Method resize

vmm/src/memory_manager.rs:2459–2493

In case this function resulted in adding a new memory region to the guest memory, the new region is returned to the caller. The virtio-mem use case never adds a new region as the whole hotpluggable memory has already been allocated at boot time.

(&mut self, desired_ram: u64)

    /// use case never adds a new region as the whole hotpluggable memory has
    /// already been allocated at boot time.
    pub fn resize(&mut self, desired_ram: u64) -> Result<Option<Arc<GuestRegionMmap>>, Error> {
        if self.user_provided_zones {
            error!(
                "Not allowed to resize guest memory when backed with user \
                defined memory zones."
            );
            return Err(Error::InvalidResizeWithMemoryZones);
        }

        let mut region: Option<Arc<GuestRegionMmap>> = None;
        match self.hotplug_method {
            HotplugMethod::VirtioMem => {
                if desired_ram >= self.boot_ram {
                    if !self.dynamic {
                        return Ok(region);
                    }

                    self.virtio_mem_resize(DEFAULT_MEMORY_ZONE, desired_ram - self.boot_ram)?;
                    self.current_ram = desired_ram;
                }
            }
            HotplugMethod::Acpi => {
                if desired_ram > self.current_ram {
                    if !self.dynamic {
                        return Ok(region);
                    }

                    region =
                        Some(self.hotplug_ram_region((desired_ram - self.current_ram) as usize)?);
                    self.current_ram = desired_ram;
                }
            }
        }
        Ok(region)
    }

    pub fn resize_zone(&mut self, id: &str, virtio_mem_size: u64) -> Result<(), Error> {
        if !self.user_provided_zones {