# hv_vmx_vcpu_read_shadow_vmcs(_:_:_:) Returns the current value of a shadow VMCS field of a vCPU. ``` func hv_vmx_vcpu_read_shadow_vmcs(_ vcpu: hv_vcpuid_t, _ field: UInt32, _ value: UnsafeMutablePointer) -> hv_return_t ``` ## Parameters `vcpu` The vCPU ID. `field` The ID of the shadow VMCS field to read. `value` The pointer to the shadow VMCS field value the Hypervisor writes following a successful operation. ## Return Value [`HV_SUCCESS`](/documentation/Hypervisor/HV_SUCCESS) if the operation was successful, otherwise an error code specified in [`hv_return_t`](/documentation/Hypervisor/hv_return_t). ## Discussion> Important: > This function must be called by the owning thread. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)