virtio-devices, vm-virtio: Refactor queue state saving/restoring

Use a separate QueueState structure which can be versioned.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vm-virtio/Cargo.toml

@@ -9,8 +9,5 @@ default = []
 
 [dependencies]
 log = "0.4.14"
-serde = ">=1.0.27"
-serde_derive = ">=1.0.27"
-serde_json = ">=1.0.9"
 virtio-bindings = { version = "0.1", features = ["virtio-v5_0_0"]}
 vm-memory = { version = "0.5.0", features = ["backend-mmap", "backend-atomic"] }

vm-virtio/src/lib.rs

@@ -12,8 +12,6 @@
 
 #[macro_use]
 extern crate log;
-#[macro_use]
-extern crate serde_derive;
 
 use std::fmt;
 

vm-virtio/src/queue.rs

@@ -384,11 +384,7 @@ impl<'a, 'b> Iterator for AvailIter<'a, 'b> {
     }
 }
 
-#[derive(Serialize, Deserialize)]
-#[serde(remote = "GuestAddress")]
-struct GuestAddressDef(pub u64);
-
-#[derive(Clone, Serialize, Deserialize)]
+#[derive(Clone)]
 /// A virtio queue's parameters.
 pub struct Queue {
     /// The maximal size in elements offered by the device
@@ -403,22 +399,18 @@ pub struct Queue {
     /// Interrupt vector index of the queue
     pub vector: u16,
 
-    #[serde(with = "GuestAddressDef")]
     /// Guest physical address of the descriptor table
     pub desc_table: GuestAddress,
 
-    #[serde(with = "GuestAddressDef")]
     /// Guest physical address of the available ring
     pub avail_ring: GuestAddress,
 
-    #[serde(with = "GuestAddressDef")]
     /// Guest physical address of the used ring
     pub used_ring: GuestAddress,
 
     pub next_avail: Wrapping<u16>,
     pub next_used: Wrapping<u16>,
 
-    #[serde(skip)]
     pub iommu_mapping_cb: Option<Arc<VirtioIommuRemapping>>,
 
     /// VIRTIO_F_RING_EVENT_IDX negotiated