Struct virtio_queue::QueueState

pub struct QueueState {
    pub max_size: u16,
    pub next_avail: Wrapping<u16>,
    pub next_used: Wrapping<u16>,
    pub event_idx_enabled: bool,
    pub signalled_used: Option<Wrapping<u16>>,
    pub size: u16,
    pub ready: bool,
    pub desc_table: GuestAddress,
    pub avail_ring: GuestAddress,
    pub used_ring: GuestAddress,
}

Struct to maintain information and manipulate state of a virtio queue.

Fields

max_size: u16

The maximum size in elements offered by the device.

next_avail: Wrapping<u16>

Tail position of the available ring.

next_used: Wrapping<u16>

Head position of the used ring.

event_idx_enabled: bool

VIRTIO_F_RING_EVENT_IDX negotiated.

signalled_used: Option<Wrapping<u16>>

The last used value when using VIRTIO_F_EVENT_IDX.

size: u16

The queue size in elements the driver selected.

ready: bool

Indicates if the queue is finished with configuration.

desc_table: GuestAddress

Guest physical address of the descriptor table.

avail_ring: GuestAddress

Guest physical address of the available ring.

used_ring: GuestAddress

Guest physical address of the used ring.

Implementations

impl QueueState

pub fn iter<M>(&mut self, mem: M) -> Result<AvailIter<'_, M>, Error> where
    M: Deref,
    M::Target: GuestMemory + Sized, 

Get a consuming iterator over all available descriptor chain heads offered by the driver.

Arguments

• mem - the GuestMemory object that can be used to access the queue buffers.

Trait Implementations

impl Clone for QueueState

fn clone(&self) -> QueueState

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QueueState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> QueueStateGuard<'a> for QueueState

type G = &'a mut Self

Type for guard returned by Self::lock().

impl QueueStateT for QueueState

fn new(max_size: u16) -> Self

Construct an empty virtio queue state object with the given max_size.

fn is_valid<M: GuestMemory>(&self, mem: &M) -> bool

Check whether the queue configuration is valid.

fn reset(&mut self)

Reset the queue to the initial state.

fn lock(&mut self) -> <Self as QueueStateGuard<'_>>::G

Get an exclusive reference to the underlying QueueState object.

fn max_size(&self) -> u16

Get the maximum size of the virtio queue.

fn set_size(&mut self, size: u16)

Configure the queue size for the virtio queue.

fn ready(&self) -> bool

Check whether the queue is ready to be processed.

fn set_ready(&mut self, ready: bool)

Configure the queue to ready for processing state.

fn set_desc_table_address(&mut self, low: Option<u32>, high: Option<u32>)

Set the descriptor table address for the queue.

fn set_avail_ring_address(&mut self, low: Option<u32>, high: Option<u32>)

Set the available ring address for the queue.

fn set_used_ring_address(&mut self, low: Option<u32>, high: Option<u32>)

Set the used ring address for the queue.

fn set_event_idx(&mut self, enabled: bool)

Enable/disable the VIRTIO_F_RING_EVENT_IDX feature for interrupt coalescing.

fn avail_idx<M: GuestMemory>(
    &self,
    mem: &M,
    order: Ordering
) -> Result<Wrapping<u16>, Error>

Read the idx field from the available ring.

fn used_idx<M: GuestMemory>(
    &self,
    mem: &M,
    order: Ordering
) -> Result<Wrapping<u16>, Error>

Read the idx field from the used ring.

fn add_used<M: GuestMemory>(
    &mut self,
    mem: &M,
    head_index: u16,
    len: u32
) -> Result<(), Error>

Put a used descriptor head into the used ring.

fn enable_notification<M: GuestMemory>(
    &mut self,
    mem: &M
) -> Result<bool, Error>

Enable notification events from the guest driver.

fn disable_notification<M: GuestMemory>(&mut self, mem: &M) -> Result<(), Error>

Disable notification events from the guest driver.

fn needs_notification<M: GuestMemory>(&mut self, mem: &M) -> Result<bool, Error>

Check whether a notification to the guest is needed.

fn next_avail(&self) -> u16

Return the index of the next entry in the available ring.

fn next_used(&self) -> u16

Return the index for the next descriptor in the used ring.

fn set_next_avail(&mut self, next_avail: u16)

Set the index of the next entry in the available ring.

fn set_next_used(&mut self, next_used: u16)

Set the index for the next descriptor in the used ring.

fn lock_with_memory<M>(
    &mut self,
    mem: M
) -> QueueGuard<M, <Self as QueueStateGuard<'_>>::G> where
    M: Deref + Clone,
    M::Target: GuestMemory + Sized, 

Get an exclusive reference to the underlying QueueState object with an associated GuestMemory object.