automatic IRQ affinity for virtio

From: Christoph Hellwig
Date: Thu Nov 17 2016 - 05:43:37 EST

Hi Michael,

this series contains a couple cleanups for the virtio_pci interrupt
handling code, including a switch to the new pci_irq_alloc_vectors
helper, and support for automatic affinity by the PCI layer if the
consumers ask for it. It then converts over virtio_blk to use this
functionality so that it's blk-mq queues are aligned to the MSI-X
vector routing. I have a similar patch in the queue for virtio-scsi,
but that would require pulling in the SCSI tree, so I'm not sure if
you'd like it for this window, but if you do I can send it in another
series. The third driver using per-CPU virtqueues is virtio_net,
but that will take some more time as I haven't started work on the
networking infrastructure yet.

Note that these patches require core IRQ changes from a stable
branch in the tip tree to be pulled in first:

git:// irq/for-block