Use proper volatile read for VirtIO config space.

src/blk.rs

@@ -185,7 +185,6 @@ impl<H: Hal, T: Transport> VirtIOBlk<H, T> {
 }
 
 #[repr(C)]
-#[derive(Debug)]
 struct BlkConfig {
     /// Number of 512 Bytes sectors
     capacity: Volatile<u64>,

src/console.rs

@@ -1,9 +1,9 @@
 use super::*;
 use crate::queue::VirtQueue;
 use crate::transport::Transport;
-use crate::volatile::{ReadOnly, WriteOnly};
+use crate::volatile::{volread, ReadOnly, WriteOnly};
 use bitflags::*;
-use core::{fmt, hint::spin_loop};
+use core::hint::spin_loop;
 use log::*;
 
 const QUEUE_RECEIVEQ_PORT_0: u16 = 0;
@@ -32,8 +32,15 @@ impl<H: Hal, T: Transport> VirtIOConsole<'_, H, T> {
             (features & supported_features).bits()
         });
         let config_space = transport.config_space().cast::<Config>();
-        let config = unsafe { config_space.as_ref() };
-        info!("Config: {:?}", config);
+        unsafe {
+            let columns = volread!(config_space, cols);
+            let rows = volread!(config_space, rows);
+            let max_ports = volread!(config_space, max_nr_ports);
+            info!(
+                "Columns: {} Rows: {} Max ports: {}",
+                columns, rows, max_ports,
+            );
+        }
         let receiveq = VirtQueue::new(&mut transport, QUEUE_RECEIVEQ_PORT_0, QUEUE_SIZE)?;
         let transmitq = VirtQueue::new(&mut transport, QUEUE_TRANSMITQ_PORT_0, QUEUE_SIZE)?;
         let queue_buf_dma = DMA::new(1)?;
@@ -110,16 +117,6 @@ struct Config {
     emerg_wr: WriteOnly<u32>,
 }
 
-impl fmt::Debug for Config {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("Config")
-            .field("cols", &self.cols)
-            .field("rows", &self.rows)
-            .field("max_nr_ports", &self.max_nr_ports)
-            .finish()
-    }
-}
-
 bitflags! {
     struct Features: u64 {
         const SIZE                  = 1 << 0;

src/gpu.rs

@@ -1,7 +1,7 @@
 use super::*;
 use crate::queue::VirtQueue;
 use crate::transport::Transport;
-use crate::volatile::{ReadOnly, Volatile, WriteOnly};
+use crate::volatile::{volread, ReadOnly, Volatile, WriteOnly};
 use bitflags::*;
 use core::{fmt, hint::spin_loop};
 use log::*;
@@ -44,8 +44,14 @@ impl<H: Hal, T: Transport> VirtIOGpu<'_, H, T> {
 
         // read configuration space
         let config_space = transport.config_space().cast::<Config>();
-        let config = unsafe { config_space.as_ref() };
-        info!("Config: {:?}", config);
+        unsafe {
+            let events_read = volread!(config_space, events_read);
+            let num_scanouts = volread!(config_space, num_scanouts);
+            info!(
+                "events_read: {:#x}, num_scanouts: {:#x}",
+                events_read, num_scanouts
+            );
+        }
 
         let control_queue = VirtQueue::new(&mut transport, QUEUE_TRANSMIT, 2)?;
         let cursor_queue = VirtQueue::new(&mut transport, QUEUE_CURSOR, 2)?;

src/net.rs

@@ -177,7 +177,6 @@ bitflags! {
 }
 
 #[repr(C)]
-#[derive(Debug)]
 struct Config {
     mac: ReadOnly<EthernetAddress>,
     status: ReadOnly<Status>,