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Diffstat (limited to 'Documentation/virtual/kvm/devices/arm-vgic.txt')
| -rw-r--r-- | Documentation/virtual/kvm/devices/arm-vgic.txt | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt deleted file mode 100644 index 97b6518148f8..000000000000 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ /dev/null @@ -1,127 +0,0 @@ -ARM Virtual Generic Interrupt Controller v2 (VGIC) -================================================== - -Device types supported: - KVM_DEV_TYPE_ARM_VGIC_V2 ARM Generic Interrupt Controller v2.0 - -Only one VGIC instance may be instantiated through either this API or the -legacy KVM_CREATE_IRQCHIP API. The created VGIC will act as the VM interrupt -controller, requiring emulated user-space devices to inject interrupts to the -VGIC instead of directly to CPUs. - -GICv3 implementations with hardware compatibility support allow creating a -guest GICv2 through this interface. For information on creating a guest GICv3 -device and guest ITS devices, see arm-vgic-v3.txt. It is not possible to -create both a GICv3 and GICv2 device on the same VM. - - -Groups: - KVM_DEV_ARM_VGIC_GRP_ADDR - Attributes: - KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit) - Base address in the guest physical address space of the GIC distributor - register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2. - This address needs to be 4K aligned and the region covers 4 KByte. - - KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit) - Base address in the guest physical address space of the GIC virtual cpu - interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2. - This address needs to be 4K aligned and the region covers 4 KByte. - Errors: - -E2BIG: Address outside of addressable IPA range - -EINVAL: Incorrectly aligned address - -EEXIST: Address already configured - -ENXIO: The group or attribute is unknown/unsupported for this device - or hardware support is missing. - -EFAULT: Invalid user pointer for attr->addr. - - KVM_DEV_ARM_VGIC_GRP_DIST_REGS - Attributes: - The attr field of kvm_device_attr encodes two values: - bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | - values: | reserved | vcpu_index | offset | - - All distributor regs are (rw, 32-bit) - - The offset is relative to the "Distributor base address" as defined in the - GICv2 specs. Getting or setting such a register has the same effect as - reading or writing the register on the actual hardware from the cpu whose - index is specified with the vcpu_index field. Note that most distributor - fields are not banked, but return the same value regardless of the - vcpu_index used to access the register. - - GICD_IIDR.Revision is updated when the KVM implementation of an emulated - GICv2 is changed in a way directly observable by the guest or userspace. - Userspace should read GICD_IIDR from KVM and write back the read value to - confirm its expected behavior is aligned with the KVM implementation. - Userspace should set GICD_IIDR before setting any other registers (both - KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_CPU_REGS) to ensure - the expected behavior. Unless GICD_IIDR has been set from userspace, writes - to the interrupt group registers (GICD_IGROUPR) are ignored. - Errors: - -ENXIO: Getting or setting this register is not yet supported - -EBUSY: One or more VCPUs are running - -EINVAL: Invalid vcpu_index supplied - - KVM_DEV_ARM_VGIC_GRP_CPU_REGS - Attributes: - The attr field of kvm_device_attr encodes two values: - bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | - values: | reserved | vcpu_index | offset | - - All CPU interface regs are (rw, 32-bit) - - The offset specifies the offset from the "CPU interface base address" as - defined in the GICv2 specs. Getting or setting such a register has the - same effect as reading or writing the register on the actual hardware. - - The Active Priorities Registers APRn are implementation defined, so we set a - fixed format for our implementation that fits with the model of a "GICv2 - implementation without the security extensions" which we present to the - guest. This interface always exposes four register APR[0-3] describing the - maximum possible 128 preemption levels. The semantics of the register - indicate if any interrupts in a given preemption level are in the active - state by setting the corresponding bit. - - Thus, preemption level X has one or more active interrupts if and only if: - - APRn[X mod 32] == 0b1, where n = X / 32 - - Bits for undefined preemption levels are RAZ/WI. - - Note that this differs from a CPU's view of the APRs on hardware in which - a GIC without the security extensions expose group 0 and group 1 active - priorities in separate register groups, whereas we show a combined view - similar to GICv2's GICH_APR. - - For historical reasons and to provide ABI compatibility with userspace we - export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask - field in the lower 5 bits of a word, meaning that userspace must always - use the lower 5 bits to communicate with the KVM device and must shift the - value left by 3 places to obtain the actual priority mask level. - - Errors: - -ENXIO: Getting or setting this register is not yet supported - -EBUSY: One or more VCPUs are running - -EINVAL: Invalid vcpu_index supplied - - KVM_DEV_ARM_VGIC_GRP_NR_IRQS - Attributes: - A value describing the number of interrupts (SGI, PPI and SPI) for - this GIC instance, ranging from 64 to 1024, in increments of 32. - - Errors: - -EINVAL: Value set is out of the expected range - -EBUSY: Value has already be set, or GIC has already been initialized - with default values. - - KVM_DEV_ARM_VGIC_GRP_CTRL - Attributes: - KVM_DEV_ARM_VGIC_CTRL_INIT - request the initialization of the VGIC or ITS, no additional parameter - in kvm_device_attr.addr. - Errors: - -ENXIO: VGIC not properly configured as required prior to calling - this attribute - -ENODEV: no online VCPU - -ENOMEM: memory shortage when allocating vgic internal data |