From: Ronak Doshi doshir@vmware.com
commit 3bced313b9a5a237c347e0f079c8c2fe4b3935aa upstream.
Currently, vmxnet3 uses GRO callback only if LRO is disabled. However, on smartNic based setups where UPT is supported, LRO can be enabled from guest VM but UPT devicve does not support LRO as of now. In such cases, there can be performance degradation as GRO is not being done.
This patch fixes this issue by calling GRO API when UPT is enabled. We use updateRxProd to determine if UPT mode is active or not.
To clarify few things discussed over the thread: The patch is not neglecting any feature bits nor disabling GRO. It uses GRO callback when UPT is active as LRO is not available in UPT. GRO callback cannot be used as default for all cases as it degrades performance for non-UPT cases or for cases when LRO is already done in ESXi.
Cc: stable@vger.kernel.org Fixes: 6f91f4ba046e ("vmxnet3: add support for capability registers") Signed-off-by: Ronak Doshi doshir@vmware.com Reviewed-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20230323200721.27622-1-doshir@vmware.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/vmxnet3/vmxnet3_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -1688,7 +1688,9 @@ not_lro: if (unlikely(rcd->ts)) __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), rcd->tci);
- if (adapter->netdev->features & NETIF_F_LRO) + /* Use GRO callback if UPT is enabled */ + if ((adapter->netdev->features & NETIF_F_LRO) && + !rq->shared->updateRxProd) netif_receive_skb(skb); else napi_gro_receive(&rq->napi, skb);