[Qemu-devel] [PATCH v3 0/8] pc: do not create invalid MADT.LAPIC/Processor entries

[Igor Mammedov <imammedo@redhat.com>]

Changes since v2:
 - build possible CPUs list only once.
     Marcel Apfelbaum <marcel@redhat.com>
 - replace MachineClass possible_cpu_arch_ids() hook with
   QOM interface, so only targets that need it would implement it
 - fix ^2 times present CPU lookup for initial CPUs
    Eduardo Habkost <ehabkost@redhat.com>
 - drop found_cpus bitmap altogether

Changes since v1:
 - rebased on top of PCI tree that contains
   Eduardo's guest_info removel series
 - fix ^2 times present CPU lookup when creating CPON
   package (spotted-by: Eduardo Habkost <ehabkost@redhat.com>)

It's mostly clean up series that removes invalid CPU
entries from MADT/DSDT/SRAT tables when APIC IDs are
sparse distributed*.
Series also removes intermediate present CPUs bitmap
in ACPI tables generation code, replacing it with
machine reported presence status. That should
help later for consolidating and sharing CPU hotplug
codebase and extending supported CPU count above 256
on ACPI side, where I'm going to replace current
"not scalable" bitmap based CPU hotplug MMIO interface
with memory-hotplug like one, which could easily
scale and provide additional info for ACPI CPU device
objects.

Tested hoptlug with: RHEL72 and WS2003 / WS2012R2.
Git tree for testing:
https://github.com/imammedo/qemu.git pc_madt_dsdt_lapic_cleanups_v3

* example topology with sparse APIC IDs:
  -smp X,sockets=2,cores=3,maxcpus=6

* it's not possible to remove notion of apic_ad_limit
  since guest visible interfaces like CPU hoptlug MMIO
  (CPON array in ACPI + corresponding MMIO in QEMU) and
  FWCFG should stay the same for compat reasons with
  current setups and legacy SeaBIOS.


Igor Mammedov (8):
  pc: init pcms->apic_id_limit once and use it throughout pc.c
  cpu: introduce possible-cpus interface
  pc: acpi: cleanup qdev_get_machine() calls
  pc: acpi: SRAT: create only valid processor lapic entries
  pc: acpi: create MADT.lapic entries only for valid lapics
  pc: acpi: create Processor and Notify objects only for valid lapics
  pc: acpi: drop cpu->found_cpus bitmap
  pc: acpi: clarify why possible LAPIC entries must be present in MADT

 hw/i386/acpi-build.c | 150 ++++++++++++++++++++++++++-------------------------
 hw/i386/pc.c         |  91 ++++++++++++++++++++-----------
 include/hw/boards.h  |   1 +
 include/hw/i386/pc.h |   1 +
 include/qom/cpu.h    |  47 ++++++++++++++++
 qom/cpu.c            |   7 +++
 6 files changed, 193 insertions(+), 104 deletions(-)

-- 
1.8.3.1