[PATCH v4 0/8] arm/arm64: KVM: dynamic VGIC sizing

[marc.zyngier@arm.com (Marc Zyngier)]

So far, the VGIC data structures have been statically sized, meaning
that we always have to support more interrupts than we actually want,
and more CPU interfaces than we should. This is a waste of resource,
and is the kind of things that should be tuneable.

This series addresses that issue by changing the data structures to be
dynamically allocated, and adds a new configuration attribute to
allocate the number of interrupts. When the attribute is not used, we
fallback to the old behaviour of allocating a fixed number of
interrupts.

This series is also the base for Andre Przywara's GICv3 distributor
emulation code (which can support far more than 8 vcpus and 1020
interrupts).

This has been tested on both ARM (TC2, A20) and arm64 (model and Juno).

The code is available from my kvm-arm64/kvmtool-vgic-dyn branch,
together with the corresponding kvmtool code.

* From v3 [3]
  - Number of comments added to the data structures, making slightly more
    obvious the various mappings
  - Dropped the nr_irqs field from bitmap and bytemap structures, as
    it was a leftover from the initial revision that only had a single
    pointer
  - Small cleanups all over the place
  - Dropped the "sub-page offset" patch for now, as this need some
    serious reworking
  - Rebased on top of Christoffer "vgic cleanup" series, with 3.17-rc4
    thrown in for a good measure

* From v2 [2]
  - Fixed bug that broke QEMU (register access can trigger allocation)
  - irq_pending_on_cpu is now dynamic (needed for more than 32 or 64 vcpus)
  - Rebased on top of Victor's BE patches

* From v1 [1]
  - Rebased on top of 3.16-rc1
  - Lots of cleanup

[1]: https://lists.cs.columbia.edu/pipermail/kvmarm/2013-October/005879.html
[2]: https://lists.cs.columbia.edu/pipermail/kvmarm/2014-June/010050.html
[3]: https://lists.cs.columbia.edu/pipermail/kvmarm/2014-July/010383.html

Marc Zyngier (8):
  KVM: ARM: vgic: plug irq injection race
  arm/arm64: KVM: vgic: switch to dynamic allocation
  arm/arm64: KVM: vgic: Parametrize VGIC_NR_SHARED_IRQS
  arm/arm64: KVM: vgic: kill VGIC_MAX_CPUS
  arm/arm64: KVM: vgic: handle out-of-range MMIO accesses
  arm/arm64: KVM: vgic: kill VGIC_NR_IRQS
  arm/arm64: KVM: vgic: delay vgic allocation until init time
  arm/arm64: KVM: vgic: make number of irqs a configurable attribute

 Documentation/virtual/kvm/devices/arm-vgic.txt |  10 +
 arch/arm/include/uapi/asm/kvm.h                |   1 +
 arch/arm/kvm/arm.c                             |  10 +-
 arch/arm64/include/uapi/asm/kvm.h              |   1 +
 include/kvm/arm_vgic.h                         |  88 ++++--
 virt/kvm/arm/vgic.c                            | 396 +++++++++++++++++++++----
 6 files changed, 413 insertions(+), 93 deletions(-)

-- 
2.0.4