No need to allocate PCI BARs after all.

Apparently crosvm does this for us, so we can save a bunch of code.

Bug: 237249743
Test: Ran vmbase and pVM firmware manually
Test: atest vmbase_example.integration_test
Change-Id: I3efde5ad1af554a8a1c50fb23d6d1d1de082d25d
diff --git a/pvmfw/src/main.rs b/pvmfw/src/main.rs
index 2f1b42a..9c5fb60 100644
--- a/pvmfw/src/main.rs
+++ b/pvmfw/src/main.rs
@@ -37,7 +37,7 @@
     avb::PUBLIC_KEY,
     entry::RebootReason,
     memory::MemoryTracker,
-    pci::{allocate_all_virtio_bars, PciError, PciInfo, PciMemory32Allocator},
+    pci::{find_virtio_devices, PciError, PciInfo},
 };
 use ::avb::verify_image;
 use dice::bcc;
@@ -65,12 +65,10 @@
     let pci_info = PciInfo::from_fdt(fdt).map_err(handle_pci_error)?;
     debug!("PCI: {:#x?}", pci_info);
     pci_info.map(memory)?;
-    let mut bar_allocator = PciMemory32Allocator::new(&pci_info);
-    debug!("Allocator: {:#x?}", bar_allocator);
     // Safety: This is the only place where we call make_pci_root, and this main function is only
     // called once.
     let mut pci_root = unsafe { pci_info.make_pci_root() };
-    allocate_all_virtio_bars(&mut pci_root, &mut bar_allocator).map_err(handle_pci_error)?;
+    find_virtio_devices(&mut pci_root).map_err(handle_pci_error)?;
 
     verify_image(signed_kernel, PUBLIC_KEY).map_err(|e| {
         error!("Failed to verify the payload: {e}");
@@ -95,8 +93,5 @@
         | PciError::FdtMissingRanges
         | PciError::RangeAddressMismatch { .. }
         | PciError::NoSuitableRange => RebootReason::InvalidFdt,
-        PciError::BarInfoFailed(_)
-        | PciError::BarAllocationFailed { .. }
-        | PciError::UnsupportedBarType(_) => RebootReason::PciError,
     }
 }