[PATCH RESEND 1/1] net: mvpp2: fix XDP rx queues registering

[PATCH RESEND 1/1] net: mvpp2: fix XDP rx queues registering

[Louis Amas]

The registration of XDP queue information is incorrect because the
RX queue id we use is invalid. When port->id == 0 it appears to works
as expected yet it's no longer the case when port->id != 0.

When we register the XDP rx queue information (using
xdp_rxq_info_reg() in function mvpp2_rxq_init()) we tell them to use
rxq->id as the queue id. This value iscomputed as:
rxq->id = port->id * max_rxq_count + queue_id

where max_rxq_count depends on the device version. In the MB case,
this value is 32, meaning that rx queues on eth2 are numbered from
32 to 35 - there are four of them.

Clearly, this is not the per-port queue id that XDP is expecting:
it wants a value in the range [0..3]. It shall directly use queue_id
which is stored in rxq->logic_rxq -- so let's use that value instead.

This is consistent with the remaining part of the code in
mvpp2_rxq_init().

Fixes: b27db2274ba8 ("mvpp2: use page_pool allocator")
Signed-off-by: Louis Amas <louis.amas@eho.link>
Signed-off-by: Emmanuel Deloget <emmanuel.deloget@eho.link>
Reviewed-by: Marcin Wojtas <mw@semihalf.com>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 6480696c979b..6da8a595026b 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -2960,11 +2960,11 @@ static int mvpp2_rxq_init(struct mvpp2_port *port,
        mvpp2_rxq_status_update(port, rxq->id, 0, rxq->size);

        if (priv->percpu_pools) {
-               err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->id, 0);
+               err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->logic_rxq, 0);
                if (err < 0)
                        goto err_free_dma;

-               err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->id, 0);
+               err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->logic_rxq, 0);
                if (err < 0)
                        goto err_unregister_rxq_short;

--
2.25.1


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Re: [PATCH RESEND 1/1] net: mvpp2: fix XDP rx queues registering

[Jesper Dangaard Brouer]

On 06/12/2021 17.20, Louis Amas wrote:
> The registration of XDP queue information is incorrect because the
> RX queue id we use is invalid. When port->id == 0 it appears to works
> as expected yet it's no longer the case when port->id != 0.
> 
> When we register the XDP rx queue information (using
> xdp_rxq_info_reg() in function mvpp2_rxq_init()) we tell them to use
> rxq->id as the queue id. This value iscomputed as:
> rxq->id = port->id * max_rxq_count + queue_id
> 
> where max_rxq_count depends on the device version. In the MB case,
> this value is 32, meaning that rx queues on eth2 are numbered from
> 32 to 35 - there are four of them.
> 
> Clearly, this is not the per-port queue id that XDP is expecting:
> it wants a value in the range [0..3]. It shall directly use queue_id
> which is stored in rxq->logic_rxq -- so let's use that value instead.
> 
> This is consistent with the remaining part of the code in
> mvpp2_rxq_init().
> 
> Fixes: b27db2274ba8 ("mvpp2: use page_pool allocator")
> Signed-off-by: Louis Amas <louis.amas@eho.link>
> Signed-off-by: Emmanuel Deloget <emmanuel.deloget@eho.link>
> Reviewed-by: Marcin Wojtas <mw@semihalf.com>

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>

Instead of "RESEND" please add a version number, so we can keep track 
which is the latest patch, IMHO this should have "V3".
You also forgot to mention in subj what git-tree this is targeted 
towards. See netdev-FAQ[0]

Track your patch progress here:
  https://patchwork.kernel.org/project/netdevbpf/list/?series=590985

In what I consider "V2" you also got an ACK from John:

Acked-by: John Fastabend <john.fastabend@gmail.com>


> ---
>   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 6480696c979b..6da8a595026b 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -2960,11 +2960,11 @@ static int mvpp2_rxq_init(struct mvpp2_port *port,
>          mvpp2_rxq_status_update(port, rxq->id, 0, rxq->size);
> 
>          if (priv->percpu_pools) {
> -               err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->id, 0);
> +               err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->logic_rxq, 0);
>                  if (err < 0)
>                          goto err_free_dma;
> 
> -               err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->id, 0);
> +               err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->logic_rxq, 0);
>                  if (err < 0)
>                          goto err_unregister_rxq_short;

[0] https://www.kernel.org/doc/html/latest/networking/netdev-FAQ.html