-
由 Jacob Pan 提交于
For the unlikely use case where multiple aux domains from the same pdev are attached to a single guest and then bound to a single process (thus same PASID) within that guest, we cannot easily support this case by refcounting the number of users. As there is only one SL page table per PASID while we have multiple aux domains thus multiple SL page tables for the same PASID. Extra unbinding guest PASID can happen due to race between normal and exception cases. Termination of one aux domain may affect others unless we actively track and switch aux domains to ensure the validity of SL page tables and TLB states in the shared PASID entry. Support for sharing second level PGDs across domains can reduce the complexity but this is not available due to the limitations on VFIO container architecture. We can revisit this decision once sharing PGDs are available. Overall, the complexity and potential glitch do not warrant this unlikely use case thereby removed by this patch. Fixes: 56722a43 ("iommu/vt-d: Add bind guest PASID support") Signed-off-by: NLiu Yi L <yi.l.liu@intel.com> Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com> Reviewed-by: NEric Auger <eric.auger@redhat.com> Cc: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20200724014925.15523-8-baolu.lu@linux.intel.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>
d315e9e6