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Diffstat (limited to 'Documentation/virtual/kvm/devices/xics.txt')
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1 files changed, 0 insertions, 66 deletions
diff --git a/Documentation/virtual/kvm/devices/xics.txt b/Documentation/virtual/kvm/devices/xics.txt deleted file mode 100644 index 42864935ac5d..000000000000 --- a/Documentation/virtual/kvm/devices/xics.txt +++ /dev/null @@ -1,66 +0,0 @@ -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. |