HvSetVpRegisters function

The HvSetVpRegisters function writes the architectural state of a virtual processor.

Syntax


HV_STATUS  HvSetVpRegisters(
  _In_     HV_PARTITION_ID PartitionId,
  _In_     HV_VP_INDEX VpIndex,
  _Inout_  PUINT32 RegisterCount,
  _In_     PCHV_REGISTER_NAME RegisterNameList,
  _Out_    PCHV_REGISTER_VALUE RegisterValueList
);

Parameters

PartitionId [in]: An HV_PARTITION_ID value that identifies the partition on which HvSetVpRegisters writes the architectural state of a virtual processor. HV_PARTITION_ID is defined as an unsigned 64-bit (UINT64) value.
VpIndex [in]: An HV_VP_INDEX value that specifies the index of the virtual processor of which HvSetVpRegisters writes the architectural state. HV_VP_INDEX is defined as an unsigned 32-bit (UINT32) value.
RegisterCount [in, out]: A pointer to a variable that contains the number of registers to modify. HvSetVpRegisters specifies the actual number of registers that it modified.
RegisterNameList [in]: A pointer to an array of HV_REGISTER_NAME variables for the names of the registers that HvSetVpRegisters modifies.
RegisterValueList [out]: A pointer to an array of HV_REGISTER_VALUE variables that contain the new values for the registers that the RegisterNameList array specifies.

Return value

HvSetVpRegisters returns one of the following values. In addition to these values, HvSetVpRegisters can also return one of the values that are specified in Common Hypercall Status Codes.

Return code	Description
HV_STATUS_SUCCESS	HvSetVpRegisters successfully wrote the architectural state of a virtual processor.
HV_STATUS_ACCESS_DENIED	The caller is neither the partition itself nor the parent of the specified partition.
HV_STATUS_INVALID_PARTITION_ID	The specified partition identifier is invalid.
HV_STATUS_INVALID_VP_INDEX	The specified VP index does not reference a virtual processor within the specified partition.
HV_STATUS_INVALID_PARAMETER	One of the following invalid parameter conditions exists: One of the specified register names is invalid. One of the specified registers is read only. One of the specified register values is not valid (for example, a reserved bit is not zero).
HV_STATUS_INVALID_PARTITION_STATE	The specified partition is not in the active state.

Remarks

The HvSetVpRegisters function is a rep call. The caller passes a valid value to the RegisterCount parameter in a call to HvSetVpRegisters as the rep count. For more information about hypercall inputs, see Hypercall Inputs.

HvSetVpRegisters writes the state of a virtual processor as a series of register values that are contained in the array that the RegisterValueList parameter specifies. Each register value that HvSetVpRegisters writes corresponds to a register name that the caller provided as input to the array that the RegisterNameList parameter specifies.

HvSetVpRegisters performs minimal error checking when it modifies a register value. In particular, the hypervisor will validate that reserved bits of a register are set to zero, bits that are architecturally defined as always containing a zero or a one are set appropriately, and specified bits beyond the architectural size of the register are zeroed.

HvSetVpRegisters cannot be used to modify the value of a read-only register.

HvSetVpRegisters does not perform any side-effects of modifying a register, which includes generation of exceptions, pipeline synchronizations, TLB flushes, and so on.

HvSetVpRegisters has the following restrictions:

The partition that PartitionId specifies must be in the active state.
The caller must be the parent of the partition that is specified by PartitionId or the partition that specifies its own partition identifier.

Native Interface

HvSetVpRegisters [rep]
	Call Code = 0x0051
Input Parameter Header
0	PartitionId (8 bytes)
8	VpIndex (4 bytes) RsvdZ (4 bytes)
Input List Element
0	RegisterName[0] (4 bytes) Padding (4 bytes)
8	Padding (8 bytes)
16	RegisterValue (low-order) (8 bytes)
24	RegisterValue (high-order) (8 bytes)

Requirements