vmm: Make desired vCPUs optional in resize command

In order to be able to support resizing either vCPUs or memory or both
make the fields in the resize command optional.

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

vmm/src/api/mod.rs

@@ -115,7 +115,7 @@ pub struct VmmPingResponse {
 
 #[derive(Clone, Deserialize, Serialize)]
 pub struct VmResizeData {
-    pub desired_vcpus: u8,
+    pub desired_vcpus: Option<u8>,
 }
 
 pub enum ApiResponsePayload {

vmm/src/api/openapi/cloud-hypervisor.yaml

@@ -427,11 +427,8 @@ components:
           default: false
 
     VmResize:
-      required:
-      - desired_vcpus
       type: object
       properties:
         desired_vcpus:
           minimum: 1
-          default: 1
           type: integer

vmm/src/lib.rs

@@ -330,7 +330,7 @@ impl Vmm {
         self.vm_delete()
     }
 
-    fn vm_resize(&mut self, desired_vcpus: u8) -> result::Result<(), VmError> {
+    fn vm_resize(&mut self, desired_vcpus: Option<u8>) -> result::Result<(), VmError> {
         if let Some(ref mut vm) = self.vm {
             vm.resize(desired_vcpus)
         } else {

vmm/src/vm.rs

@@ -481,16 +481,19 @@ impl Vm {
         Ok(())
     }
 
-    pub fn resize(&mut self, desired_vcpus: u8) -> Result<()> {
-        self.cpu_manager
-            .lock()
-            .unwrap()
-            .resize(desired_vcpus)
-            .map_err(Error::CpuManager)?;
-        self.devices
-            .notify_hotplug(HotPlugNotificationType::CPUDevicesChanged)
-            .map_err(Error::DeviceManager)?;
-        self.config.lock().unwrap().cpus.boot_vcpus = desired_vcpus;
+    pub fn resize(&mut self, desired_vcpus: Option<u8>) -> Result<()> {
+        if let Some(desired_vcpus) = desired_vcpus {
+            self.cpu_manager
+                .lock()
+                .unwrap()
+                .resize(desired_vcpus)
+                .map_err(Error::CpuManager)?;
+            self.devices
+                .notify_hotplug(HotPlugNotificationType::CPUDevicesChanged)
+                .map_err(Error::DeviceManager)?;
+            self.config.lock().unwrap().cpus.boot_vcpus = desired_vcpus;
+        }
+
         Ok(())
     }