Re: [PATCH v3] net/9p: add vsock transport

[Dominique Martinet]

skvarlamatus@xxxxxxxxx wrote on Wed, Sep 16, 2026 at 09:42:04PM +0200:
> On Mon, Sep 14, 2026 at 23:44 +0000, asmadeus@xxxxxxxxxxxxx wrote:
> > Right, diod has an open issue[1] for vsock but since there were no
> > obvious client available either it was never done.
> > I don't think it's difficult to do (probably more work to add the option
> > parsing than the actual vsock support)
> 
> Definitely agree. I think with this in the client, it could encourage
> more servers to add vsock support too.

Just had a quick look at diod code and their handling of the listen
option is purely string based, passed to getaddrinfo() to figure out if
the user requested ipv4/ipv6 -- I'm pretty sure getaddrinfo() doesn't
want to have anything to do with vsock, but I don't suppose there's a
canonical string representation for vsock is there? (something like
`cid:<cid>:<port>` instead of the usual <cid>:<port> couple printed?)

I didn't want to add a new option such as --vsock-listen, but I'd hate
to disambiguate vsock from ipv4/v6 as a string even more... :)



FWIW commit message ended up like this (everything ellipsed is exactly
as you sent), so just extending the sentence a bit to mention Hyper-V
and podman machine:
```
    net/9p: add vsock transport
    
    Add vsock as a transport option for 9P client connections. This
    allows mounting 9P filesystems over VM sockets without requiring TCP/IP
    networking or additional userspace tools, which can be useful with
    hypervisors other than Qemu/KVM, for example Hyper-V/WSL which is used
    by podman machine on Windows[1][2].

    [implementation details]

    Usage:
      mount -t 9p -o trans=vsock[,port=<port>] <CID> /mnt/point
    
    Link: https://github.com/podman-container-tools/podman/blob/main/cmd/podman/machine/server9p.go [1]
    Link: https://github.com/podman-container-tools/podman/blob/main/cmd/podman/machine/client9p.go [2]
    [sign-offs/reviews]
```

Thanks,
-- 
Dominique Martinet | Asmadeus