diff mbox series

[net,v2] gve: Secure enough bytes in the first TX desc for all TCP pkts

Message ID 20230403172809.2939306-1-shailend@google.com (mailing list archive)
State Accepted
Commit 3ce9345580974863c060fa32971537996a7b2d57
Delegated to: Netdev Maintainers
Headers show
Series [net,v2] gve: Secure enough bytes in the first TX desc for all TCP pkts | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 18 this patch: 18
netdev/cc_maintainers fail 4 blamed authors not CCed: willemb@google.com csully@google.com lrizzo@google.com jonolson@google.com; 8 maintainers not CCed: pabeni@redhat.com jesse.brandeburg@intel.com edumazet@google.com csully@google.com lrizzo@google.com jonolson@google.com willemb@google.com jeroendb@google.com
netdev/build_clang success Errors and warnings before: 21 this patch: 21
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 18 this patch: 18
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Shailend Chand April 3, 2023, 5:28 p.m. UTC
Non-GSO TCP packets whose SKBs' linear portion did not include the
entire TCP header were not populating the first Tx descriptor with
as many bytes as the vNIC expected. This change ensures that all
TCP packets populate the first descriptor with the correct number of
bytes.

Fixes: 893ce44df565 ("gve: Add basic driver framework for Compute Engine Virtual NIC")
Signed-off-by: Shailend Chand <shailend@google.com>
---
Changes in v2:
  - Clarify that the spec being mentioned is the gVNIC spec
  - Add a define for the "182" magic number

 drivers/net/ethernet/google/gve/gve.h    |  2 ++
 drivers/net/ethernet/google/gve/gve_tx.c | 12 +++++-------
 2 files changed, 7 insertions(+), 7 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org April 5, 2023, 2 a.m. UTC | #1
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon,  3 Apr 2023 10:28:09 -0700 you wrote:
> Non-GSO TCP packets whose SKBs' linear portion did not include the
> entire TCP header were not populating the first Tx descriptor with
> as many bytes as the vNIC expected. This change ensures that all
> TCP packets populate the first descriptor with the correct number of
> bytes.
> 
> Fixes: 893ce44df565 ("gve: Add basic driver framework for Compute Engine Virtual NIC")
> Signed-off-by: Shailend Chand <shailend@google.com>
> 
> [...]

Here is the summary with links:
  - [net,v2] gve: Secure enough bytes in the first TX desc for all TCP pkts
    https://git.kernel.org/netdev/net/c/3ce934558097

You are awesome, thank you!
Matthieu Baerts April 5, 2023, 1:13 p.m. UTC | #2
Hello,

On 03/04/2023 19:28, Shailend Chand wrote:
> Non-GSO TCP packets whose SKBs' linear portion did not include the
> entire TCP header were not populating the first Tx descriptor with
> as many bytes as the vNIC expected. This change ensures that all
> TCP packets populate the first descriptor with the correct number of
> bytes.
> 
> Fixes: 893ce44df565 ("gve: Add basic driver framework for Compute Engine Virtual NIC")
> Signed-off-by: Shailend Chand <shailend@google.com>

FYI, we got a small conflict when merging 'net' in 'net-next' in the
MPTCP tree due to this patch applied in 'net':

  3ce934558097 ("gve: Secure enough bytes in the first TX desc for all
TCP pkts")

and this one from 'net-next':

  75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format")

----- Generic Message -----
The best is to avoid conflicts between 'net' and 'net-next' trees but if
they cannot be avoided when preparing patches, a note about how to fix
them is much appreciated.

The conflict has been resolved on our side[1] and the resolution we
suggest is attached to this email. Please report any issues linked to
this conflict resolution as it might be used by others. If you worked on
the mentioned patches, don't hesitate to ACK this conflict resolution.
---------------------------

Regarding this conflict, the new "define"'s have been kept. Note that
now, two "define"'s have the same value (182) but used in different
contexts. Maybe someone will want to create a new patch to merge them.

Cheers,
Matt

[1] https://github.com/multipath-tcp/mptcp_net-next/commit/5ea299ff55b5
diff mbox series

Patch

diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/google/gve/gve.h
index 64eb0442c82f..005cb9dfe078 100644
--- a/drivers/net/ethernet/google/gve/gve.h
+++ b/drivers/net/ethernet/google/gve/gve.h
@@ -47,6 +47,8 @@ 
 
 #define GVE_RX_BUFFER_SIZE_DQO 2048
 
+#define GVE_GQ_TX_MIN_PKT_DESC_BYTES 182
+
 /* Each slot in the desc ring has a 1:1 mapping to a slot in the data ring */
 struct gve_rx_desc_queue {
 	struct gve_rx_desc *desc_ring; /* the descriptor ring */
diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 4888bf05fbed..5e11b8236754 100644
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -284,8 +284,8 @@  static inline int gve_skb_fifo_bytes_required(struct gve_tx_ring *tx,
 	int bytes;
 	int hlen;
 
-	hlen = skb_is_gso(skb) ? skb_checksum_start_offset(skb) +
-				 tcp_hdrlen(skb) : skb_headlen(skb);
+	hlen = skb_is_gso(skb) ? skb_checksum_start_offset(skb) + tcp_hdrlen(skb) :
+				 min_t(int, GVE_GQ_TX_MIN_PKT_DESC_BYTES, skb->len);
 
 	pad_bytes = gve_tx_fifo_pad_alloc_one_frag(&tx->tx_fifo,
 						   hlen);
@@ -454,13 +454,11 @@  static int gve_tx_add_skb_copy(struct gve_priv *priv, struct gve_tx_ring *tx, st
 	pkt_desc = &tx->desc[idx];
 
 	l4_hdr_offset = skb_checksum_start_offset(skb);
-	/* If the skb is gso, then we want the tcp header in the first segment
-	 * otherwise we want the linear portion of the skb (which will contain
-	 * the checksum because skb->csum_start and skb->csum_offset are given
-	 * relative to skb->head) in the first segment.
+	/* If the skb is gso, then we want the tcp header alone in the first segment
+	 * otherwise we want the minimum required by the gVNIC spec.
 	 */
 	hlen = is_gso ? l4_hdr_offset + tcp_hdrlen(skb) :
-			skb_headlen(skb);
+			min_t(int, GVE_GQ_TX_MIN_PKT_DESC_BYTES, skb->len);
 
 	info->skb =  skb;
 	/* We don't want to split the header, so if necessary, pad to the end