virtq: use enum_dispatch

Cargo.toml

@@ -107,6 +107,7 @@ talc = { version = "4" }
 time = { version = "0.3", default-features = false }
 volatile = "0.6"
 zerocopy = { version = "0.7", default-features = false }
+enum_dispatch = "0.3.13"
 
 [dependencies.smoltcp]
 version = "0.11"

src/drivers/fs/virtio_fs.rs

@@ -18,7 +18,7 @@ use crate::drivers::virtio::transport::pci::{ComCfg, IsrStatus, NotifCfg};
 use crate::drivers::virtio::virtqueue::error::VirtqError;
 use crate::drivers::virtio::virtqueue::split::SplitVq;
 use crate::drivers::virtio::virtqueue::{
-	AvailBufferToken, BufferElem, BufferType, Virtq, VqIndex, VqSize,
+	AvailBufferToken, BufferElem, BufferType, VirtQueue, Virtq, VqIndex, VqSize,
 };
 use crate::fs::fuse::{self, FuseInterface, Rsp, RspHeader};
 use crate::mm::device_alloc::DeviceAlloc;
@@ -42,7 +42,7 @@ pub(crate) struct VirtioFsDriver {
 	pub(super) com_cfg: ComCfg,
 	pub(super) isr_stat: IsrStatus,
 	pub(super) notif_cfg: NotifCfg,
-	pub(super) vqueues: Vec<Box<dyn Virtq>>,
+	pub(super) vqueues: Vec<VirtQueue>,
 	pub(super) irq: InterruptLine,
 }
 
@@ -130,15 +130,17 @@ impl VirtioFsDriver {
 
 		// create the queues and tell device about them
 		for i in 0..vqnum as u16 {
-			let vq = SplitVq::new(
-				&mut self.com_cfg,
-				&self.notif_cfg,
-				VqSize::from(VIRTIO_MAX_QUEUE_SIZE),
-				VqIndex::from(i),
-				self.dev_cfg.features.into(),
-			)
-			.unwrap();
-			self.vqueues.push(Box::new(vq));
+			let vq = VirtQueue::Split(
+				SplitVq::new(
+					&mut self.com_cfg,
+					&self.notif_cfg,
+					VqSize::from(VIRTIO_MAX_QUEUE_SIZE),
+					VqIndex::from(i),
+					self.dev_cfg.features.into(),
+				)
+				.unwrap(),
+			);
+			self.vqueues.push(vq);
 		}
 
 		// At this point the device is "live"

src/drivers/net/virtio/mmio.rs

@@ -2,7 +2,6 @@
 //!
 //! The module contains ...
 
-use alloc::boxed::Box;
 use alloc::vec::Vec;
 use core::str::FromStr;
 
@@ -13,7 +12,7 @@ use volatile::VolatileRef;
 use crate::drivers::net::virtio::{CtrlQueue, NetDevCfg, RxQueues, TxQueues, VirtioNetDriver};
 use crate::drivers::virtio::error::{VirtioError, VirtioNetError};
 use crate::drivers::virtio::transport::mmio::{ComCfg, IsrStatus, NotifCfg};
-use crate::drivers::virtio::virtqueue::Virtq;
+use crate::drivers::virtio::virtqueue::VirtQueue;
 
 // Backend-dependent interface for Virtio network driver
 impl VirtioNetDriver {
@@ -46,8 +45,8 @@ impl VirtioNetDriver {
 			1514
 		};
 
-		let send_vqs = TxQueues::new(Vec::<Box<dyn Virtq>>::new(), &dev_cfg);
-		let recv_vqs = RxQueues::new(Vec::<Box<dyn Virtq>>::new(), &dev_cfg);
+		let send_vqs = TxQueues::new(Vec::<VirtQueue>::new(), &dev_cfg);
+		let recv_vqs = RxQueues::new(Vec::<VirtQueue>::new(), &dev_cfg);
 		Ok(VirtioNetDriver {
 			dev_cfg,
 			com_cfg: ComCfg::new(registers, 1),

src/drivers/net/virtio/mod.rs

@@ -32,7 +32,7 @@ use crate::drivers::virtio::transport::pci::{ComCfg, IsrStatus, NotifCfg};
 use crate::drivers::virtio::virtqueue::packed::PackedVq;
 use crate::drivers::virtio::virtqueue::split::SplitVq;
 use crate::drivers::virtio::virtqueue::{
-	AvailBufferToken, BufferElem, BufferType, UsedBufferToken, Virtq, VqIndex, VqSize,
+	AvailBufferToken, BufferElem, BufferType, UsedBufferToken, VirtQueue, Virtq, VqIndex, VqSize,
 };
 use crate::executor::device::{RxToken, TxToken};
 use crate::mm::device_alloc::DeviceAlloc;
@@ -46,23 +46,23 @@ pub(crate) struct NetDevCfg {
 	pub features: virtio::net::F,
 }
 
-pub struct CtrlQueue(Option<Box<dyn Virtq>>);
+pub struct CtrlQueue(Option<VirtQueue>);
 
 impl CtrlQueue {
-	pub fn new(vq: Option<Box<dyn Virtq>>) -> Self {
+	pub fn new(vq: Option<VirtQueue>) -> Self {
 		CtrlQueue(vq)
 	}
 }
 
 pub struct RxQueues {
-	vqs: Vec<Box<dyn Virtq>>,
+	vqs: Vec<VirtQueue>,
 	poll_sender: async_channel::Sender<UsedBufferToken>,
 	poll_receiver: async_channel::Receiver<UsedBufferToken>,
 	packet_size: u32,
 }
 
 impl RxQueues {
-	pub fn new(vqs: Vec<Box<dyn Virtq>>, dev_cfg: &NetDevCfg) -> Self {
+	pub fn new(vqs: Vec<VirtQueue>, dev_cfg: &NetDevCfg) -> Self {
 		let (poll_sender, poll_receiver) = async_channel::unbounded();
 
 		// See Virtio specification v1.1 - 5.1.6.3.1
@@ -92,11 +92,11 @@ impl RxQueues {
 	/// Adds a given queue to the underlying vector and populates the queue with RecvBuffers.
 	///
 	/// Queues are all populated according to Virtio specification v1.1. - 5.1.6.3.1
-	fn add(&mut self, mut vq: Box<dyn Virtq>) {
+	fn add(&mut self, mut vq: VirtQueue) {
 		const BUFF_PER_PACKET: u16 = 2;
 		let num_packets: u16 = u16::from(vq.size()) / BUFF_PER_PACKET;
 		fill_queue(
-			vq.as_mut(),
+			&mut vq,
 			num_packets,
 			self.packet_size,
 			self.poll_sender.clone(),
@@ -185,14 +185,14 @@ fn fill_queue(
 /// Structure which handles transmission of packets and delegation
 /// to the respective queue structures.
 pub struct TxQueues {
-	vqs: Vec<Box<dyn Virtq>>,
+	vqs: Vec<VirtQueue>,
 	/// Indicates, whether the Driver/Device are using multiple
 	/// queues for communication.
 	packet_length: u32,
 }
 
 impl TxQueues {
-	pub fn new(vqs: Vec<Box<dyn Virtq>>, dev_cfg: &NetDevCfg) -> Self {
+	pub fn new(vqs: Vec<VirtQueue>, dev_cfg: &NetDevCfg) -> Self {
 		let packet_length = if dev_cfg.features.contains(virtio::net::F::GUEST_TSO4)
 			| dev_cfg.features.contains(virtio::net::F::GUEST_TSO6)
 			| dev_cfg.features.contains(virtio::net::F::GUEST_UFO)
@@ -224,7 +224,7 @@ impl TxQueues {
 		}
 	}
 
-	fn add(&mut self, vq: Box<dyn Virtq>) {
+	fn add(&mut self, vq: VirtQueue) {
 		// Currently we are doing nothing with the additional queues. They are inactive and might be used in the
 		// future
 		self.vqs.push(vq);
@@ -370,7 +370,7 @@ impl NetworkDriver for VirtioNetDriver {
 		}
 
 		fill_queue(
-			self.recv_vqs.vqs[0].as_mut(),
+			&mut self.recv_vqs.vqs[0],
 			num_buffers,
 			self.recv_vqs.packet_size,
 			self.recv_vqs.poll_sender.clone(),
@@ -672,7 +672,7 @@ impl VirtioNetDriver {
 		// Add a control if feature is negotiated
 		if self.dev_cfg.features.contains(virtio::net::F::CTRL_VQ) {
 			if self.dev_cfg.features.contains(virtio::net::F::RING_PACKED) {
-				self.ctrl_vq = CtrlQueue(Some(Box::new(
+				self.ctrl_vq = CtrlQueue(Some(VirtQueue::Packed(
 					PackedVq::new(
 						&mut self.com_cfg,
 						&self.notif_cfg,
@@ -683,7 +683,7 @@ impl VirtioNetDriver {
 					.unwrap(),
 				)));
 			} else {
-				self.ctrl_vq = CtrlQueue(Some(Box::new(
+				self.ctrl_vq = CtrlQueue(Some(VirtQueue::Split(
 					SplitVq::new(
 						&mut self.com_cfg,
 						&self.notif_cfg,
@@ -759,7 +759,7 @@ impl VirtioNetDriver {
 				// Interrupt for receiving packets is wanted
 				vq.enable_notifs();
 
-				self.recv_vqs.add(Box::from(vq));
+				self.recv_vqs.add(VirtQueue::Packed(vq));
 
 				let mut vq = PackedVq::new(
 					&mut self.com_cfg,
@@ -772,7 +772,7 @@ impl VirtioNetDriver {
 				// Interrupt for comunicating that a sended packet left, is not needed
 				vq.disable_notifs();
 
-				self.send_vqs.add(Box::from(vq));
+				self.send_vqs.add(VirtQueue::Packed(vq));
 			} else {
 				let mut vq = SplitVq::new(
 					&mut self.com_cfg,
@@ -785,7 +785,7 @@ impl VirtioNetDriver {
 				// Interrupt for receiving packets is wanted
 				vq.enable_notifs();
 
-				self.recv_vqs.add(Box::from(vq));
+				self.recv_vqs.add(VirtQueue::Split(vq));
 
 				let mut vq = SplitVq::new(
 					&mut self.com_cfg,
@@ -798,7 +798,7 @@ impl VirtioNetDriver {
 				// Interrupt for comunicating that a sended packet left, is not needed
 				vq.disable_notifs();
 
-				self.send_vqs.add(Box::from(vq));
+				self.send_vqs.add(VirtQueue::Split(vq));
 			}
 		}
 

src/drivers/virtio/virtqueue/mod.rs

@@ -20,13 +20,12 @@ use core::mem::MaybeUninit;
 use core::{mem, ptr};
 
 use async_channel::TryRecvError;
+use enum_dispatch::enum_dispatch;
+use packed::PackedVq;
+use split::SplitVq;
 use virtio::{le32, le64, pvirtq, virtq};
 
 use self::error::VirtqError;
-#[cfg(not(feature = "pci"))]
-use super::transport::mmio::{ComCfg, NotifCfg};
-#[cfg(feature = "pci")]
-use super::transport::pci::{ComCfg, NotifCfg};
 use crate::arch::mm::{paging, VirtAddr};
 use crate::mm::device_alloc::DeviceAlloc;
 
@@ -99,6 +98,7 @@ type UsedBufferTokenSender = async_channel::Sender<UsedBufferToken>;
 /// might not provide the complete feature set of each queue. Drivers who
 /// do need these features should refrain from providing support for both
 /// Virtqueue types and use the structs directly instead.
+#[enum_dispatch]
 pub trait Virtq {
 	/// The `notif` parameter indicates if the driver wants to have a notification for this specific
 	/// transfer. This is only for performance optimization. As it is NOT ensured, that the device sees the
@@ -193,21 +193,6 @@ pub trait Virtq {
 		notif: bool,
 	) -> Result<(), VirtqError>;
 
-	/// Creates a new Virtq of the specified [VqSize] and the [VqIndex].
-	/// The index represents the "ID" of the virtqueue.
-	/// Upon creation the virtqueue is "registered" at the device via the `ComCfg` struct.
-	///
-	/// Be aware, that devices define a maximum number of queues and a maximal size they can handle.
-	fn new(
-		com_cfg: &mut ComCfg,
-		notif_cfg: &NotifCfg,
-		size: VqSize,
-		index: VqIndex,
-		features: virtio::F,
-	) -> Result<Self, VirtqError>
-	where
-		Self: Sized;
-
 	/// Returns the size of a Virtqueue. This represents the overall size and not the capacity the
 	/// queue currently has for new descriptors.
 	fn size(&self) -> VqSize;
@@ -292,6 +277,12 @@ trait VirtqPrivate {
 	}
 }
 
+#[enum_dispatch(Virtq)]
+pub(crate) enum VirtQueue {
+	Split(SplitVq),
+	Packed(PackedVq),
+}
+
 trait VirtqDescriptor {
 	fn flags_mut(&mut self) -> &mut virtq::DescF;
 

src/drivers/virtio/virtqueue/packed.rs

@@ -649,7 +649,30 @@ impl Virtq for PackedVq {
 		self.index
 	}
 
-	fn new(
+	fn size(&self) -> VqSize {
+		self.size
+	}
+
+	fn has_used_buffers(&self) -> bool {
+		let desc = &self.descr_ring.ring[usize::from(self.descr_ring.poll_index)];
+		self.descr_ring.is_marked_used(desc.flags)
+	}
+}
+
+impl VirtqPrivate for PackedVq {
+	type Descriptor = pvirtq::Desc;
+
+	fn create_indirect_ctrl(
+		buffer_tkn: &AvailBufferToken,
+	) -> Result<Box<[Self::Descriptor]>, VirtqError> {
+		Ok(Self::descriptor_iter(buffer_tkn)?
+			.collect::<Vec<_>>()
+			.into_boxed_slice())
+	}
+}
+
+impl PackedVq {
+	pub(crate) fn new(
 		com_cfg: &mut ComCfg,
 		notif_cfg: &NotifCfg,
 		size: VqSize,
@@ -740,25 +763,4 @@ impl Virtq for PackedVq {
 			last_next: Default::default(),
 		})
 	}
-
-	fn size(&self) -> VqSize {
-		self.size
-	}
-
-	fn has_used_buffers(&self) -> bool {
-		let desc = &self.descr_ring.ring[usize::from(self.descr_ring.poll_index)];
-		self.descr_ring.is_marked_used(desc.flags)
-	}
-}
-
-impl VirtqPrivate for PackedVq {
-	type Descriptor = pvirtq::Desc;
-
-	fn create_indirect_ctrl(
-		buffer_tkn: &AvailBufferToken,
-	) -> Result<Box<[Self::Descriptor]>, VirtqError> {
-		Ok(Self::descriptor_iter(buffer_tkn)?
-			.collect::<Vec<_>>()
-			.into_boxed_slice())
-	}
 }