead of APIC ID
  * split off resume_vcpu() into separate patch
  * move notifier from rtc code into pc.c

v2->v3:
  * use local error & propagate_error() instead of operating on
    passed in errp in several places
  * replace CPUClass.get_firmware_id() with CPUClass.get_arch_id()
  * leave IOAPIC creation to board and just set bus to icc-bus
  * include kvm-stub.o in cpu libary if no KVM is configured
  * create resume_vcpu() stub and include it in libqemustub,
    and use it directly instead of CPU method
  * acpi_piix4: s/cpu_add_notifier/cpu_added_notifier/

v1->v2:
  * generalize cpu sync to KVM, resume and hot-plug notification and
    invoke them form CPUClass, to make available to all targets.
  * introduce cpu_exists() and CPUClass.get_firmware_id() and use
    the last one in acpi_piix to make code target independent.
  * move IOAPIC to ICC bus, it was suggested and easy to convert.
  * leave kvmvapic as SysBusDevice, it doesn't affect hot-plug and
    created only once for all APIC instances. I haven't found yet
    good/clean enough way to convert it to ICCDevice. May be follow-up
    though.
  * split one big ICC patch into several, one per converted device
  * add cpu_hot_add hook to machine and implement it for target-i386,
    instead of adding stabs. Could be used by other targets to
    implement cpu-add.
  * pre-allocate links<CPU> for all possible CPUs and make them available
    at /machine/icc-bridge/cpu[0..N] QOM path, so users could find out
    possible/free CPU IDs to use in cpu-add command.

CC: pbonzini@redhat.com
CC: afaerber@suse.de
CC: ehabkost@redhat.com

Igor Mammedov (16):
  cpu: make kvm-stub.o a part of CPU library
  cpu: call cpu_synchronize_post_init() from CPUClass.realize() if
    hotplugged
  introduce resume_vcpu(), for single CPU
  cpu: resume CPU from CPUClass.cpu_common_realizefn() when it is
    hot-plugged
  introduce CPU hot-plug notifier
  target-i386: pc: update rtc_cmos on CPU hot-plug
  cpu: introduce get_arch_id() method and override it for target-i386
  cpu: add helper cpu_exists(), to check if CPU with specified id exists
  acpi_piix4: add infrastructure to send CPU hot-plug GPE to guest
  target-i386: introduce apic-id property
  introduce ICC bus/device/bridge
  target-i386: cpu: attach ICC bus to CPU on its creation
  target-i386: replace MSI_SPACE_SIZE with APIC_SPACE_SIZE
  target-i386: move APIC to ICC bus
  target-i386: move IOAPIC to ICC bus
  add cpu-add qmp command and implement CPU hot-add for target-i386

 Makefile.target                    |  14 ++---
 cpus.c                             |  11 +++-
 default-configs/i386-softmmu.mak   |   1 +
 default-configs/x86_64-softmmu.mak |   1 +
 hw/acpi/piix4.c                    | 114 ++++++++++++++++++++++++++++++++++++-
 hw/cpu/Makefile.objs               |   1 +
 hw/cpu/icc_bus.c                   | 104 +++++++++++++++++++++++++++++++++
 hw/i386/kvm/apic.c                 |   2 +-
 hw/i386/kvm/ioapic.c               |   2 +-
 hw/i386/kvmvapic.c                 |   1 +
 hw/i386/pc.c                       |  91 +++++++++++++++++++++++++++--
 hw/i386/pc_piix.c                  |   7 +++
 hw/i386/pc_q35.c                   |   7 +++
 hw/intc/apic.c                     |   2 +-
 hw/intc/apic_common.c              |  17 ++++--
 hw/intc/ioapic_common.c            |  15 +++--
 hw/timer/mc146818rtc.c             |   7 +++
 hw/xen/xen_apic.c                  |   2 +-
 include/exec/memory.h              |  10 ++++
 include/hw/boards.h                |   3 +
 include/hw/i386/apic_internal.h    |   8 +--
 include/hw/i386/icc_bus.h          |  53 +++++++++++++++++
 include/hw/i386/ioapic_internal.h  |   6 +-
 include/hw/pci/msi.h               |   2 +
 include/hw/timer/mc146818rtc.h     |   1 +
 include/qom/cpu.h                  |  21 +++++++
 include/sysemu/kvm.h               |  22 +++----
 include/sysemu/sysemu.h            |   3 +
 kvm-all.c                          |   1 +
 kvm-stub.c                         |   3 +
 memory.c                           |  11 ++++
 qapi-schema.json                   |  11 ++++
 qmp-commands.hx                    |  23 ++++++++
 qmp.c                              |  10 ++++
 qom/cpu.c                          |  44 ++++++++++++++
 stubs/Makefile.objs                |   1 +
 stubs/cpus.c                       |   5 ++
 target-i386/cpu.c                  |  75 +++++++++++++++++++-----
 target-i386/cpu.h                  |   1 +
 vl.c                               |   7 ++-
 40 files changed, 656 insertions(+), 64 deletions(-)
 create mode 100644 hw/cpu/icc_bus.c
 create mode 100644 include/hw/i386/icc_bus.h
 create mode 100644 stubs/cpus.c

-- 
1.8.2