virtio: Port codebase to the latest virtio-queue version

The new virtio-queue version introduced some breaking changes which need
to be addressed so that Cloud Hypervisor can still work with this
version.

The most important change is about removing a handle to the guest memory
from the Queue, meaning the caller has to provide the guest memory
handle for multiple methods from the QueueT trait.

One interesting aspect is that QueueT has been widely extended to
provide every getter and setter we need to access and update the Queue
structure without having direct access to its internal fields.

This patch ports all the virtio and vhost-user devices to this new crate
definition. It also updates both vhost-user-block and vhost-user-net
backends based on the updated vhost-user-backend crate. It also updates
the fuzz directory.

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

vm-virtio/src/queue.rs

@@ -11,9 +11,8 @@
 pub mod testing {
     use std::marker::PhantomData;
     use std::mem;
-    use virtio_queue::{Queue, QueueState, VirtqUsedElem};
-    use vm_memory::{bitmap::AtomicBitmap, Address, GuestAddress, GuestUsize};
-    use vm_memory::{Bytes, GuestMemoryAtomic};
+    use virtio_queue::{Queue, QueueT, VirtqUsedElem};
+    use vm_memory::{bitmap::AtomicBitmap, Address, Bytes, GuestAddress, GuestUsize};
 
     type GuestMemoryMmap = vm_memory::GuestMemoryMmap<AtomicBitmap>;
 
@@ -225,16 +224,14 @@ pub mod testing {
         }
 
         // Creates a new Queue, using the underlying memory regions represented by the VirtQueue.
-        pub fn create_queue(&self) -> Queue<GuestMemoryAtomic<GuestMemoryMmap>> {
-            let mem = GuestMemoryAtomic::new(self.mem.clone());
-            let mut q =
-                Queue::<GuestMemoryAtomic<GuestMemoryMmap>, QueueState>::new(mem, self.size());
+        pub fn create_queue(&self) -> Queue {
+            let mut q = Queue::new(self.size()).unwrap();
 
-            q.state.size = self.size();
-            q.state.ready = true;
-            q.state.desc_table = self.dtable_start();
-            q.state.avail_ring = self.avail_start();
-            q.state.used_ring = self.used_start();
+            q.set_size(self.size());
+            q.set_ready(true);
+            q.try_set_desc_table_address(self.dtable_start()).unwrap();
+            q.try_set_avail_ring_address(self.avail_start()).unwrap();
+            q.try_set_used_ring_address(self.used_start()).unwrap();
 
             q
         }