diff mbox series

[net,v3,1/3] ixgbe: allow to increase MTU to 3K with XDP enabled

Message ID 20230204133535.99921-2-kerneljasonxing@gmail.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series Fix MTU related issues | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 1 this patch: 2
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/build_clang fail Errors and warnings before: 0 this patch: 1
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn fail Errors and warnings before: 1 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/kdoc fail Errors and warnings before: 0 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Jason Xing Feb. 4, 2023, 1:35 p.m. UTC 
From: Jason Xing <kernelxing@tencent.com>

Recently I encountered one case where I cannot increase the MTU size
directly from 1500 to a much bigger value with XDP enabled if the
server is equipped with IXGBE card, which happened on thousands of
servers in production environment. After appling the current patch,
we can set the maximum MTU size to 3K.

This patch follows the behavior of changing MTU as i40e/ice does.

Referrences:
[1] commit 23b44513c3e6 ("ice: allow 3k MTU for XDP")
[2] commit 0c8493d90b6b ("i40e: add XDP support for pass and drop actions")

Fixes: fabf1bce103a ("ixgbe: Prevent unsupported configurations with XDP")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
v3:
1) modify the titile and body message.

v2:
1) change the commit message.
2) modify the logic when changing MTU size suggested by Maciej and Alexander.
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 25 ++++++++++++-------
 1 file changed, 16 insertions(+), 9 deletions(-)

Comments

Tony Nguyen Feb. 7, 2023, 7:03 p.m. UTC | #1 
On 2/4/2023 5:35 AM, Jason Xing wrote:
> From: Jason Xing <kernelxing@tencent.com>

...

> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index ab8370c413f3..2c1b6eb60436 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -6777,6 +6777,18 @@ static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter)
>   			ixgbe_free_rx_resources(adapter->rx_ring[i]);
>   }
>   
> +/**
> + * ixgbe_max_xdp_frame_size - returns the maximum allowed frame size for XDP
> + * @adapter - device handle, pointer to adapter
> + */

Please use ':' instead of '-' for kdoc

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:6785: warning: Function 
parameter or member 'adapter' not described in 'ixgbe_max_xdp_frame_size'

i.e.

@adapter: device handle, pointer to adapter

> +static int ixgbe_max_xdp_frame_size(struct ixgbe_adapter *adapter)
> +{
> +	if (PAGE_SIZE >= 8192 || adapter->flags2 & IXGBE_FLAG2_RX_LEGACY)
> +		return IXGBE_RXBUFFER_2K;
> +	else
> +		return IXGBE_RXBUFFER_3K;
> +}
> +
Jason Xing Feb. 8, 2023, 2:09 a.m. UTC | #2 
On Wed, Feb 8, 2023 at 3:03 AM Tony Nguyen <anthony.l.nguyen@intel.com> wrote:
>
> On 2/4/2023 5:35 AM, Jason Xing wrote:
> > From: Jason Xing <kernelxing@tencent.com>
>
> ...
>
> > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> > index ab8370c413f3..2c1b6eb60436 100644
> > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> > @@ -6777,6 +6777,18 @@ static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter)
> >                       ixgbe_free_rx_resources(adapter->rx_ring[i]);
> >   }
> >
> > +/**
> > + * ixgbe_max_xdp_frame_size - returns the maximum allowed frame size for XDP
> > + * @adapter - device handle, pointer to adapter
> > + */
>
> Please use ':' instead of '-' for kdoc
>
> drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:6785: warning: Function
> parameter or member 'adapter' not described in 'ixgbe_max_xdp_frame_size'
>
> i.e.
>
> @adapter: device handle, pointer to adapter

Thanks for correcting the format. Now I understand.

Thanks,
Jason

>
> > +static int ixgbe_max_xdp_frame_size(struct ixgbe_adapter *adapter)
> > +{
> > +     if (PAGE_SIZE >= 8192 || adapter->flags2 & IXGBE_FLAG2_RX_LEGACY)
> > +             return IXGBE_RXBUFFER_2K;
> > +     else
> > +             return IXGBE_RXBUFFER_3K;
> > +}
> > +
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index ab8370c413f3..2c1b6eb60436 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6777,6 +6777,18 @@  static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter)
 			ixgbe_free_rx_resources(adapter->rx_ring[i]);
 }
 
+/**
+ * ixgbe_max_xdp_frame_size - returns the maximum allowed frame size for XDP
+ * @adapter - device handle, pointer to adapter
+ */
+static int ixgbe_max_xdp_frame_size(struct ixgbe_adapter *adapter)
+{
+	if (PAGE_SIZE >= 8192 || adapter->flags2 & IXGBE_FLAG2_RX_LEGACY)
+		return IXGBE_RXBUFFER_2K;
+	else
+		return IXGBE_RXBUFFER_3K;
+}
+
 /**
  * ixgbe_change_mtu - Change the Maximum Transfer Unit
  * @netdev: network interface device structure
@@ -6788,18 +6800,13 @@  static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
 
-	if (adapter->xdp_prog) {
+	if (ixgbe_enabled_xdp_adapter(adapter)) {
 		int new_frame_size = new_mtu + ETH_HLEN + ETH_FCS_LEN +
 				     VLAN_HLEN;
-		int i;
-
-		for (i = 0; i < adapter->num_rx_queues; i++) {
-			struct ixgbe_ring *ring = adapter->rx_ring[i];
 
-			if (new_frame_size > ixgbe_rx_bufsz(ring)) {
-				e_warn(probe, "Requested MTU size is not supported with XDP\n");
-				return -EINVAL;
-			}
+		if (new_frame_size > ixgbe_max_xdp_frame_size(adapter)) {
+			e_warn(probe, "Requested MTU size is not supported with XDP\n");
+			return -EINVAL;
 		}
 	}