devices: Adding Suspendable to ConstantDevice and DummyDevice

Added suspendable trait to ConstantDevice.
Generate tests for ConstantDevice.
Added suspendable trait to DummyDevice.
Generate tests for DummyDevice.

Bug=b:232437513
Test=cargo test

Change-Id: I38b7b84350c503a9b307a10789b5f328135ac036
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3831266
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Elie Kheirallah <khei@google.com>

devices/src/bus.rs

@@ -551,8 +551,14 @@ impl Bus {
 mod tests {
     use super::*;
     use crate::pci::CrosvmDeviceId;
+    use crate::suspendable::Suspendable;
+    use crate::suspendable_tests;
+    use anyhow::Context;
+    use anyhow::Result as AnyhowResult;
 
+    #[derive(Copy, Clone, Serialize, Deserialize, Eq, PartialEq, Debug)]
     struct DummyDevice;
+
     impl BusDevice for DummyDevice {
         fn device_id(&self) -> DeviceId {
             CrosvmDeviceId::Cmos.into()
@@ -562,6 +568,27 @@ mod tests {
         }
     }
 
+    impl Suspendable for DummyDevice {
+        fn snapshot(&self) -> AnyhowResult<String> {
+            serde_json::to_string_pretty(&self).context("error serializing")
+        }
+
+        fn restore(&mut self, data: &str) -> AnyhowResult<()> {
+            let deser = serde_json::from_str(data).context("error deserializing");
+            *self = deser.unwrap();
+            Ok(())
+        }
+
+        fn sleep(&mut self) -> AnyhowResult<()> {
+            Ok(())
+        }
+
+        fn wake(&mut self) -> AnyhowResult<()> {
+            Ok(())
+        }
+    }
+
+    #[derive(Copy, Clone, Serialize, Deserialize, Eq, PartialEq, Debug)]
     struct ConstantDevice {
         uses_full_addr: bool,
     }
@@ -598,6 +625,26 @@ mod tests {
         }
     }
 
+    impl Suspendable for ConstantDevice {
+        fn snapshot(&self) -> AnyhowResult<String> {
+            serde_json::to_string_pretty(&self).context("error serializing")
+        }
+
+        fn restore(&mut self, data: &str) -> AnyhowResult<()> {
+            let deser = serde_json::from_str(data).context("error deserializing");
+            *self = deser.unwrap();
+            Ok(())
+        }
+
+        fn sleep(&mut self) -> AnyhowResult<()> {
+            Ok(())
+        }
+
+        fn wake(&mut self) -> AnyhowResult<()> {
+            Ok(())
+        }
+    }
+
     #[test]
     fn bus_insert() {
         let bus = Bus::new();
@@ -683,6 +730,16 @@ mod tests {
         assert!(bus.write(0x15, &values));
     }
 
+    suspendable_tests! {
+        dummy_device: DummyDevice,
+        constant_device_true: ConstantDevice {
+            uses_full_addr: true,
+        },
+        constant_device_false: ConstantDevice {
+            uses_full_addr: false,
+        },
+    }
+
     #[test]
     fn bus_range_contains() {
         let a = BusRange {