[PATCH V1 2/5] vfio: option to unmap all

[Steve Sistare <steven.sistare@oracle.com>]

For VFIO_IOMMU_UNMAP_DMA, delete all mappings if iova=0 and size=0.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 drivers/vfio/vfio_iommu_type1.c | 11 ++++++++---
 include/uapi/linux/vfio.h       |  3 ++-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 02228d0..3dc501d 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1079,6 +1079,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 	size_t unmapped = 0, pgsize;
 	int ret = 0, retries = 0;
 	unsigned long pgshift;
+	dma_addr_t iova;
+	unsigned long size;
 
 	mutex_lock(&iommu->lock);
 
@@ -1090,7 +1092,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 		goto unlock;
 	}
 
-	if (!unmap->size || unmap->size & (pgsize - 1)) {
+	if ((!unmap->size && unmap->iova) || unmap->size & (pgsize - 1)) {
 		ret = -EINVAL;
 		goto unlock;
 	}
@@ -1154,8 +1156,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 		}
 	}
 
-	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
-		if (!iommu->v2 && unmap->iova > dma->iova)
+	iova = unmap->iova;
+	size = unmap->size ? unmap->size : SIZE_MAX;
+
+	while ((dma = vfio_find_dma(iommu, iova, size))) {
+		if (!iommu->v2 && iova > dma->iova)
 			break;
 		/*
 		 * Task with same address space who mapped this iova range is
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 9204705..896e527 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -1073,7 +1073,8 @@ struct vfio_bitmap {
  * Caller sets argsz.  The actual unmapped size is returned in the size
  * 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.
+ * succeed.  If iova=0 and size=0, all addresses are unmapped.
+ *
  * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get the dirty bitmap
  * before unmapping IO virtual addresses. When this flag is set, the user must
  * provide a struct vfio_bitmap in data[]. User must provide zero-allocated
-- 
1.8.3.1