Struct VmConfig 

pub struct VmConfig { /* private fields */ }

Configuration for Vm::start. Built via the chainable VmConfig::with_* methods or constructed directly:

use supermachine::VmConfig;
let cfg = VmConfig::new()
    .with_memory_mib(512)
    .with_vcpus(2);

Implementations

impl VmConfig

pub fn new() -> Self

Use the image’s baked defaults for memory + vCPUs; auto-discover assets; vsock-mux socket in $TMPDIR; 10 s restore timeout.

pub fn with_memory_mib(self, mib: u32) -> Self

Override the image’s baked memory.

pub fn with_vcpus(self, vcpus: u32) -> Self

Override the image’s baked vCPU count.

pub fn with_balloon(self, enable: bool) -> Self

Attach a virtio-balloon device so the host can reclaim guest memory via Vm::request_balloon_inflate (KVM cold boot — Image::start). The guest needs CONFIG_VIRTIO_BALLOON (the bundled supermachine kernel has it). Off by default; the warm-pool acquire path ignores it (balloon is a cold-boot reclaim lever, not snapshotted — matching HVF’s restore default).

pub fn with_volume(self, spec: VolumeSpec) -> Self

Attach a data volume (KVM): a host-backed virtio-blk mounted in the guest at spec.guest_path. The backing file is created sparse + formatted ext4 on first use and reused (so data persists across runs); pass the same host_path to keep state. Multiple volumes become vdb, vdc, … Honored on the cold-boot start path (snapshots/pools don’t carry volume mounts yet).

let image = Image::from_oci("postgres:16-alpine")?;
let cfg = VmConfig::new()
    .with_volume(VolumeSpec::new("/srv/pgdata.img", "/var/lib/postgresql/data"));
let vm = image.start(&cfg)?;

pub fn with_virtiofs(self, spec: MountSpec) -> Self

Expose a host directory to the guest over virtio-fs (KVM), mounted at spec.guest_path. Served by an in-process FUSE backend with a DAX window (the guest init mounts -o dax for zero-copy reads). Mounts survive a snapshot: the device + FUSE backend tables + DAX slot table are captured (SMSNAP05) and re-attached on restore (lazy fd reopen + eager DAX rebind).

let image = Image::from_oci("alpine")?;
let cfg = VmConfig::new()
    .with_virtiofs(MountSpec::new("/srv/assets", "assets", "/mnt/assets"));
let vm = image.start(&cfg)?;

pub fn with_assets(self, assets: AssetPaths) -> Self

Override asset auto-discovery. Useful for .app bundles that ship the kernel + init shim under Contents/Resources/.

pub fn with_vsock_mux_dir(self, dir: impl Into<PathBuf>) -> Self

Where to put the host-side vsock-mux unix socket. Default is $TMPDIR. Use this if you need the socket inside an app-private dir for sandboxing reasons.

pub fn with_restore_timeout(self, timeout: Duration) -> Self

How long to wait for the snapshot to restore. Default 10 s.

Trait Implementations

impl Clone for VmConfig

fn clone(&self) -> VmConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for VmConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for VmConfig

fn default() -> VmConfig

Returns the “default value” for a type.