remove sending transport_reset event on snapshot creation

Signed-off-by: Amory Hoste <[email protected]>

Author: amohoste

src/devices/src/lib.rs

@@ -14,7 +14,7 @@ pub mod pseudo;
 pub mod virtio;
 
 pub use self::bus::{Bus, BusDevice, Error as BusError};
-use crate::virtio::{QueueError, VsockError};
+use crate::virtio::{QueueError};
 use logger::{error, IncMetric, METRICS};
 
 // Function used for reporting error in terms of logging
@@ -43,6 +43,4 @@ pub enum Error {
     MalformedDescriptor,
     /// Error during queue processing.
     QueueError(QueueError),
-    /// Vsock device error.
-    VsockError(VsockError),
 }

src/devices/src/virtio/vsock/device.rs

@@ -26,7 +26,7 @@ use std::sync::Arc;
 use logger::{debug, error, warn, IncMetric, METRICS};
 use utils::byte_order;
 use utils::eventfd::EventFd;
-use vm_memory::{Bytes, GuestMemoryMmap};
+use vm_memory::{GuestMemoryMmap};
 
 use super::super::super::Error as DeviceError;
 use super::super::{
@@ -41,8 +41,6 @@ pub(crate) const RXQ_INDEX: usize = 0;
 pub(crate) const TXQ_INDEX: usize = 1;
 pub(crate) const EVQ_INDEX: usize = 2;
 
-pub(crate) const VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: u32 = 0;
-
 /// The virtio features supported by our vsock device:
 /// - VIRTIO_F_VERSION_1: the device conforms to at least version 1.0 of the VirtIO spec.
 /// - VIRTIO_F_IN_ORDER: the device returns used buffers in the same order that the driver makes
@@ -228,35 +226,6 @@ where
 
         have_used
     }
-
-    // Send TRANSPORT_RESET_EVENT to driver. According to specs, the driver shuts down established
-    // connections and the guest_cid configuration field is fetched again. Existing listen sockets remain
-    // but their CID is updated to reflect the current guest_cid.
-    pub fn send_transport_reset_event(&mut self) -> result::Result<(), DeviceError> {
-        let mem = match self.device_state {
-            DeviceState::Activated(ref mem) => mem,
-            // This should never happen, it's been already validated in the caller function.
-            DeviceState::Inactive => unreachable!(),
-        };
-
-        let head = self.queues[EVQ_INDEX].pop(mem).ok_or_else(|| {
-            METRICS.vsock.ev_queue_event_fails.inc();
-            DeviceError::VsockError(VsockError::EmptyQueue)
-        })?;
-
-        mem.write_obj::<u32>(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET, head.addr)
-            .unwrap_or_else(|e| error!("Failed to write virtio vsock reset event: {:?}", e));
-
-        self.queues[EVQ_INDEX]
-            .add_used(mem, head.index, head.len)
-            .unwrap_or_else(|e| {
-                error!("Failed to add used descriptor {}: {}", head.index, e);
-            });
-
-        self.signal_used_queue()?;
-
-        Ok(())
-    }
 }
 
 impl<B> VirtioDevice for Vsock<B>

src/devices/src/virtio/vsock/mod.rs

@@ -99,8 +99,6 @@ pub enum VsockError {
     BufDescTooSmall,
     /// The vsock data/buffer virtio descriptor is expected, but missing.
     BufDescMissing,
-    /// Empty queue
-    EmptyQueue,
     /// EventFd error
     EventFd(std::io::Error),
     /// Chained GuestMemoryMmap error.

src/vmm/src/device_manager/persist.rs

@@ -9,7 +9,6 @@ use std::sync::{Arc, Mutex};
 
 use super::mmio::*;
 use crate::EventManager;
-use logger::error;
 
 #[cfg(target_arch = "aarch64")]
 use arch::DeviceType;
@@ -188,7 +187,7 @@ impl<'a> Persist<'a> for MMIODeviceManager {
 
             let transport_state = mmio_transport.save();
 
-            let mut locked_device = mmio_transport.locked_device();
+            let locked_device = mmio_transport.locked_device();
             match locked_device.device_type() {
                 TYPE_BALLOON => {
                     let balloon_state = locked_device
@@ -227,24 +226,16 @@ impl<'a> Persist<'a> for MMIODeviceManager {
                 }
                 TYPE_VSOCK => {
                     let vsock = locked_device
-                        .as_mut_any()
+                        .as_any()
                         // Currently, VsockUnixBackend is the only implementation of VsockBackend.
-                        .downcast_mut::<Vsock<VsockUnixBackend>>()
+                        .downcast_ref::<Vsock<VsockUnixBackend>>()
                         .unwrap();
 
                     let vsock_state = VsockState {
                         backend: vsock.backend().save(),
                         frontend: vsock.save(),
                     };
 
-                    // Send Transport event to reset connections if device
-                    // is activated.
-                    if vsock.is_activated() {
-                        vsock.send_transport_reset_event().unwrap_or_else(|e| {
-                            error!("Failed to send reset transport event: {:?}", e);
-                        });
-                    }
-
                     states.vsock_device = Some(ConnectedVsockState {
                         device_id: devid.clone(),
                         device_state: vsock_state,