boards/qemu_rv32_virt: instantiate EthernetTapDriver for VirtIO Netwo…

…rkCard

boards/qemu_rv32_virt/src/main.rs

@@ -82,6 +82,12 @@ struct QemuRv32VirtPlatform {
             qemu_rv32_virt_chip::virtio::devices::virtio_rng::VirtIORng<'static, 'static>,
         >,
     >,
+    virtio_ethernet_tap: Option<
+        &'static capsules_extra::ethernet_tap::EthernetTapDriver<
+            'static,
+            qemu_rv32_virt_chip::virtio::devices::virtio_net::VirtIONet<'static>,
+        >,
+    >,
 }
 
 /// Mapping of integer syscalls to objects that implement syscalls.
@@ -101,6 +107,13 @@ impl SyscallDriverLookup for QemuRv32VirtPlatform {
                     f(None)
                 }
             }
+            capsules_extra::ethernet_tap::DRIVER_NUM => {
+                if let Some(ethernet_tap_driver) = self.virtio_ethernet_tap {
+                    f(Some(ethernet_tap_driver))
+                } else {
+                    f(None)
+                }
+            }
             kernel::ipc::DRIVER_NUM => f(Some(&self.ipc)),
             _ => f(None),
         }
@@ -366,14 +379,16 @@ unsafe fn start() -> (
     };
 
     // If there is a VirtIO NetworkCard present, use the appropriate VirtIONet
-    // driver. Currently this is not used, as work on the userspace network
-    // driver and kernel network stack is in progress.
-    //
-    // A template dummy driver is provided to verify basic functionality of this
-    // interface.
-    let _virtio_net_if: Option<
-        &'static qemu_rv32_virt_chip::virtio::devices::virtio_net::VirtIONet<'static>,
+    // driver, and expose this device through the Ethernet Tap driver
+    // (forwarding raw Ethernet frames from and to userspace).
+    let virtio_ethernet_tap: Option<
+        &'static capsules_extra::ethernet_tap::EthernetTapDriver<
+            'static,
+            qemu_rv32_virt_chip::virtio::devices::virtio_net::VirtIONet<'static>,
+        >,
     > = if let Some(net_idx) = virtio_net_idx {
+        use capsules_extra::ethernet_tap::EthernetTapDriver;
+        use kernel::hil::ethernet::EthernetAdapterDatapath;
         use qemu_rv32_virt_chip::virtio::devices::virtio_net::VirtIONet;
         use qemu_rv32_virt_chip::virtio::queues::split_queue::{
             SplitVirtqueue, VirtqueueAvailableRing, VirtqueueDescriptors, VirtqueueUsedRing,
@@ -434,14 +449,28 @@ unsafe fn start() -> (
             .initialize(virtio_net, mmio_queues)
             .unwrap();
 
-        // Don't forget to enable RX once when integrating this into a
-        // proper Ethernet stack:
-        // virtio_net.enable_rx();
+        // Instantiate the userspace tap network driver over this device:
+        let virtio_ethernet_tap_tx_buffer = static_init!(
+            [u8; capsules_extra::ethernet_tap::MAX_MTU],
+            [0; capsules_extra::ethernet_tap::MAX_MTU],
+        );
+        let virtio_ethernet_tap = static_init!(
+            EthernetTapDriver<'static, VirtIONet<'static>>,
+            EthernetTapDriver::new(
+                virtio_net,
+                board_kernel.create_grant(
+                    capsules_extra::ethernet_tap::DRIVER_NUM,
+                    &memory_allocation_cap
+                ),
+                virtio_ethernet_tap_tx_buffer,
+            ),
+        );
+        virtio_net.set_client(virtio_ethernet_tap);
 
-        // TODO: When we have a proper Ethernet driver available for userspace,
-        // return that. For now, just return a reference to the raw VirtIONet
-        // driver:
-        Some(virtio_net as &'static VirtIONet)
+        // This enables reception on the underlying device:
+        virtio_ethernet_tap.initialize();
+
+        Some(virtio_ethernet_tap as &'static EthernetTapDriver<'static, VirtIONet<'static>>)
     } else {
         // No VirtIO NetworkCard discovered
         None
@@ -520,6 +549,7 @@ unsafe fn start() -> (
         scheduler,
         scheduler_timer,
         virtio_rng: virtio_rng_driver,
+        virtio_ethernet_tap,
         ipc: kernel::ipc::IPC::new(
             board_kernel,
             kernel::ipc::DRIVER_NUM,
@@ -531,6 +561,21 @@ unsafe fn start() -> (
     let _ = platform.pconsole.start();
 
     debug!("QEMU RISC-V 32-bit \"virt\" machine, initialization complete.");
+
+    // This board dynamically discovers VirtIO devices like a randomness source
+    // or a network card. Print a message indicating whether or not each such
+    // device and corresponding userspace driver is present:
+    if virtio_rng_driver.is_some() {
+        debug!("- Found VirtIO EntropySource device, enabling RngDriver");
+    } else {
+        debug!("- VirtIO EntropySource device not found, disabling RngDriver");
+    }
+    if virtio_ethernet_tap.is_some() {
+        debug!("- Found VirtIO NetworkCard device, enabling EthernetTapDriver");
+    } else {
+        debug!("- VirtIO NetworkCard device not found, disabling EthernetTapDriver");
+    }
+
     debug!("Entering main loop.");
 
     // ---------- PROCESS LOADING, SCHEDULER LOOP ----------