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+ARM Virtual Generic Interrupt Controller v3 and later (VGICv3)
+==============================================================
+
+
+Device types supported:
+ KVM_DEV_TYPE_ARM_VGIC_V3 ARM Generic Interrupt Controller v3.0
+
+Only one VGIC instance may be instantiated through this 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. It is not
+possible to create both a GICv3 and GICv2 on the same VM.
+
+Creating a guest GICv3 device requires a host GICv3 as well.
+
+
+Groups:
+ KVM_DEV_ARM_VGIC_GRP_ADDR
+ Attributes:
+ KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit)
+ Base address in the guest physical address space of the GICv3 distributor
+ register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+ This address needs to be 64K aligned and the region covers 64 KByte.
+
+ KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit)
+ Base address in the guest physical address space of the GICv3
+ redistributor register mappings. There are two 64K pages for each
+ VCPU and all of the redistributor pages are contiguous.
+ Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
+ This address needs to be 64K aligned.
+ 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
+ KVM_DEV_ARM_VGIC_GRP_REDIST_REGS
+ Attributes:
+ The attr field of kvm_device_attr encodes two values:
+ bits: | 63 .... 32 | 31 .... 0 |
+ values: | mpidr | offset |
+
+ All distributor regs are (rw, 32-bit) and kvm_device_attr.addr points to a
+ __u32 value. 64-bit registers must be accessed by separately accessing the
+ lower and higher word.
+
+ Writes to read-only registers are ignored by the kernel.
+
+ KVM_DEV_ARM_VGIC_GRP_DIST_REGS accesses the main distributor registers.
+ KVM_DEV_ARM_VGIC_GRP_REDIST_REGS accesses the redistributor of the CPU
+ specified by the mpidr.
+
+ The offset is relative to the "[Re]Distributor base address" as defined
+ in the GICv3/4 specs. Getting or setting such a register has the same
+ effect as reading or writing the register on real hardware, except for the
+ following registers: GICD_STATUSR, GICR_STATUSR, GICD_ISPENDR,
+ GICR_ISPENDR0, GICD_ICPENDR, and GICR_ICPENDR0. These registers behave
+ differently when accessed via this interface compared to their
+ architecturally defined behavior to allow software a full view of the
+ VGIC's internal state.
+
+ The mpidr field is used to specify which
+ redistributor is accessed. The mpidr is ignored for the distributor.
+
+ The mpidr encoding is based on the affinity information in the
+ architecture defined MPIDR, and the field is encoded as follows:
+ | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 |
+ | Aff3 | Aff2 | Aff1 | Aff0 |
+
+ Note that distributor fields are not banked, but return the same value
+ regardless of the mpidr used to access the register.
+
+ The GICD_STATUSR and GICR_STATUSR registers are architecturally defined such
+ that a write of a clear bit has no effect, whereas a write with a set bit
+ clears that value. To allow userspace to freely set the values of these two
+ registers, setting the attributes with the register offsets for these two
+ registers simply sets the non-reserved bits to the value written.
+
+
+ Accesses (reads and writes) to the GICD_ISPENDR register region and
+ GICR_ISPENDR0 registers get/set the value of the latched pending state for
+ the interrupts.
+
+ This is identical to the value returned by a guest read from ISPENDR for an
+ edge triggered interrupt, but may differ for level triggered interrupts.
+ For edge triggered interrupts, once an interrupt becomes pending (whether
+ because of an edge detected on the input line or because of a guest write
+ to ISPENDR) this state is "latched", and only cleared when either the
+ interrupt is activated or when the guest writes to ICPENDR. A level
+ triggered interrupt may be pending either because the level input is held
+ high by a device, or because of a guest write to the ISPENDR register. Only
+ ISPENDR writes are latched; if the device lowers the line level then the
+ interrupt is no longer pending unless the guest also wrote to ISPENDR, and
+ conversely writes to ICPENDR or activations of the interrupt do not clear
+ the pending status if the line level is still being held high. (These
+ rules are documented in the GICv3 specification descriptions of the ICPENDR
+ and ISPENDR registers.) For a level triggered interrupt the value accessed
+ here is that of the latch which is set by ISPENDR and cleared by ICPENDR or
+ interrupt activation, whereas the value returned by a guest read from
+ ISPENDR is the logical OR of the latch value and the input line level.
+
+ Raw access to the latch state is provided to userspace so that it can save
+ and restore the entire GIC internal state (which is defined by the
+ combination of the current input line level and the latch state, and cannot
+ be deduced from purely the line level and the value of the ISPENDR
+ registers).
+
+ Accesses to GICD_ICPENDR register region and GICR_ICPENDR0 registers have
+ RAZ/WI semantics, meaning that reads always return 0 and writes are always
+ ignored.
+
+ Errors:
+ -ENXIO: Getting or setting this register is not yet supported
+ -EBUSY: One or more VCPUs are running
+
+
+ KVM_DEV_ARM_VGIC_CPU_SYSREGS
+ Attributes:
+ The attr field of kvm_device_attr encodes two values:
+ bits: | 63 .... 32 | 31 .... 16 | 15 .... 0 |
+ values: | mpidr | RES | instr |
+
+ The mpidr field encodes the CPU ID based on the affinity information in the
+ architecture defined MPIDR, and the field is encoded as follows:
+ | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 |
+ | Aff3 | Aff2 | Aff1 | Aff0 |
+
+ The instr field encodes the system register to access based on the fields
+ defined in the A64 instruction set encoding for system register access
+ (RES means the bits are reserved for future use and should be zero):
+
+ | 15 ... 14 | 13 ... 11 | 10 ... 7 | 6 ... 3 | 2 ... 0 |
+ | Op 0 | Op1 | CRn | CRm | Op2 |
+
+ All system regs accessed through this API are (rw, 64-bit) and
+ kvm_device_attr.addr points to a __u64 value.
+
+ KVM_DEV_ARM_VGIC_CPU_SYSREGS accesses the CPU interface registers for the
+ CPU specified by the mpidr field.
+
+ Errors:
+ -ENXIO: Getting or setting this register is not yet supported
+ -EBUSY: VCPU is running
+ -EINVAL: Invalid mpidr 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.
+
+ kvm_device_attr.addr points to a __u32 value.
+
+ Errors:
+ -EINVAL: Value set is out of the expected range
+ -EBUSY: Value has already be set.
+
+
+ KVM_DEV_ARM_VGIC_GRP_CTRL
+ Attributes:
+ KVM_DEV_ARM_VGIC_CTRL_INIT
+ request the initialization of the VGIC, 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
+
+
+ KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO
+ Attributes:
+ The attr field of kvm_device_attr encodes the following values:
+ bits: | 63 .... 32 | 31 .... 10 | 9 .... 0 |
+ values: | mpidr | info | vINTID |
+
+ The vINTID specifies which set of IRQs is reported on.
+
+ The info field specifies which information userspace wants to get or set
+ using this interface. Currently we support the following info values:
+
+ VGIC_LEVEL_INFO_LINE_LEVEL:
+ Get/Set the input level of the IRQ line for a set of 32 contiguously
+ numbered interrupts.
+ vINTID must be a multiple of 32.
+
+ kvm_device_attr.addr points to a __u32 value which will contain a
+ bitmap where a set bit means the interrupt level is asserted.
+
+ Bit[n] indicates the status for interrupt vINTID + n.
+
+ SGIs and any interrupt with a higher ID than the number of interrupts
+ supported, will be RAZ/WI. LPIs are always edge-triggered and are
+ therefore not supported by this interface.
+
+ PPIs are reported per VCPU as specified in the mpidr field, and SPIs are
+ reported with the same value regardless of the mpidr specified.
+
+ The mpidr field encodes the CPU ID based on the affinity information in the
+ architecture defined MPIDR, and the field is encoded as follows:
+ | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 |
+ | Aff3 | Aff2 | Aff1 | Aff0 |