From: Andy Gospodarek gospo@broadcom.com
[ Upstream commit facc173cf700e55b2ad249ecbd3a7537f7315691 ]
Insufficient space was being reserved in the page used for packet reception, so the interface MTU could be set too large to still have room for the contents of the packet when doing XDP redirect. This resulted in the following message when redirecting a packet between 3520 and 3822 bytes with an MTU of 3822:
[311815.561880] XDP_WARN: xdp_update_frame_from_buff(line:200): Driver BUG: missing reserved tailroom
Fixes: f18c2b77b2e4 ("bnxt_en: optimized XDP_REDIRECT support") Reviewed-by: Somnath Kotur somnath.kotur@broadcom.com Reviewed-by: Pavan Chebbi pavan.chebbi@broadcom.com Signed-off-by: Andy Gospodarek gospo@broadcom.com Signed-off-by: Michael Chan michael.chan@broadcom.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 5f4a0bb36af3..bbf93310da1f 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -593,7 +593,8 @@ struct nqe_cn { #define BNXT_MAX_MTU 9500 #define BNXT_MAX_PAGE_MODE_MTU \ ((unsigned int)PAGE_SIZE - VLAN_ETH_HLEN - NET_IP_ALIGN - \ - XDP_PACKET_HEADROOM) + XDP_PACKET_HEADROOM - \ + SKB_DATA_ALIGN((unsigned int)sizeof(struct skb_shared_info)))
#define BNXT_MIN_PKT_SIZE 52