Struct IommuMemory 

pub struct IommuMemory<M: GuestMemoryBackend, I: Iommu> { /* private fields */ }

Available on crate feature iommu only.

GuestMemory type that consists of an underlying GuestMemoryBackend object plus an Iommu.

The underlying GuestMemoryBackend is basically the physical memory, and the Iommu translates the I/O virtual address space that IommuMemory provides into that underlying physical address space.

Note that this type’s implementation of memory write tracking (“logging”) is specific to what is required by vhost-user:

• When the IOMMU is disabled (IommuMemory::set_iommu_enabled()), writes to memory are tracked by the underlying GuestMemoryBackend in its bitmap(s).
• When it is enabled, they are instead tracked in the IommuMemory’s dirty bitmap; the offset in the bitmap is calculated from the write’s IOVA.

That is, there are two bitmap levels, one in the underlying GuestMemoryBackend, and one in IommuMemory. The former is used when the IOMMU is disabled, the latter when it is enabled.

If you need a different model (e.g. always use the GuestMemoryBackend bitmaps), you should not use this type.

Implementations

impl<M: GuestMemoryBackend, I: Iommu> IommuMemory<M, I>

pub fn new( backend: M, iommu: I, use_iommu: bool, bitmap: <Self as GuestMemory>::Bitmap, ) -> Self

Create a new IommuMemory instance.

pub fn with_replaced_backend(&self, new_backend: M) -> Self

Create a new version of self with the underlying physical memory replaced.

Note that the inner Arc references to the IOMMU and bitmap are cloned, i.e. both the existing and the new IommuMemory object will share the IOMMU and bitmap instances. (The use_iommu flag however is copied, so is independent between the two instances.)

pub fn bitmap(&self) -> &Arc<<Self as GuestMemory>::Bitmap>

Return a reference to the IOVA address space’s dirty bitmap.

This bitmap tracks write accesses done while the IOMMU is enabled.

pub fn set_iommu_enabled(&mut self, enabled: bool)

Enable or disable the IOMMU.

Disabling the IOMMU switches to pass-through mode, where every access is done directly on the underlying physical memory.

pub fn get_iommu_enabled(&self) -> bool

Check whether the IOMMU is enabled.

If the IOMMU is disabled, we operate in pass-through mode, where every access is done directly on the underlying physical memory.

pub fn iommu(&self) -> &Arc<I>

Return a reference to the IOMMU.

pub fn get_backend(&self) -> &M

Return a reference to the underlying physical memory object.

Trait Implementations

impl<M: GuestMemoryBackend + Clone, I: Iommu> Clone for IommuMemory<M, I>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<M: GuestMemoryBackend + Debug, I: Iommu> Debug for IommuMemory<M, I>

where <M::R as GuestMemoryRegion>::B: Debug,

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

Formats the value using the given formatter.

impl<M: GuestMemoryBackend + Default, I: Iommu + Default> Default for IommuMemory<M, I>

where <M::R as GuestMemoryRegion>::B: Default,

fn default() -> Self

Returns the “default value” for a type.

impl<M: GuestMemoryBackend, I: Iommu> GuestMemory for IommuMemory<M, I>

type PhysicalMemory = M

Underlying GuestMemoryBackend type.

type Bitmap = <<M as GuestMemoryBackend>::R as GuestMemoryRegion>::B

Dirty bitmap type for tracking writes to the IOVA address space.

fn check_range( &self, addr: GuestAddress, count: usize, access: Permissions, ) -> bool

Return true if addr..(addr + count) is accessible with access.

fn get_slices<'a>( &'a self, addr: GuestAddress, count: usize, access: Permissions, ) -> GuestMemoryResult<impl GuestMemorySliceIterator<'a, BS<'a, Self::Bitmap>>>

Returns a VolatileSlice of count bytes starting at addr.

fn physical_memory(&self) -> Option<&Self::PhysicalMemory>

If this virtual memory is just a plain GuestMemoryBackend object underneath without an IOMMU translation layer in between, return that GuestMemoryBackend object.