Method create_vcpus

vmm/src/cpu.rs:1072–1101

Only create new vCPUs if there aren't any inactive ones to reuse

(
        &mut self,
        desired_vcpus: u32,
        snapshot: Option<&Snapshot>,
    )

    /// Only create new vCPUs if there aren't any inactive ones to reuse
    fn create_vcpus(
        &mut self,
        desired_vcpus: u32,
        snapshot: Option<&Snapshot>,
    ) -> Result<Vec<Arc<Mutex<Vcpu>>>> {
        let mut vcpus: Vec<Arc<Mutex<Vcpu>>> = vec![];
        info!(
            "Request to create new vCPUs: desired = {}, max = {}, allocated = {}, present = {}",
            desired_vcpus,
            self.config.max_vcpus,
            self.vcpus.len(),
            self.present_vcpus()
        );

        if desired_vcpus > self.config.max_vcpus {
            return Err(Error::DesiredVCpuCountExceedsMax);
        }

        // Only create vCPUs in excess of all the allocated vCPUs.
        for cpu_id in self.vcpus.len() as u32..desired_vcpus {
            vcpus.push(self.create_vcpu(
                cpu_id,
                // TODO: The special format of the CPU id can be removed once
                // ready to break live upgrade.
                snapshot_from_id(snapshot, cpu_id.to_string().as_str()),
            )?);
        }

        Ok(vcpus)
    }

    #[cfg(target_arch = "aarch64")]
    pub fn init_pmu(&self, irq: u32) -> Result<bool> {