Hi Alex, On 04/07/2016 07:50 PM, Alex Williamson wrote: > On Thu, 7 Apr 2016 14:28:59 +0200 > Eric Auger <eric.auger@xxxxxxxxxx> wrote: > >> Hi Alex, >> On 04/07/2016 01:15 AM, Alex Williamson wrote: >>> On Mon, 4 Apr 2016 08:06:55 +0000 >>> Eric Auger <eric.auger@xxxxxxxxxx> wrote: >>> >>>> This series introduces the dma-reserved-iommu api used to: >>>> - create/destroy an iova domain dedicated to reserved iova bindings >>>> - map/unmap physical addresses onto reserved IOVAs. >>>> - unmap and destroy all IOVA reserved bindings >>> >>> Why are we making the decision to have an unbalanced map vs unmap, we >>> can create individual mappings, but only unmap the whole thing and >>> start over? That's a strange interface. Thanks, >> The "individual" balanced unmap also exists (iommu_put_reserved_iova) >> and this is the "normal" path. This happens on msi_domain_deactivate >> (and possibly on msi_domain_set_affinity). >> >> I added iommu_unmap_reserved to handle the case where the userspace >> registers a reserved iova domain and fails to unregister it. In that >> case one need to handle the cleanup on kernel-side and I chose to >> implement this on vfio_iommu_type1 release. All the reserved IOMMU >> bindings get destroyed on that event. >> >> Any advice to handle this situation? > > If we want to model it similar to regular iommu domains, then > iommu_free_reserved_iova_domain() should release all the mappings and > destroy the iova domain. Yes this sounds obvious now. Additionally, since the reserved iova domain > is just a construct on top of an iommu domain, it should be sufficient > to call iommu_domain_free() to also remove the reserved iova domain if > one exists. Thanks, Yes. For dma cookie (iommu_put_dma_cookie) I see this is done from the iommu driver domain_free callback. Thanks Eric > > Alex > -- 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
