VFIO TCE IOMMU v2 owns IOMMU tables so when detach a IOMMU group from a container, we need to unset those from a group so we call unset_window() so do we unconditionally. We also unset tables when removing a DMA window via the VFIO_IOMMU_SPAPR_TCE_REMOVE ioctl. The window removal checks if the table actually exists (hidden inside tce_iommu_find_table()) but the group detaching does not so the user may see duplicating messages: pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 pci 0009:03 : [PE# fd] Removing DMA window #0 pci 0009:03 : [PE# fd] Removing DMA window #1 At the moment this is not a problem as the second invocation of unset_window() writes zeroes to the HW registers again and exits early as there is no table. Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx> --- When doing VFIO PCI hot unplug, first we remove the DMA window and set container->tables[num] - this is a first couple of messages. Then we detach the group and then we see another couple of the same messages which confused myself. --- drivers/vfio/vfio_iommu_spapr_tce.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index c424913..8dbb270 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -1235,7 +1235,8 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container, } for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) - table_group->ops->unset_window(table_group, i); + if (container->tables[i]) + table_group->ops->unset_window(table_group, i); table_group->ops->release_ownership(table_group); } -- 2.17.1
