Build dedicated structs/interfaces for Pio

The design to multiplex IoAddress/IoSize for MMIO and PIO makes
the device driver implmentation a little complex, so build dedicated
data structs and interfaces to handle PIO requests. Also make PIO
related code x86 specific.

Signed-off-by: Liu Jiang <[email protected]>

Author: jiangliu

src/device_manager.rs

@@ -12,6 +12,8 @@
 //! devices IO ranges, and finally set resources to virtual device.
 
 use crate::resources::Resource;
+#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+use crate::PioAddress;
 use crate::{DeviceIo, IoAddress, IoSize};
 
 use std::cmp::{Ord, Ordering, PartialEq, PartialOrd};
@@ -32,29 +34,29 @@ pub enum Error {
 pub type Result<T> = result::Result<T, Error>;
 
 /// Structure describing an IO range.
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Eq)]
 pub struct IoRange {
     base: IoAddress,
     size: IoSize,
 }
 
 impl IoRange {
+    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     fn new_pio_range(base: u16, size: u16) -> Self {
         IoRange {
-            base: IoAddress::Pio(base),
-            size: IoSize::Pio(size),
+            base: IoAddress(base as u64),
+            size: IoSize(size as u64),
         }
     }
+
     fn new_mmio_range(base: u64, size: u64) -> Self {
         IoRange {
-            base: IoAddress::Mmio(base),
-            size: IoSize::Mmio(size),
+            base: IoAddress(base),
+            size: IoSize(size),
         }
     }
 }
 
-impl Eq for IoRange {}
-
 impl PartialEq for IoRange {
     fn eq(&self, other: &IoRange) -> bool {
         self.base == other.base
@@ -76,6 +78,7 @@ impl PartialOrd for IoRange {
 /// System IO manager serving for all devices management and VM exit handling.
 #[derive(Clone, Default)]
 pub struct IoManager {
+    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     /// Range mapping for VM exit pio operations.
     pio_bus: BTreeMap<IoRange, Arc<dyn DeviceIo>>,
     /// Range mapping for VM exit mmio operations.
@@ -87,6 +90,7 @@ impl IoManager {
     pub fn new() -> Self {
         IoManager::default()
     }
+
     /// Register a new device IO with its allocated resources.
     /// VMM is responsible for providing the allocated resources to virtual device.
     ///
@@ -104,6 +108,7 @@ impl IoManager {
         // The resources addresses being registered are sucessfully allocated before.
         for (idx, res) in resources.iter().enumerate() {
             match *res {
+                #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
                 Resource::PioAddressRange { base, size } => {
                     if self
                         .pio_bus
@@ -147,6 +152,7 @@ impl IoManager {
     pub fn unregister_device_io(&mut self, resources: &[Resource]) -> Result<()> {
         for res in resources.iter() {
             match *res {
+                #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
                 Resource::PioAddressRange { base, size } => {
                     self.pio_bus.remove(&IoRange::new_pio_range(base, size));
                 }
@@ -159,79 +165,69 @@ impl IoManager {
         Ok(())
     }
 
-    fn get_entry(&self, addr: IoAddress) -> Option<(&IoRange, &Arc<dyn DeviceIo>)> {
-        match addr {
-            IoAddress::Pio(a) => self
-                .pio_bus
-                .range(..=&IoRange::new_pio_range(a, 0))
-                .nth_back(0),
-            IoAddress::Mmio(a) => self
-                .mmio_bus
-                .range(..=&IoRange::new_mmio_range(a, 0))
-                .nth_back(0),
-        }
+    /// A helper function handling MMIO read command during VM exit.
+    /// The virtual device itself provides mutable ability and thead-safe protection.
+    ///
+    /// Return error if failed to get the device.
+    pub fn mmio_read(&self, addr: u64, data: &mut [u8]) -> Result<()> {
+        self.get_device(IoAddress(addr))
+            .map(|(device, base)| device.read(base, IoAddress(addr - base.raw_value()), data))
+            .ok_or(Error::NoDevice)
+    }
+
+    /// A helper function handling MMIO write command during VM exit.
+    /// The virtual device itself provides mutable ability and thead-safe protection.
+    ///
+    /// Return error if failed to get the device.
+    pub fn mmio_write(&self, addr: u64, data: &[u8]) -> Result<()> {
+        self.get_device(IoAddress(addr))
+            .map(|(device, base)| device.write(base, IoAddress(addr - base.raw_value()), data))
+            .ok_or(Error::NoDevice)
     }
 
     // Return the Device mapped `addr` and the base address.
     fn get_device(&self, addr: IoAddress) -> Option<(&Arc<dyn DeviceIo>, IoAddress)> {
-        if let Some((range, dev)) = self.get_entry(addr) {
+        let range = IoRange::new_mmio_range(addr.raw_value(), 0);
+        if let Some((range, dev)) = self.mmio_bus.range(..=&range).nth_back(0) {
             if (addr.raw_value() - range.base.raw_value()) < range.size.raw_value() {
                 return Some((dev, range.base));
             }
         }
         None
     }
+}
 
+#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+impl IoManager {
     /// A helper function handling PIO read command during VM exit.
     /// The virtual device itself provides mutable ability and thead-safe protection.
     ///
     /// Return error if failed to get the device.
     pub fn pio_read(&self, addr: u16, data: &mut [u8]) -> Result<()> {
-        if let Some((device, base)) = self.get_device(IoAddress::Pio(addr)) {
-            device.read(base, IoAddress::Pio(addr - (base.raw_value() as u16)), data);
-            Ok(())
-        } else {
-            Err(Error::NoDevice)
-        }
+        self.get_pio_device(PioAddress(addr))
+            .map(|(device, base)| device.pio_read(base, PioAddress(addr - base.raw_value()), data))
+            .ok_or(Error::NoDevice)
     }
 
     /// A helper function handling PIO write command during VM exit.
     /// The virtual device itself provides mutable ability and thead-safe protection.
     ///
     /// Return error if failed to get the device.
     pub fn pio_write(&self, addr: u16, data: &[u8]) -> Result<()> {
-        if let Some((device, base)) = self.get_device(IoAddress::Pio(addr)) {
-            device.write(base, IoAddress::Pio(addr - (base.raw_value() as u16)), data);
-            Ok(())
-        } else {
-            Err(Error::NoDevice)
-        }
-    }
-
-    /// A helper function handling MMIO read command during VM exit.
-    /// The virtual device itself provides mutable ability and thead-safe protection.
-    ///
-    /// Return error if failed to get the device.
-    pub fn mmio_read(&self, addr: u64, data: &mut [u8]) -> Result<()> {
-        if let Some((device, base)) = self.get_device(IoAddress::Mmio(addr)) {
-            device.read(base, IoAddress::Mmio(addr - base.raw_value()), data);
-            Ok(())
-        } else {
-            Err(Error::NoDevice)
-        }
+        self.get_pio_device(PioAddress(addr))
+            .map(|(device, base)| device.pio_write(base, PioAddress(addr - base.raw_value()), data))
+            .ok_or(Error::NoDevice)
     }
 
-    /// A helper function handling MMIO write command during VM exit.
-    /// The virtual device itself provides mutable ability and thead-safe protection.
-    ///
-    /// Return error if failed to get the device.
-    pub fn mmio_write(&self, addr: u64, data: &[u8]) -> Result<()> {
-        if let Some((device, base)) = self.get_device(IoAddress::Mmio(addr)) {
-            device.write(base, IoAddress::Mmio(addr - base.raw_value()), data);
-            Ok(())
-        } else {
-            Err(Error::NoDevice)
+    // Return the Device mapped `addr` and the base address.
+    fn get_pio_device(&self, addr: PioAddress) -> Option<(&Arc<dyn DeviceIo>, PioAddress)> {
+        let range = IoRange::new_pio_range(addr.raw_value(), 0);
+        if let Some((range, dev)) = self.pio_bus.range(..=&range).nth_back(0) {
+            if (addr.raw_value() as u64 - range.base.raw_value()) < range.size.raw_value() {
+                return Some((dev, PioAddress(range.base.0 as u16)));
+            }
         }
+        None
     }
 }
 
@@ -240,7 +236,9 @@ mod tests {
     use super::*;
     use std::sync::Mutex;
 
+    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     const PIO_ADDRESS_SIZE: u16 = 4;
+    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     const PIO_ADDRESS_BASE: u16 = 0x40;
     const MMIO_ADDRESS_SIZE: u64 = 0x8765_4321;
     const MMIO_ADDRESS_BASE: u64 = 0x1234_5678;
@@ -274,6 +272,23 @@ mod tests {
             let mut config = self.config.lock().expect("failed to acquire lock");
             *config = u32::from(data[0]) & 0xff;
         }
+
+        #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+        fn pio_read(&self, _base: PioAddress, _offset: PioAddress, data: &mut [u8]) {
+            if data.len() > 4 {
+                return;
+            }
+            for (idx, iter) in data.iter_mut().enumerate() {
+                let config = self.config.lock().expect("failed to acquire lock");
+                *iter = (*config >> (idx * 8) & 0xff) as u8;
+            }
+        }
+
+        #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+        fn pio_write(&self, _base: PioAddress, _offset: PioAddress, data: &[u8]) {
+            let mut config = self.config.lock().expect("failed to acquire lock");
+            *config = u32::from(data[0]) & 0xff;
+        }
     }
 
     #[test]
@@ -287,32 +302,42 @@ mod tests {
             base: MMIO_ADDRESS_BASE,
             size: MMIO_ADDRESS_SIZE,
         };
-        let pio = Resource::PioAddressRange {
-            base: PIO_ADDRESS_BASE,
-            size: PIO_ADDRESS_SIZE,
-        };
         let irq = Resource::LegacyIrq(LEGACY_IRQ);
 
         resource.push(mmio);
-        resource.push(pio);
         resource.push(irq);
+
+        #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+        {
+            let pio = Resource::PioAddressRange {
+                base: PIO_ADDRESS_BASE,
+                size: PIO_ADDRESS_SIZE,
+            };
+            resource.push(pio);
+        }
+
         assert!(io_mgr.register_device_io(dum.clone(), &resource).is_ok());
 
         let io_mgr2 = io_mgr.clone();
-        assert_eq!(io_mgr2.pio_bus.len(), 1);
         assert_eq!(io_mgr2.mmio_bus.len(), 1);
 
-        let (dev, addr) = io_mgr2
-            .get_device(IoAddress::Mmio(MMIO_ADDRESS_BASE + 1))
-            .unwrap();
-        assert_eq!(Arc::strong_count(dev), 5);
-        assert_eq!(addr, IoAddress::Mmio(MMIO_ADDRESS_BASE));
+        #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+        {
+            assert_eq!(io_mgr2.pio_bus.len(), 1);
+
+            let (dev, addr) = io_mgr2
+                .get_device(IoAddress(MMIO_ADDRESS_BASE + 1))
+                .unwrap();
+            assert_eq!(Arc::strong_count(dev), 5);
 
-        drop(io_mgr);
-        assert_eq!(Arc::strong_count(dev), 3);
+            assert_eq!(addr, IoAddress(MMIO_ADDRESS_BASE));
 
-        drop(io_mgr2);
-        assert_eq!(Arc::strong_count(&dum), 1);
+            drop(io_mgr);
+            assert_eq!(Arc::strong_count(dev), 3);
+
+            drop(io_mgr2);
+            assert_eq!(Arc::strong_count(&dum), 1);
+        }
     }
 
     #[test]
@@ -365,6 +390,7 @@ mod tests {
             .is_err());
     }
 
+    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     #[test]
     fn test_pio_read_write() {
         let mut io_mgr: IoManager = Default::default();
@@ -394,4 +420,15 @@ mod tests {
             .pio_write(PIO_ADDRESS_BASE + PIO_ADDRESS_SIZE, &data)
             .is_err());
     }
+
+    #[test]
+    fn test_device_manager_data_structs() {
+        let range1 = IoRange::new_mmio_range(0x1000, 0x1000);
+        let range2 = IoRange::new_mmio_range(0x1000, 0x2000);
+        let range3 = IoRange::new_mmio_range(0x2000, 0x1000);
+
+        assert_eq!(range1, range1.clone());
+        assert_eq!(range1, range2);
+        assert!(range1 < range3);
+    }
 }