diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 239f61764d03..e79c1ff6fb41 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -962,7 +962,8 @@ static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size)
 }
 
 static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
-			     struct vfio_iommu_type1_dma_unmap *unmap)
+			     struct vfio_iommu_type1_dma_unmap *unmap,
+			     struct vfio_bitmap *bitmap)
 {
 	uint64_t mask;
 	struct vfio_dma *dma, *dma_last = NULL;
@@ -1013,6 +1014,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 	 * will be returned if these conditions are not met.  The v2 interface
 	 * will only return success and a size of zero if there were no
 	 * mappings within the range.
+	 *
+	 * When VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP flag is set, unmap request
+	 * must be for single mapping. Multiple mappings with this flag set is
+	 * not supported.
 	 */
 	if (iommu->v2) {
 		dma = vfio_find_dma(iommu, unmap->iova, 1);
@@ -1020,6 +1025,13 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 			ret = -EINVAL;
 			goto unlock;
 		}
+
+		if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
+		    (dma->iova != unmap->iova || dma->size != unmap->size)) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
 		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
 		if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
 			ret = -EINVAL;
@@ -1037,6 +1049,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 		if (dma->task->mm != current->mm)
 			break;
 
+		if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
+		     iommu->dirty_page_tracking)
+			vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size,
+						bitmap->pgsize, bitmap->data);
+
 		if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
 			struct vfio_iommu_type1_dma_unmap nb_unmap;
 
@@ -2398,17 +2415,46 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 	} else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
 		struct vfio_iommu_type1_dma_unmap unmap;
-		long ret;
+		struct vfio_bitmap bitmap = { 0 };
+		int ret;
 
 		minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
 
 		if (copy_from_user(&unmap, (void __user *)arg, minsz))
 			return -EFAULT;
 
-		if (unmap.argsz < minsz || unmap.flags)
+		if (unmap.argsz < minsz ||
+		    unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP)
 			return -EINVAL;
 
-		ret = vfio_dma_do_unmap(iommu, &unmap);
+		if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
+			unsigned long pgshift;
+			uint64_t iommu_pgsize =
+					 1 << __ffs(vfio_pgsize_bitmap(iommu));
+
+			if (unmap.argsz < (minsz + sizeof(bitmap)))
+				return -EINVAL;
+
+			if (copy_from_user(&bitmap,
+					   (void __user *)(arg + minsz),
+					   sizeof(bitmap)))
+				return -EFAULT;
+
+			/* allow only min supported pgsize */
+			if (bitmap.pgsize != iommu_pgsize)
+				return -EINVAL;
+			if (!access_ok((void __user *)bitmap.data, bitmap.size))
+				return -EINVAL;
+
+			pgshift = __ffs(bitmap.pgsize);
+			ret = verify_bitmap_size(unmap.size >> pgshift,
+						 bitmap.size);
+			if (ret)
+				return ret;
+
+		}
+
+		ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
 		if (ret)
 			return ret;
 
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 8138f94cac15..2780a5742c04 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -1010,12 +1010,22 @@ struct vfio_bitmap {
  * field.  No guarantee is made to the user that arbitrary unmaps of iova
  * or size different from those used in the original mapping call will
  * succeed.
+ * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap
+ * before unmapping IO virtual addresses. When this flag is set, user must
+ * provide data[] as structure vfio_bitmap. User must allocate memory to get
+ * bitmap and must set size of allocated memory in vfio_bitmap.size field.
+ * A bit in bitmap represents one page of user provided page size in 'pgsize',
+ * consecutively starting from iova offset. Bit set indicates page at that
+ * offset from iova is dirty. Bitmap of pages in the range of unmapped size is
+ * returned in vfio_bitmap.data
  */
 struct vfio_iommu_type1_dma_unmap {
 	__u32	argsz;
 	__u32	flags;
+#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0)
 	__u64	iova;				/* IO virtual address */
 	__u64	size;				/* Size of mapping (bytes) */
+	__u8    data[];
 };
 
 #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)
