On Fri, Oct 4, 2024 at 3:35 AM Brett Creeley <bcreeley@xxxxxxx> wrote:
>
Hi Brett,
Thanks a lot for your review!
>
>
> On 10/3/2024 9:06 AM, Taehee Yoo wrote:
> > Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> >
> >
> > If driver doesn't support ring parameter or tcp-data-split configuration
> > is not sufficient, the devmem should not be set up.
> > Before setup the devmem, tcp-data-split should be ON and
> > tcp-data-split-thresh value should be 0.
> >
> > Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
> > ---
> >
> > v3:
> > - Patch added.
> >
> > net/core/devmem.c | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/net/core/devmem.c b/net/core/devmem.c
> > index 11b91c12ee11..a9e9b15028e0 100644
> > --- a/net/core/devmem.c
> > +++ b/net/core/devmem.c
> > @@ -8,6 +8,8 @@
> > */
> >
> > #include <linux/dma-buf.h>
> > +#include <linux/ethtool.h>
> > +#include <linux/ethtool_netlink.h>
> > #include <linux/genalloc.h>
> > #include <linux/mm.h>
> > #include <linux/netdevice.h>
> > @@ -131,6 +133,8 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
> > struct net_devmem_dmabuf_binding *binding,
> > struct netlink_ext_ack *extack)
> > {
> > + struct kernel_ethtool_ringparam kernel_ringparam = {};
> > + struct ethtool_ringparam ringparam = {};
> > struct netdev_rx_queue *rxq;
> > u32 xa_idx;
> > int err;
> > @@ -146,6 +150,20 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
> > return -EEXIST;
> > }
> >
> > + if (!dev->ethtool_ops->get_ringparam) {
> > + NL_SET_ERR_MSG(extack, "can't get ringparam");
> > + return -EINVAL;
> > + }
>
> Is EINVAL the correct return value here? I think it makes more sense as
> EOPNOTSUPP.
Yes, Thanks for catching this.
>
> > +
> > + dev->ethtool_ops->get_ringparam(dev, &ringparam,
> > + &kernel_ringparam, extack);
> > + if (kernel_ringparam.tcp_data_split != ETHTOOL_TCP_DATA_SPLIT_ENABLED ||
> > + kernel_ringparam.tcp_data_split_thresh) {
> > + NL_SET_ERR_MSG(extack,
> > + "tcp-header-data-split is disabled or threshold is not zero");
> > + return -EINVAL;
> > + }
> > +
> Maybe just my personal opinion, but IMHO these checks should be separate
> so the error message can be more concise/clear.
I agree, the error message is not clear, it contains two conditions.
>
> Also, a small nit, but I think both of these checks should be before
> getting the rxq via __netif_get_rx_queue().
>
I will drop this patch in a v4 patch.
Thanks a lot!
Taehee Yoo
>
> Thanks,
>
> Brett
> > #ifdef CONFIG_XDP_SOCKETS
> > if (rxq->pool) {
> > NL_SET_ERR_MSG(extack, "designated queue already in use by AF_XDP");
> > --
> > 2.34.1
> >
