From: Bailey Forrest bcf@google.com
The NIC requires each TSO segment to not span more than 10 descriptors. gve_can_send_tso() performs this check. However, the current code misses an edge case when a TSO skb has a large frag that needs to be split into multiple descriptors, causing the 10 descriptor limit per TSO-segment to be exceeded. This change fixes the edge case.
Fixes: a57e5de476be ("gve: DQO: Add TX path") Signed-off-by: Praveen Kaligineedi pkaligineedi@google.com Signed-off-by: Bailey Forrest bcf@google.com Reviewed-by: Jeroen de Borst jeroendb@google.com --- drivers/net/ethernet/google/gve/gve_tx_dqo.c | 22 +++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c index 0b3cca3fc792..dc39dc481f21 100644 --- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c +++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c @@ -866,22 +866,42 @@ static bool gve_can_send_tso(const struct sk_buff *skb) const int header_len = skb_tcp_all_headers(skb); const int gso_size = shinfo->gso_size; int cur_seg_num_bufs; + int last_frag_size; int cur_seg_size; int i;
cur_seg_size = skb_headlen(skb) - header_len; + last_frag_size = skb_headlen(skb); cur_seg_num_bufs = cur_seg_size > 0;
for (i = 0; i < shinfo->nr_frags; i++) { if (cur_seg_size >= gso_size) { cur_seg_size %= gso_size; cur_seg_num_bufs = cur_seg_size > 0; + + /* If the last buffer is split in the middle of a TSO + * segment, then it will count as two descriptors. + */ + if (last_frag_size > GVE_TX_MAX_BUF_SIZE_DQO) { + int last_frag_remain = last_frag_size % + GVE_TX_MAX_BUF_SIZE_DQO; + + /* If the last frag was evenly divisible by + * GVE_TX_MAX_BUF_SIZE_DQO, then it will not be + * split in the current segment. + */ + if (last_frag_remain && + cur_seg_size > last_frag_remain) { + cur_seg_num_bufs++; + } + } }
if (unlikely(++cur_seg_num_bufs > max_bufs_per_seg)) return false;
- cur_seg_size += skb_frag_size(&shinfo->frags[i]); + last_frag_size = skb_frag_size(&shinfo->frags[i]); + cur_seg_size += last_frag_size; }
return true;