<!--
{
  "availability" : [
    "macOS: 27.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Virtualization",
  "identifier" : "/documentation/Virtualization/VZCustomVirtioDevice/update(_:completionHandler:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Virtualization"
    ],
    "preciseIdentifier" : "c:objc(cs)VZCustomVirtioDevice(im)updateDeviceSpecificConfiguration:completionHandler:"
  },
  "title" : "update(_:completionHandler:)"
}
-->

# update(_:completionHandler:)

Updates the device’s device-specific configuration.

```
func update(_ newConfiguration: VZVirtioDeviceSpecificConfiguration, completionHandler: @escaping @Sendable ((any Error)?) -> Void)
```

```
func update(_ newConfiguration: VZVirtioDeviceSpecificConfiguration) async throws
```

## Parameters

`newConfiguration`

The [`VZVirtioDeviceSpecificConfiguration`](/documentation/Virtualization/VZVirtioDeviceSpecificConfiguration) object that contains the new configuration data.

`completionHandler`

A block the framework calls after the device’s configuration updates successfully, or on error.
The error parameter the framework passes to the block is `nil` if the configuration update was successful.

## Discussion

The size of the underlying data for the new configuration must be the same as the previous
configuration. The framework raises an exception if this condition isn’t met.

---

Copyright &copy; 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)