On Fri, Jul 19, 2019 at 05:52:37PM +1000, Alexey Kardashevskiy wrote: > > > On 19/07/2019 17:10, Christoph Hellwig wrote: > > Hey Alexey, > > > > what is the use case for the above commit? Shouldn't we handle all > > addressing limits using the iommu? > > Our secure VMs is the use case, when only a fraction of system memory is > available for DMA.
But shouldn't we force usage of the direct ops in that case as the IOMMU is not neededed at all? Also isn't that support non-upstream so far?