Re: [Qemu-devel] [Consult] nfs-vsocks support

[Liu, Jing2]

On 4/4/2018 5:45 PM, Stefan Hajnoczi wrote:
> On Wed, Mar 28, 2018 at 07:25:21PM +0800, Liu, Jing2 wrote:
> > On 3/26/2018 6:12 PM, Liu, Jing2 wrote:
> > > Hi Stefan,
> > >
> > > Thank you very much for the response! It truly gave me much help.
> > >
> > > On 3/24/2018 12:02 AM, Stefan Hajnoczi wrote:
> > [...]
> > > > > Could you give me some help and thanks in advance!
> > > >
> > > > Here is a script that launches nfsd and runs a guest:
> > > > https://github.com/stefanha/linux/commit/38cbc15661a6dd44b69c4f318091f2047d707035#diff-05f3fe8941076453942a8c059b409009
> >
> > Using the script, I met some problems making the
> > initramfs.gz. It confused me a lot... I don't have busybox under
> > /usr/bin or /usr/sbin. Where to get it?

> It may be easier to use a full guest disk image instead of the disk
> image generation in my go.sh script.  The initramfs is very specific to
> the development machine I was using at the time.  The main thing to look
> at the in the go.sh script is how the NFS services are launched on the
> host.
>
> Busybox is a package that is available on most Linux distributions.

I realized the rhel-7.x doesn't has busybox anymore. And yes, I used 
some other image to continue.

> Before you spend more time on this, NFS over AF_VSOCK is only suitable
> for developers right now.  It is not ready for production and I am not
> supporting it for end users.  So if you want to hack on NFS, please go
> ahead, but otherwise it's probably not what you want.
Yes, so far we didn't plan for production. And thank you very much for 
your kind response.

Jing

> Stefan
>
> > (host)$./go.sh nfs_tcp
> >
> > File /usr/sbin/busybox could not be opened for reading
> >   line 55
> > File /lib64/libtirpc.so.3 could not be opened for reading
> >   line 306
> > File nc-vsock could not be opened for reading
> >   line 321
> > File ../netperf-2.7.0/src/netserver could not be opened for reading
> >   line 325
> >
> > It results in guest kernel_panic when gdb launches the guest:
> >
> > [    0.425738] Failed to execute /init (error -2)
> > [    0.426074] Kernel panic - not syncing: No working init found.  Try
> > passing .
> > [    0.427077] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0+ #3
> > [    0.427507] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> > rel-4
> > [    0.428354] Call Trace:
> > [    0.428538]  dump_stack+0x63/0x89
> > [    0.428774]  ? rest_init+0x60/0xc0
> > [    0.429017]  panic+0xeb/0x245
> > [    0.429225]  ? putname+0x53/0x60
> > [    0.429455]  ? rest_init+0xc0/0xc0
> > [    0.429722]  kernel_init+0xf1/0x104
> > [    0.430017]  ret_from_fork+0x25/0x30
> >
> > Looking forward to the kind reply.
> > BTW, for the following questions that I sent two days ago, I have some
> > ideas in mind and it could be ignored now.
> >
> > Jing
> >
> > > I have updated both host and guest kernel with vsock-nfsd repo and
> > > installed nfs-utils in both host and guest successfully.
> > >
> > > There're two different manuals in
> > > https://www.spinics.net/lists/linux-nfs/msg64563.html(Quickstart 3~7)
> > > and nfs-utils (README step 3 DAEMON STARTUP ORDER).
> > > Which one should be the best usage?
> > >
> > > For the first quickstart manual step 7-Mount the export from the guest,
> > > two questions as follows.
> > > 1. why hypervisor's CID is 2? I didn't notice when it is specified?
> > > 2. Though I did step 3~7 successfully, I can't see the synchronistical
> > > changing on host folder /export/ and guest /mnt? So how to test the
> > > communcation between host and guest on the folder?
> > >
> > > Thanks again!
> > >
> > > Jing
> > [...]
> > > > Stefan