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| author | Stefano Garzarella <sgarzare@redhat.com> | 2021-03-15 17:34:40 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2021-05-03 04:55:53 -0400 |
| commit | 69c13c58bd10f036d6e697e664948952e61acfb1 (patch) | |
| tree | efe6c7b1cf26981ec7b234b04f7bf6a8c13c63e8 /drivers/vhost/vringh.c | |
| parent | bbc2c372a83d74d5499ad21d0ade2b71f5bde620 (diff) | |
| download | lwn-69c13c58bd10f036d6e697e664948952e61acfb1.tar.gz lwn-69c13c58bd10f036d6e697e664948952e61acfb1.zip | |
vringh: explain more about cleaning riov and wiov
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.
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210315163450.254396-5-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost/vringh.c')
| -rw-r--r-- | drivers/vhost/vringh.c | 15 |
1 files changed, 12 insertions, 3 deletions
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, |