# vCPU Management Create and run virtual CPUs, and manage CPU-specific registers and features. ## Topics ### Creation and destruction [`func hv_vcpu_create(UnsafeMutablePointer, UnsafeMutablePointer?>, hv_vcpu_config_t?) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_create(_:_:_:)) Creates a vCPU instance for the current thread. [`func hv_vcpu_destroy(hv_vcpu_t) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_destroy(_:)) Destroys the vCPU instance associated with the current thread. [`typealias hv_vcpu_options_t`](/documentation/Hypervisor/hv_vcpu_options_t) Options for creating a new vCPU instance. [vCPU Creation Behavior](/documentation/Hypervisor/1447317-vcpu-creation-behavior) An enumeration representing the default creation options for virtual CPUs. [`typealias hv_vcpuid_t`](/documentation/Hypervisor/hv_vcpuid_t) The type that describes a vCPU ID. ### Runtime [`func hv_vcpu_run_until(hv_vcpuid_t, UInt64) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_run_until(_:_:)) Executes a vCPU until it reaches the deadline defined in absolute time units you provide. [`func hv_vcpu_interrupt(UnsafeMutablePointer, UInt32) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_interrupt(_:_:)) Forces the vCPU instances you provide to immediately exit the VM. [`func hv_vcpu_flush(hv_vcpuid_t) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_flush(_:)) Flushes the cached state of a vCPU. [`func hv_vcpu_get_exec_time(hv_vcpu_t, UnsafeMutablePointer) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_get_exec_time(_:_:)) Returns, by reference, the cumulative execution time of a vCPU, in nanoseconds. [`func hv_vcpu_run(hv_vcpu_t) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_run(_:)) Starts the execution of a vCPU. [Execution Deadlines](/documentation/Hypervisor/3553338-execution-deadlines) An enumeration that describes available execution deadlines available to vCPUs. ### Synchronization [`func hv_vm_sync_tsc(UInt64) -> hv_return_t`](/documentation/Hypervisor/hv_vm_sync_tsc(_:)) Synchronizes guest timestamp counters (TSC) across all vCPUs. ### Model-Specific Registers [Extending vCPU Capabilities Using Model-Specific Registers](/documentation/Hypervisor/extending-vcpu-capabilities-using-model-specific-registers) Configure specific client performance monitoring and enable other vCPU capabilities using Model-Specific Registers. [`func hv_vcpu_read_msr(hv_vcpuid_t, UInt32, UnsafeMutablePointer) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_read_msr(_:_:_:)) Returns, by reference, the current value of a Model-Specific Register (MSR) of a vCPU. [`func hv_vcpu_write_msr(hv_vcpuid_t, UInt32, UInt64) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_write_msr(_:_:_:)) Sets the value of a Model-Specific Register (MSR) of a vCPU. [`func hv_vcpu_enable_native_msr(hv_vcpuid_t, UInt32, Bool) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_enable_native_msr(_:_:_:)) Enables or disables a Model-Specific Register (MSR) that the VM uses natively. [`func hv_vcpu_set_msr_access(hv_vcpuid_t, UInt32, hv_msr_flags_t) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_set_msr_access(_:_:_:)) Controls the guest access of a managed Model-Specific Register (MSR). [`func hv_vcpu_enable_managed_msr(hv_vcpuid_t, UInt32, Bool) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_enable_managed_msr(_:_:_:)) Enables the guest access of a managed Model-Specific Register (MSR). [`typealias hv_msr_flags_t`](/documentation/Hypervisor/hv_msr_flags_t) The type representing the native Model-Specific Register (MSR) permissions. [Model-Specific Registers](/documentation/Hypervisor/3727856-model-specific-registers) [MSR Permissions](/documentation/Hypervisor/3567078-msr_permissions-enum) An enumeration that describes possible Model-Specific Register (MSR) permisssions. ### CPU Registers [`func hv_vcpu_read_register(hv_vcpuid_t, hv_x86_reg_t, UnsafeMutablePointer) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_read_register(_:_:_:)) Returns, by reference, the current value of an architectural x86 register of a vCPU. [`func hv_vcpu_write_register(hv_vcpuid_t, hv_x86_reg_t, UInt64) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_write_register(_:_:_:)) Sets the value of an architectural x86 register of a vCPU. [`struct hv_x86_reg_t`](/documentation/Hypervisor/hv_x86_reg_t) The type that defines x86 architectural registers. ### Floating Point (FP) State [`func hv_vcpu_read_fpstate(hv_vcpuid_t, UnsafeMutableRawPointer, Int) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_read_fpstate(_:_:_:)) Returns, by reference, the current architectural x86 floating point and SIMD state of a vCPU. [`func hv_vcpu_write_fpstate(hv_vcpuid_t, UnsafeMutableRawPointer, Int) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_write_fpstate(_:_:_:)) Sets the architectural x86 floating point and SIMD state of a vCPU. ### Memory Affinity [`func hv_vcpu_set_space(hv_vcpuid_t, hv_vm_space_t) -> hv_return_t`](/documentation/Hypervisor/hv_vcpu_set_space(_:_:)) Associates the vCPU instance with an allocated address space. --- 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)