virtio-pci: map BAR with the information from capabilities

Currently, we map the BAR spaces ahead of time and then match them with the capability they belong to. We can get the slot index from the capability and map the space based on that instead. Although creating a BAR list independent of the capability list could be useful for devices that do not support capability lists, we assume the existence of that support anyways. Fixes hermit-os#1392.

src/drivers/virtio/mod.rs

@@ -1,7 +1,6 @@
 //! A module containing virtios core infrastructure for hermit-rs.
 //!
 //! The module contains virtios transport mechanisms, virtqueues and virtio specific errors
-pub mod env;
 pub mod transport;
 pub mod virtqueue;
 

src/drivers/virtio/transport/pci.rs

@@ -37,6 +37,7 @@ use crate::drivers::virtio::error::VirtioError;
 	any(feature = "tcp", feature = "udp", feature = "vsock")
 ))]
 use crate::drivers::virtio::transport::hardware;
+use crate::drivers::virtio::transport::pci::PciBar as VirtioPciBar;
 #[cfg(feature = "vsock")]
 use crate::drivers::vsock::VirtioVsockDriver;
 
@@ -765,10 +766,7 @@ impl PciBar {
 ///
 /// Returns ONLY Virtio specific capabilities, which allow to locate the actual capability
 /// structures inside the memory areas, indicated by the BaseAddressRegisters (BAR's).
-fn read_caps(
-	device: &PciDevice<PciConfigRegion>,
-	bars: &[PciBar],
-) -> Result<Vec<PciCap>, PciError> {
+fn read_caps(device: &PciDevice<PciConfigRegion>) -> Result<Vec<PciCap>, PciError> {
 	let device_id = device.device_id();
 
 	let capabilities = device
@@ -780,10 +778,14 @@ fn read_caps(
 		})
 		.map(|addr| CapData::read(addr, device.access()).unwrap())
 		.filter(|cap| cap.cfg_type != CapCfgType::Pci)
-		.map(|cap| PciCap {
-			bar: *bars.iter().find(|bar| bar.index == cap.bar).unwrap(),
-			dev_id: device_id,
-			cap,
+		.map(|cap| {
+			let slot = cap.bar;
+			let (addr, size) = device.memory_map_bar(slot, true).unwrap();
+			PciCap {
+				bar: VirtioPciBar::new(slot, addr.as_u64(), size.try_into().unwrap()),
+				dev_id: device_id,
+				cap,
+			}
 		})
 		.collect::<Vec<_>>();
 
@@ -795,11 +797,6 @@ fn read_caps(
 	}
 }
 
-/// Maps memory areas indicated by devices BAR's into virtual address space.
-fn map_bars(device: &PciDevice<PciConfigRegion>) -> Result<Vec<PciBar>, PciError> {
-	crate::drivers::virtio::env::pci::map_bar_mem(device)
-}
-
 /// Checks if minimal set of capabilities is present.
 ///
 /// INFO: Currently only checks if at least one common config struct has been found and mapped.
@@ -828,7 +825,7 @@ pub(crate) fn map_caps(device: &PciDevice<PciConfigRegion>) -> Result<UniCapsCol
 	};
 
 	// Get list of PciCaps pointing to capabilities
-	let cap_list = match read_caps(device, &bar_list) {
+	let cap_list = match read_caps(device) {
 		Ok(list) => list,
 		Err(pci_error) => return Err(pci_error),
 	};