HV_EMULATED_TIMER_CONTROL union

The HV_EMULATED_TIMER_CONTROL union describes the timer control, which encodes the local APIC destination.

Syntax

typedef union _HV_EMULATED_TIMER_CONTROL {
  UINT64 AsUINT64;
  struct {
    UINT32 Vector  :8;
    UINT32 DeliveryMode  :3;
    UINT32 LogicalDestinationMode  :1;
    UINT32 Enabled  :1;
    UINT32 Reserved1  :19;
    UINT32 Reserved2  :24;
    UINT32 Mda  :8;
  };
} HV_EMULATED_TIMER_CONTROL, *PHV_EMULATED_TIMER_CONTROL;

Members

AsUINT64

A member in the union that can hold one 64-bit value that describes the timer control.

Vector

A UINT32 value that indicates the vector to use for the timer control. The vector value is set in the first through eighth bits of the 64-bit AsUINT64 member (0x00000000000000FF).

DeliveryMode

A UINT32 value that indicates the delivery mode to use for the timer control. The delivery-mode value is set in the ninth through eleventh bits of the 64-bit AsUINT64 member (0x0000000000000700).

LogicalDestinationMode

A UINT32 value that indicates whether the virtual interrupt is a logical destination mode. Setting this member is equivalent to setting the twelfth bit of the 64-bit AsUINT64 member (0x0000000000000800).

Enabled

A UINT32 value that indicates whether to enable the timer control. Setting this member is equivalent to setting the thirteenth bit of the 64-bit AsUINT64 member (0x0000000000001000).

Reserved1

This member is reserved and should be set to zero. Setting this member to zero is equivalent to setting the remaining 19 bits (0x00000000FFFFE000) in the first group of 32 bits of the 64-bit AsUINT64 member to zeros.

Reserved2

This member is reserved and should be set to zero. Setting this member to zero is equivalent to setting each of the first 24 bits (0x00FFFFFF00000000) in the second group of 32 bits of the 64-bit AsUINT64 member to zero.

Mda

A UINT32 value that indicates the message destination address. This value is set in the last 8 bits of the second group of 32 bits of the 64-bit AsUINT64 member (0xFF00000000000000).

Remarks

The members of the periodic timer assist control conform to those members that are used by the local APIC's Interrupt Command Register (ICR). When the timer assist control property (HvPartitionPropertyEmulatedTimerPeriod of HV_PARTITION_PROPERTY_CODE) is set to zero, the timer assist control Enabled flag will be cleared, which disables the timer assist.

Requirements

See also

HV_PARTITION_PROPERTY_CODE

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Build date: 11/16/2013