[Qemu-devel] [PATCH v2 00/14] pc: q35: x2APIC support in kvm_apic mode

[Igor Mammedov <imammedo@redhat.com>]

Changes since v1:
  - rebase on top of 2.7
  - drop add 2.8 machine and linux headers update patches
  - drop numa related patches (will post separately as unrelated)
  - change default mc->maxcpus only for q35

Changes since RFC:
  - use new KVM_CAP_X2APIC_API to detect x2APIC IDs support
  - rebase on top of 2.7-rc1, since many deps were merged
  - fix etc/boot-cpus to account for -device provided cpus
  - include not yet merged _PXM fix as prereq
  - add 2.8 machine type and bump up maxcpus count since it

Series extends current CPU/kvm_apic/generic pc machine
code to support x2APIC and upto 288 VCPUs when QEMU
is used with KVM's lapic.

Due to FW_CFG_MAX_CPUS (which is actually apic_id_limit)
being limited to uint16_t, the max possible APIC ID is
limitted to 2^16 with this series but that should
be sufficient for bumping VCPUs number for quite a while.

Tested with following CLI:
 QEMU -M q35 -enable-kvm \
      -device intel-iommu,intremap=on -machine kernel_irqchip=split \
      -smp 1,sockets=9,cores=32,threads=1,maxcpus=288 \
      -device qemu64-x86_64-cpu,socket-id=8,core-id=30,thread-id=0       \
      -bios x2apic_bios.bin


git gree for testing:
https://github.com/imammedo/qemu.git x2apic_v2

To play with the feature, one would also need x2apic enabled
seabios counterpart:
https://github.com/imammedo/seabios.git x2apic_v4

Igor Mammedov (14):
  numa: reduce code duplication by adding helper numa_get_node_for_cpu()
  pc: acpi: x2APIC support for MADT table
  pc: acpi: x2APIC support for SRAT table
  acpi: cphp: support x2APIC entry in cpu._MAT
  acpi: cphp: force switch to modern cpu hotplug if APIC ID > 254
  pc: leave max apic_id_limit only in legacy cpu hotplug code
  pc: apic_common: extend APIC ID property to 32bit
  pc: apic_common: restore APIC ID to initial ID on reset
  pc: apic_common: reset APIC ID to initial ID when switching into
    x2APIC mode
  pc: kvm_apic: pass APIC ID depending on xAPIC/x2APIC mode
  pc: clarify FW_CFG_MAX_CPUS usage comment
  increase MAX_CPUMASK_BITS from 255 to 288
  pc: add 'etc/boot-cpus' fw_cfg file for machine with more than 255
    CPUs
  pc: q35: bump max_cpus to 288

 include/hw/acpi/acpi-defs.h     |  29 ++++++++++
 include/hw/i386/apic_internal.h |   3 +-
 include/sysemu/numa.h           |   3 ++
 include/sysemu/sysemu.h         |   2 +-
 target-i386/cpu.h               |   1 +
 target-i386/kvm_i386.h          |   1 +
 hw/acpi/cpu.c                   |   5 ++
 hw/acpi/cpu_hotplug.c           |  17 ++++--
 hw/arm/virt-acpi-build.c        |   6 +--
 hw/arm/virt.c                   |   9 ++--
 hw/i386/acpi-build.c            | 117 +++++++++++++++++++++++++++-------------
 hw/i386/kvm/apic.c              |  13 ++++-
 hw/i386/pc.c                    |  45 ++++++++--------
 hw/i386/pc_q35.c                |   2 +
 hw/intc/apic_common.c           |  46 +++++++++++++++-
 hw/ppc/spapr.c                  |   2 +-
 hw/ppc/spapr_cpu_core.c         |   6 +--
 numa.c                          |  12 +++++
 target-i386/cpu.c               |   2 +-
 target-i386/kvm.c               |  14 +++++
 20 files changed, 249 insertions(+), 86 deletions(-)

-- 
2.7.4