[PATCH 3/5] vfio/iommu_type1: Populate dirty bitmap when attach group

[Keqian Zhu]

Attach an iommu backend group will potentially access all dma
ranges. We should traverse all dma ranges to mark dirty.

Fixes: d6a4c185660c ("vfio iommu: Implementation of ioctl for dirty pages tracking")
Signed-off-by: Keqian Zhu <zhukeqian1 at huawei.com>
---
 drivers/vfio/vfio_iommu_type1.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 29c8702c3b6e..26b7eb2a5cfc 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -255,6 +255,17 @@ static void vfio_dma_populate_bitmap(struct vfio_iommu *iommu,
 		vfio_dma_populate_bitmap_full(dma, pgsize);
 }
 
+static void vfio_iommu_populate_bitmap(struct vfio_iommu *iommu)
+{
+	struct rb_node *n;
+	struct vfio_dma *dma;
+
+	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
+		dma = rb_entry(n, struct vfio_dma, node);
+		vfio_dma_populate_bitmap(iommu, dma);
+	}
+}
+
 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu)
 {
 	struct rb_node *n;
@@ -2190,7 +2201,12 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	 * demotes the iommu scope until it declares itself dirty tracking
 	 * capable via the page pinning interface.
 	 */
-	iommu->pinned_page_dirty_scope = false;
+	if (iommu->pinned_page_dirty_scope) {
+		iommu->pinned_page_dirty_scope = false;
+		if (iommu->dirty_page_tracking)
+			vfio_iommu_populate_bitmap(iommu);
+	}
+
 	mutex_unlock(&iommu->lock);
 	vfio_iommu_resv_free(&group_resv_regions);
 
-- 
2.19.1