[Qemu-devel] [RFC 0/8] KVM/ARM: Relax the max 123 vcpus limitation along with KVM GICv3

[Eric Auger <eric.auger@redhat.com>]

Currently the max number of VCPUs usable along with the KVM GICv3
device is limited to 123. The rationale is a single redistributor
region was supported and this latter was set to [0x80A0000, 0x9000000]
within the guest physical address space, surrounded with DIST and UART
MMIO regions.

[1] now allows to register several redistributor regions.
So this series overcomes the max 123 vcpu limitation by registering
a new redistributor region located just after the VIRT_MEM RAM region.
The total redistributor region capacity is set to 512 vcpus.

The max supported VCPUs in non accelerated mode is not modified.

Best Regards

Eric

Host Kernel dependencies:
[1] [RFC v2 00/12] KVM: arm/arm64: Allow multiple GICv3 redistributor regions
https://github.com/eauger/linux/tree/4.16-rc7-rdist-regions-rfc-v2

This QEMU series can be found at:
https://github.com/eauger/qemu/tree/v2.12.0-rc0-rdist_regions-rfc

Eric Auger (8):
  linux-headers: Partial update for KVM/ARM multiple redistributor
    region registration
  hw/intc/arm_gicv3: Use an array of redistributor regions
  kvm: Expose kvm_max_vcpus()
  hw/intc/arm_gicv3: Implement register_redist_region API
  hw/intc/arm_gicv3_kvm: Allow multiple redistributor regions
  hw/arm/virt: Allow GICv3 DT node with multiple redistributor regions
  hw/arm/virt-acpi-build: Handle multiple GICR structures
  hw/arm/virt: Allow up to 512 vcpus along with KVM VGICv3

 accel/kvm/kvm-all.c                |  2 +-
 accel/stubs/kvm-stub.c             |  5 ++++
 hw/arm/virt-acpi-build.c           | 21 ++++++++++----
 hw/arm/virt.c                      | 55 +++++++++++++++++++++++++++++++-----
 hw/intc/arm_gicv3.c                | 21 ++++++++++++++
 hw/intc/arm_gicv3_common.c         |  9 ++++--
 hw/intc/arm_gicv3_kvm.c            | 57 ++++++++++++++++++++++++++++++++++++--
 include/hw/arm/virt.h              |  3 ++
 include/hw/intc/arm_gicv3_common.h | 14 +++++++++-
 include/sysemu/kvm.h               |  7 +++++
 linux-headers/asm-arm/kvm.h        |  7 +++--
 linux-headers/asm-arm64/kvm.h      |  7 +++--
 12 files changed, 182 insertions(+), 26 deletions(-)

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2.5.5