add logging about virtq and swiotlb region placement

This will make it easier to validate in an integration test that virt
queues are actually placed in the swiotlb region, as a sort of sanity
check that on Firecracker's side the swiotlb regions are actually passed
to the virtio devices, and that the guest is honoring the request to
place virtio stuff into the swiotlb regions.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

src/vmm/src/arch/aarch64/fdt.rs

@@ -257,6 +257,12 @@ fn create_memory_node(
         fdt.property_array_u64("reg", &[region.start_addr().0, region.len()])?;
         fdt.end_node(dma)?;
         fdt.end_node(rmem)?;
+
+        log::info!(
+            "Placed swiotlb region at [{}, {})",
+            region.start_addr().0,
+            region.start_addr().0 + region.len()
+        );
     }
 
     Ok(())

src/vmm/src/devices/virtio/queue.rs

@@ -308,6 +308,15 @@ impl Queue {
         Ok(slice.ptr_guard_mut().as_ptr())
     }
 
+    fn log_queue_component_address(component: &'static str, addr: GuestAddress, size: usize) {
+        log::info!(
+            "Placed virt queue {} at [{}, {})",
+            component,
+            addr.0,
+            addr.0 + size as u64
+        );
+    }
+
     /// Set up pointers to the queue objects in the guest memory
     /// and mark memory dirty for those objects
     pub fn initialize<M: GuestMemory>(&mut self, mem: &M) -> Result<(), QueueError> {
@@ -353,6 +362,22 @@ impl Queue {
             ));
         }
 
+        Self::log_queue_component_address(
+            "descriptor table",
+            self.desc_table_address,
+            self.desc_table_size(),
+        );
+        Self::log_queue_component_address(
+            "avail ring",
+            self.avail_ring_address,
+            self.avail_ring_size(),
+        );
+        Self::log_queue_component_address(
+            "used ring",
+            self.used_ring_address,
+            self.used_ring_size(),
+        );
+
         Ok(())
     }