[PATCH kernel v9 30/32] vfio: powerpc/spapr: Use 32bit DMA window properties from table_group

Alexey Kardashevskiy
2015-04-25T12:17:14Z

A table group might not have a table but it always has the default 32bit
window parameters so use these.

No change in behavior is expected.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v9:
* new in the series - to make the next patch simpler
---
drivers/vfio/vfio_iommu_spapr_tce.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 4cfc2c1..a7d6729 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -185,7 +185,6 @@ static int tce_iommu_enable(struct tce_container *container)
{
int ret = 0;
unsigned long locked;
- struct iommu_table *tbl;
struct iommu_table_group *table_group;

if (!container->grp)
@@ -221,13 +220,19 @@ static int tce_iommu_enable(struct tce_container *container)
* this is that we cannot tell here the amount of RAM used by the guest
* as this information is only available from KVM and VFIO is
* KVM agnostic.
+ *
+ * So we do not allow enabling a container without a group attached
+ * as there is no way to know how much we should increment
+ * the locked_vm counter.
*/
table_group = iommu_group_get_iommudata(container->grp);
if (!table_group)
return -ENODEV;

- tbl = &table_group->tables[0];
- locked = (tbl->it_size << tbl->it_page_shift) >> PAGE_SHIFT;
+ if (!table_group->tce32_size)
+ return -EPERM;
+
+ locked = table_group->tce32_size >> PAGE_SHIFT;
ret = try_increment_locked_vm(locked);
if (ret)
return ret;
@@ -504,7 +509,6 @@ static long tce_iommu_ioctl(void *iommu_data,

case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
struct vfio_iommu_spapr_tce_info info;
- struct iommu_table *tbl;
struct iommu_table_group *table_group;

if (WARN_ON(!container->grp))
@@ -512,8 +516,7 @@ static long tce_iommu_ioctl(void *iommu_data,

table_group = iommu_group_get_iommudata(container->grp);

- tbl = &table_group->tables[0];
- if (WARN_ON_ONCE(!tbl))
+ if (!table_group)
return -ENXIO;

minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
@@ -525,8 +528,8 @@ static long tce_iommu_ioctl(void *iommu_data,
if (info.argsz < minsz)
return -EINVAL;

- info.dma32_window_start = tbl->it_offset << tbl->it_page_shift;
- info.dma32_window_size = tbl->it_size << tbl->it_page_shift;
+ info.dma32_window_start = table_group->tce32_start;
+ info.dma32_window_size = table_group->tce32_size;
info.flags = 0;

if (copy_to_user((void __user *)arg, &info, minsz))
--
2.0.0