Struct virtio_device::fake_queue::IdentityDriverMem

pub struct IdentityDriverMem { /* private fields */ }

Implementation of crate::mem::DriverMem assuming the identity translation.

Can be used to allocate valid DeviceRange using the [range_with_layout] or [new_range] methods. This then implements the identity transformation in [translate] meaning that:

let range = identity_driver_mem.new_range(64)?;
assert_eq!(identity_driver_mem.translate(range.get().into()), Some(range)

There is no mechanism to free or deallocate any constructed ranges, this is neccessary to ensure they remain valid their provided lifetimes. Allocations will be freed once the IdentityDriverMem is dropped.

Implementations

impl IdentityDriverMem

pub fn new() -> IdentityDriverMem

Construct a new IdentityDriverMem

pub fn range_with_layout<'a>( &'a self, layout: Layout, ) -> Option<DeviceRange<'a>>

Allocate with a specific alloc::Layout

Specifying a specific alloc::Layout for the range is to allow for alignments to be specified so that underlying DeviceRange can be accessed directly as a desired object using DeviceRange::try_ptr.

The allocated range will be zeroed.

pub fn new_range<'a>(&'a self, size_bytes: usize) -> Option<DeviceRange<'a>>

Allocate a range to hold size_bytes

The backing allocation will be aligned to match a u64, but the DeviceRange reported by get will be exactly size_bytes long.

The allocated range will be zeroed.

pub fn alloc_queue_memory<'a>( &'a self, queue_size: u16, ) -> Option<QueueMemory<'a>>

Allocates ranges to fill and return a QueueMemory

Trait Implementations

impl DriverMem for IdentityDriverMem

fn translate<'a>(&'a self, driver: DriverRange) -> Option<DeviceRange<'a>>

Attempt to turn a DriverRange into a DeviceRange.