At the moment the KVM VGICv3 only supports a single redistributor region (whose base address is set through the GICv3 kvm device KVM_DEV_ARM_VGIC_GRP_ADDR/KVM_VGIC_V3_ADDR_TYPE_REDIST). There, all the redistributors are laid out contiguously. The size of this single redistributor region is not set explicitly but instead induced at a late stage by the number of online vcpus.
The GIC specification does not mandate all redistributors to be contiguous. Moreover DT and ACPI were specified so that multiple redistributors regions can be defined. The current interface brings a limitation on QEMU where ARM virt machine available GPA holes only allowed to assign a redistributor region fitting a max of 123 vcpus. Overcoming this limitation would force either to create a new machine or relocate the single rdist region or allow the allocation of multiple rdist regions. This series enables this last alternative. A new GICv3 KVM device KVM_DEV_ARM_VGIC_GRP_ADDR/KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION allows to register individual redistributor regions whose size is defined explicitly. Those rdist regions then are filled by vcpu rdist frames according to the need. The vgic init and related base address checks are impacted. Best Regards Eric Git: complete series available at https://github.com/eauger/linux/tree/v4.16-rdist-regions-v3 Previous version: https://github.com/eauger/linux/tree/4.16-rc7-rdist-regions-rfc-v2 History: v2 -> v3: - Add details to the user API documentation - early exit if vgic_v3_rdist_region_from_index() fails - return -EINVAL if legacy and new redist region API are mixed v1 -> v2: - Rework the uapi. Only bits [51:16] of the redist region are exposed. Also a new flags field was introduced - Do not store the last bit in the vgic_cpu struct anymore - remove dist->spis check in 1st patch - add last patch to bump VGIC_V3_MAX_CPUS to 512 - advertise the new attribute Eric Auger (12): KVM: arm/arm64: Set dist->spis to NULL after kfree KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION KVM: arm/arm64: Replace the single rdist region by a list KVM: arm/arm64: Helper to locate free rdist index KVM: arm/arm64: Revisit Redistributor TYPER last bit computation KVM: arm/arm64: Helper to register a new redistributor region KVM: arm/arm64: Adapt vgic_v3_check_base to multiple rdist regions KVM: arm/arm64: Check vcpu redist base before registering an iodev KVM: arm/arm64: Check all vcpu redistributors are set on map_resources KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512 Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 25 ++++- arch/arm/include/uapi/asm/kvm.h | 7 +- arch/arm64/include/uapi/asm/kvm.h | 7 +- include/kvm/arm_vgic.h | 16 ++- virt/kvm/arm/vgic/vgic-init.c | 20 +++- virt/kvm/arm/vgic/vgic-kvm-device.c | 55 +++++++++- virt/kvm/arm/vgic/vgic-mmio-v3.c | 120 +++++++++++++++++++--- virt/kvm/arm/vgic/vgic-v3.c | 87 ++++++++++++---- virt/kvm/arm/vgic/vgic.h | 34 +++++- 9 files changed, 320 insertions(+), 51 deletions(-) -- 2.5.5