The 1/10GbaseT modes were set up for cards with SFP+ cages in
3497ed8c ("sfc: report supported link speeds on SFP connections").
10GbaseT was likely used since no 10G fibre mode existed.

The missing fibre modes for 1/10G were added to ethtool.h in 5711a982
("net: ethtool: add support for 1000BaseX and missing 10G link modes")
shortly thereafter.

The user guide available at https://support-nic.xilinx.com/wp/drivers
lists support for the following cable and transceiver types in section 2.9:
- QSFP28 100G Direct Attach Cables
- QSFP28 100G SR Optical Transceivers (with SR4 modules listed)
- SFP28 25G Direct Attach Cables
- SFP28 25G SR Optical Transceivers
- QSFP+ 40G Direct Attach Cables
- QSFP+ 40G Active Optical Cables
- QSFP+ 40G SR4 Optical Transceivers
- QSFP+ to SFP+ Breakout Direct Attach Cables
- QSFP+ to SFP+ Breakout Active Optical Cables
- SFP+ 10G Direct Attach Cables
- SFP+ 10G SR Optical Transceivers
- SFP+ 10G LR Optical Transceivers
- SFP 1000BASE‐T Transceivers
- 1G Optical Transceivers
(From user guide issue 28. Issue 16 which also includes older cards like
SFN5xxx/SFN6xxx has matching lists for 1/10/40G transceiver types.)

Regarding SFP+ 10GBASE‐T transceivers the latest guide says:
"Solarflare adapters do not support 10GBASE‐T transceiver modules."

Tested using SFN5122F-R7 (with 2 SFP+ ports). Supported link modes do not change
depending on module used (tested with 1000BASE-T, 1000BASE-BX10, 10GBASE-LR).
Before:

$ ethtool ext
Settings for ext:
	Supported ports: [ FIBRE ]
	Supported link modes:   1000baseT/Full
	                        10000baseT/Full
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: No
	Supported FEC modes: Not reported
	Advertised link modes:  Not reported
	Advertised pause frame use: No
	Advertised auto-negotiation: No
	Advertised FEC modes: Not reported
	Link partner advertised link modes:  Not reported
	Link partner advertised pause frame use: No
	Link partner advertised auto-negotiation: No
	Link partner advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Auto-negotiation: off
	Port: FIBRE
	PHYAD: 255
	Transceiver: internal
        Current message level: 0x000020f7 (8439)
                               drv probe link ifdown ifup rx_err tx_err hw
	Link detected: yes

After:

$ ethtool ext
Settings for ext:
	Supported ports: [ FIBRE ]
	Supported link modes:   1000baseT/Full
	                        1000baseX/Full
	                        10000baseCR/Full
	                        10000baseSR/Full
	                        10000baseLR/Full
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: No
	Supported FEC modes: Not reported
	Advertised link modes:  Not reported
	Advertised pause frame use: No
	Advertised auto-negotiation: No
	Advertised FEC modes: Not reported
	Link partner advertised link modes:  Not reported
	Link partner advertised pause frame use: No
	Link partner advertised auto-negotiation: No
	Link partner advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Auto-negotiation: off
	Port: FIBRE
	PHYAD: 255
	Transceiver: internal
	Supports Wake-on: g
	Wake-on: d
        Current message level: 0x000020f7 (8439)
                               drv probe link ifdown ifup rx_err tx_err hw
	Link detected: yes
Signed-off-by: Erik Ekman <erik@kryo.se>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>