Crate msb_krun 

msb_krun - Native Rust API for libkrun microVMs.

This crate provides a builder-pattern API for creating and entering microVMs using libkrun’s VMM infrastructure.

Lifecycle

Vm::enter() never returns on success. When the guest shuts down, the VMM calls _exit(), killing the entire process. enter() only returns Err if something fails before the VMM takes over.

Example

use msb_krun::{VmBuilder, Result};

fn main() -> Result<()> {
    VmBuilder::new()
        .machine(|m| m.vcpus(4).memory_mib(2048))
        .fs(|fs| fs.root("/path/to/rootfs"))
        .exec(|e| e.path("/bin/myapp").args(["--flag"]).env("HOME", "/root"))
        .build()?
        .enter()?;

    unreachable!()
}

Re-exports

pub use api::builder::VmBuilder;

pub use api::builders::FsBuilder;

pub use api::builders::VsockBuilder;

pub use api::builders::ConsoleBuilder;

pub use api::builders::ConsolePortOptions;

pub use api::builders::ExecBuilder;

pub use api::builders::KernelBuilder;

pub use api::builders::MachineBuilder;

pub use api::builders::NumaBuilder;

pub use api::builders::NumaNodeBuilder;

pub use api::error::BuildError;

pub use api::error::ConfigError;

pub use api::error::Error;

pub use api::error::Result;

pub use api::error::RuntimeError;

pub use api::exit_handle::ExitHandle;

pub use api::vm::Vm;

pub use api::vm::VmControl;

pub use api::vm::VmCpuState;

pub use api::vm::VmExecutionState;

pub use api::vm::VmGenerationId;

pub use api::vm::VmGenerationRequest;

pub use api::vm::VmGenerationState;

pub use api::vm::VmGenerationWaitOutcome;

pub use api::vm::VmMemoryRestoreSource;

pub use api::vm::VmMemoryRestoreTarget;

pub use api::vm::VmMemoryState;

pub use api::vm::VmPauseGeneration;

Modules

api

Native Rust API for libkrun.

backends

Custom backend support for libkrun.

Structs

BlockDeviceMetrics

Per-device block metrics.

BlockMetrics

Aggregate block metrics.

CpuMetrics

CPU metrics.

ExecutionState

Complete hypervisor-owned execution state at one VM-wide pause generation.

FilesystemMetrics

Filesystem metrics.

GuestMemoryRange

One non-empty guest-physical byte range.

HostCpuId

Identifies one logical processor in the host’s processor topology.

MemoryBaselineToken

Runtime-local capability naming the latest successfully published memory baseline.

MemoryCaptureOptions

Bounded streaming configuration for memory generation production.

MemoryCapturePlan

Candidate memory generation that has not yet become the retained baseline.

MemoryCaptureStats

Measurements from producing one full or incremental memory generation.

MemoryGeneration

Identifies one candidate or published memory-content generation.

MemoryMetrics

Memory metrics.

MemoryTopologyGeneration

Identifies one immutable guest-memory topology within a running VMM.

MetricsHandle

Cloneable handle for point-in-time VM metrics.

NumaDistance

One entry in the dense guest NUMA distance matrix.

NumaNodeConfig

One dense guest proximity domain and the host policy for its backing memory.

NumaTopology

A fully resolved guest NUMA description supplied by the embedding runtime.

PlacementReport

The host placement that was actually established before guest execution begins.

PrivateMemoryBacking

Immutable, read-only file ownership retained by every resulting mapping.

PrivateMemoryRegion

One complete guest RAM region in an immutable flat memory image.

VcpuExecutionState

Opaque state for one vCPU, interpreted only by its matching backend codec.

VmMetrics

Point-in-time VM metrics.

VsockConnectRequest

Metadata for a guest-initiated connection to a registered host port.

VsockNotifier

Cloneable wake handle for a custom vsock stream.

Enums

ExecutionArchitecture

Guest instruction-set architecture represented by an execution-state artifact.

ExecutionBackend

Hypervisor backend that produced an execution-state artifact.

FullCaptureReason

Reason an incremental request must safely use complete capture instead.

HostMemoryPolicy

Host backing policy for guest RAM belonging to a resolved node.

IncrementalCaptureDecision

Result of requesting capture relative to a retained baseline.

MemoryCaptureKind

Describes whether a candidate capture is complete or relative to a retained baseline.

MemoryPlacementResult

The effective host-memory placement of ordinary guest RAM and hotplug capacity.

VcpuPlacementResult

The effective host placement of one guest vCPU.

VsockShutdown

Direction requested by a guest shutdown packet.

Traits

ConsolePortBackend

Trait for custom virtio-console port backends.

DynFileSystem

Object-safe filesystem trait for dynamic dispatch.

MemoryCaptureSink

Receives one bounded, ordered memory-generation stream.

VsockPortBackend

Factory for custom, in-process services exposed on one host vsock port.

VsockStreamBackend

One nonblocking byte stream served by a custom vsock backend.