Fix nda(4) PCIe link status output

[chuck]

Summary

Differentiate between PCI Express Endpoint devices and Root Complex Integrated Endpoints in the nda driver. The Link Status and Capability registers are not valid for Integrated Endpoints and should not be displayed. The bhyve emulated NVMe device will advertise as being an Integrated Endpoint.

Note this fix is dependent on D19904

[imp]

This looks good. The multiple printfs give me heart-burn, but that's for another day. This part of the code they should be safe, but they aren't safe in a future where we do device discovery in parallel.

[chuck]

In D20282#437333, @imp wrote:

This looks good. The multiple printfs give me heart-burn, but that's for another day. This part of the code they should be safe, but they aren't safe in a future where we do device discovery in parallel.

It would be easy to turn this into a series of snprintfs() and then a single printf(). Would that clear the heartburn?

[ken]

In D20282#437525, @chuck wrote:

In D20282#437333, @imp wrote:

This looks good. The multiple printfs give me heart-burn, but that's for another day. This part of the code they should be safe, but they aren't safe in a future where we do device discovery in parallel.

It would be easy to turn this into a series of snprintfs() and then a single printf(). Would that clear the heartburn?

Yes, I think that would be better. The unfortunate thing is that multiple printfs often end up interleaved in the logs. A single printf should be done in one contiguous chunk.

At some point we should also implement the announce_sbuf() transport function for NVMe.

[chuck]

Convert to using sbuf to avoid log messages from being interleaved once the discovery is done in parallel

[imp]

thanks for going the extra mile and fixing the printf thing too.