33.10.5. ARM GIC
Generic Interrupt Controller.
Examples:
ARM publishes both a GIC standard architecture specification, and specific implementations of these specifications.
The specification can be found at: https://developer.arm.com/docs/ihi0069/latest
As of 2019Q2 the latest version if v4.0, often called GICv4: https://static.docs.arm.com/ihi0069/e/Q1-IHI0069E_gic_architecture_specification_v3.1_19_01_21.pdf
That document clarifies that GICv2 is a legacy specification only:
Version 2.0 (GICv2) is only described in terms of the GICv3 optional support for legacy operation
The specific models have names of type GIC-600, GIC-500, etc.
In QEMU v4.0.0, the GICv3 can be selected with an extra -machine gic_version=3 option.
In gem5 3126e84db773f64e46b1d02a9a27892bf6612d30, the GIC is determined by selecting the platform as explained at: gem5 ARM platforms.