Add module for PCI transport, with function to match device IDs.

src/lib.rs

@@ -28,6 +28,7 @@ pub use self::input::{InputConfigSelect, InputEvent, VirtIOInput};
 pub use self::net::VirtIONet;
 use self::queue::VirtQueue;
 pub use self::transport::mmio::{MmioError, MmioTransport, MmioVersion, VirtIOHeader};
+pub use self::transport::pci;
 pub use self::transport::{DeviceStatus, DeviceType, Transport};
 use core::mem::size_of;
 use hal::*;

src/transport/mod.rs

@@ -1,6 +1,7 @@
 #[cfg(test)]
 pub mod fake;
 pub mod mmio;
+pub mod pci;
 
 use crate::{PhysAddr, PAGE_SIZE};
 use bitflags::bitflags;

src/transport/pci.rs

@@ -0,0 +1,52 @@
+//! PCI transport for VirtIO.
+
+use super::DeviceType;
+
+/// The PCI vendor ID for VirtIO devices.
+const VIRTIO_VENDOR_ID: u16 = 0x1af4;
+
+/// The offset to add to a VirtIO device ID to get the corresponding PCI device ID.
+const PCI_DEVICE_ID_OFFSET: u16 = 0x1040;
+
+const TRANSITIONAL_NETWORK: u16 = 0x1000;
+const TRANSITIONAL_BLOCK: u16 = 0x1001;
+const TRANSITIONAL_MEMORY_BALLOONING: u16 = 0x1002;
+const TRANSITIONAL_CONSOLE: u16 = 0x1003;
+const TRANSITIONAL_SCSI_HOST: u16 = 0x1004;
+const TRANSITIONAL_ENTROPY_SOURCE: u16 = 0x1005;
+const TRANSITIONAL_9P_TRANSPORT: u16 = 0x1009;
+
+fn device_type(pci_device_id: u16) -> DeviceType {
+    match pci_device_id {
+        TRANSITIONAL_NETWORK => DeviceType::Network,
+        TRANSITIONAL_BLOCK => DeviceType::Block,
+        TRANSITIONAL_MEMORY_BALLOONING => DeviceType::MemoryBalloon,
+        TRANSITIONAL_CONSOLE => DeviceType::Console,
+        TRANSITIONAL_SCSI_HOST => DeviceType::ScsiHost,
+        TRANSITIONAL_ENTROPY_SOURCE => DeviceType::EntropySource,
+        TRANSITIONAL_9P_TRANSPORT => DeviceType::_9P,
+        id if id >= PCI_DEVICE_ID_OFFSET => DeviceType::from(id - PCI_DEVICE_ID_OFFSET),
+        _ => DeviceType::Invalid,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn transitional_device_ids() {
+        assert_eq!(device_type(0x1000), DeviceType::Network);
+        assert_eq!(device_type(0x1002), DeviceType::MemoryBalloon);
+        assert_eq!(device_type(0x1009), DeviceType::_9P);
+    }
+
+    #[test]
+    fn offset_device_ids() {
+        assert_eq!(device_type(0x1045), DeviceType::MemoryBalloon);
+        assert_eq!(device_type(0x1049), DeviceType::_9P);
+        assert_eq!(device_type(0x1058), DeviceType::Memory);
+        assert_eq!(device_type(0x1040), DeviceType::Invalid);
+        assert_eq!(device_type(0x1059), DeviceType::Invalid);
+    }
+}