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>
---
This is an additional option and not inside
vfio_iommu_spapr_tce_ddw_info as the new option gets
a new flag and one would expect a new member in
vfio_iommu_spapr_tce_info per a flag but can squash it
into vfio_iommu_spapr_tce_ddw_info, should I?
---
include/uapi/linux/vfio.h | 2 ++
drivers/vfio/vfio_iommu_spapr_tce.c | 10 ++++++++--
2 files changed, 10 insertions(+), 2 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 26cef65b41e7..470008c3359f 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_dmaoff << tbl->it_page_shift;
return 0;
@@ -842,7 +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);
+ ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info,
+ dma64_window_start);
+
+ if (info.argsz >= ddwsz) {
+ info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW_START;
+ info.dma64_window_start = table_group->tce64_start;
+ }
if (info.argsz >= ddwsz)
minsz = ddwsz;
--
2.17.1
