pkg/59163: emulators/qemu: missing virtfs option for NetBSD

[campbell+netbsd%mumble.net@localhost]

>Number:         59163
>Category:       pkg
>Synopsis:       emulators/qemu: missing virtfs option for NetBSD
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 09 19:30:00 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, ...; pkgsrc-current, 2024Q4, ...
>Organization:
The Net9P Qemulation
>Environment:
>Description:
It would be nice if emulators/qemu had an option, say `qemu-virtfs', which could enable virtfs support, and if it supported that option on NetBSD.
>How-To-Repeat:
qemu-system-x86_64 ... -fsdev local,id=share,path=./share,security_model=mapped-file -device virtio-9p-pci,fsdev=share,mount_tag=share ...
>Fix:
drafted, patch is a little involved but not too invasive, seems to work in cursory testing (modulo PR bin/58768: mount_9p: missing pathconf(2) support <https://gnats.NetBSD.org/58768>)