diff mbox series

[v3,04/13] vringh: explain more about cleaning riov and wiov

Message ID 20210204172230.85853-5-sgarzare@redhat.com (mailing list archive)
State New, archived
Headers show
Series vdpa: add vdpa simulator for block device | expand

Commit Message

Stefano Garzarella Feb. 4, 2021, 5:22 p.m. UTC
riov and wiov can be reused with subsequent calls of vringh_getdesc_*().

Let's add a paragraph in the documentation of these functions to better
explain when riov and wiov need to be cleaned up.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vringh.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Comments

Jason Wang Feb. 5, 2021, 3:18 a.m. UTC | #1
On 2021/2/5 上午1:22, Stefano Garzarella wrote:
> riov and wiov can be reused with subsequent calls of vringh_getdesc_*().
>
> Let's add a paragraph in the documentation of these functions to better
> explain when riov and wiov need to be cleaned up.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>   drivers/vhost/vringh.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)


Acked-by: Jason Wang <jasowang@redhat.com>


>
> diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> index bee63d68201a..2a88e087afd8 100644
> --- a/drivers/vhost/vringh.c
> +++ b/drivers/vhost/vringh.c
> @@ -662,7 +662,10 @@ EXPORT_SYMBOL(vringh_init_user);
>    * *head will be vrh->vring.num.  You may be able to ignore an invalid
>    * descriptor, but there's not much you can do with an invalid ring.
>    *
> - * Note that you may need to clean up riov and wiov, even on error!
> + * Note that you can reuse riov and wiov with subsequent calls. Content is
> + * overwritten and memory reallocated if more space is needed.
> + * When you don't have to use riov and wiov anymore, you should clean up them
> + * calling vringh_iov_cleanup() to release the memory, even on error!
>    */
>   int vringh_getdesc_user(struct vringh *vrh,
>   			struct vringh_iov *riov,
> @@ -932,7 +935,10 @@ EXPORT_SYMBOL(vringh_init_kern);
>    * *head will be vrh->vring.num.  You may be able to ignore an invalid
>    * descriptor, but there's not much you can do with an invalid ring.
>    *
> - * Note that you may need to clean up riov and wiov, even on error!
> + * Note that you can reuse riov and wiov with subsequent calls. Content is
> + * overwritten and memory reallocated if more space is needed.
> + * When you don't have to use riov and wiov anymore, you should clean up them
> + * calling vringh_kiov_cleanup() to release the memory, even on error!
>    */
>   int vringh_getdesc_kern(struct vringh *vrh,
>   			struct vringh_kiov *riov,
> @@ -1292,7 +1298,10 @@ EXPORT_SYMBOL(vringh_set_iotlb);
>    * *head will be vrh->vring.num.  You may be able to ignore an invalid
>    * descriptor, but there's not much you can do with an invalid ring.
>    *
> - * Note that you may need to clean up riov and wiov, even on error!
> + * Note that you can reuse riov and wiov with subsequent calls. Content is
> + * overwritten and memory reallocated if more space is needed.
> + * When you don't have to use riov and wiov anymore, you should clean up them
> + * calling vringh_kiov_cleanup() to release the memory, even on error!
>    */
>   int vringh_getdesc_iotlb(struct vringh *vrh,
>   			 struct vringh_kiov *riov,
diff mbox series

Patch

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index bee63d68201a..2a88e087afd8 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -662,7 +662,10 @@  EXPORT_SYMBOL(vringh_init_user);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_iov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_user(struct vringh *vrh,
 			struct vringh_iov *riov,
@@ -932,7 +935,10 @@  EXPORT_SYMBOL(vringh_init_kern);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_kiov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_kern(struct vringh *vrh,
 			struct vringh_kiov *riov,
@@ -1292,7 +1298,10 @@  EXPORT_SYMBOL(vringh_set_iotlb);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_kiov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_iotlb(struct vringh *vrh,
 			 struct vringh_kiov *riov,