* [PATCH net-next 0/2] net: add support for ip generic checksum offload for gre
@ 2021-01-24 8:44 Xin Long
2021-01-24 8:44 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Xin Long
0 siblings, 1 reply; 5+ messages in thread
From: Xin Long @ 2021-01-24 8:44 UTC (permalink / raw)
To: network dev
Cc: Marcelo Ricardo Leitner, davem, Jakub Kicinski, Davide Caratti,
Alexander Duyck
This patchset it to add ip generic csum processing first in
skb_csum_hwoffload_help() in Patch 1/2 and then add csum
offload support for GRE header in Patch 2/2.
v1->v2:
- See each patch's changelog.
Xin Long (2):
net: support ip generic csum processing in skb_csum_hwoffload_help
ip_gre: add csum offload support for gre header
include/net/gre.h | 19 +++++++------------
net/core/dev.c | 13 ++++++++++++-
net/ipv4/gre_offload.c | 15 +++++++++++++--
3 files changed, 32 insertions(+), 15 deletions(-)
--
2.1.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help
2021-01-24 8:44 [PATCH net-next 0/2] net: add support for ip generic checksum offload for gre Xin Long
@ 2021-01-24 8:44 ` Xin Long
2021-01-24 8:44 ` [PATCH net-next 2/2] ip_gre: add csum offload support for gre header Xin Long
2021-01-26 1:58 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Willem de Bruijn
0 siblings, 2 replies; 5+ messages in thread
From: Xin Long @ 2021-01-24 8:44 UTC (permalink / raw)
To: network dev
Cc: Marcelo Ricardo Leitner, davem, Jakub Kicinski, Davide Caratti,
Alexander Duyck
NETIF_F_IP|IPV6_CSUM feature flag indicates UDP and TCP csum offload
while NETIF_F_HW_CSUM feature flag indicates ip generic csum offload
for HW, which includes not only for TCP/UDP csum, but also for other
protocols' csum like GRE's.
However, in skb_csum_hwoffload_help() it only checks features against
NETIF_F_CSUM_MASK(NETIF_F_HW|IP|IPV6_CSUM). So if it's a non TCP/UDP
packet and the features doesn't support NETIF_F_HW_CSUM, but supports
NETIF_F_IP|IPV6_CSUM only, it would still return 0 and leave the HW
to do csum.
This patch is to support ip generic csum processing by checking
NETIF_F_HW_CSUM for all protocols, and check (NETIF_F_IP_CSUM |
NETIF_F_IPV6_CSUM) only for TCP and UDP.
v1->v2:
- not extend skb->csum_not_inet, but use skb->csum_offset to tell
if it's an UDP/TCP csum packet.
Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
net/core/dev.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 6df3f1b..aae116d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3621,7 +3621,18 @@ int skb_csum_hwoffload_help(struct sk_buff *skb,
return !!(features & NETIF_F_SCTP_CRC) ? 0 :
skb_crc32c_csum_help(skb);
- return !!(features & NETIF_F_CSUM_MASK) ? 0 : skb_checksum_help(skb);
+ if (features & NETIF_F_HW_CSUM)
+ return 0;
+
+ if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
+ switch (skb->csum_offset) {
+ case offsetof(struct tcphdr, check):
+ case offsetof(struct udphdr, check):
+ return 0;
+ }
+ }
+
+ return skb_checksum_help(skb);
}
EXPORT_SYMBOL(skb_csum_hwoffload_help);
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net-next 2/2] ip_gre: add csum offload support for gre header
2021-01-24 8:44 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Xin Long
@ 2021-01-24 8:44 ` Xin Long
2021-01-26 1:58 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Willem de Bruijn
1 sibling, 0 replies; 5+ messages in thread
From: Xin Long @ 2021-01-24 8:44 UTC (permalink / raw)
To: network dev
Cc: Marcelo Ricardo Leitner, davem, Jakub Kicinski, Davide Caratti,
Alexander Duyck
This patch is to add csum offload support for gre header:
On the TX path in gre_build_header(), when CHECKSUM_PARTIAL's set
for inner proto, it will calculate the csum for outer proto, and
inner csum will be offloaded later. Otherwise, CHECKSUM_PARTIAL
and csum_start/offset will be set for outer proto, and the outer
csum will be offloaded later.
On the GSO path in gre_gso_segment(), when CHECKSUM_PARTIAL is
not set for inner proto and the hardware supports csum offload,
CHECKSUM_PARTIAL and csum_start/offset will be set for outer
proto, and outer csum will be offloaded later. Otherwise, it
will do csum for outer proto by calling gso_make_checksum().
Note that SCTP has to do the csum by itself for non GSO path in
sctp_packet_pack(), as gre_build_header() can't handle the csum
with CHECKSUM_PARTIAL set for SCTP CRC csum offload.
v1->v2:
- remove the SCTP part, as GRE dev doesn't support SCTP CRC CSUM
and it will always do checksum for SCTP in sctp_packet_pack()
when it's not a GSO packet.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
include/net/gre.h | 19 +++++++------------
net/ipv4/gre_offload.c | 15 +++++++++++++--
2 files changed, 20 insertions(+), 14 deletions(-)
diff --git a/include/net/gre.h b/include/net/gre.h
index b60f212..4e20970 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -106,17 +106,6 @@ static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)
return flags;
}
-static inline __sum16 gre_checksum(struct sk_buff *skb)
-{
- __wsum csum;
-
- if (skb->ip_summed == CHECKSUM_PARTIAL)
- csum = lco_csum(skb);
- else
- csum = skb_checksum(skb, 0, skb->len, 0);
- return csum_fold(csum);
-}
-
static inline void gre_build_header(struct sk_buff *skb, int hdr_len,
__be16 flags, __be16 proto,
__be32 key, __be32 seq)
@@ -146,7 +135,13 @@ static inline void gre_build_header(struct sk_buff *skb, int hdr_len,
!(skb_shinfo(skb)->gso_type &
(SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
*ptr = 0;
- *(__sum16 *)ptr = gre_checksum(skb);
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ *(__sum16 *)ptr = csum_fold(lco_csum(skb));
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = sizeof(*greh);
+ }
}
}
}
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 10bc49b..1121a9d 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -15,10 +15,10 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
+ bool need_csum, offload_csum, gso_partial, need_ipsec;
struct sk_buff *segs = ERR_PTR(-EINVAL);
u16 mac_offset = skb->mac_header;
__be16 protocol = skb->protocol;
- bool need_csum, gso_partial;
u16 mac_len = skb->mac_len;
int gre_offset, outer_hlen;
@@ -47,6 +47,11 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
if (need_csum)
features &= ~NETIF_F_SCTP_CRC;
+ need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
+ /* Try to offload checksum if possible */
+ offload_csum = !!(need_csum && !need_ipsec &&
+ (skb->dev->features & NETIF_F_HW_CSUM));
+
/* segment inner packet. */
segs = skb_mac_gso_segment(skb, features);
if (IS_ERR_OR_NULL(segs)) {
@@ -100,7 +105,13 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
}
*(pcsum + 1) = 0;
- *pcsum = gso_make_checksum(skb, 0);
+ if (skb->encapsulation || !offload_csum) {
+ *pcsum = gso_make_checksum(skb, 0);
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = sizeof(*greh);
+ }
} while ((skb = skb->next));
out:
return segs;
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help
2021-01-24 8:44 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Xin Long
2021-01-24 8:44 ` [PATCH net-next 2/2] ip_gre: add csum offload support for gre header Xin Long
@ 2021-01-26 1:58 ` Willem de Bruijn
2021-01-28 9:13 ` Xin Long
1 sibling, 1 reply; 5+ messages in thread
From: Willem de Bruijn @ 2021-01-26 1:58 UTC (permalink / raw)
To: Xin Long
Cc: network dev, Marcelo Ricardo Leitner, David Miller,
Jakub Kicinski, Davide Caratti, Alexander Duyck
On Sun, Jan 24, 2021 at 3:47 AM Xin Long <lucien.xin@gmail.com> wrote:
>
> NETIF_F_IP|IPV6_CSUM feature flag indicates UDP and TCP csum offload
> while NETIF_F_HW_CSUM feature flag indicates ip generic csum offload
> for HW, which includes not only for TCP/UDP csum, but also for other
> protocols' csum like GRE's.
>
> However, in skb_csum_hwoffload_help() it only checks features against
> NETIF_F_CSUM_MASK(NETIF_F_HW|IP|IPV6_CSUM). So if it's a non TCP/UDP
> packet and the features doesn't support NETIF_F_HW_CSUM, but supports
> NETIF_F_IP|IPV6_CSUM only, it would still return 0 and leave the HW
> to do csum.
>
> This patch is to support ip generic csum processing by checking
> NETIF_F_HW_CSUM for all protocols, and check (NETIF_F_IP_CSUM |
> NETIF_F_IPV6_CSUM) only for TCP and UDP.
>
> v1->v2:
> - not extend skb->csum_not_inet, but use skb->csum_offset to tell
> if it's an UDP/TCP csum packet.
>
> Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
> net/core/dev.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 6df3f1b..aae116d 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -3621,7 +3621,18 @@ int skb_csum_hwoffload_help(struct sk_buff *skb,
> return !!(features & NETIF_F_SCTP_CRC) ? 0 :
> skb_crc32c_csum_help(skb);
>
> - return !!(features & NETIF_F_CSUM_MASK) ? 0 : skb_checksum_help(skb);
> + if (features & NETIF_F_HW_CSUM)
> + return 0;
> +
> + if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
> + switch (skb->csum_offset) {
> + case offsetof(struct tcphdr, check):
> + case offsetof(struct udphdr, check):
This relies on no other protocols requesting CHECKSUM_PARTIAL
with these csum_offset values.
That is a fragile assumption. It may well be correct, and Alex argues
that point in v1 of the patch. I think that argumentation at the least
should be captured as a comment or in the commit message.
Or perhaps limit this optimization over s/w checksumming to
skb->sk &&
(skb->sk->sk_family == AF_INET || .. ) &&
(skb->sk->sk_type == SOCK_STREAM || ..)
?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help
2021-01-26 1:58 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Willem de Bruijn
@ 2021-01-28 9:13 ` Xin Long
0 siblings, 0 replies; 5+ messages in thread
From: Xin Long @ 2021-01-28 9:13 UTC (permalink / raw)
To: Willem de Bruijn
Cc: network dev, Marcelo Ricardo Leitner, David Miller,
Jakub Kicinski, Davide Caratti, Alexander Duyck
On Tue, Jan 26, 2021 at 9:59 AM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Sun, Jan 24, 2021 at 3:47 AM Xin Long <lucien.xin@gmail.com> wrote:
> >
> > NETIF_F_IP|IPV6_CSUM feature flag indicates UDP and TCP csum offload
> > while NETIF_F_HW_CSUM feature flag indicates ip generic csum offload
> > for HW, which includes not only for TCP/UDP csum, but also for other
> > protocols' csum like GRE's.
> >
> > However, in skb_csum_hwoffload_help() it only checks features against
> > NETIF_F_CSUM_MASK(NETIF_F_HW|IP|IPV6_CSUM). So if it's a non TCP/UDP
> > packet and the features doesn't support NETIF_F_HW_CSUM, but supports
> > NETIF_F_IP|IPV6_CSUM only, it would still return 0 and leave the HW
> > to do csum.
> >
> > This patch is to support ip generic csum processing by checking
> > NETIF_F_HW_CSUM for all protocols, and check (NETIF_F_IP_CSUM |
> > NETIF_F_IPV6_CSUM) only for TCP and UDP.
> >
> > v1->v2:
> > - not extend skb->csum_not_inet, but use skb->csum_offset to tell
> > if it's an UDP/TCP csum packet.
> >
> > Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
> > Signed-off-by: Xin Long <lucien.xin@gmail.com>
> > ---
> > net/core/dev.c | 13 ++++++++++++-
> > 1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index 6df3f1b..aae116d 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -3621,7 +3621,18 @@ int skb_csum_hwoffload_help(struct sk_buff *skb,
> > return !!(features & NETIF_F_SCTP_CRC) ? 0 :
> > skb_crc32c_csum_help(skb);
> >
> > - return !!(features & NETIF_F_CSUM_MASK) ? 0 : skb_checksum_help(skb);
> > + if (features & NETIF_F_HW_CSUM)
> > + return 0;
> > +
> > + if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
> > + switch (skb->csum_offset) {
> > + case offsetof(struct tcphdr, check):
> > + case offsetof(struct udphdr, check):
>
> This relies on no other protocols requesting CHECKSUM_PARTIAL
> with these csum_offset values.
>
> That is a fragile assumption. It may well be correct, and Alex argues
> that point in v1 of the patch. I think that argumentation at the least
> should be captured as a comment or in the commit message.
will add a note in changelog and repost, thanks!
>
> Or perhaps limit this optimization over s/w checksumming to
>
> skb->sk &&
> (skb->sk->sk_family == AF_INET || .. ) &&
> (skb->sk->sk_type == SOCK_STREAM || ..)
>
> ?
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-01-28 9:20 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-24 8:44 [PATCH net-next 0/2] net: add support for ip generic checksum offload for gre Xin Long
2021-01-24 8:44 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Xin Long
2021-01-24 8:44 ` [PATCH net-next 2/2] ip_gre: add csum offload support for gre header Xin Long
2021-01-26 1:58 ` [PATCH net-next 1/2] net: support ip generic csum processing in skb_csum_hwoffload_help Willem de Bruijn
2021-01-28 9:13 ` Xin Long
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.