Hi Eric, On Fri, Nov 11, 2016 at 05:45:19PM +0100, Auger Eric wrote: > On 11/11/2016 17:22, Joerg Roedel wrote: > > So I think we need a way to tell userspace about the reserved regions > > (per iommu-group) so that userspace knows where it can not map anything, > Current plan is to expose that info through an iommu-group sysfs > attribute, as you and Robin advised. Great. > > and VFIO can enforce that. But the right struct here is not an > > iova-allocator rb-tree, a ordered linked list should be sufficient. > I plan a linked list to store the reserved regions (P2P regions, MSI > region, ...). get_dma_regions is called with a list local to a function > for that. Might be needed to move that list head in the iommu_group to > avoid calling the get_dm_regions again in the attribute show function? You can re-use the get_dm_regions() call-back available in the iommu-ops already. Just rename it and add a flag to it which tells the iommu-core whether that region needs to be mapped or not. > But to allocate the IOVAs within the MSI reserved region, I understand > you don't want us to use the iova.c allocator, is that correct? We need > an allocator though, even a very basic one based on bitmap or whatever. > There potentially have several different physical MSI frame pages to map. I don't get this, what do you need and address-allocator for? Joerg -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
