Module guest_memory 

Traits to track and access the physical memory of the guest.

To make the abstraction as generic as possible, all the core traits declared here only define methods to access guest’s memory, and never define methods to manage (create, delete, insert, remove etc) guest’s memory. This way, the guest memory consumers (virtio device drivers, vhost drivers and boot loaders etc) may be decoupled from the guest memory provider (typically a hypervisor).

Traits and Structs

• GuestAddress: represents a guest physical address (GPA).
• MemoryRegionAddress: represents an offset inside a region.
• GuestMemoryRegion: represent a continuous region of guest’s physical memory.
• GuestMemoryBackend: represent a collection of GuestMemoryRegion objects. The main responsibilities of the GuestMemoryBackend trait are:
  • hide the detail of accessing guest’s physical address.
  • map a request address to a GuestMemoryRegion object and relay the request to it.
  • handle cases where an access request spanning two or more GuestMemoryRegion objects.

Whenever a collection of GuestMemoryRegion objects is mutable, GuestAddressSpace should be implemented for clients to obtain a GuestMemoryBackend reference or smart pointer.

The GuestMemoryRegion trait has an associated B: Bitmap type which is used to handle dirty bitmap tracking. Backends are free to define the granularity (or whether tracking is actually performed at all). Those that do implement tracking functionality are expected to ensure the correctness of the underlying Bytes implementation. The user has to explicitly record (using the handle returned by GuestRegionMmap::bitmap) write accesses performed via pointers, references, or slices returned by methods of GuestMemoryBackend,GuestMemoryRegion, VolatileSlice, VolatileRef, or VolatileArrayRef.

Structs

FileOffset

Represents the start point within a File that backs a GuestMemoryRegion.

GuestAddress

Represents a guest physical address (GPA).

GuestMemoryBackendSliceIterator

Iterates over VolatileSlices that together form a guest memory area.

MemoryRegionAddress

Represents an offset inside a region.

Enums

Error

Errors associated with handling guest memory accesses.

Permissions

Permissions for accessing virtual memory.

Traits

GuestAddressSpace

GuestAddressSpace provides a way to retrieve a GuestMemoryBackend object. The vm-memory crate already provides trivial implementation for references to GuestMemoryBackend or reference-counted GuestMemoryBackend objects, but the trait can also be implemented by any other struct in order to provide temporary access to a snapshot of the memory map.

GuestMemory

Represents virtual I/O memory.

GuestMemoryBackend

GuestMemoryBackend represents a container for an immutable collection of GuestMemoryRegion objects. GuestMemoryBackend provides the Bytes<GuestAddress> trait to hide the details of accessing guest memory by physical address. Interior mutability is not allowed for implementations of GuestMemoryBackend so that they always provide a consistent view of the memory map.

GuestMemorySliceIterator

Iterates over VolatileSlices that together form an I/O memory area.

Type Aliases

GuestUsize

Type of the raw value stored in a GuestAddress object.

Result

Result of guest memory operations.