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hv_vmx_vcpu_get_cap_write_vmcs(_:_:_:_:)

Returns the allowed_0 and allowed_1 masks for a VMCS field of a vCPU.

Declaration

func hv_vmx_vcpu_get_cap_write_vmcs(_ vcpu: hv_vcpuid_t, _ field: UInt32, _ allowed_0: UnsafeMutablePointer<UInt64>, _ allowed_1: UnsafeMutablePointer<UInt64>) -> hv_return_t

Parameters

  • vcpu:

    The vCPU ID.

  • field:

    The ID of the VMCS field for which to return capabilities.

  • allowed_0:

    The pointer to the VMCS allowed_0 mask (written on success).

  • allowed_1:

    The pointer to the VMCS allowed_1 mask (written on success).

Return Value

HV_SUCCESS if the operation was successful, otherwise an error code specified in hv_return_t.

Discussion

Returns the constraints imposed by the Hypervisor framework on the given VMCS field, in the form of allowed_0 and allowed_1 masks, that indicate what bit values may be set when writing the given VMCS field.

When writing to a VMCS field, the caller is allowed to set bits that are 0 in its allowed_0 mask to 0, and bits that are 1 in its allowed_1 mask to 1. This means:

  • If allowed_0 = 0, allowed_1 = 0 -> must be NOT SET.

  • If allowed_0 = 0, allowed_1 = 1 -> can be either SET or NOT SET.

  • If allowed_0 = 1, allowed_1 = 0 -> undefined (shouldn’t happen).

  • If allowed_0 = 1, allowed_1 = 1 -> must be SET.

See Also

Field management