Re: kern/59165: vio9p(4): expose tag through sysctl or device properties

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

The following reply was made to PR kern/59165; it has been noted by GNATS.

From: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/59165: vio9p(4): expose tag through sysctl or device properties
Date: Tue, 11 Mar 2025 12:30:58 +0900

 On Mon, Mar 10, 2025 at 7:50=E2=80=AFAM <campbell+netbsd%mumble.net@localhost> wrote:
 >
 > >Number:         59165
 > >Category:       kern
 > >Synopsis:       vio9p(4): expose tag through sysctl or device properties
 > >Confidential:   no
 > >Severity:       serious
 > >Priority:       medium
 > >Responsible:    kern-bug-people
 > >State:          open
 > >Class:          change-request
 > >Submitter-Id:   net
 > >Arrival-Date:   Sun Mar 09 22:50:00 +0000 2025
 > >Originator:     Taylor R Campbell
 > >Release:        current, 10, 9, ...
 > >Organization:
 > The Net9P Mountation
 > >Environment:
 > >Description:
 > In virtio-9p, the host passes a tag identifying each possible 9p mount po=
 int to the guest.  The mount tag is an arbitrary(?) string configured in th=
 e host (e.g., qemu -device virtio-9p-pci,mount_tag=3DFOO,...).
 >
 > Currently, NetBSD only prints it to dmesg:
 >
 > [     1.049667] vio9p0: tagged as FOO
 >
 > It would be nice if this were exposed to userland via sysctl, device prop=
 erties, or something, so that, e.g., a devpubd(8) hook could automatically =
 create a symlink for it.
 > >How-To-Repeat:
 > try to juggle a collection of /dev/vio9pN mount points in the guest and h=
 ost VM configuration
 > >Fix:
 > Yes, please!
 >
 
 I have a patch for systctl:
 https://www.netbsd.org/~ozaki-r/vio9p-tag-sysctl.patch
 Does it satisfy the demand?
 
   ozaki-r