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.
- 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.
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.