Managing I/O memory isolation (iommu_api.h)
The API is defined in the sysroot-*-kos/include/coresrv/iommu/iommu_api.h header file from the KasperskyOS SDK.
The API is intended for managing the isolation of physical memory regions used by devices on a PCIe bus for DMA. (Isolation is provided by the IOMMU.)
Information about API functions is provided in the table below.
Using the API
A device on the PCIe bus cannot use DMA unless the device is attached to the IOMMU domain. After a device is attached to the IOMMU domain, the device can access all DMA buffers that are associated with this IOMMU domain. A device can be attached to only one IOMMU domain at a time, but multiple devices can be attached to the same IOMMU domain. A DMA buffer can be associated with multiple IOMMU domains at the same time. Each process is associated with a separate IOMMU domain.
The API attaches devices on the PCIe bus to an IOMMU domain associated with the calling process, and performs the inverse operation. A device is normally attached to an IOMMU domain when its driver is initialized. A device is usually detached from an IOMMU domain when errors are encountered during driver initialization or driver finalization.
A DMA buffer is associated with an IOMMU domain when calling the KnIoDmaBegin() function that is included in the API dma.h.
Information about API functions
iommu_api.h functions
Function | Information about the function |
|---|---|
| Purpose Attaches a device on a PCIe bus to the IOMMU domain associated with the calling process. Parameters
Returned values If successful, the function returns Additional information If IOMMU is not enabled, |
| Purpose Detaches a device on a PCIe bus from the IOMMU domain associated with the calling process. Parameters
Returned values If successful, the function returns Additional information If IOMMU is not enabled, |
