devices: Simplify device state to support Versionize

In order to support using Versionize for state structures it is necessary
to use simpler, primitive, data types in the state definitions used for
snapshot restore.

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

devices/src/ioapic.rs

@@ -23,10 +23,6 @@ use vm_memory::GuestAddress;
 use vm_migration::{Migratable, MigratableError, Pausable, Snapshot, Snapshottable, Transportable};
 use vmm_sys_util::eventfd::EventFd;
 
-#[derive(Serialize, Deserialize)]
-#[serde(remote = "GuestAddress")]
-pub struct GuestAddressDef(pub u64);
-
 type Result<T> = result::Result<T, Error>;
 
 // I/O REDIRECTION TABLE REGISTER
@@ -143,8 +139,7 @@ pub struct IoapicState {
     reg_sel: u32,
     reg_entries: [RedirectionTableEntry; NUM_IOAPIC_PINS],
     used_entries: [bool; NUM_IOAPIC_PINS],
-    #[serde(with = "GuestAddressDef")]
-    apic_address: GuestAddress,
+    apic_address: u64,
 }
 
 impl BusDevice for Ioapic {
@@ -281,7 +276,7 @@ impl Ioapic {
             reg_sel: self.reg_sel,
             reg_entries: self.reg_entries,
             used_entries: self.used_entries,
-            apic_address: self.apic_address,
+            apic_address: self.apic_address.0,
         }
     }
 
@@ -290,7 +285,7 @@ impl Ioapic {
         self.reg_sel = state.reg_sel;
         self.reg_entries = state.reg_entries;
         self.used_entries = state.used_entries;
-        self.apic_address = state.apic_address;
+        self.apic_address = GuestAddress(state.apic_address);
         for (irq, entry) in self.used_entries.iter().enumerate() {
             if *entry {
                 self.update_entry(irq)?;