| Message ID | 163700859087.565980.3578855072170209153.stgit@firesoul (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | igc: driver change to support XDP metadata | expand |
On 11/15/2021 22:36, Jesper Dangaard Brouer wrote: > Enabling the XDP bpf_prog access to data_meta area is a very small > change. Hint passing 'true' to xdp_prepare_buff(). > > The SKB layers can also access data_meta area, which required more > driver changes to support. Reviewers, notice the igc driver have two > different functions that can create SKBs, depending on driver config. > > Hint for testers, ethtool priv-flags legacy-rx enables > the function igc_construct_skb() > > ethtool --set-priv-flags DEV legacy-rx on > > Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> > --- > drivers/net/ethernet/intel/igc/igc_main.c | 29 +++++++++++++++++++---------- > 1 file changed, 19 insertions(+), 10 deletions(-) Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
From: Jesper Dangaard Brouer <brouer@redhat.com> Date: Mon, 15 Nov 2021 21:36:30 +0100 > Enabling the XDP bpf_prog access to data_meta area is a very small > change. Hint passing 'true' to xdp_prepare_buff(). > > The SKB layers can also access data_meta area, which required more > driver changes to support. Reviewers, notice the igc driver have two > different functions that can create SKBs, depending on driver config. > > Hint for testers, ethtool priv-flags legacy-rx enables > the function igc_construct_skb() > > ethtool --set-priv-flags DEV legacy-rx on > > Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> > --- > drivers/net/ethernet/intel/igc/igc_main.c | 29 +++++++++++++++++++---------- > 1 file changed, 19 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c > index 76b0a7311369..b516f1b301b4 100644 > --- a/drivers/net/ethernet/intel/igc/igc_main.c > +++ b/drivers/net/ethernet/intel/igc/igc_main.c > @@ -1718,24 +1718,26 @@ static void igc_add_rx_frag(struct igc_ring *rx_ring, > > static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, > struct igc_rx_buffer *rx_buffer, > - union igc_adv_rx_desc *rx_desc, > - unsigned int size) > + struct xdp_buff *xdp) > { > - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; > + unsigned int size = xdp->data_end - xdp->data; > unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); > + unsigned int metasize = xdp->data - xdp->data_meta; > struct sk_buff *skb; > > /* prefetch first cache line of first page */ > - net_prefetch(va); > + net_prefetch(xdp->data); I'd prefer prefetching xdp->data_meta here. GRO layer accesses it. Maximum meta size for now is 32, so at least 96 bytes of the frame will stil be prefetched. > > /* build an skb around the page buffer */ > - skb = build_skb(va - IGC_SKB_PAD, truesize); > + skb = build_skb(xdp->data_hard_start, truesize); > if (unlikely(!skb)) > return NULL; > > /* update pointers within the skb to store the data */ > - skb_reserve(skb, IGC_SKB_PAD); > + skb_reserve(skb, xdp->data - xdp->data_hard_start); > __skb_put(skb, size); > + if (metasize) > + skb_metadata_set(skb, metasize); > > igc_rx_buffer_flip(rx_buffer, truesize); > return skb; > @@ -1746,6 +1748,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > struct xdp_buff *xdp, > ktime_t timestamp) > { > + unsigned int metasize = xdp->data - xdp->data_meta; > unsigned int size = xdp->data_end - xdp->data; > unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); > void *va = xdp->data; > @@ -1756,7 +1759,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > net_prefetch(va); ...here as well. > > /* allocate a skb to store the frags */ > - skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN); > + skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN + metasize); > if (unlikely(!skb)) > return NULL; > > @@ -1769,7 +1772,13 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > headlen = eth_get_headlen(skb->dev, va, IGC_RX_HDR_LEN); > > /* align pull length to size of long to optimize memcpy performance */ > - memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long))); > + memcpy(__skb_put(skb, headlen + metasize), xdp->data_meta, > + ALIGN(headlen + metasize, sizeof(long))); > + > + if (metasize) { > + skb_metadata_set(skb, metasize); > + __skb_pull(skb, metasize); > + } > > /* update all of the pointers */ > size -= headlen; > @@ -2354,7 +2363,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) > if (!skb) { > xdp_init_buff(&xdp, truesize, &rx_ring->xdp_rxq); > xdp_prepare_buff(&xdp, pktbuf - igc_rx_offset(rx_ring), > - igc_rx_offset(rx_ring) + pkt_offset, size, false); > + igc_rx_offset(rx_ring) + pkt_offset, size, true); > > skb = igc_xdp_run_prog(adapter, &xdp); > } > @@ -2378,7 +2387,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) > } else if (skb) > igc_add_rx_frag(rx_ring, rx_buffer, skb, size); > else if (ring_uses_build_skb(rx_ring)) > - skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size); > + skb = igc_build_skb(rx_ring, rx_buffer, &xdp); > else > skb = igc_construct_skb(rx_ring, rx_buffer, &xdp, > timestamp); Thanks! Al
On 26/11/2021 17.16, Alexander Lobakin wrote: > From: Jesper Dangaard Brouer <brouer@redhat.com> > Date: Mon, 15 Nov 2021 21:36:30 +0100 > >> Enabling the XDP bpf_prog access to data_meta area is a very small >> change. Hint passing 'true' to xdp_prepare_buff(). >> >> The SKB layers can also access data_meta area, which required more >> driver changes to support. Reviewers, notice the igc driver have two >> different functions that can create SKBs, depending on driver config. >> >> Hint for testers, ethtool priv-flags legacy-rx enables >> the function igc_construct_skb() >> >> ethtool --set-priv-flags DEV legacy-rx on >> >> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> >> --- >> drivers/net/ethernet/intel/igc/igc_main.c | 29 +++++++++++++++++++---------- >> 1 file changed, 19 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c >> index 76b0a7311369..b516f1b301b4 100644 >> --- a/drivers/net/ethernet/intel/igc/igc_main.c >> +++ b/drivers/net/ethernet/intel/igc/igc_main.c >> @@ -1718,24 +1718,26 @@ static void igc_add_rx_frag(struct igc_ring *rx_ring, >> >> static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, >> struct igc_rx_buffer *rx_buffer, >> - union igc_adv_rx_desc *rx_desc, >> - unsigned int size) >> + struct xdp_buff *xdp) >> { >> - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; >> + unsigned int size = xdp->data_end - xdp->data; >> unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); >> + unsigned int metasize = xdp->data - xdp->data_meta; >> struct sk_buff *skb; >> >> /* prefetch first cache line of first page */ >> - net_prefetch(va); >> + net_prefetch(xdp->data); > > I'd prefer prefetching xdp->data_meta here. GRO layer accesses it. > Maximum meta size for now is 32, so at least 96 bytes of the frame > will stil be prefetched. Prefetch works for "full" cachelines. Intel CPUs often prefect two cache-lines, when doing this, thus I guess we still get xdp->data. I don't mind prefetching xdp->data_meta, but (1) I tried to keep the change minimal as current behavior was data area I kept that. (2) xdp->data starts on a cacheline and we know NIC hardware have touched that, it is not a full-cache-miss due to DDIO/DCA it is known to be in L3 cache (gain is around 2-3 ns in my machine for data prefetch). Given this is only a 2.5 Gbit/s driver/HW I doubt this make any difference. Tony is it worth resending a V2 of this patch? >> >> /* build an skb around the page buffer */ >> - skb = build_skb(va - IGC_SKB_PAD, truesize); >> + skb = build_skb(xdp->data_hard_start, truesize); >> if (unlikely(!skb)) >> return NULL; >> >> /* update pointers within the skb to store the data */ >> - skb_reserve(skb, IGC_SKB_PAD); >> + skb_reserve(skb, xdp->data - xdp->data_hard_start); >> __skb_put(skb, size); >> + if (metasize) >> + skb_metadata_set(skb, metasize); >> >> igc_rx_buffer_flip(rx_buffer, truesize); >> return skb; >> @@ -1746,6 +1748,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, >> struct xdp_buff *xdp, >> ktime_t timestamp) >> { >> + unsigned int metasize = xdp->data - xdp->data_meta; >> unsigned int size = xdp->data_end - xdp->data; >> unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); >> void *va = xdp->data; >> @@ -1756,7 +1759,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, >> net_prefetch(va); > > ...here as well. >
From: Jesper Dangaard Brouer <jbrouer@redhat.com> Date: Mon, 29 Nov 2021 15:39:04 +0100 > On 26/11/2021 17.16, Alexander Lobakin wrote: > > From: Jesper Dangaard Brouer <brouer@redhat.com> > > Date: Mon, 15 Nov 2021 21:36:30 +0100 > > > >> Enabling the XDP bpf_prog access to data_meta area is a very small > >> change. Hint passing 'true' to xdp_prepare_buff(). > >> > >> The SKB layers can also access data_meta area, which required more > >> driver changes to support. Reviewers, notice the igc driver have two > >> different functions that can create SKBs, depending on driver config. > >> > >> Hint for testers, ethtool priv-flags legacy-rx enables > >> the function igc_construct_skb() > >> > >> ethtool --set-priv-flags DEV legacy-rx on > >> > >> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> > >> --- > >> drivers/net/ethernet/intel/igc/igc_main.c | 29 +++++++++++++++++++---------- > >> 1 file changed, 19 insertions(+), 10 deletions(-) > >> > >> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c > >> index 76b0a7311369..b516f1b301b4 100644 > >> --- a/drivers/net/ethernet/intel/igc/igc_main.c > >> +++ b/drivers/net/ethernet/intel/igc/igc_main.c > >> @@ -1718,24 +1718,26 @@ static void igc_add_rx_frag(struct igc_ring *rx_ring, > >> > >> static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, > >> struct igc_rx_buffer *rx_buffer, > >> - union igc_adv_rx_desc *rx_desc, > >> - unsigned int size) > >> + struct xdp_buff *xdp) > >> { > >> - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; > >> + unsigned int size = xdp->data_end - xdp->data; > >> unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); > >> + unsigned int metasize = xdp->data - xdp->data_meta; > >> struct sk_buff *skb; > >> > >> /* prefetch first cache line of first page */ > >> - net_prefetch(va); > >> + net_prefetch(xdp->data); > > > > I'd prefer prefetching xdp->data_meta here. GRO layer accesses it. > > Maximum meta size for now is 32, so at least 96 bytes of the frame > > will stil be prefetched. > > Prefetch works for "full" cachelines. Intel CPUs often prefect two > cache-lines, when doing this, thus I guess we still get xdp->data. Sure. I mean, net_prefetch() prefetches 128 bytes in a row. xdp->data is usually aligned to XDP_PACKET_HEADROOM (or two bytes to the right). If our CL is 64 and the meta is present, then... ah right, 64 to the left and 64 starting from data to the right. > I don't mind prefetching xdp->data_meta, but (1) I tried to keep the > change minimal as current behavior was data area I kept that. (2) > xdp->data starts on a cacheline and we know NIC hardware have touched > that, it is not a full-cache-miss due to DDIO/DCA it is known to be in > L3 cache (gain is around 2-3 ns in my machine for data prefetch). > Given this is only a 2.5 Gbit/s driver/HW I doubt this make any difference. Code constistency at least. On 10+ Gbps we prefetch meta, and I plan to continue doing this in my series. > Tony is it worth resending a V2 of this patch? Tony, you can take it as it is if you want, I'll correct it later in mine. Up to you. Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> > >> > >> /* build an skb around the page buffer */ > >> - skb = build_skb(va - IGC_SKB_PAD, truesize); > >> + skb = build_skb(xdp->data_hard_start, truesize); > >> if (unlikely(!skb)) > >> return NULL; > >> > >> /* update pointers within the skb to store the data */ > >> - skb_reserve(skb, IGC_SKB_PAD); > >> + skb_reserve(skb, xdp->data - xdp->data_hard_start); > >> __skb_put(skb, size); > >> + if (metasize) > >> + skb_metadata_set(skb, metasize); > >> > >> igc_rx_buffer_flip(rx_buffer, truesize); > >> return skb; > >> @@ -1746,6 +1748,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > >> struct xdp_buff *xdp, > >> ktime_t timestamp) > >> { > >> + unsigned int metasize = xdp->data - xdp->data_meta; > >> unsigned int size = xdp->data_end - xdp->data; > >> unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); > >> void *va = xdp->data; > >> @@ -1756,7 +1759,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > >> net_prefetch(va); > > > > ...here as well. > > Thanks, Al
From: Alexander Lobakin <alexandr.lobakin@intel.com> Date: Mon, 29 Nov 2021 15:53:03 +0100 > From: Jesper Dangaard Brouer <jbrouer@redhat.com> > Date: Mon, 29 Nov 2021 15:39:04 +0100 > > > On 26/11/2021 17.16, Alexander Lobakin wrote: > > > From: Jesper Dangaard Brouer <brouer@redhat.com> > > > Date: Mon, 15 Nov 2021 21:36:30 +0100 > > > > > >> Enabling the XDP bpf_prog access to data_meta area is a very small > > >> change. Hint passing 'true' to xdp_prepare_buff(). [ snip ] > > Prefetch works for "full" cachelines. Intel CPUs often prefect two > > cache-lines, when doing this, thus I guess we still get xdp->data. > > Sure. I mean, net_prefetch() prefetches 128 bytes in a row. > xdp->data is usually aligned to XDP_PACKET_HEADROOM (or two bytes > to the right). If our CL is 64 and the meta is present, then... ah > right, 64 to the left and 64 starting from data to the right. > > > I don't mind prefetching xdp->data_meta, but (1) I tried to keep the > > change minimal as current behavior was data area I kept that. (2) > > xdp->data starts on a cacheline and we know NIC hardware have touched > > that, it is not a full-cache-miss due to DDIO/DCA it is known to be in > > L3 cache (gain is around 2-3 ns in my machine for data prefetch). > > Given this is only a 2.5 Gbit/s driver/HW I doubt this make any difference. > > Code constistency at least. On 10+ Gbps we prefetch meta, and I plan > to continue doing this in my series. > > > Tony is it worth resending a V2 of this patch? > > Tony, you can take it as it is if you want, I'll correct it later in > mine. Up to you. My "fixup" looks like (in case of v2 needed or so): diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index b516f1b301b4..142c57b7a451 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -1726,7 +1726,7 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, struct sk_buff *skb; /* prefetch first cache line of first page */ - net_prefetch(xdp->data); + net_prefetch(xdp->data_meta); /* build an skb around the page buffer */ skb = build_skb(xdp->data_hard_start, truesize); @@ -1756,10 +1756,11 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, struct sk_buff *skb; /* prefetch first cache line of first page */ - net_prefetch(va); + net_prefetch(xdp->data_meta); /* allocate a skb to store the frags */ - skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN + metasize); + skb = napi_alloc_skb(&rx_ring->q_vector->napi, + IGC_RX_HDR_LEN + metasize); if (unlikely(!skb)) return NULL; @@ -2363,7 +2364,8 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) if (!skb) { xdp_init_buff(&xdp, truesize, &rx_ring->xdp_rxq); xdp_prepare_buff(&xdp, pktbuf - igc_rx_offset(rx_ring), - igc_rx_offset(rx_ring) + pkt_offset, size, true); + igc_rx_offset(rx_ring) + pkt_offset, + size, true); skb = igc_xdp_run_prog(adapter, &xdp); } > Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> > > > >> > > >> /* build an skb around the page buffer */ > > >> - skb = build_skb(va - IGC_SKB_PAD, truesize); > > >> + skb = build_skb(xdp->data_hard_start, truesize); > > >> if (unlikely(!skb)) > > >> return NULL; > > >> > > >> /* update pointers within the skb to store the data */ > > >> - skb_reserve(skb, IGC_SKB_PAD); > > >> + skb_reserve(skb, xdp->data - xdp->data_hard_start); > > >> __skb_put(skb, size); > > >> + if (metasize) > > >> + skb_metadata_set(skb, metasize); > > >> > > >> igc_rx_buffer_flip(rx_buffer, truesize); > > >> return skb; > > >> @@ -1746,6 +1748,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > > >> struct xdp_buff *xdp, > > >> ktime_t timestamp) > > >> { > > >> + unsigned int metasize = xdp->data - xdp->data_meta; > > >> unsigned int size = xdp->data_end - xdp->data; > > >> unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); > > >> void *va = xdp->data; > > >> @@ -1756,7 +1759,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, > > >> net_prefetch(va); > > > > > > ...here as well. > > > > > Thanks, > Al Al
On Mon, 2021-11-29 at 19:13 +0100, Alexander Lobakin wrote: > From: Alexander Lobakin <alexandr.lobakin@intel.com> > Date: Mon, 29 Nov 2021 15:53:03 +0100 > > > From: Jesper Dangaard Brouer <jbrouer@redhat.com> > > Date: Mon, 29 Nov 2021 15:39:04 +0100 > > > > > On 26/11/2021 17.16, Alexander Lobakin wrote: > > > > From: Jesper Dangaard Brouer <brouer@redhat.com> > > > > Date: Mon, 15 Nov 2021 21:36:30 +0100 > > > > > > > > > Enabling the XDP bpf_prog access to data_meta area is a very > > > > > small > > > > > change. Hint passing 'true' to xdp_prepare_buff(). > > [ snip ] > > > > Prefetch works for "full" cachelines. Intel CPUs often prefect > > > two > > > cache-lines, when doing this, thus I guess we still get xdp- > > > >data. > > > > Sure. I mean, net_prefetch() prefetches 128 bytes in a row. > > xdp->data is usually aligned to XDP_PACKET_HEADROOM (or two bytes > > to the right). If our CL is 64 and the meta is present, then... ah > > right, 64 to the left and 64 starting from data to the right. > > > > > I don't mind prefetching xdp->data_meta, but (1) I tried to keep > > > the > > > xdp->data starts on a cacheline and we know NIC hardware have > > > touched > > > that, it is not a full-cache-miss due to DDIO/DCA it is known to > > > be in > > > L3 cache (gain is around 2-3 ns in my machine for data prefetch). > > > Given this is only a 2.5 Gbit/s driver/HW I doubt this make any > > > difference. > > > > Code constistency at least. On 10+ Gbps we prefetch meta, and I > > plan > > to continue doing this in my series. > > > > > Tony is it worth resending a V2 of this patch? > > > > Tony, you can take it as it is if you want, I'll correct it later > > in > > mine. Up to you. > > My "fixup" looks like (in case of v2 needed or so): Thanks Al. If Jesper is ok with this, I'll incorporate it in before sending the pull request to netdev. Otherwise, you can do it as follow on in the other series you previously referenced. Thanks, Tony > diff --git a/drivers/net/ethernet/intel/igc/igc_main.c > b/drivers/net/ethernet/intel/igc/igc_main.c > index b516f1b301b4..142c57b7a451 100644 > --- a/drivers/net/ethernet/intel/igc/igc_main.c > +++ b/drivers/net/ethernet/intel/igc/igc_main.c > @@ -1726,7 +1726,7 @@ static struct sk_buff *igc_build_skb(struct > igc_ring *rx_ring, > struct sk_buff *skb; > > /* prefetch first cache line of first page */ > - net_prefetch(xdp->data); > + net_prefetch(xdp->data_meta); > > /* build an skb around the page buffer */ > skb = build_skb(xdp->data_hard_start, truesize); > @@ -1756,10 +1756,11 @@ static struct sk_buff > *igc_construct_skb(struct igc_ring *rx_ring, > struct sk_buff *skb; > > /* prefetch first cache line of first page */ > - net_prefetch(va); > + net_prefetch(xdp->data_meta); > > /* allocate a skb to store the frags */ > - skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN > + metasize); > + skb = napi_alloc_skb(&rx_ring->q_vector->napi, > + IGC_RX_HDR_LEN + metasize); > if (unlikely(!skb)) > return NULL; > > @@ -2363,7 +2364,8 @@ static int igc_clean_rx_irq(struct igc_q_vector > *q_vector, const int budget) > if (!skb) { > xdp_init_buff(&xdp, truesize, &rx_ring- > >xdp_rxq); > xdp_prepare_buff(&xdp, pktbuf - > igc_rx_offset(rx_ring), > - igc_rx_offset(rx_ring) + > pkt_offset, size, true); > + igc_rx_offset(rx_ring) + > pkt_offset, > + size, true); > > skb = igc_xdp_run_prog(adapter, &xdp); > }
On 29/11/2021 20.03, Nguyen, Anthony L wrote: > On Mon, 2021-11-29 at 19:13 +0100, Alexander Lobakin wrote: >> From: Alexander Lobakin <alexandr.lobakin@intel.com> >> Date: Mon, 29 Nov 2021 15:53:03 +0100 >> >>> From: Jesper Dangaard Brouer <jbrouer@redhat.com> >>> Date: Mon, 29 Nov 2021 15:39:04 +0100 >>> >>>> On 26/11/2021 17.16, Alexander Lobakin wrote: >>>>> From: Jesper Dangaard Brouer <brouer@redhat.com> >>>>> Date: Mon, 15 Nov 2021 21:36:30 +0100 >>>>> >>>>>> Enabling the XDP bpf_prog access to data_meta area is a very >>>>>> small >>>>>> change. Hint passing 'true' to xdp_prepare_buff(). >> >> [ snip ] [ snip ] >> >>> >>>> Tony is it worth resending a V2 of this patch? >>> >>> Tony, you can take it as it is if you want, I'll correct it later >>> in >>> mine. Up to you. >> >> My "fixup" looks like (in case of v2 needed or so): > > Thanks Al. If Jesper is ok with this, I'll incorporate it in before > sending the pull request to netdev. Otherwise, you can do it as follow > on in the other series you previously referenced. I'm fine with you incorporating this change. Thanks! :-) --Jesper
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 76b0a7311369..b516f1b301b4 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -1718,24 +1718,26 @@ static void igc_add_rx_frag(struct igc_ring *rx_ring, static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring, struct igc_rx_buffer *rx_buffer, - union igc_adv_rx_desc *rx_desc, - unsigned int size) + struct xdp_buff *xdp) { - void *va = page_address(rx_buffer->page) + rx_buffer->page_offset; + unsigned int size = xdp->data_end - xdp->data; unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); + unsigned int metasize = xdp->data - xdp->data_meta; struct sk_buff *skb; /* prefetch first cache line of first page */ - net_prefetch(va); + net_prefetch(xdp->data); /* build an skb around the page buffer */ - skb = build_skb(va - IGC_SKB_PAD, truesize); + skb = build_skb(xdp->data_hard_start, truesize); if (unlikely(!skb)) return NULL; /* update pointers within the skb to store the data */ - skb_reserve(skb, IGC_SKB_PAD); + skb_reserve(skb, xdp->data - xdp->data_hard_start); __skb_put(skb, size); + if (metasize) + skb_metadata_set(skb, metasize); igc_rx_buffer_flip(rx_buffer, truesize); return skb; @@ -1746,6 +1748,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, struct xdp_buff *xdp, ktime_t timestamp) { + unsigned int metasize = xdp->data - xdp->data_meta; unsigned int size = xdp->data_end - xdp->data; unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size); void *va = xdp->data; @@ -1756,7 +1759,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, net_prefetch(va); /* allocate a skb to store the frags */ - skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN); + skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN + metasize); if (unlikely(!skb)) return NULL; @@ -1769,7 +1772,13 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring, headlen = eth_get_headlen(skb->dev, va, IGC_RX_HDR_LEN); /* align pull length to size of long to optimize memcpy performance */ - memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long))); + memcpy(__skb_put(skb, headlen + metasize), xdp->data_meta, + ALIGN(headlen + metasize, sizeof(long))); + + if (metasize) { + skb_metadata_set(skb, metasize); + __skb_pull(skb, metasize); + } /* update all of the pointers */ size -= headlen; @@ -2354,7 +2363,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) if (!skb) { xdp_init_buff(&xdp, truesize, &rx_ring->xdp_rxq); xdp_prepare_buff(&xdp, pktbuf - igc_rx_offset(rx_ring), - igc_rx_offset(rx_ring) + pkt_offset, size, false); + igc_rx_offset(rx_ring) + pkt_offset, size, true); skb = igc_xdp_run_prog(adapter, &xdp); } @@ -2378,7 +2387,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) } else if (skb) igc_add_rx_frag(rx_ring, rx_buffer, skb, size); else if (ring_uses_build_skb(rx_ring)) - skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size); + skb = igc_build_skb(rx_ring, rx_buffer, &xdp); else skb = igc_construct_skb(rx_ring, rx_buffer, &xdp, timestamp);
Enabling the XDP bpf_prog access to data_meta area is a very small change. Hint passing 'true' to xdp_prepare_buff(). The SKB layers can also access data_meta area, which required more driver changes to support. Reviewers, notice the igc driver have two different functions that can create SKBs, depending on driver config. Hint for testers, ethtool priv-flags legacy-rx enables the function igc_construct_skb() ethtool --set-priv-flags DEV legacy-rx on Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> --- drivers/net/ethernet/intel/igc/igc_main.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-)