Replace AsSliceU8 trait with zerocopy::AsBytes for VirtioNetHdr struct.

Changed VirtioNetHdr to derive from AsBytes instead of AsSliceU8 and
changed related functions as necessary. AsSliceU8 cannot be completely
removed yet because of lack of support for deriving AsBytes for
generics.

Author: Joanne Chen

Cargo.lock

@@ -57,14 +57,14 @@ smp = ["include-transformed"]
 fsgsbase = []
 trace = []
 tcp = [
-    "async-task",
-    "futures-lite",
-    "smoltcp",
+	"async-task",
+	"futures-lite",
+	"smoltcp"
 ]
 dhcpv4 = [
-    "tcp",
-    "smoltcp/proto-dhcpv4",
-    "smoltcp/socket-dhcpv4",
+	"tcp",
+	"smoltcp/proto-dhcpv4",
+	"smoltcp/socket-dhcpv4"
 ]
 
 [dependencies]
@@ -90,6 +90,7 @@ lock_api = "0.4"
 num = { version = "0.4", default-features = false }
 num-traits = { version = "0.2", default-features = false }
 num-derive = "0.3"
+zerocopy = "0.6"
 
 [dependencies.smoltcp]
 version = "0.9"

Cargo.toml

@@ -11,6 +11,8 @@ use core::cmp::Ordering;
 use core::mem;
 use core::result::Result;
 
+use zerocopy::AsBytes;
+
 use self::constants::{FeatureSet, Features, NetHdrGSO, Status, MAX_NUM_VQ};
 use self::error::VirtioNetError;
 use crate::arch::kernel::core_local::increment_irq_counter;
@@ -25,7 +27,7 @@ use crate::drivers::virtio::transport::mmio::{ComCfg, IsrStatus, NotifCfg};
 #[cfg(feature = "pci")]
 use crate::drivers::virtio::transport::pci::{ComCfg, IsrStatus, NotifCfg};
 use crate::drivers::virtio::virtqueue::{
-	AsSliceU8, BuffSpec, BufferToken, Bytes, Transfer, Virtq, VqIndex, VqSize, VqType,
+	BuffSpec, BufferToken, Bytes, Transfer, Virtq, VqIndex, VqSize, VqType,
 };
 
 pub const ETH_HDR: usize = 14usize;
@@ -41,7 +43,7 @@ pub struct NetDevCfg {
 	pub features: FeatureSet,
 }
 
-#[derive(Debug)]
+#[derive(AsBytes, Debug)]
 #[repr(C)]
 pub struct VirtioNetHdr {
 	flags: u8,
@@ -58,9 +60,6 @@ pub struct VirtioNetHdr {
 	num_buffers: u16,
 }
 
-// Using the default implementation of the trait for VirtioNetHdr
-impl AsSliceU8 for VirtioNetHdr {}
-
 impl VirtioNetHdr {
 	pub fn get_tx_hdr() -> VirtioNetHdr {
 		VirtioNetHdr {

src/drivers/net/virtio_net.rs

@@ -21,6 +21,7 @@ use core::cell::RefCell;
 use core::ops::{BitAnd, Deref, DerefMut};
 
 use align_address::Align;
+use zerocopy::AsBytes;
 
 use self::error::{BufferError, VirtqError};
 use self::packed::PackedVq;
@@ -1683,15 +1684,15 @@ impl BufferToken {
 	///   * Will result in 4 bytes written to the second buffer descriptor of the recv buffer. Nothing is written into the second buffer descriptor.
 	/// * Third Write: `write_seq(Some(10 bytes, Some(4 bytes))`:
 	///   * Will result in 10 bytes written to the second buffer descriptor of the send buffer and 4 bytes written to the third buffer descriptor of the recv buffer.
-	pub fn write_seq<K: AsSliceU8, H: AsSliceU8 + ?Sized>(
+	pub fn write_seq<K: AsBytes, H: AsBytes + ?Sized>(
 		mut self,
 		send_seq: Option<&K>,
 		recv_seq: Option<&H>,
 	) -> Result<Self, VirtqError> {
 		if let Some(data) = send_seq {
 			match self.send_buff.as_mut() {
 				Some(buff) => {
-					match buff.next_write(data.as_slice_u8()) {
+					match buff.next_write(data.as_bytes()) {
 						Ok(_) => (), // Do nothing, write fitted inside descriptor and not to many writes to buffer happened
 						Err(_) => {
 							// Need no match here, as result is the same, but for the future one could
@@ -1707,7 +1708,7 @@ impl BufferToken {
 		if let Some(data) = recv_seq {
 			match self.recv_buff.as_mut() {
 				Some(buff) => {
-					match buff.next_write(data.as_slice_u8()) {
+					match buff.next_write(data.as_bytes()) {
 						Ok(_) => (), // Do nothing, write fitted inside descriptor and not to many writes to buffer happened
 						Err(_) => {
 							// Need no match here, as result is the same, but for the future one could