GICV_RPR, Virtual Machine Running Priority Register

The GICV_RPR characteristics are:

Purpose

This register indicates the running priority of the virtual CPU interface.

This register corresponds to the physical CPU interface register GICC_RPR.

Configuration

This register is present only when FEAT_GICv3_LEGACY is implemented and EL2 is implemented. Otherwise, direct accesses to GICV_RPR are RES0.

This register is available when the GIC implementation supports interrupt virtualization.

Attributes

GICV_RPR is a 32-bit register.

Field descriptions

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
RES0																								Priority

Bits [31:8]

Reserved, RES0.

Priority, bits [7:0]

The current running priority on the virtual CPU interface. This is the group priority of the current active interrupt.

If there are no active interrupts on the CPU interface, or all active interrupts have undergone a priority drop, the value returned is the Idle priority.

The priority returned is the group priority as if the BPR was set to the minimum value.

Accessing GICV_RPR

This register is used only when System register access is not enabled. When System register access is enabled:

For AArch32 implementations, ICC_RPR provides equivalent functionality.
For AArch64 implementations, ICC_RPR_EL1 provides equivalent functionality.

Depending on the implementation, if no bits are set to 1 in GICH_APR<n>, indicating no active virtual interrupts in the virtual CPU interface, the priority reads as 0xFF or 0xF8 to reflect the number of supported interrupt priority bits defined by GICH_VTR.PRIbits.

GICV_RPR can be accessed through the memory-mapped interfaces:

Component	Offset	Instance
GIC Virtual CPU interface	0x0014	GICV_RPR

This interface is accessible as follows:

When GICD_CTLR.DS == 0, accesses to this register are RO.
When an access is Secure, accesses to this register are RO.
When an access is Non-secure, accesses to this register are RO.

26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6