4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexey Kardashevskiy <aik@xxxxxxxxx>
[ Upstream commit 930a42ded3fede7ca3acafc9153f4f2d0f56a92c ]
If a container already has a group attached, attaching a new group
should just program already created IOMMU tables to the hardware via
the iommu_table_group_ops::set_window() callback.
However commit 6f01cc692a16 ("vfio/spapr: Add a helper to create
default DMA window") did not just simplify the code but also removed
the set_window() calls in the case of attaching groups to a container
which already has tables so it broke VFIO PCI hotplug.
This reverts set_window() bits in tce_iommu_take_ownership_ddw().
Fixes: 6f01cc692a16 ("vfio/spapr: Add a helper to create default DMA window")
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vfio/vfio_iommu_spapr_tce.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1246,6 +1246,8 @@ static void tce_iommu_release_ownership_
static long tce_iommu_take_ownership_ddw(struct tce_container *container,
struct iommu_table_group *table_group)
{
+ long i, ret = 0;
+
if (!table_group->ops->create_table || !table_group->ops->set_window ||
!table_group->ops->release_ownership) {
WARN_ON_ONCE(1);
@@ -1254,7 +1256,27 @@ static long tce_iommu_take_ownership_ddw
table_group->ops->take_ownership(table_group);
+ /* Set all windows to the new group */
+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+ struct iommu_table *tbl = container->tables[i];
+
+ if (!tbl)
+ continue;
+
+ ret = table_group->ops->set_window(table_group, i, tbl);
+ if (ret)
+ goto release_exit;
+ }
+
return 0;
+
+release_exit:
+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
+ table_group->ops->unset_window(table_group, i);
+
+ table_group->ops->release_ownership(table_group);
+
+ return ret;
}
static int tce_iommu_attach_group(void *iommu_data,