WIP: Virtio network adapter

README.org

@@ -174,7 +174,7 @@ direction...
   to control user capabilities
 - [[./doc/journal/26-servers.org][26. Servers]], generalising the RAMdisk server code
 - [[./doc/journal/27-text-editor.org][27. Text editor]]. Writing a text editor to run on EuraliOS.
-
+- [[./doc/journal/27-virtio.org][28. Virtio devices]]
 
 ** Notes
 

doc/journal/27-virtio.org

@@ -0,0 +1,32 @@
+* Virtio devices
+
+http://www.dumais.io/index.php?article=aca38a9a2b065b24dfa1dee728062a12
+
+
+[[https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html][Virtio 1.1 draft specificiation]]
+
+In July 2022 a new version of Virtio was released, [[https://docs.oasis-open.org/virtio/virtio/v1.2/cs01/virtio-v1.2-cs01.pdf][Virtio 1.2]] that
+includes filesystem devices.
+
+
+There is a description of [[https://wiki.osdev.org/Virtio][Virtio on OSdev.org]], but it seems to
+describe the pre-1.0 "legacy" interface.
+
+** Configuration
+
+PCI devices provide a 256-byte configuration space that should be read
+in 32-bit chunks by reading and writing ports.
+
+
+** Network adapter
+
+The QEMU run arguments can be set in =kernel/Cargo.toml=, specifying
+that the Virtio network adapter should be used:
+
+#+begin_src ini
+[package.metadata.bootimage]
+run-args = ["-nic", "user,model=virtio-net-pci"]
+#+end_src
+
+A lot of the initial setup for the Virtio network card is
+very similar to the [[./14-network.org][RTL8139 network card]] 

init/src/main.rs

@@ -201,13 +201,13 @@ fn main() {
           syscalls::EXEC_PERM_IO, // I/O permissions
           writer_sys.clone());
 
-    mount("/dev/nic", include_bytes!("../../user/rtl8139"),
+    mount("/dev/nic", include_bytes!("../../user/virtio_net"),
           syscalls::EXEC_PERM_IO,
           writer_sys.clone());
 
-    mount("/tcp", include_bytes!("../../user/tcp"),
-          0, // No I/O permissions
-          writer_sys.clone());
+    // mount("/tcp", include_bytes!("../../user/tcp"),
+    //       0, // No I/O permissions
+    //       writer_sys.clone());
 
     // Start a user shell on new Console
     consoles[1] = {

kernel/Cargo.toml

@@ -22,8 +22,9 @@ version = "1.0"
 features = ["spin_no_std"]
 
 [package.metadata.bootimage]
-run-args = ["-cpu", "Skylake-Client-v3", "-nic", "user,model=rtl8139,hostfwd=tcp::5555-:23"]
+#run-args = ["-cpu", "Skylake-Client-v3", "-nic", "user,model=rtl8139,hostfwd=tcp::5555-:23"]
 #run-args = ["-netdev", "user,id=u1", "-device", "rtl8139,netdev=u1", "-object", "filter-dump,id=f1,netdev=u1,file=dump.dat"]
+run-args = ["-cpu", "Skylake-Client-v3", "-nic", "user,model=virtio-net-pci"]
 
 test-args = ["-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
              "-display", "none"]

virtio_net/src/main.rs

@@ -1,13 +1,41 @@
+// Parts adapted from
+// https://github.com/torokernel/torokernel/blob/7d6df4c40fa4cc85febd5fd5799404592ffdff53/rtl/drivers/VirtIONet.pas
+
 #![no_std]
 #![no_main]
 
 use euralios_std::{println,
                    syscalls,
-                   message::{self, rcall, pci, MessageData}};
+                   net::MacAddress,
+                   message::{self, rcall, pci, MessageData},
+                   ports::{outportb, outportw, outportd,
+                           inportb, inportw, inportd}};
+
+// Device status field, in the order the bits are typically set
+const VIRTIO_RESET: u8 = 0;
+const VIRTIO_ACKNOWLEDGE: u8 = 1;
+const VIRTIO_DRIVER_LOADED: u8 = 2;
+const VIRTIO_DRIVER_FAILED: u8 = 128;
+const VIRTIO_DRIVER_FEATURES_OK: u8 = 8;
+const VIRTIO_DRIVER_OK: u8 = 4;
+const VIRTIO_DEVICE_NEEDS_RESET: u8 = 64;
+
+// Feature bits
+// 0 to 23, and 50 to 127 Feature bits for the specific device type
+// 24 to 40 Feature bits reserved for extensions to the queue and feature negotiation mechanisms
+// 41 to 49, and 128 and above Feature bits reserved for future extensions.
+
+//const VIRTIO_F_VERSION_1
+
+const REG_DEVICE_FEATURES: u16 = 0;
+const REG_GUEST_FEATURES: u16 = 4;
+const REG_STATUS: u16 = 0x12;
+const REG_QUEUE_SIZE: u16 = 0x0C;
+const REG_QUEUE_SELECT: u16 = 0x0E;
 
 #[no_mangle]
 fn main() {
-    println!("[virtio-net] Starting driver");
+    println!("[virtio_net] Starting driver");
 
     let handle = syscalls::open("/pci", message::O_READ).expect("Couldn't open pci");
 
@@ -17,9 +45,71 @@ fn main() {
                                           None).unwrap();
     let address = md_address.value();
     if msg_type != pci::ADDRESS {
-        println!("[virtio-net] Device not found. Exiting.");
+        println!("[virtio_net] Device not found. Exiting.");
         return;
     }
-    println!("[virtio-net] Found at address: {:08X}", address);
+    println!("[virtio_net] Found at address: {:08X}", address);
+
+    // Read BAR0 to get the I/O address
+    let (_, md_bar0, _) = rcall(&handle, pci::READ_BAR,
+                                address.into(), 0.into(),
+                                Some(pci::BAR)).unwrap();
+    let bar0 = md_bar0.value();
+    let ioaddr = (bar0 & 0xFFFC) as u16;
+    println!("[virtio_net] BAR0: {:08X}. I/O addr: {:04X}", bar0, ioaddr);
 
+    let mut device = Device{ioaddr};
+    device.reset();
+    println!("[virtio_net] MAC address {}", device.mac_address());
+
+
+}
+
+struct Device {
+    ioaddr: u16
+}
+
+impl Device {
+    /// Perform a software reset
+    fn reset(&mut self) -> Result<(), &'static str> {
+        // reset device
+        outportb(self.ioaddr + REG_STATUS, VIRTIO_RESET);
+
+        // Wait for the device to present 0 device status
+        while inportb(self.ioaddr + REG_STATUS) != VIRTIO_RESET {
+            syscalls::thread_yield(); // Wait for a while
+        }
+
+        // Tell the device that we found it
+        outportb(self.ioaddr + REG_STATUS, VIRTIO_ACKNOWLEDGE);
+        outportb(self.ioaddr + REG_STATUS, VIRTIO_ACKNOWLEDGE | VIRTIO_DRIVER_LOADED);
+
+        // Negotiation phase
+
+        let features = inportd(self.ioaddr + REG_DEVICE_FEATURES);
+        println!("[virtio_net] features: {:0x}", features);
+
+        // Setup virtual queues
+        for i in 0..16 {
+            outportw(self.ioaddr + REG_QUEUE_SELECT, i);
+            // Read the size of the queue needed
+            let queue_size = inportw(self.ioaddr + REG_QUEUE_SIZE);
+            if queue_size == 0 {
+                continue;
+            }
+
+            println!("Queue {}: {}", i, queue_size);
+        }
+        Err("Incomplete")
+    }
+
+    /// Read the Media Access Control (MAC) address
+    /// from the network card.
+    fn mac_address(&self) -> MacAddress {
+        let mut octet: [u8; 6] = [0; 6];
+        for ind in 0..octet.len() {
+            octet[ind] = inportb(self.ioaddr + 0x14 + ind as u16);
+        }
+        MacAddress::new(octet)
+    }
 }