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@xxxxxxxxxx> --- drivers/vhost/vringh.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
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,
