HV_X64_MSR_POWER_STATE_TRIGGER union

The HV_X64_MSR_POWER_STATE_TRIGGER union describes how power state trigger registers are encoded.

Syntax

typedef union _HV_X64_MSR_POWER_STATE_TRIGGER {
  UINT64 AsUINT64;
  struct {
    UINT8  IdleEntryCount;
    UINT8  Reserved[3];
    UINT32 Reserved2  :31;
    UINT32 ActiveBM_STS  :1;
  };
} HV_X64_MSR_POWER_STATE_TRIGGER, *PHV_X64_MSR_POWER_STATE_TRIGGER;

Members

AsUINT64

A member in the union that can hold one 64-bit value that identifies the encoding of a power state trigger register.

IdleEntryCount

A UINT8 value that contains the number of times that the logical processor went idle since the power management partition took the partition's affinity bound virtual processor idle. Setting this member is equivalent to setting bits 1 through 8 of the 64-bit AsUINT64 member (0x00000000000000FF).

Reserved

An array of three UINT8 values. All values are reserved and should be set to zero. Setting this member is equivalent to setting bits 9 through 32 of the 64-bit AsUINT64 member (0x00000000FFFFFF00).

Reserved2

This member is reserved and should be set to zero. Setting this member to zero is equivalent to setting each of bits 33 through 63 (0x7FFFFFFF00000000) of the 64-bit AsUINT64 member to zero.

ActiveBM_STS

A UINT32 value that indicates whether to specify the value of the ACPI power management bit BM_STS, which determines the power state to enter when considering a transition to or from the C2 and C3 power states. Setting this member is equivalent to setting bit 64 of the 64-bit AsUINT64 member (0x8000000000000000).

Remarks

Reading from the trigger register takes the processor idle from the perspective of the power management partition. When the processor wakes, the value returned contains information about the idle operation attempted. For more information about power state trigger registers, see Hardware Management Data Types.

The following table shows how to set power state trigger registers to trigger power state changes.

Requirements

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Build date: 11/16/2013