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Diffstat (limited to 'Documentation/virtual/kvm/devices/s390_flic.txt')
| -rw-r--r-- | Documentation/virtual/kvm/devices/s390_flic.txt | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt deleted file mode 100644 index a4e20a090174..000000000000 --- a/Documentation/virtual/kvm/devices/s390_flic.txt +++ /dev/null @@ -1,163 +0,0 @@ -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) -- purge one pending floating I/O interrupt (KVM_DEV_FLIC_CLEAR_IO_IRQ) -- enable/disable for the guest transparent async page faults -- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*) -- modify AIS (adapter-interruption-suppression) mode state (KVM_DEV_FLIC_AISM) -- inject adapter interrupts on a specified adapter (KVM_DEV_FLIC_AIRQ_INJECT) -- get/set all AIS mode states (KVM_DEV_FLIC_AISM_ALL) - -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_CLEAR_IO_IRQ - Deletes one (if any) I/O interrupt for a subchannel identified by the - subsystem identification word passed via the buffer specified by - attr->addr (address) and attr->attr (length). - - 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 flags; -}; - - 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), - swap whether the indicators need to be byte swapped, and flags contains - further characteristics of the adapter. - Currently defined values for 'flags' are: - - KVM_S390_ADAPTER_SUPPRESSIBLE: adapter is subject to AIS - (adapter-interrupt-suppression) facility. This flag only has an effect if - the AIS capability is enabled. - Unknown flag values are ignored. - - - KVM_DEV_FLIC_ADAPTER_MODIFY - Modifies attributes of an existing I/O adapter interrupt source. Takes - a kvm_s390_io_adapter_req specifying 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 - Note: A new mapping will be created unconditionally; therefore, - the calling code should avoid making duplicate mappings. - - KVM_S390_IO_ADAPTER_UNMAP - release a userspace page for the translated address specified in addr - from the list of mappings - - KVM_DEV_FLIC_AISM - modify the adapter-interruption-suppression mode for a given isc if the - AIS capability is enabled. Takes a kvm_s390_ais_req describing: - -struct kvm_s390_ais_req { - __u8 isc; - __u16 mode; -}; - - isc contains the target I/O interruption subclass, mode the target - adapter-interruption-suppression mode. The following modes are - currently supported: - - KVM_S390_AIS_MODE_ALL: ALL-Interruptions Mode, i.e. airq injection - is always allowed; - - KVM_S390_AIS_MODE_SINGLE: SINGLE-Interruption Mode, i.e. airq - injection is only allowed once and the following adapter interrupts - will be suppressed until the mode is set again to ALL-Interruptions - or SINGLE-Interruption mode. - - KVM_DEV_FLIC_AIRQ_INJECT - Inject adapter interrupts on a specified adapter. - attr->attr contains the unique id for the adapter, which allows for - adapter-specific checks and actions. - For adapters subject to AIS, handle the airq injection suppression for - an isc according to the adapter-interruption-suppression mode on condition - that the AIS capability is enabled. - - KVM_DEV_FLIC_AISM_ALL - Gets or sets the adapter-interruption-suppression mode for all ISCs. Takes - a kvm_s390_ais_all describing: - -struct kvm_s390_ais_all { - __u8 simm; /* Single-Interruption-Mode mask */ - __u8 nimm; /* No-Interruption-Mode mask * -}; - - simm contains Single-Interruption-Mode mask for all ISCs, nimm contains - No-Interruption-Mode mask for all ISCs. Each bit in simm and nimm corresponds - to an ISC (MSB0 bit 0 to ISC 0 and so on). The combination of simm bit and - nimm bit presents AIS mode for a ISC. - - KVM_DEV_FLIC_AISM_ALL is indicated by KVM_CAP_S390_AIS_MIGRATION. - -Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR device ioctls executed on -FLIC with an unknown group or attribute gives the error code EINVAL (instead of -ENXIO, as specified in the API documentation). It is not possible to conclude -that a FLIC operation is unavailable based on the error code resulting from a -usage attempt. - -Note: The KVM_DEV_FLIC_CLEAR_IO_IRQ ioctl will return EINVAL in case a zero -schid is specified. |