From: Stanislav Fomichev <sdf@google.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, kuba@kernel.org,
toke@kernel.org, willemb@google.com, dsahern@kernel.org,
magnus.karlsson@intel.com, bjorn@kernel.org,
maciej.fijalkowski@intel.com, hawk@kernel.org,
yoong.siang.song@intel.com, netdev@vger.kernel.org,
xdp-hints@xdp-project.net
Subject: [xdp-hints] [PATCH bpf-next v5 08/13] xsk: Add option to calculate TX checksum in SW
Date: Thu, 2 Nov 2023 15:58:32 -0700 [thread overview]
Message-ID: <20231102225837.1141915-9-sdf@google.com> (raw)
In-Reply-To: <20231102225837.1141915-1-sdf@google.com>
For XDP_COPY mode, add a UMEM option XDP_UMEM_TX_SW_CSUM
to call skb_checksum_help in transmit path. Might be useful
to debugging issues with real hardware. I also use this mode
in the selftests.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
Documentation/networking/xsk-tx-metadata.rst | 9 +++++++++
include/net/xsk_buff_pool.h | 1 +
include/uapi/linux/if_xdp.h | 8 +++++++-
net/xdp/xdp_umem.c | 7 ++++++-
net/xdp/xsk.c | 6 ++++++
net/xdp/xsk_buff_pool.c | 1 +
tools/include/uapi/linux/if_xdp.h | 8 +++++++-
7 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/Documentation/networking/xsk-tx-metadata.rst b/Documentation/networking/xsk-tx-metadata.rst
index 4f376560b23f..97ecfa480d00 100644
--- a/Documentation/networking/xsk-tx-metadata.rst
+++ b/Documentation/networking/xsk-tx-metadata.rst
@@ -50,6 +50,15 @@ packet's ``struct xdp_desc`` descriptor should set ``XDP_TX_METADATA``
bit in the ``options`` field. Also note that in a multi-buffer packet
only the first chunk should carry the metadata.
+Software TX Checksum
+====================
+
+For development and testing purposes its possible to pass
+``XDP_UMEM_TX_SW_CSUM`` flag to ``XDP_UMEM_REG`` UMEM registration call.
+In this case, when running in ``XDK_COPY`` mode, the TX checksum
+is calculated on the CPU. Do not enable this option in production because
+it will negatively affect performance.
+
Querying Device Capabilities
============================
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index 97f5cc10d79e..8d48d37ab7c0 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -83,6 +83,7 @@ struct xsk_buff_pool {
bool uses_need_wakeup;
bool dma_need_sync;
bool unaligned;
+ bool tx_sw_csum;
void *addrs;
/* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect:
* NAPI TX thread and sendmsg error paths in the SKB destructor callback and when
diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index b0ee7ad19b51..bed6adc3e9b4 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -33,7 +33,13 @@
#define XDP_USE_SG (1 << 4)
/* Flags for xsk_umem_config flags */
-#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
+#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
+
+/* Force checksum calculation in software. Can be used for testing or
+ * working around potential HW issues. This option causes performance
+ * degradation and only works in XDP_COPY mode.
+ */
+#define XDP_UMEM_TX_SW_CSUM (1 << 1)
struct sockaddr_xdp {
__u16 sxdp_family;
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 946a687fb8e8..caa340134b0e 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -148,6 +148,11 @@ static int xdp_umem_account_pages(struct xdp_umem *umem)
return 0;
}
+#define XDP_UMEM_FLAGS_VALID ( \
+ XDP_UMEM_UNALIGNED_CHUNK_FLAG | \
+ XDP_UMEM_TX_SW_CSUM | \
+ 0)
+
static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
{
bool unaligned_chunks = mr->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
@@ -167,7 +172,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
return -EINVAL;
}
- if (mr->flags & ~XDP_UMEM_UNALIGNED_CHUNK_FLAG)
+ if (mr->flags & ~XDP_UMEM_FLAGS_VALID)
return -EINVAL;
if (!unaligned_chunks && !is_power_of_2(chunk_size))
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 0e81ae6bfff4..e109b2aaeb2a 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -744,6 +744,12 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
skb->csum_start = hr + meta->request.csum_start;
skb->csum_offset = meta->request.csum_offset;
skb->ip_summed = CHECKSUM_PARTIAL;
+
+ if (unlikely(xs->pool->tx_sw_csum)) {
+ err = skb_checksum_help(skb);
+ if (err)
+ goto free_err;
+ }
}
}
}
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 386eddcdf837..4f6f538a5462 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -86,6 +86,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
pool->umem = umem;
pool->addrs = umem->addrs;
pool->tx_metadata_len = umem->tx_metadata_len;
+ pool->tx_sw_csum = umem->flags & XDP_UMEM_TX_SW_CSUM;
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->xskb_list);
INIT_LIST_HEAD(&pool->xsk_tx_list);
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
index 29942c2c32dc..8ed2ed9d1b17 100644
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -33,7 +33,13 @@
#define XDP_USE_SG (1 << 4)
/* Flags for xsk_umem_config flags */
-#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
+#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
+
+/* Force checksum calculation in software. Can be used for testing or
+ * working around potential HW issues. This option causes performance
+ * degradation and only works in XDP_COPY mode.
+ */
+#define XDP_UMEM_TX_SW_CSUM (1 << 1)
struct sockaddr_xdp {
__u16 sxdp_family;
--
2.42.0.869.gea05f2083d-goog
next prev parent reply other threads:[~2023-11-02 22:58 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-02 22:58 [xdp-hints] [PATCH bpf-next v5 00/13] xsk: TX metadata Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 01/13] xsk: Support tx_metadata_len Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 02/13] xsk: Add TX timestamp and TX checksum offload support Stanislav Fomichev
2023-11-13 13:16 ` [xdp-hints] " Jesper Dangaard Brouer
2023-11-13 14:10 ` Stanislav Fomichev
2023-11-13 16:29 ` Jesper Dangaard Brouer
2023-11-13 17:02 ` Stanislav Fomichev
2023-11-15 10:05 ` Jesper Dangaard Brouer
2023-11-15 13:37 ` Stanislav Fomichev
2023-11-16 14:30 ` Jesper Dangaard Brouer
2023-11-20 20:45 ` Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 03/13] tools: ynl: Print xsk-features from the sample Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 04/13] net/mlx5e: Implement AF_XDP TX timestamp and checksum offload Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 05/13] net: stmmac: Add Tx HWTS support to XDP ZC Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 06/13] xsk: Document tx_metadata_len layout Stanislav Fomichev
2023-11-05 12:45 ` [xdp-hints] " Simon Horman
2023-11-06 16:47 ` Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 07/13] xsk: Validate xsk_tx_metadata flags Stanislav Fomichev
2023-11-02 22:58 ` Stanislav Fomichev [this message]
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 09/13] selftests/xsk: Support tx_metadata_len Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 10/13] selftests/bpf: Add csum helpers Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 11/13] selftests/bpf: Add TX side to xdp_metadata Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 12/13] selftests/bpf: Convert xdp_hw_metadata to XDP_USE_NEED_WAKEUP Stanislav Fomichev
2023-11-02 22:58 ` [xdp-hints] [PATCH bpf-next v5 13/13] selftests/bpf: Add TX side to xdp_hw_metadata Stanislav Fomichev
2023-11-06 23:31 ` [xdp-hints] Re: [PATCH bpf-next v5 00/13] xsk: TX metadata Jakub Kicinski
2023-11-09 18:03 ` Alexei Starovoitov
2023-11-09 18:07 ` Stanislav Fomichev
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://lists.xdp-project.net/postorius/lists/xdp-hints.xdp-project.net/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231102225837.1141915-9-sdf@google.com \
--to=sdf@google.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bjorn@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=dsahern@kernel.org \
--cc=haoluo@google.com \
--cc=hawk@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=maciej.fijalkowski@intel.com \
--cc=magnus.karlsson@intel.com \
--cc=martin.lau@linux.dev \
--cc=netdev@vger.kernel.org \
--cc=song@kernel.org \
--cc=toke@kernel.org \
--cc=willemb@google.com \
--cc=xdp-hints@xdp-project.net \
--cc=yhs@fb.com \
--cc=yoong.siang.song@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox