Permit the name of the /dev/iov entry to be set by the driver.

[jhb]

Summary

Permit the name of the /dev/iov entry to be set by the driver.

The PCI_IOV option creates character devices in /dev/iov for each PF
device driver that registers support for creating VFs. By default the
character device is named after the PF device (e.g. /dev/iov/foo0).
This change adds a variant of pci_iov_attach() called pci_iov_attach_name()
that allows the name of the /dev/iov entry to be specified by the
driver.

Test Plan

• tested chelsio PF driver with pci_iov_attach first and then changed it to specify an alternate name
• The manpages for iovctl(8) and iovctl.conf(5) manpages may need changes related to the "device" attribute.

[rstone]

sys/dev/pci/pci_iov.h

37

Should declare this as __printf_like() so cc will error on bad format strings

43

will coverity or related tools start whining about passing a non-literal as the format string?

[jhb]

sys/dev/pci/pci_iov.h

43

Not in this case as the kobj method just accepts a 'const char *', not var args. Only the pciv_attach_name() wrapper accepts var args.

[jhb]

• Add __printflike().