Re: [PATCH v3 04/19] vhost/iotlb: add VHOST_IOTLB_UNLIMITED macro

From: Jason Wang
Date: Sun Dec 06 2020 - 22:57:29 EST



On 2020/12/4 上午1:04, Stefano Garzarella wrote:
It's possible to allocate an unlimited IOTLB calling
vhost_iotlb_alloc() with 'limit' = 0.

Add a new macro (VHOST_IOTLB_UNLIMITED) for this case and document
it in the vhost_iotlb_alloc() documentation block.

Suggested-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>


---
include/linux/vhost_iotlb.h | 2 ++
drivers/vhost/iotlb.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
index 6b09b786a762..47019f97f795 100644
--- a/include/linux/vhost_iotlb.h
+++ b/include/linux/vhost_iotlb.h
@@ -4,6 +4,8 @@
#include <linux/interval_tree_generic.h>
+#define VHOST_IOTLB_UNLIMITED 0
+
struct vhost_iotlb_map {
struct rb_node rb;
struct list_head link;
diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
index 0fd3f87e913c..80fdde78ee5a 100644
--- a/drivers/vhost/iotlb.c
+++ b/drivers/vhost/iotlb.c
@@ -100,7 +100,8 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_del_range);
/**
* vhost_iotlb_alloc - add a new vhost IOTLB
- * @limit: maximum number of IOTLB entries
+ * @limit: maximum number of IOTLB entries (use VHOST_IOTLB_UNLIMITED for an
+ * unlimited IOTLB)
* @flags: VHOST_IOTLB_FLAG_XXX
*
* Returns an error is memory allocation fails