Trait virtio_queue::QueueT

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pub trait QueueT: for<'a> QueueGuard<'a> {

Show 28 methods    fn new(max_size: u16) -> Result<Self, Error>
    where
        Self: Sized;
    fn is_valid<M: GuestMemory>(&self, mem: &M) -> bool;
    fn reset(&mut self);
    fn lock(&mut self) -> <Self as QueueGuard<'_>>::G;
    fn max_size(&self) -> u16;
    fn size(&self) -> u16;
    fn set_size(&mut self, size: u16);
    fn ready(&self) -> bool;
    fn set_ready(&mut self, ready: bool);
    fn set_desc_table_address(&mut self, low: Option<u32>, high: Option<u32>);
    fn set_avail_ring_address(&mut self, low: Option<u32>, high: Option<u32>);
    fn set_used_ring_address(&mut self, low: Option<u32>, high: Option<u32>);
    fn set_event_idx(&mut self, enabled: bool);
    fn avail_idx<M>(
        &self,
        mem: &M,
        order: Ordering
    ) -> Result<Wrapping<u16>, Error>
    where
        M: GuestMemory + ?Sized;
    fn used_idx<M: GuestMemory>(
        &self,
        mem: &M,
        order: Ordering
    ) -> Result<Wrapping<u16>, Error>;
    fn add_used<M: GuestMemory>(
        &mut self,
        mem: &M,
        head_index: u16,
        len: u32
    ) -> Result<(), Error>;
    fn enable_notification<M: GuestMemory>(
        &mut self,
        mem: &M
    ) -> Result<bool, Error>;
    fn disable_notification<M: GuestMemory>(
        &mut self,
        mem: &M
    ) -> Result<(), Error>;
    fn needs_notification<M: GuestMemory>(
        &mut self,
        mem: &M
    ) -> Result<bool, Error>;
    fn next_avail(&self) -> u16;
    fn set_next_avail(&mut self, next_avail: u16);
    fn next_used(&self) -> u16;
    fn set_next_used(&mut self, next_used: u16);
    fn desc_table(&self) -> u64;
    fn avail_ring(&self) -> u64;
    fn used_ring(&self) -> u64;
    fn event_idx_enabled(&self) -> bool;
    fn pop_descriptor_chain<M>(&mut self, mem: M) -> Option<DescriptorChain<M>>
    where
        M: Clone + Deref,
        M::Target: GuestMemory;

}
Expand description

Trait to access and manipulate a virtio queue.

To optimize for performance, different implementations of the QueueT trait may be provided for single-threaded context and multi-threaded context.

Using Higher-Rank Trait Bounds (HRTBs) to effectively define an associated type that has a lifetime parameter, without tagging the QueueT trait with a lifetime as well.

Required Methods

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

Returns an error if max_size is invalid.

Check whether the queue configuration is valid.

Reset the queue to the initial state.

Get an exclusive reference to the underlying Queue object.

Logically this method will acquire the underlying lock protecting the Queue Object. The lock will be released when the returned object gets dropped.

Get the maximum size of the virtio queue.

Get the actual size configured by the guest.

Configure the queue size for the virtio queue.

Check whether the queue is ready to be processed.

Configure the queue to ready for processing state.

Set the descriptor table address for the queue.

The descriptor table address is 64-bit, the corresponding part will be updated if ‘low’ and/or high is Some and valid.

Set the available ring address for the queue.

The available ring address is 64-bit, the corresponding part will be updated if ‘low’ and/or high is Some and valid.

Set the used ring address for the queue.

The used ring address is 64-bit, the corresponding part will be updated if ‘low’ and/or high is Some and valid.

Enable/disable the VIRTIO_F_RING_EVENT_IDX feature for interrupt coalescing.

Read the idx field from the available ring.

Panics

Panics if order is Release or AcqRel.

Read the idx field from the used ring.

Panics

Panics if order is Release or AcqRel.

Put a used descriptor head into the used ring.

Enable notification events from the guest driver.

Return true if one or more descriptors can be consumed from the available ring after notifications were enabled (and thus it’s possible there will be no corresponding notification).

Disable notification events from the guest driver.

Check whether a notification to the guest is needed.

Please note this method has side effects: once it returns true, it considers the driver will actually be notified, remember the associated index in the used ring, and won’t return true again until the driver updates used_event and/or the notification conditions hold once more.

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

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

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

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

Return the address of the descriptor table.

Return the address of the available ring.

Return the address of the used ring.

Checks whether VIRTIO_F_RING_EVENT_IDX is negotiated.

This getter is only returning the correct value after the device passes the FEATURES_OK status.

Pop and return the next available descriptor chain, or None when there are no more descriptor chains available.

This enables the consumption of available descriptor chains in a “one at a time” manner, without having to hold a borrow after the method returns.

Implementors