This series addresses a peculiarity of the current VGIC implementation, namely that we don't support interrupt grouping. KVM either implements a GICv2 without support for the security extensions, or a GICv3 with DS=1. For GICv2, on systems without the security extensions, group 0 interrupts can be configured to be either signalled as FIQs or as IRQs by the VM, whereas group 1 interrupts are always IRQs. For GICv3, with DS=1, group 1 interrupts are always IRQs and group 0 interrupts are always FIQs, and there is no concept of secure vs. non-secure group 1 interrupts when DS=1. We were treating all interrupts on GICv2 as group 0, but yet telling the guest that they were group 1. The first patch changes this behavior, which seems to have no effect on no known guests, but still. The remaining patches introduce proper interrupt grouping support, along with MMIO accessors for the VM and userspace to retrieve and set the which group SGIs, PPIs, and SPIs belong to. LPIs are always group 1 interrupts as per the architecture, and there is no way to modify this configuration (no IGROUPR registers for LPIs or equivalent ITS commands). Tested on Seattle, TX1, and the foundation model. I've run a GICv2 guest on a GICv3 host on the foundation model. I've tested migration on Seattle, and migration from an old kernel to a newer kernel with an unmodified QEMU binary continues to work. I also tested a modified userspace that sets some interrupts to group 1, and that is reflected in the vgic debug output. Applies to v4.18-rc3. Changes since v2: - Patch 6 doesn't allow configuraiton of groups from userspace for GICv2. - Patches 7 through 9 are new in v3 of this series, and prevents userspace from restoring an incompatible IIDR without seeing an error in the future, and supports legacy userspace migration from old to new kernels. Changes since v1: - Bumped implementation revision field in GICD_IIDR along with changes - Changed logic in init code to correctly detect vgic emulation type - Rebased to v4.18-rc3 Christoffer Dall (9): KVM: arm/arm64: vgic: Define GICD_IIDR fields for GICv2 and GIv3 KVM: arm/arm64: vgic: Keep track of implementation revision KVM: arm/arm64: vgic: GICv2 IGROUPR should read as zero KVM: arm/arm64: vgic: Add group field to struct irq KVM: arm/arm64: vgic: Signal IRQs using their configured group KVM: arm/arm64: vgic: Allow configuration of interrupt groups KVM: arm/arm64: vgic: Permit uaccess writes to return errors KVM: arm/arm64: vgic: Let userspace opt-in to writable v2 IGROUPR KVM: arm/arm64: vgic: Update documentation of the GICv2 device Documentation/virtual/kvm/devices/arm-vgic.txt | 12 +++--- include/kvm/arm_vgic.h | 7 +++ include/linux/irqchip/arm-gic-v3.h | 10 +++++ include/linux/irqchip/arm-gic.h | 11 +++++ virt/kvm/arm/vgic/vgic-debug.c | 8 ++-- virt/kvm/arm/vgic/vgic-init.c | 20 ++++++++- virt/kvm/arm/vgic/vgic-its.c | 1 + virt/kvm/arm/vgic/vgic-mmio-v2.c | 60 +++++++++++++++++++++++--- virt/kvm/arm/vgic/vgic-mmio-v3.c | 51 ++++++++++++++++------ virt/kvm/arm/vgic/vgic-mmio.c | 56 +++++++++++++++++++++--- virt/kvm/arm/vgic/vgic-mmio.h | 25 +++++++---- virt/kvm/arm/vgic/vgic-v2.c | 3 ++ virt/kvm/arm/vgic/vgic-v3.c | 6 +-- 13 files changed, 223 insertions(+), 47 deletions(-) -- 2.7.4 IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
