Fix for Virtio_net probing

Makefile

@@ -119,6 +119,7 @@ endif
 ifeq ($(VIRTIO_NET),true)
 qemu_common 	+= -device virtio-net-pci,netdev=net0
 qemu_common		+= -netdev tap,id=net0,ifname=virtio,script=no,downscript=no
+DOMAIN_FEATURES += --features "virtio_net"
 endif
 
 QEMU            ?= $(shell which qemu-system-x86_64)

domains/sys/driver/virtio_net/Cargo.toml

@@ -18,7 +18,6 @@ redhttpd = { path = "../../../lib/redhttpd" }
 virtio_device = { path = "../../../../lib/devices/virtio" }
 virtio_network_device = { path = "../../../../lib/devices/virtio_net" }
 
-
 # Interfaces
 syscalls = { path = "../../../../lib/core/interfaces/syscalls" }
 pci_driver = { path = "../../../../lib/core/interfaces/dev/pci/pci_driver" }
@@ -30,4 +29,10 @@ interface = { path = "../../../../interface/generated" }
 [dependencies.smoltcp]
 path = "../../../../lib/external/smoltcp"
 default-features = false
-features = ["alloc", "proto-ipv4", "socket-tcp", "socket-icmp", "ethernet"]
+features = ["alloc", "proto-ipv4", "socket-tcp", "socket-icmp", "ethernet"]
+
+[features]
+default = [
+]
+
+virtio_net = []

domains/sys/driver/virtio_net/src/main.rs

@@ -30,6 +30,8 @@ pub use interface::error::{ErrorKind, Result};
 use virtio_network_device::pci::PciFactory;
 use virtio_network_device::VirtioNetInner;
 
+mod nullnet;
+
 use interface::rref::{RRef, RRefDeque};
 
 use smolnet::{self, SmolPhy};
@@ -105,16 +107,22 @@ pub fn trusted_entry(
     libsyscalls::syscalls::init(s);
     interface::rref::init(heap, libsyscalls::syscalls::sys_get_current_domain_id());
 
+    #[cfg(feature = "virtio_net")]
     let net = {
-        let mut pci_factory = PciFactory::new();
-        if pci.pci_register_driver(&mut pci_factory, 4, None).is_err() {
-            panic!("Failed to probe VirtioNet PCI");
-        }
-        let dev = pci_factory.to_device().unwrap();
-        VirtioNet(Arc::new(Mutex::new(dev)))
+        let net = {
+            let mut pci_factory = PciFactory::new();
+            if pci.pci_register_driver(&mut pci_factory, 4, None).is_err() {
+                panic!("Failed to probe VirtioNet PCI");
+            }
+            let dev = pci_factory.to_device().unwrap();
+            VirtioNet(Arc::new(Mutex::new(dev)))
+        };
+        net.0.lock().init();
+        net
     };
 
-    net.0.lock().init();
+    #[cfg(not(feature = "virtio_net"))]
+    let net = { nullnet::NullNet::new() };
 
     /*
     // VIRTIO DEMO LOOP

domains/sys/driver/virtio_net/src/nullnet.rs

@@ -0,0 +1,68 @@
+use alloc::boxed::Box;
+use alloc::collections::VecDeque;
+use alloc::vec::Vec;
+use interface::error::Result;
+use interface::net::NetworkStats;
+use interface::rpc::RpcResult;
+use interface::rref::RRefDeque;
+
+pub struct NullNet {}
+
+impl NullNet {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl interface::net::Net for NullNet {
+    fn clone_net(&self) -> RpcResult<Box<dyn interface::net::Net>> {
+        Ok(box Self::new())
+    }
+
+    fn submit_and_poll(
+        &self,
+        packets: &mut VecDeque<Vec<u8>>,
+        collect: &mut VecDeque<Vec<u8>>,
+        _tx: bool,
+    ) -> RpcResult<Result<usize>> {
+        let ret = packets.len();
+        while let Some(pkt) = packets.pop_front() {
+            collect.push_back(pkt);
+        }
+        Ok(Ok(ret))
+    }
+
+    fn submit_and_poll_rref(
+        &self,
+        mut packets: RRefDeque<[u8; 1514], 32>,
+        mut collect: RRefDeque<[u8; 1514], 32>,
+        _tx: bool,
+        _pkt_len: usize,
+    ) -> RpcResult<Result<(usize, RRefDeque<[u8; 1514], 32>, RRefDeque<[u8; 1514], 32>)>> {
+        while let Some(pkt) = packets.pop_front() {
+            collect.push_back(pkt);
+        }
+
+        Ok(Ok((collect.len(), packets, collect)))
+    }
+
+    fn poll(&self, _collect: &mut VecDeque<Vec<u8>>, _tx: bool) -> RpcResult<Result<usize>> {
+        Ok(Ok(0))
+    }
+
+    fn poll_rref(
+        &self,
+        collect: RRefDeque<[u8; 1514], 512>,
+        _tx: bool,
+    ) -> RpcResult<Result<(usize, RRefDeque<[u8; 1514], 512>)>> {
+        Ok(Ok((0, collect)))
+    }
+
+    fn get_stats(&self) -> RpcResult<Result<NetworkStats>> {
+        Ok(Ok(NetworkStats::new()))
+    }
+
+    fn test_domain_crossing(&self) -> RpcResult<()> {
+        Ok(())
+    }
+}