So far the only option for a big 64big DMA window was a window located
at 0x800.0000.0000.0000 (1<<59) which creates problems for devices
supporting smaller DMA masks.
This exploits a POWER9 PHB option to allow the second DMA window to map
at 0 and advertises it with a 4GB offset to avoid overlap with
the default 32bit window.
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
include/uapi/linux/vfio.h | 2 ++
drivers/vfio/vfio_iommu_spapr_tce.c | 13 +++++++------
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 9e843a147ead..c7f89d47335a 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -831,9 +831,11 @@ struct vfio_iommu_spapr_tce_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_SPAPR_INFO_DDW (1 << 0) /* DDW supported */
+#define VFIO_IOMMU_SPAPR_INFO_DDW_START (1 << 1) /* DDW offset */
__u32 dma32_window_start; /* 32 bit window start (bytes) */
__u32 dma32_window_size; /* 32 bit window size (bytes) */
struct vfio_iommu_spapr_tce_ddw_info ddw;
+ __u64 dma64_window_start;
};
#define VFIO_IOMMU_SPAPR_TCE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 750a0676e9b7..315fd56e51a7 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -691,7 +691,7 @@ static long tce_iommu_create_window(struct tce_container *container,
container->tables[num] = tbl;
/* Return start address assigned by platform in create_table() */
- *start_addr = tbl->it_offset << tbl->it_page_shift;
+ *start_addr = (tbl->it_offset + tbl->it_tceoff) << tbl->it_page_shift;
return 0;
@@ -777,7 +777,7 @@ static long tce_iommu_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
struct tce_container *container = iommu_data;
- unsigned long minsz, ddwsz;
+ unsigned long minsz;
long ret;
switch (cmd) {
@@ -842,12 +842,13 @@ static long tce_iommu_ioctl(void *iommu_data,
info.ddw.levels = table_group->max_levels;
}
- ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
+ info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW_START;
+ info.dma64_window_start = table_group->tce64_start;
- if (info.argsz >= ddwsz)
- minsz = ddwsz;
+ if (info.argsz > sizeof(info))
+ info.argsz = sizeof(info);
- if (copy_to_user((void __user *)arg, &info, minsz))
+ if (copy_to_user((void __user *)arg, &info, info.argsz))
return -EFAULT;
return 0;
--
2.17.1
