Virtio device specific MSIX arming

[Shahaf Shuler <shahafs@mellanox.com>]

Hi,

 

Below question mainly raise when looking on the ways to have vDPA implementation of virtio-net device.

 

One complexity we encounter is with the MSIX relay between the device and the guest.

Reading the spec, and looking on the driver implementation, it seems there is no way for the driver to re-arm the virtio device after MSIX was triggered.

 

There is a way to suppress interrupt by setting some flags on the available rings, however it is hard to poll on it from a real (not emulated) PCI device.

 

Is above correct? Or there is a way to re-arm virtio device for next interrupt?

 

If no way to re-arm,

1. are there any thoughts on adding such addition to spec?

2. What is the recommended approach for vDPA implementation? Use static

    interrupt moderation?