[Qemu-devel] [PATCH 00/21 v5] 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.v5

based on qom-cpu-nex tree due to dependency on "mc146818rtc: QOM'ify"

v5->v4:
  * style fixes
  * new helper qemu_for_each_cpu()
  * switch to qemu_for_each_cpu() in cpu_exists()
  * "pc: update rtc ..." patch make depend it on "mc146818rtc: QOM'ify"
    and use QOM cast style
  * call CPU added notifier right before CPU becomes runable
  * s/resume_vcpu/cpu_resume/
  * acpi/piix4: add spec documentation for QEMU<->Seabios CPU hotplug
    interface
  * use error_propagate() in pc_new_cpu()
  * skip cpu_exists() check in apic-id property setter if new value is
    the same as current
  * embed icc-bus inside icc-bridge and use qbus_create_inplace()
  * move include/hw/i386/icc_bus.h into include/hw/cpu/
  * make missing icc-bus fatal error for softmmu target
  * split "move APIC to ICC bus" and "move IOAPIC to ICC bus" on smaller
    patches
  * use qdev_get_parent_bus() to get parent bus
  * split "add cpu-add command..." on smaller patches

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: gleb@redhat.com
CC: mst@redhat.com
CC: afaerber@suse.de
CC: ehabkost@redhat.com

Igor Mammedov (21):
  cpu: make kvm-stub.o a part of CPU library
  cpu: call cpu_synchronize_post_init() from CPUClass.realize() if
    hotplugged
  introduce cpu_resume(), 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
  exec: add qemu_for_each_cpu
  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
  target-i386: 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: kvmvapic: make expilict dependency on sysbus.h
  target-i386: move APIC to ICC bus
  introduce memory_region_get_address() and use it in kvm/ioapic
  target-i386: move IOAPIC to ICC bus
  add hot_add_cpu hook to QEMUMachine and export machine_args
  target-i386: implement machine->hot_add_cpu hook
  QMP: add cpu-add command

 MAINTAINERS                        |    6 ++
 Makefile.target                    |   14 ++--
 cpus.c                             |   24 +++++---
 default-configs/i386-softmmu.mak   |    1 +
 default-configs/x86_64-softmmu.mak |    1 +
 docs/specs/acpi_cpu_hotplug.txt    |   22 +++++++
 exec.c                             |   10 +++
 hw/acpi/piix4.c                    |  117 ++++++++++++++++++++++++++++++++++-
 hw/cpu/Makefile.objs               |    1 +
 hw/cpu/icc_bus.c                   |  120 ++++++++++++++++++++++++++++++++++++
 hw/i386/kvm/apic.c                 |    2 +-
 hw/i386/kvm/ioapic.c               |    2 +-
 hw/i386/kvmvapic.c                 |    1 +
 hw/i386/pc.c                       |   93 ++++++++++++++++++++++++++--
 hw/i386/pc_piix.c                  |    7 ++
 hw/i386/pc_q35.c                   |    7 ++
 hw/intc/apic.c                     |    2 +-
 hw/intc/apic_common.c              |   18 ++++--
 hw/intc/ioapic_common.c            |   14 +++-
 hw/timer/mc146818rtc.c             |    7 ++
 hw/xen/xen_apic.c                  |    2 +-
 include/exec/memory.h              |   10 +++
 include/hw/boards.h                |    3 +
 include/hw/cpu/icc_bus.h           |   63 +++++++++++++++++++
 include/hw/i386/apic_internal.h    |    8 +--
 include/hw/i386/ioapic_internal.h  |    6 +-
 include/hw/timer/mc146818rtc.h     |    1 +
 include/qom/cpu.h                  |   27 ++++++++
 include/sysemu/kvm.h               |   24 ++++----
 include/sysemu/sysemu.h            |    3 +
 kvm-all.c                          |    1 +
 kvm-stub.c                         |    8 ++-
 memory.c                           |   11 +++
 qapi-schema.json                   |   11 +++
 qmp-commands.hx                    |   23 +++++++
 qmp.c                              |   10 +++
 qom/cpu.c                          |   49 +++++++++++++++
 stubs/Makefile.objs                |    1 +
 stubs/cpus.c                       |    5 ++
 target-i386/cpu.c                  |   83 +++++++++++++++++++++----
 target-i386/cpu.h                  |    1 +
 vl.c                               |    7 ++-
 42 files changed, 752 insertions(+), 74 deletions(-)
 create mode 100644 docs/specs/acpi_cpu_hotplug.txt
 create mode 100644 hw/cpu/icc_bus.c
 create mode 100644 include/hw/cpu/icc_bus.h
 create mode 100644 stubs/cpus.c