-
Kirti Wankhede authored
VFIO IOMMU drivers are designed for the devices which are IOMMU capable. Mediated device only uses IOMMU APIs, the underlying hardware can be managed by an IOMMU domain. Aim of this change is: - To use most of the code of TYPE1 IOMMU driver for mediated devices - To support direct assigned device and mediated device in single module This change adds pin and unpin support for mediated device to TYPE1 IOMMU backend module. More details: - Domain for external user is tracked separately in vfio_iommu structure. It is allocated when group for first mdev device is attached. - Pages pinned for external domain are tracked in each vfio_dma structure for that iova range. - Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of rb-tree is iova, but it actually aims to track pfns. - On external pin request for an iova, page is pinned once, if iova is already pinned and tracked, ref_count is incremented. - External unpin request unpins pages only when ref_count is 0. - Pinned pages list is used to find pfn from iova and then unpin it. WARN_ON is added if there are entires in pfn_list while detaching the group and releasing the domain. - Page accounting is updated to account in its address space where the pages are pinned/unpinned, i.e dma->task - Accouting for mdev device is only done if there is no iommu capable domain in the container. When there is a direct device assigned to the container and that domain is iommu capable, all pages are already pinned during DMA_MAP. - Page accouting is updated on hot plug and unplug mdev device and pass through device. Tested by assigning below combinations of devices to a single VM: - GPU pass through only - vGPU device only - One GPU pass through and one vGPU device - Linux VM hot plug and unplug vGPU device while GPU pass through device exist - Linux VM hot plug and unplug GPU pass through device while vGPU device exist Signed-off-by:
Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by:
Neo Jia <cjia@nvidia.com> Signed-off-by:
Alex Williamson <alex.williamson@redhat.com>
a54eb550