ixgbe: Enable jumbo frames support w/ SR-IOV
This change makes it so that we can have limited support for jumbo frames
when SR-IOV is enabled. In order to accomplish this it is necessary to
disable all VFs when the PF has jumbo frames enabled. If the VFs then
request the same maximum frame size as the PF they will be re-enabled. A
follow on patch will add a means of identifying when a VF can support
spanning buffers and does not need to be worried about the actual supported
max frame size.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Tested-by: Robert Garrett <robertx.e.garrett@intel.com>
Tested-by: Sibai Li <Sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index fa3d552..e2a6691 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3263,6 +3263,11 @@
max_frame = IXGBE_FCOE_JUMBO_FRAME_SIZE;
#endif /* IXGBE_FCOE */
+
+ /* adjust max frame to be at least the size of a standard frame */
+ if (max_frame < (ETH_FRAME_LEN + ETH_FCS_LEN))
+ max_frame = (ETH_FRAME_LEN + ETH_FCS_LEN);
+
mhadd = IXGBE_READ_REG(hw, IXGBE_MHADD);
if (max_frame != (mhadd >> IXGBE_MHADD_MFS_SHIFT)) {
mhadd &= ~IXGBE_MHADD_MFS_MASK;
@@ -4828,14 +4833,14 @@
return -EINVAL;
/*
- * For 82599EB we cannot allow PF to change MTU greater than 1500
- * in SR-IOV mode as it may cause buffer overruns in guest VFs that
- * don't allocate and chain buffers correctly.
+ * For 82599EB we cannot allow legacy VFs to enable their receive
+ * paths when MTU greater than 1500 is configured. So display a
+ * warning that legacy VFs will be disabled.
*/
if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) &&
(adapter->hw.mac.type == ixgbe_mac_82599EB) &&
(max_frame > MAXIMUM_ETHERNET_VLAN_SIZE))
- return -EINVAL;
+ e_warn(probe, "Setting MTU > 1500 will disable legacy VFs\n");
e_info(probe, "changing MTU from %d to %d\n", netdev->mtu, new_mtu);