Seems to me that the issue is not that the MTU isn't being honoured, but that the MTU should be checked *before* TSO assembly and not *after*. Assembly should happen outside the VM if the VM has enabled it on the interface internally, and clearly the incoming segments (not packets, at this point) may be longer than the MTU.
Seems to me that the issue is not that the MTU isn't being honoured, but that the MTU should be checked *before* TSO assembly and not *after*. Assembly should happen outside the VM if the VM has enabled it on the interface internally, and clearly the incoming segments (not packets, at this point) may be longer than the MTU.