ICH_VMCR, Interrupt Controller Virtual Machine Control Register

The ICH_VMCR characteristics are:

Purpose

Enables the hypervisor to save and restore the virtual machine view of the GIC state.

Configuration

AArch32 System register ICH_VMCR bits [31:0] are architecturally mapped to AArch64 System register ICH_VMCR_EL2[31:0] .

If EL2 is not implemented, this register is RES0 from EL3.

RW fields in this register reset to architecturally UNKNOWN values.

Attributes

ICH_VMCR is a 32-bit register.

Field descriptions

The ICH_VMCR bit assignments are:

VPMR, bits [31:24]

Virtual Priority Mask. The priority mask level for the virtual CPU interface. If the priority of a pending virtual interrupt is higher than the value indicated by this field, the interface signals the virtual interrupt to the PE.

This field is an alias of ICV_PMR.Priority.

This field resets to an architecturally UNKNOWN value.

VBPR0, bits [23:21]

Virtual Binary Point Register, Group 0. Defines the point at which the priority value fields split into two parts, the group priority field and the subpriority field. The group priority field determines Group 0 interrupt preemption, and also determines Group 1 interrupt preemption if ICH_VMCR.VCBPR == 1.

This field is an alias of ICV_BPR0.BinaryPoint.

This field resets to an architecturally UNKNOWN value.

VBPR1, bits [20:18]

Virtual Binary Point Register, Group 1. Defines the point at which the priority value fields split into two parts, the group priority field and the subpriority field. The group priority field determines Group 1 interrupt preemption if ICH_VMCR.VCBPR == 0.

This field is an alias of ICV_BPR1.BinaryPoint.

This field resets to an architecturally UNKNOWN value.

Bits [17:10]

Reserved, RES0.

VEOIM, bit [9]

Virtual EOI mode. Controls whether a write to an End of Interrupt register also deactivates the virtual interrupt:

This bit is an alias of ICV_CTLR.EOImode.

This field resets to an architecturally UNKNOWN value.

Bits [8:5]

Reserved, RES0.

VCBPR, bit [4]

Virtual Common Binary Point Register. Possible values of this bit are:

This field is an alias of ICV_CTLR.CBPR.

This field resets to an architecturally UNKNOWN value.

VFIQEn, bit [3]

Virtual FIQ enable. Possible values of this bit are:

This bit is an alias of GICV_CTLR.FIQEn.

In implementations where the Non-secure copy of ICC_SRE.SRE is always 1, this bit is RES1.

This field resets to an architecturally UNKNOWN value.

VAckCtl, bit [2]

Virtual AckCtl. Possible values of this bit are:

This bit is an alias of GICV_CTLR.AckCtl.

This field is supported for backwards compatibility with GICv2. Arm deprecates the use of this field.

In implementations where the Non-secure copy of ICC_SRE.SRE is always 1, this bit is RES0.

This field resets to an architecturally UNKNOWN value.

VENG1, bit [1]

Virtual Group 1 interrupt enable. Possible values of this bit are:

This bit is an alias of ICV_IGRPEN1.Enable.

This field resets to an architecturally UNKNOWN value.

VENG0, bit [0]

Virtual Group 0 interrupt enable. Possible values of this bit are:

This bit is an alias of ICV_IGRPEN0.Enable.

This field resets to an architecturally UNKNOWN value.

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then
        AArch32.TakeHypTrapException(0x03);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if ICC_HSRE.SRE == '0' then
        UNDEFINED;
    else
        return ICH_VMCR;
elsif PSTATE.EL == EL3 then
    if ICC_MSRE.SRE == '0' then
        UNDEFINED;
    else
        return ICH_VMCR;
              

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then
        AArch32.TakeHypTrapException(0x03);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if ICC_HSRE.SRE == '0' then
        UNDEFINED;
    else
        ICH_VMCR = R[t];
elsif PSTATE.EL == EL3 then
    if ICC_MSRE.SRE == '0' then
        UNDEFINED;
    else
        ICH_VMCR = R[t];