[RFC PATCH 00/45] KVM: arm/arm64: Rework virtual GIC emulation

[Andre Przywara]

This series is a joint effort to re-implement KVM's GIC emulation.

While the current implementation is centered around providing
efficient MMIO emulation, the hot path for most guests is actually
the guest entry and exit, which currently is rather costly.
Also the existing emulation has a global distributor lock, which
quickly becomes a bottleneck once the number of VCPUs increases.
Additionally the emulation was originally designed for GICv2, adding
GICv3 ITS emulation support to this proved to be rather painful.
Last, but not least the existing code became less and less
maintainable, with many special cases handled explicitly.

The new implementation is build around a struct vgic_irq data data
structure, which holds all information about a virtual interrupt.
Interruts which should be injected are hold in a per-VCPU list, this
make the entry/exit path much more efficient. Also the new structure
allows to have more fine grained locking - per IRQ and per VCPU -
getting rid of the global distributor lock.
As a result of the new design ITS emulation fits in more nicely, the
respective code will be provided as a follow-up series.

This series implements the same feature set as the existing emulation,
as a goodie we now implement priorities correctly.
To allow an easy transition with good test coverage, but still maintain
stability, both implementations live side by side, selectable via a
Kconfig option. The default is the new implementation.
If this code proves to be reliable, we will later remove the current
implementation with an extra patch set.

Please have a look at the series, review it and give the code some
serious testing (and possibly debugging). All feedback is appreciated.

Cheers,
Andre.

Andre Przywara (26):
  KVM: arm/arm64: add missing MMIO data write-back
  KVM: arm/arm64: pmu: abstract access to number of SPIs
  KVM: arm/arm64: arch_timer: rework VGIC <-> timer interface
  KVM: arm/arm64: vgic-new: Add MMIO handling framework
  KVM: arm/arm64: vgic-new: Export register access interface
  KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlers
  KVM: arm/arm64: vgic-new: Add ENABLE registers handlers
  KVM: arm/arm64: vgic-new: Add PENDING registers handlers
  KVM: arm/arm64: vgic-new: Add PRIORITY registers handlers
  KVM: arm/arm64: vgic-new: Add ACTIVE registers handlers
  KVM: arm/arm64: vgic-new: Add CONFIG registers handlers
  KVM: arm/arm64: vgic-new: Add TARGET registers handlers
  KVM: arm/arm64: vgic-new: Add SGIR register handler
  KVM: arm/arm64: vgic-new: Add SGIPENDR register handlers
  KVM: arm/arm64: vgic-new: Add GICv3 emulation framework
  KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers
  KVM: arm/arm64: vgic-new: Add GICv3 redistributor TYPER handler
  KVM: arm/arm64: vgic-new: Add GICv3 IDREGS register handler
  KVM: arm/arm64: vgic-new: Add GICv3 IROUTER register handlers
  KVM: arm/arm64: vgic-new: Add GICv3 SGI system register trap handler
  KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers
  KVM: arm/arm64: vgic-new: Add GICH_VMCR accessors
  KVM: arm/arm64: vgic-new: Add userland GIC CPU interface access
  KVM: arm/arm64: vgic-new: implement mapped IRQ handling
  KVM: arm/arm64: vgic-new: Add dummy MSI implementation
  KVM: arm/arm64: vgic-new: enable build

Christoffer Dall (5):
  KVM: arm/arm64: vgic-new: Add data structure definitions
  KVM: arm/arm64: vgic-new: Add acccessor to new struct vgic_irq
    instance
  KVM: arm/arm64: vgic-new: Implement virtual IRQ injection
  KVM: arm/arm64: vgic-new: Add vgic GICv2 change_affinity
  KVM: arm/arm64: vgic-new: Add IRQ sorting

Eric Auger (12):
  KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irq
  KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM device ops registration
  KVM: arm/arm64: vgic-new: vgic_kvm_device:
    KVM_DEV_ARM_VGIC_GRP_NR_IRQS
  KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_CTRL
  KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_ADDR
  KVM: arm/arm64: vgic-new: vgic_kvm_device: access to VGIC registers
  KVM: arm/arm64: vgic-new: vgic_kvm_device: implement kvm_vgic_addr
  KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init
  KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create
  KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init
  KVM: arm/arm64: vgic-new: vgic_init: implement map_resources
  KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable

Marc Zyngier (2):
  KVM: arm/arm64: vgic-new: Add GICv2 IRQ sync/flush
  KVM: arm/arm64: vgic-new: Add GICv3 world switch backend

 arch/arm/kvm/Kconfig                |    7 +
 arch/arm/kvm/Makefile               |   10 +
 arch/arm/kvm/mmio.c                 |    2 +-
 arch/arm64/kvm/Kconfig              |    7 +
 arch/arm64/kvm/Makefile             |   10 +
 include/kvm/arm_vgic.h              |   14 +-
 include/kvm/vgic/vgic.h             |  256 +++++++
 virt/kvm/arm/arch_timer.c           |   11 +-
 virt/kvm/arm/pmu.c                  |    2 +-
 virt/kvm/arm/vgic.c                 |   18 +-
 virt/kvm/arm/vgic/vgic-v2.c         |  381 +++++++++++
 virt/kvm/arm/vgic/vgic-v3.c         |  357 ++++++++++
 virt/kvm/arm/vgic/vgic.c            |  614 +++++++++++++++++
 virt/kvm/arm/vgic/vgic.h            |  136 ++++
 virt/kvm/arm/vgic/vgic_init.c       |  447 ++++++++++++
 virt/kvm/arm/vgic/vgic_irqfd.c      |   51 ++
 virt/kvm/arm/vgic/vgic_kvm_device.c |  522 ++++++++++++++
 virt/kvm/arm/vgic/vgic_mmio.c       | 1277 +++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic_mmio.h       |   47 ++
 19 files changed, 4149 insertions(+), 20 deletions(-)
 create mode 100644 include/kvm/vgic/vgic.h
 create mode 100644 virt/kvm/arm/vgic/vgic-v2.c
 create mode 100644 virt/kvm/arm/vgic/vgic-v3.c
 create mode 100644 virt/kvm/arm/vgic/vgic.c
 create mode 100644 virt/kvm/arm/vgic/vgic.h
 create mode 100644 virt/kvm/arm/vgic/vgic_init.c
 create mode 100644 virt/kvm/arm/vgic/vgic_irqfd.c
 create mode 100644 virt/kvm/arm/vgic/vgic_kvm_device.c
 create mode 100644 virt/kvm/arm/vgic/vgic_mmio.c
 create mode 100644 virt/kvm/arm/vgic/vgic_mmio.h

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2.7.3