Struct pci_driver::iommu::PciIommu

pub struct PciIommu<'a> { /* private fields */ }

Represents an IOMMU that controls DMA done by some PCI function, device, or group of devices.

You’ll probably need std::sync::atomic::fence or use types like AtomicU32 somewhere to synchronize accesses properly with the device.

Implementations

impl PciIommu<'_>

pub fn alignment(&self) -> usize

Both iova and process address must be aligned to this value.

This is always a power of 2, and never less than the system’s page size.

pub fn valid_iova_ranges(&self) -> &[Range<u64>]

IOVA ranges given to PciIommu::map must be contained in one of the ranges that this method returns.

pub unsafe fn map(
    &self,
    iova: u64,
    length: usize,
    address: *const u8,
    device_permissions: Permissions
) -> Result<()>

Add the given mapping to the IOMMU.

• iova is the start address of the region in the device’s address space.
• size is the length of the region.
• address is a pointer (in the current process’ address space) to the start of the region to be mapped.

TODO: Alignment constraints?

Safety

Must make sense.

pub fn unmap(&self, iova: u64, size: usize) -> Result<()>

Remove the given mapping from the IOMMU.

TODO: Alignment constraints?

Must unmap exactly a full range that was previously mapped using PciIommu::map, or several full ranges as long as they are contiguous. Otherwise, this fails.