IXGBE by-default shares msix vector between RxQ and TxQ. IFLIB ignores Tx IRQ and adopted soft-irq for Tx. Provide a tuneable if anyone wish to use IRQ for Tx completions. If AIM is enabled, AIM can be used to moderate Tx interrupts too. This is somewhat similar to BSD11 behavior where Rx and Tx completions are IRQ.
How is this performing versus the combined IRQ in your testing? I can do some basic smoke tests and suspect we'd want to couple it with the TX AIM patch.
Although I would still prefer to fix the combined IRQ handler, I haven't made any progress there and haven't found anyone wanting to collaborate on it.