virtio::devices

Trait VirtIODeviceDriver

Source 
pub trait VirtIODeviceDriver {
    // Required methods
    fn negotiate_features(&self, offered_features: u64) -> Option<u64>;
    fn device_type(&self) -> VirtIODeviceType;

    // Provided methods
    fn pre_device_initialization(&self) -> Result<(), ErrorCode> { ... }
    fn device_initialized(&self) -> Result<(), ErrorCode> { ... }
}
Expand description

VirtIO Device Driver.

This trait is to be implemented by drivers for exposed VirtIO devices, using the transports provided in crate::transports and queues in crate::queues to communicate with VirtIO devices.

Required Methods§

Source

fn negotiate_features(&self, offered_features: u64) -> Option<u64>

VirtIO feature negotiation.

This function is passed all driver-specific feature bits which the device exposes. Based on this function, the driver can select which features to enable through the return value of this function. This function is executed through the VirtIO transport, potentially before the device is initialized. As such, implementations of this function should be pure and only depend on the offered_features input parameter.

Source

fn device_type(&self) -> VirtIODeviceType

VirtIO device type which the driver supports.

This function must return the VirtIO device type that the driver is able to drive. Implementations of this function must be pure and return a constant value.

Provided Methods§

Source

fn pre_device_initialization(&self) -> Result<(), ErrorCode>

Hook called before the transport indicates DRIVER_OK to the device.

Because this trait must be object safe, a device cannot convey arbitrary errors through this interface. When this function returns an error, the transport will indicate FAILED to the device and return the error to the caller of VirtIOTransport::initialize. The driver can store a more elaborate error internally and expose it through a custom interface.

A default implementation of this function is provided which does nothing and returns Ok(()).

Source

fn device_initialized(&self) -> Result<(), ErrorCode>

Hook called after the transport indicated DRIVER_OK to the device.

Because this trait must be object safe, a device cannot convey arbitrary errors through this interface. When this function returns an error, the transport will NOT indicate FAILED to the device, but return the error to the caller of VirtIOTransport::initialize. The driver can store a more elaborate error internally and expose it through a custom interface. The driver remains responsible for any deinitialization of the device as a result of this error.

A default implementation of this function is provided which does nothing and returns Ok(()).

Implementors§