vmm: Use new Resource type PciBar

Instead of defining some very generic resources as PioAddressRange or
MmioAddressRange for each PCI BAR, let's move to the new Resource type
PciBar in order to make things clearer. This allows the code for being
more readable, but also removes the need for hard assumptions about the
MMIO and PIO ranges. PioAddressRange and MmioAddressRange types can be
used to describe everything except PCI BARs. BARs are very special as
they can be relocated and have special information we want to carry
along with them.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

pci/src/device.rs

@@ -19,10 +19,8 @@ pub enum Error {
     IoAllocationFailed(u64),
     /// Registering an IO BAR failed.
     IoRegistrationFailed(u64, configuration::Error),
-    /// Not enough resources
+    /// Expected resource not found.
     MissingResource,
-    /// Invalid type of resource
-    InvalidResourceType,
 }
 pub type Result<T> = std::result::Result<T, Error>;
 
@@ -38,8 +36,7 @@ impl Display for Error {
             IoRegistrationFailed(addr, e) => {
                 write!(f, "failed to register an IO BAR, addr={} err={}", addr, e)
             }
-            MissingResource => write!(f, "Missing resource"),
-            InvalidResourceType => write!(f, "Invalid type of resource"),
+            MissingResource => write!(f, "failed to find expected resource"),
         }
     }
 }