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# VZVirtioFeatureSet

Values that represent a set of Virtio feature bits.

```
class VZVirtioFeatureSet
```

## Overview

A `VZVirtioFeatureSet` encapsulates the 64-bit Virtio feature set as two 32-bit subsets.
The Virtio specification currently supports up to 64 feature bits, where subset0 represents
bits 0 through 31 and subset1 represents bits 32 through 63.

Don’t instantiate `VZVirtioFeatureSet` directly. It’s provided through the
`VZCustomVirtioDeviceConfiguration.mandatoryFeatures` and
`VZCustomVirtioDeviceConfiguration.optionalFeatures` properties.

## Topics

### Instance Properties

[`var subset0: UInt32`](/documentation/Virtualization/VZVirtioFeatureSet/subset0)

An unsigned 32-bit integer that represents Virtio feature bits 0 through 31.

[`var subset1: UInt32`](/documentation/Virtualization/VZVirtioFeatureSet/subset1)

An unsigned 32-bit integer that represents Virtio feature bits 32 through 63.

## See Also

[`class VZNegotiatedVirtioFeatureSet`](/documentation/Virtualization/VZNegotiatedVirtioFeatureSet)

Values that represent a set of negotiated Virtio feature bits.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`CVarArg`](/documentation/Swift/CVarArg)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`Hashable`](/documentation/Swift/Hashable)

[`NSCopying`](/documentation/Foundation/NSCopying)

### Inherits From

[`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class)

---

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