diff options
Diffstat (limited to 'Documentation/virtual/kvm/devices')
| -rw-r--r-- | Documentation/virtual/kvm/devices/arm-vgic.txt | 73 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/s390_flic.txt | 91 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vfio.txt | 22 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 26 |
4 files changed, 212 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt new file mode 100644 index 00000000000..7f4e91b1316 --- /dev/null +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -0,0 +1,73 @@ +ARM Virtual Generic Interrupt Controller (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. + +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. + + 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. + + 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 | cpu id | 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 + specified with cpu id field. Note that most distributor fields are not + banked, but return the same value regardless of the cpu id used to access + the register. + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + 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 | cpu id | 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. + + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt new file mode 100644 index 00000000000..4ceef53164b --- /dev/null +++ b/Documentation/virtual/kvm/devices/s390_flic.txt @@ -0,0 +1,91 @@ +FLIC (floating interrupt controller) +==================================== + +FLIC handles floating (non per-cpu) interrupts, i.e. I/O, service and some +machine check interruptions. All interrupts are stored in a per-vm list of +pending interrupts. FLIC performs operations on this list. + +Only one FLIC instance may be instantiated. + +FLIC provides support to +- add interrupts (KVM_DEV_FLIC_ENQUEUE) +- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS) +- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS) +- enable/disable for the guest transparent async page faults +- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*) + +Groups: + KVM_DEV_FLIC_ENQUEUE + Passes a buffer and length into the kernel which are then injected into + the list of pending interrupts. + attr->addr contains the pointer to the buffer and attr->attr contains + the length of the buffer. + The format of the data structure kvm_s390_irq as it is copied from userspace + is defined in usr/include/linux/kvm.h. + + KVM_DEV_FLIC_GET_ALL_IRQS + Copies all floating interrupts into a buffer provided by userspace. + When the buffer is too small it returns -ENOMEM, which is the indication + for userspace to try again with a bigger buffer. + All interrupts remain pending, i.e. are not deleted from the list of + currently pending interrupts. + attr->addr contains the userspace address of the buffer into which all + interrupt data will be copied. + attr->attr contains the size of the buffer in bytes. + + KVM_DEV_FLIC_CLEAR_IRQS + Simply deletes all elements from the list of currently pending floating + interrupts. No interrupts are injected into the guest. + + KVM_DEV_FLIC_APF_ENABLE + Enables async page faults for the guest. So in case of a major page fault + the host is allowed to handle this async and continues the guest. + + KVM_DEV_FLIC_APF_DISABLE_WAIT + Disables async page faults for the guest and waits until already pending + async page faults are done. This is necessary to trigger a completion interrupt + for every init interrupt before migrating the interrupt list. + + KVM_DEV_FLIC_ADAPTER_REGISTER + Register an I/O adapter interrupt source. Takes a kvm_s390_io_adapter + describing the adapter to register: + +struct kvm_s390_io_adapter { + __u32 id; + __u8 isc; + __u8 maskable; + __u8 swap; + __u8 pad; +}; + + id contains the unique id for the adapter, isc the I/O interruption subclass + to use, maskable whether this adapter may be masked (interrupts turned off) + and swap whether the indicators need to be byte swapped. + + + KVM_DEV_FLIC_ADAPTER_MODIFY + Modifies attributes of an existing I/O adapter interrupt source. Takes + a kvm_s390_io_adapter_req specifiying the adapter and the operation: + +struct kvm_s390_io_adapter_req { + __u32 id; + __u8 type; + __u8 mask; + __u16 pad0; + __u64 addr; +}; + + id specifies the adapter and type the operation. The supported operations + are: + + KVM_S390_IO_ADAPTER_MASK + mask or unmask the adapter, as specified in mask + + KVM_S390_IO_ADAPTER_MAP + perform a gmap translation for the guest address provided in addr, + pin a userspace page for the translated address and add it to the + list of mappings + + KVM_S390_IO_ADAPTER_UNMAP + release a userspace page for the translated address specified in addr + from the list of mappings diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt new file mode 100644 index 00000000000..ef51740c67c --- /dev/null +++ b/Documentation/virtual/kvm/devices/vfio.txt @@ -0,0 +1,22 @@ +VFIO virtual device +=================== + +Device types supported: + KVM_DEV_TYPE_VFIO + +Only one VFIO instance may be created per VM. The created device +tracks VFIO groups in use by the VM and features of those groups +important to the correctness and acceleration of the VM. As groups +are enabled and disabled for use by the VM, KVM should be updated +about their presence. When registered with KVM, a reference to the +VFIO-group is held by KVM. + +Groups: + KVM_DEV_VFIO_GROUP + +KVM_DEV_VFIO_GROUP attributes: + KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking + KVM_DEV_VFIO_GROUP_DEL: Remove a VFIO group from VFIO-KVM device tracking + +For each, kvm_device_attr.addr points to an int32_t file descriptor +for the VFIO group. diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt new file mode 100644 index 00000000000..0d16f96c0ea --- /dev/null +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -0,0 +1,26 @@ +Generic vm interface +==================================== + +The virtual machine "device" also accepts the ioctls KVM_SET_DEVICE_ATTR, +KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same +struct kvm_device_attr as other devices, but targets VM-wide settings +and controls. + +The groups and attributes per virtual machine, if any, are architecture +specific. + +1. GROUP: KVM_S390_VM_MEM_CTRL +Architectures: s390 + +1.1. ATTRIBUTE: KVM_S390_VM_MEM_CTRL +Parameters: none +Returns: -EBUSY if already a vcpus is defined, otherwise 0 + +Enables CMMA for the virtual machine + +1.2. ATTRIBUTE: KVM_S390_VM_CLR_CMMA +Parameteres: none +Returns: 0 + +Clear the CMMA status for all guest pages, so any pages the guest marked +as unused are again used any may not be reclaimed by the host. |