[ Upstream commit 7d6e1329652ed971d1b6e0e7bea66fba5044e271 ]
The following functional changes were needed for backport:
- vfio_iommu_type1_get_info doesn't exist, call
vfio_iommu_dma_avail_build_caps from vfio_iommu_type1_ioctl.
- As further fallout from this, vfio_iommu_dma_avail_build_caps must
acquire and release the iommu mutex lock. To do so, the return value is
stored in a local variable as in vfio_iommu_iova_build_caps.
Upstream commit description:
Commit 492855939bdb ("vfio/type1: Limit DMA mappings per container")
added the ability to limit the number of memory backed DMA mappings.
However on s390x, when lazy mapping is in use, we use a very large
number of concurrent mappings. Let's provide the current allowable
number of DMA mappings to userspace via the IOMMU info chain so that
userspace can take appropriate mitigation.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Matthew Rosato