Re: [PATCH bpf-next 08/10] [bpf]: make netronome nfp compatible w/ bpf_xdp_adjust_tail

[Jakub Kicinski]

On Tue, 17 Apr 2018 16:08:29 -0700, Alexei Starovoitov wrote:
> On Mon, Apr 16, 2018 at 11:51:29PM -0700, Nikita V. Shirokov wrote:
> > w/ bpf_xdp_adjust_tail helper xdp's data_end pointer could be changed as
> > well (only "decrease" of pointer's location is going to be supported).
> > changing of this pointer will change packet's size.
> > for nfp driver we will just calculate packet's length unconditionally
> > 
> > Signed-off-by: Nikita V. Shirokov 
> > ---
> >  drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c 
> > b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > index 1eb6549f2a54..d9111c077699 100644
> > --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > @@ -1722,7 +1722,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring 
> > *rx_ring, int budget)
> >  
> > act = bpf_prog_run_xdp(xdp_prog, );
> >  
> > -   pkt_len -= xdp.data - orig_data;
> > +   pkt_len = xdp.data_end - xdp.data;  
> 
> Looks correct, but Jakub please review.

Indeed:

Acked-by: Jakub Kicinski 

Thanks!

Re: [PATCH bpf-next 08/10] [bpf]: make netronome nfp compatible w/ bpf_xdp_adjust_tail

[Alexei Starovoitov]

On Mon, Apr 16, 2018 at 11:51:29PM -0700, Nikita V. Shirokov wrote:
> w/ bpf_xdp_adjust_tail helper xdp's data_end pointer could be changed as
> well (only "decrease" of pointer's location is going to be supported).
> changing of this pointer will change packet's size.
> for nfp driver we will just calculate packet's length unconditionally
> 
> Signed-off-by: Nikita V. Shirokov 
> ---
>  drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c 
> b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> index 1eb6549f2a54..d9111c077699 100644
> --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> @@ -1722,7 +1722,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, 
> int budget)
>  
>   act = bpf_prog_run_xdp(xdp_prog, );
>  
> - pkt_len -= xdp.data - orig_data;
> + pkt_len = xdp.data_end - xdp.data;

Looks correct, but Jakub please review.

[PATCH bpf-next 08/10] [bpf]: make netronome nfp compatible w/ bpf_xdp_adjust_tail

[Nikita V. Shirokov]

w/ bpf_xdp_adjust_tail helper xdp's data_end pointer could be changed as
well (only "decrease" of pointer's location is going to be supported).
changing of this pointer will change packet's size.
for nfp driver we will just calculate packet's length unconditionally

Signed-off-by: Nikita V. Shirokov 
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c 
b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 1eb6549f2a54..d9111c077699 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1722,7 +1722,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, 
int budget)
 
act = bpf_prog_run_xdp(xdp_prog, );
 
-   pkt_len -= xdp.data - orig_data;
+   pkt_len = xdp.data_end - xdp.data;
pkt_off += xdp.data - orig_data;
 
switch (act) {
-- 
2.15.1