vmm: Reset device queues and TX/RX buffers

Author: acj

resources/seccomp/x86_64-unknown-linux-musl.json

@@ -799,6 +799,12 @@
                 "syscall": "sigaltstack",
                 "comment": "sigaltstack is used by Rust stdlib to remove alternative signal stack during thread teardown."
             },
+            {
+                "syscall": "fcntl"
+            },
+            {
+                "syscall": "ftruncate"
+            },
             {
                 "syscall": "futex",
                 "comment": "Used for synchronization (during thread teardown when joining multiple vcpu threads at once)",
@@ -890,6 +896,56 @@
                     }
                 ]
             },
+            {
+                "syscall": "memfd_create"
+            },
+            {
+                "syscall": "mmap",
+                "comment": "Used to recreate TX/RX queues in VirtIO net device",
+                "args": [
+                    {
+                        "index": 3,
+                        "type": "dword",
+                        "op": "eq",
+                        "val": 34,
+                        "comment": "libc::MAP_ANONYMOUS|libc::MAP_PRIVATE"
+                    },
+                    {
+                        "index": 2,
+                        "type": "dword",
+                        "op": "eq",
+                        "val": 0,
+                        "comment": "libc::PROT_NONE"
+                    }
+                ]
+            },
+            {
+                "syscall": "mmap",
+                "comment": "Used to recreate TX/RX queues in VirtIO net device",
+                "args": [
+                    {
+                        "index": 4,
+                        "type": "dword",
+                        "op": "eq",
+                        "val": 5,
+                        "comment": "file descriptor"
+                    },
+                    {
+                        "index": 3,
+                        "type": "dword",
+                        "op": "eq",
+                        "val": 17,
+                        "comment": "libc::MAP_SHARED|libc::MAP_FIXED"
+                    },
+                    {
+                        "index": 2,
+                        "type": "dword",
+                        "op": "eq",
+                        "val": 3,
+                        "comment": "libc::PROT_READ|libc::PROT_WRITE"
+                    }
+                ]
+            },
             {
                 "syscall": "mmap",
                 "comment": "Used for reading the timezone in LocalTime::now()",

src/vmm/src/devices/virtio/mod.rs

@@ -79,6 +79,8 @@ pub enum ActivateError {
 // Errors triggered when resetting a VirtioDevice.
 #[derive(Debug, thiserror::Error, displaydoc::Display)]
 pub enum ResetError {
+    /// Error when creating RX buffers
+    RxBuffer,
     /// Reset is not implemented for the device.
     NotImplemented,
 }

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

@@ -1036,6 +1036,18 @@ impl VirtioDevice for Net {
         self.rx_frame_buf = [0u8; MAX_BUFFER_SIZE];
         self.acked_features = 0;
         self.metrics.device_resets.inc();
+        let mut queues = Vec::new();
+        for size in NET_QUEUE_SIZES {
+            queues.push(Queue::new(size));
+        }
+        self.tx_buffer = Default::default();
+        self.rx_buffer = match RxBuffers::new() {
+            Ok(rx_buffer) => rx_buffer,
+            Err(err) => {
+                error!("Failed to reset RX buffers: {:?}", err);
+                return Err(ResetError::RxBuffer);
+            }
+        };
         Ok(())
     }
 }