bhyve: do not exit if LPC finds no host selector

[corvink]

Summary

The host selector is only required when the user likes to use the same
LPC device IDs as the physical LPC device. This is an uncommon use case.
For that reason, it makes no sense to exit when we don't find the host
selector.

[markj]

usr.sbin/bhyve/pci_lpc.c

456

457

Or else this shouldn't compile...?

487

The caller also emits a warning message in this case. It'd be better to have a single warning.

532

Isn't sel leaked now? What's the purpose of dynamically allocating the selector in the first place?

[corvink]

usr.sbin/bhyve/pci_lpc.c

532

That's true. Thanks.

I need an invalid sel value. sel is only required if the user specifies host as LPC ID. So, if no LPC is found, it's not an error but sel should be set to an invalid value. If you have a better solution, feel free to post it.

[markj]

usr.sbin/bhyve/pci_lpc.c

532

Can't you just pass NULL instead of &sel if we fail to find a matching LPC? That is:

selp = &sel;
if (pci_lpc_get_sel(selp) != 0)
    selp = NULL;
vendor = pci_config_read_reg(selp, ...);
...

[andy_omniosce.org]

usr.sbin/bhyve/pci_lpc.c

532

Here's what I've done for the illumos port

https://github.com/citrus-it/illumos-omnios/commit/d3cfd6b9db8ce8f49bbe85f523bd18c47eb01eb0#diff-8642b5a298720c290ad98183a08b837080658ec94b4679785a42a01149b68bd0R532-R565

[corvink]

• don't allocate LPC host selector dynamically