Feature #2239: Integrate the virtio net driver
MSI(-X) support on legacy PCI.
The PCI 2.2 standard adds MSI support, and PCI 3.0 extended it to MSI-X.
Currently, illumos only supports MSI on PCI-express, but not on legacy PCI.
This feature is important to run illumos efficiently in kvm/qemu. Judging from the Linux numbers, MSI support should give at least a 2x performance improvement for virtio-net.
Unfortunately, I don't have time to work on this task.