Revert "net: support serializing RxBuffer"

This reverts commit 667aba4.

Signed-off-by: Babis Chalios <[email protected]>

Author: bchalios

src/vmm/src/devices/virtio/iovec.rs

@@ -4,7 +4,6 @@
 use std::io::ErrorKind;
 
 use libc::{c_void, iovec, size_t};
-use serde::{Deserialize, Serialize};
 #[cfg(not(kani))]
 use smallvec::SmallVec;
 use vm_memory::bitmap::Bitmap;
@@ -219,7 +218,7 @@ impl IoVecBuffer {
     }
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug)]
 pub struct ParsedDescriptorChain {
     pub head_index: u16,
     pub length: u32,
@@ -234,9 +233,9 @@ pub struct ParsedDescriptorChain {
 #[derive(Debug)]
 pub struct IoVecBufferMut {
     // container of the memory regions included in this IO vector
-    pub vecs: IovDeque,
+    vecs: IovDeque,
     // Total length of the IoVecBufferMut
-    pub len: usize,
+    len: usize,
 }
 
 impl IoVecBufferMut {

src/vmm/src/devices/virtio/net/persist.rs

@@ -9,10 +9,9 @@ use std::sync::{Arc, Mutex};
 
 use serde::{Deserialize, Serialize};
 
-use super::device::{Net, RxBuffers};
-use super::{TapError, NET_NUM_QUEUES, RX_INDEX};
+use super::device::Net;
+use super::{TapError, NET_NUM_QUEUES};
 use crate::devices::virtio::device::DeviceState;
-use crate::devices::virtio::iovec::ParsedDescriptorChain;
 use crate::devices::virtio::persist::{PersistError as VirtioStateError, VirtioDeviceState};
 use crate::devices::virtio::queue::FIRECRACKER_MAX_QUEUE_SIZE;
 use crate::devices::virtio::TYPE_NET;
@@ -32,23 +31,6 @@ pub struct NetConfigSpaceState {
     guest_mac: Option<MacAddr>,
 }
 
-/// Information about the parsed RX buffers
-#[derive(Debug, Default, Clone, Serialize, Deserialize)]
-pub struct RxBufferState {
-    // Number of iovecs we have parsed from the guest
-    parsed_descriptor_chains_nr: u16,
-    deferred_descriptor: Option<ParsedDescriptorChain>,
-}
-
-impl RxBufferState {
-    fn from_rx_buffers(rx_buffer: &RxBuffers) -> Self {
-        RxBufferState {
-            parsed_descriptor_chains_nr: rx_buffer.parsed_descriptors.len().try_into().unwrap(),
-            deferred_descriptor: rx_buffer.deferred_descriptor.clone(),
-        }
-    }
-}
-
 /// Information about the network device that are saved
 /// at snapshot.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -61,7 +43,6 @@ pub struct NetState {
     pub mmds_ns: Option<MmdsNetworkStackState>,
     config_space: NetConfigSpaceState,
     virtio_state: VirtioDeviceState,
-    rx_buffers_state: RxBufferState,
 }
 
 /// Auxiliary structure for creating a device when resuming from a snapshot.
@@ -104,7 +85,6 @@ impl Persist<'_> for Net {
                 guest_mac: self.guest_mac,
             },
             virtio_state: VirtioDeviceState::from_device(self),
-            rx_buffers_state: RxBufferState::from_rx_buffers(&self.rx_buffer),
         }
     }
 
@@ -157,14 +137,6 @@ impl Persist<'_> for Net {
                 .map_err(NetPersistError::TapSetOffload)?;
 
             net.device_state = DeviceState::Activated(constructor_args.mem);
-
-            // Recreate `Net::rx_buffer`. We do it by re-parsing the RX queue. We're temporarily
-            // rolling back `next_avail` in the RX queue and call `parse_rx_descriptors`.
-            net.queues[RX_INDEX].next_avail -= state.rx_buffers_state.parsed_descriptor_chains_nr;
-            net.parse_rx_descriptors();
-            net.rx_buffer
-                .deferred_descriptor
-                .clone_from(&state.rx_buffers_state.deferred_descriptor);
         }
 
         Ok(net)