# MSR Information Fields The type that describes Machine Specific Register (MSR) fields. ## Topics ### Fields [`HV_VMX_INFO_MSR_IA32_ARCH_CAPABILITIES`](/documentation/Hypervisor/HV_VMX_INFO_MSR_IA32_ARCH_CAPABILITIES) The value of the IA32 architecture capabilities model specific register. [`HV_VMX_INFO_MSR_IA32_PERF_CAPABILITIES`](/documentation/Hypervisor/HV_VMX_INFO_MSR_IA32_PERF_CAPABILITIES) The value of the IA32 performance capabilities model specific register. [`HV_VMX_VALID_MSR_IA32_PERFEVNTSEL`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_PERFEVNTSEL) The bitmask of the supported fields of the IA32 Performance-Event Selection Mode model specific register. [`HV_VMX_VALID_MSR_IA32_FIXED_CTR_CTRL`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_FIXED_CTR_CTRL) The bitmask fo the supported fields of the Fixed-Function-Counter Control Register. [`HV_VMX_VALID_MSR_IA32_PERF_GLOBAL_CTRL`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_PERF_GLOBAL_CTRL) The bitmask of the supported fields of the IA32 Global-Counter Control Facility Register. [`HV_VMX_VALID_MSR_IA32_PERF_GLOBAL_STATUS`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_PERF_GLOBAL_STATUS) The bitmast of the supported fields of the Global-Counter-Control Status model specific register. [`HV_VMX_VALID_MSR_IA32_DEBUGCTL`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_DEBUGCTL) The bitmask of the IA32 Debug-Control model specific register. [`HV_VMX_VALID_MSR_IA32_SPEC_CTRL`](/documentation/Hypervisor/HV_VMX_VALID_MSR_IA32_SPEC_CTRL) The bitmask of the suppported fields of the Speculation Control model specific register. [`HV_VMX_NEED_MSR_IA32_SPEC_CTRL`](/documentation/Hypervisor/HV_VMX_NEED_MSR_IA32_SPEC_CTRL) The bitmask of the required fields of the IA32 Speculation Control model specific register. --- 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)