10G autoneg values not reported in dladm show-ether -x
The 10Gbps property support in dladm (and libdladm) was developed before 10GBase-T became available.
Now it exists, and 10GBase-T NICs can autoneg to other speeds. ixgbe is one such nic we support.
Unfortunately, while testing the work for 40Gbps, 100Gbps, 2.5 Gbps, and 5Gbps speeds, I noticed that 10Gbps autonegotiation values were not reported properly in dladm, even though the NIC reports some of the kstats. (Note that ixgbe in particular does not seem to report peer settings for 10Gbps peers; I'm not sure why not -- clause 45 registers would give this information, I think.)
Anyway, the framework should support this, and then we can update individual drivers to report correctly.