copy_from_user is pretty high on perf top profile, replacing it with __copy_from_user helps. It's also safe because we do access_ok checks during setup.
Signed-off-by: Michael S. Tsirkin <[email protected]> --- drivers/vhost/vhost.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index ade0568..01701b8 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1153,7 +1153,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, i, vq->num, head); return -EINVAL; } - ret = copy_from_user(&desc, vq->desc + i, sizeof desc); + ret = __copy_from_user(&desc, vq->desc + i, sizeof desc); if (unlikely(ret)) { vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", i, vq->desc + i); -- 1.7.3.2.91.g446ac _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
