diff options
Diffstat (limited to 'kernel/Documentation/virtual/kvm/devices')
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/README | 1 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/arm-vgic.txt | 116 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/mpic.txt | 53 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/s390_flic.txt | 94 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/vfio.txt | 22 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/vm.txt | 85 | ||||
| -rw-r--r-- | kernel/Documentation/virtual/kvm/devices/xics.txt | 66 |
7 files changed, 437 insertions, 0 deletions
diff --git a/kernel/Documentation/virtual/kvm/devices/README b/kernel/Documentation/virtual/kvm/devices/README new file mode 100644 index 000000000..34a698341 --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/README @@ -0,0 +1 @@ +This directory contains specific device bindings for KVM_CAP_DEVICE_CTRL. diff --git a/kernel/Documentation/virtual/kvm/devices/arm-vgic.txt b/kernel/Documentation/virtual/kvm/devices/arm-vgic.txt new file mode 100644 index 000000000..3fb905429 --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -0,0 +1,116 @@ +ARM Virtual Generic Interrupt Controller (VGIC) +=============================================== + +Device types supported: + KVM_DEV_TYPE_ARM_VGIC_V2 ARM Generic Interrupt Controller v2.0 + KVM_DEV_TYPE_ARM_VGIC_V3 ARM Generic Interrupt Controller v3.0 + +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. + +Creating a guest GICv3 device requires a host GICv3 as well. +GICv3 implementations with hardware compatibility support allow a guest GICv2 +as well. + +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. + + 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. + + + 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 + - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2. + 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 + - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2. + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + 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, 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 diff --git a/kernel/Documentation/virtual/kvm/devices/mpic.txt b/kernel/Documentation/virtual/kvm/devices/mpic.txt new file mode 100644 index 000000000..8257397ad --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/mpic.txt @@ -0,0 +1,53 @@ +MPIC interrupt controller +========================= + +Device types supported: + KVM_DEV_TYPE_FSL_MPIC_20 Freescale MPIC v2.0 + KVM_DEV_TYPE_FSL_MPIC_42 Freescale MPIC v4.2 + +Only one MPIC instance, of any type, may be instantiated. The created +MPIC will act as the system interrupt controller, connecting to each +vcpu's interrupt inputs. + +Groups: + KVM_DEV_MPIC_GRP_MISC + Attributes: + KVM_DEV_MPIC_BASE_ADDR (rw, 64-bit) + Base address of the 256 KiB MPIC register space. Must be + naturally aligned. A value of zero disables the mapping. + Reset value is zero. + + KVM_DEV_MPIC_GRP_REGISTER (rw, 32-bit) + Access an MPIC register, as if the access were made from the guest. + "attr" is the byte offset into the MPIC register space. Accesses + must be 4-byte aligned. + + MSIs may be signaled by using this attribute group to write + to the relevant MSIIR. + + KVM_DEV_MPIC_GRP_IRQ_ACTIVE (rw, 32-bit) + IRQ input line for each standard openpic source. 0 is inactive and 1 + is active, regardless of interrupt sense. + + For edge-triggered interrupts: Writing 1 is considered an activating + edge, and writing 0 is ignored. Reading returns 1 if a previously + signaled edge has not been acknowledged, and 0 otherwise. + + "attr" is the IRQ number. IRQ numbers for standard sources are the + byte offset of the relevant IVPR from EIVPR0, divided by 32. + +IRQ Routing: + + The MPIC emulation supports IRQ routing. Only a single MPIC device can + be instantiated. Once that device has been created, it's available as + irqchip id 0. + + This irqchip 0 has 256 interrupt pins, which expose the interrupts in + the main array of interrupt sources (a.k.a. "SRC" interrupts). + + The numbering is the same as the MPIC device tree binding -- based on + the register offset from the beginning of the sources array, without + regard to any subdivisions in chip documentation such as "internal" + or "external" interrupts. + + Access to non-SRC interrupts is not implemented through IRQ routing mechanisms. diff --git a/kernel/Documentation/virtual/kvm/devices/s390_flic.txt b/kernel/Documentation/virtual/kvm/devices/s390_flic.txt new file mode 100644 index 000000000..d1ad9d5ca --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/s390_flic.txt @@ -0,0 +1,94 @@ +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. + -ENOBUFS is returned when the allocation of a kernelspace buffer has + failed. + -EFAULT is returned when copying data to userspace failed. + 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/kernel/Documentation/virtual/kvm/devices/vfio.txt b/kernel/Documentation/virtual/kvm/devices/vfio.txt new file mode 100644 index 000000000..ef51740c6 --- /dev/null +++ b/kernel/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/kernel/Documentation/virtual/kvm/devices/vm.txt b/kernel/Documentation/virtual/kvm/devices/vm.txt new file mode 100644 index 000000000..5542c4641 --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/vm.txt @@ -0,0 +1,85 @@ +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_ENABLE_CMMA +Parameters: none +Returns: -EBUSY if a vcpu is already defined, otherwise 0 + +Enables Collaborative Memory Management Assist (CMMA) for the virtual machine. + +1.2. ATTRIBUTE: KVM_S390_VM_MEM_CLR_CMMA +Parameters: 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. + +1.3. ATTRIBUTE KVM_S390_VM_MEM_LIMIT_SIZE +Parameters: in attr->addr the address for the new limit of guest memory +Returns: -EFAULT if the given address is not accessible + -EINVAL if the virtual machine is of type UCONTROL + -E2BIG if the given guest memory is to big for that machine + -EBUSY if a vcpu is already defined + -ENOMEM if not enough memory is available for a new shadow guest mapping + 0 otherwise + +Allows userspace to query the actual limit and set a new limit for +the maximum guest memory size. The limit will be rounded up to +2048 MB, 4096 GB, 8192 TB respectively, as this limit is governed by +the number of page table levels. + +2. GROUP: KVM_S390_VM_CPU_MODEL +Architectures: s390 + +2.1. ATTRIBUTE: KVM_S390_VM_CPU_MACHINE (r/o) + +Allows user space to retrieve machine and kvm specific cpu related information: + +struct kvm_s390_vm_cpu_machine { + __u64 cpuid; # CPUID of host + __u32 ibc; # IBC level range offered by host + __u8 pad[4]; + __u64 fac_mask[256]; # set of cpu facilities enabled by KVM + __u64 fac_list[256]; # set of cpu facilities offered by host +} + +Parameters: address of buffer to store the machine related cpu data + of type struct kvm_s390_vm_cpu_machine* +Returns: -EFAULT if the given address is not accessible from kernel space + -ENOMEM if not enough memory is available to process the ioctl + 0 in case of success + +2.2. ATTRIBUTE: KVM_S390_VM_CPU_PROCESSOR (r/w) + +Allows user space to retrieve or request to change cpu related information for a vcpu: + +struct kvm_s390_vm_cpu_processor { + __u64 cpuid; # CPUID currently (to be) used by this vcpu + __u16 ibc; # IBC level currently (to be) used by this vcpu + __u8 pad[6]; + __u64 fac_list[256]; # set of cpu facilities currently (to be) used + # by this vcpu +} + +KVM does not enforce or limit the cpu model data in any form. Take the information +retrieved by means of KVM_S390_VM_CPU_MACHINE as hint for reasonable configuration +setups. Instruction interceptions triggered by additionally set facilitiy bits that +are not handled by KVM need to by imlemented in the VM driver code. + +Parameters: address of buffer to store/set the processor related cpu + data of type struct kvm_s390_vm_cpu_processor*. +Returns: -EBUSY in case 1 or more vcpus are already activated (only in write case) + -EFAULT if the given address is not accessible from kernel space + -ENOMEM if not enough memory is available to process the ioctl + 0 in case of success diff --git a/kernel/Documentation/virtual/kvm/devices/xics.txt b/kernel/Documentation/virtual/kvm/devices/xics.txt new file mode 100644 index 000000000..42864935a --- /dev/null +++ b/kernel/Documentation/virtual/kvm/devices/xics.txt @@ -0,0 +1,66 @@ +XICS interrupt controller + +Device type supported: KVM_DEV_TYPE_XICS + +Groups: + KVM_DEV_XICS_SOURCES + Attributes: One per interrupt source, indexed by the source number. + +This device emulates the XICS (eXternal Interrupt Controller +Specification) defined in PAPR. The XICS has a set of interrupt +sources, each identified by a 20-bit source number, and a set of +Interrupt Control Presentation (ICP) entities, also called "servers", +each associated with a virtual CPU. + +The ICP entities are created by enabling the KVM_CAP_IRQ_ARCH +capability for each vcpu, specifying KVM_CAP_IRQ_XICS in args[0] and +the interrupt server number (i.e. the vcpu number from the XICS's +point of view) in args[1] of the kvm_enable_cap struct. Each ICP has +64 bits of state which can be read and written using the +KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctls on the vcpu. The 64 bit +state word has the following bitfields, starting at the +least-significant end of the word: + +* Unused, 16 bits + +* Pending interrupt priority, 8 bits + Zero is the highest priority, 255 means no interrupt is pending. + +* Pending IPI (inter-processor interrupt) priority, 8 bits + Zero is the highest priority, 255 means no IPI is pending. + +* Pending interrupt source number, 24 bits + Zero means no interrupt pending, 2 means an IPI is pending + +* Current processor priority, 8 bits + Zero is the highest priority, meaning no interrupts can be + delivered, and 255 is the lowest priority. + +Each source has 64 bits of state that can be read and written using +the KVM_GET_DEVICE_ATTR and KVM_SET_DEVICE_ATTR ioctls, specifying the +KVM_DEV_XICS_SOURCES attribute group, with the attribute number being +the interrupt source number. The 64 bit state word has the following +bitfields, starting from the least-significant end of the word: + +* Destination (server number), 32 bits + This specifies where the interrupt should be sent, and is the + interrupt server number specified for the destination vcpu. + +* Priority, 8 bits + This is the priority specified for this interrupt source, where 0 is + the highest priority and 255 is the lowest. An interrupt with a + priority of 255 will never be delivered. + +* Level sensitive flag, 1 bit + This bit is 1 for a level-sensitive interrupt source, or 0 for + edge-sensitive (or MSI). + +* Masked flag, 1 bit + This bit is set to 1 if the interrupt is masked (cannot be delivered + regardless of its priority), for example by the ibm,int-off RTAS + call, or 0 if it is not masked. + +* Pending flag, 1 bit + This bit is 1 if the source has a pending interrupt, otherwise 0. + +Only one XICS instance may be created per VM. |