# hv_vmx_read_capability(_:_:) Returns, by reference, the VMX virtualization capabilities of the host processor. ``` func hv_vmx_read_capability(_ field: hv_vmx_capability_t, _ value: UnsafeMutablePointer) -> hv_return_t ``` ## Parameters `field` The capability of the host processor to return. For a list of field IDs, see [`hv_vmx_capability_t`](/documentation/Hypervisor/hv_vmx_capability_t). `value` The value of the capability `field`, on output. For a list of possible values, see `VMX Capability Field Values`. ## 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)