vfb console inhibiting Xen console?

vfb console inhibiting Xen console?

[Jeremy Fitzhardinge]

If I create a domain with a vfb:

    vfb=['type=vnc']
    vnc=1
    vncpasswd=''
    vnclisten='0.0.0.0'

then I can no longer access the Xen console:

    # xm create -c xenpv64
    Using config file "/etc/xen/xenpv64".
    Started domain xenpv64 (id=3)
    xenconsole: Could not read tty from store: No such file or directory

If I comment out the vfb line, then I can start the domain with a
console as expected.

Diffing xenstore is mostly boring except for:

    -   console = ""
    -    ring-ref = "401255"
    -    port = "2"
    -    limit = "1048576"
    -    type = "xenconsoled"
    -    tty = "/dev/pts/1"

    +   console = ""
    +    vnc-port = "5900"
    +    ring-ref = "277012"
    +    port = "2"
    +    limit = "1048576"
    +    type = "ioemu"

Can I have both at once?

    J

Re: vfb console inhibiting Xen console?

[Gerd Hoffmann]

   Hi,

>      -    type = "xenconsoled"
>      -    tty = "/dev/pts/1"

>      +   console = ""
>      +    type = "ioemu"

Should work, yes.  qemu-dm is supposed to write the tty to xenstore as 
well (xenstore.c, xenstore_store_serial_port_info()), so xenconsole can 
connect.  Something is wrong here ...

cheers,
   Gerd

Re: vfb console inhibiting Xen console?

[Ian Campbell]

Something to do with Stefano's recent changes to enable extra serial
ports etc on HVM leaking through into PV land?

On Thu, 2009-07-02 at 23:22 +0100, Jeremy Fitzhardinge wrote:
> If I create a domain with a vfb:
> 
>     vfb=['type=vnc']
>     vnc=1
>     vncpasswd=''
>     vnclisten='0.0.0.0'
> 
> then I can no longer access the Xen console:
> 
>     # xm create -c xenpv64
>     Using config file "/etc/xen/xenpv64".
>     Started domain xenpv64 (id=3)
>     xenconsole: Could not read tty from store: No such file or directory
> 
> If I comment out the vfb line, then I can start the domain with a
> console as expected.
> 
> Diffing xenstore is mostly boring except for:
> 
>     -   console = ""
>     -    ring-ref = "401255"
>     -    port = "2"
>     -    limit = "1048576"
>     -    type = "xenconsoled"
>     -    tty = "/dev/pts/1"
> 
>     +   console = ""
>     +    vnc-port = "5900"
>     +    ring-ref = "277012"
>     +    port = "2"
>     +    limit = "1048576"
>     +    type = "ioemu"
> 
> Can I have both at once?
> 
>     J

Re: vfb console inhibiting Xen console?

[Stefano Stabellini]

On Thu, 2 Jul 2009, Jeremy Fitzhardinge wrote:
> If I create a domain with a vfb:
> 
>     vfb=['type=vnc']
>     vnc=1
>     vncpasswd=''
>     vnclisten='0.0.0.0'
> 
> then I can no longer access the Xen console:
> 
>     # xm create -c xenpv64
>     Using config file "/etc/xen/xenpv64".
>     Started domain xenpv64 (id=3)
>     xenconsole: Could not read tty from store: No such file or directory
> 
> If I comment out the vfb line, then I can start the domain with a
> console as expected.
> 
> Diffing xenstore is mostly boring except for:
> 
>     -   console = ""
>     -    ring-ref = "401255"
>     -    port = "2"
>     -    limit = "1048576"
>     -    type = "xenconsoled"
>     -    tty = "/dev/pts/1"
> 
>     +   console = ""
>     +    vnc-port = "5900"
>     +    ring-ref = "277012"
>     +    port = "2"
>     +    limit = "1048576"
>     +    type = "ioemu"
> 
> Can I have both at once?
> 

Yes, you can.
Check that /local/domain/$DOMID/serial/0/tty exists and contains the
tty path in dom0.
If you specify vfb in your config file then qemu provides the console
backend and creates that node on xenstore that specify the tty device
path.
I just tried to start a pv guest with a vfb and didn't have any problem
connecting to the console, maybe you don't have an updated qemu tree?

Re: vfb console inhibiting Xen console?

[Jeremy Fitzhardinge]

On 07/03/09 04:38, Stefano Stabellini wrote:
> Yes, you can.
> Check that /local/domain/$DOMID/serial/0/tty exists and contains the
> tty path in dom0.
> If you specify vfb in your config file then qemu provides the console
> backend and creates that node on xenstore that specify the tty device
> path.
> I just tried to start a pv guest with a vfb and didn't have any problem
> connecting to the console, maybe you don't have an updated qemu tree?
>   

I can never tell whether the versions match up or not.  I did a clean
build and it appeared to do some git pulling.

But I just did an specific "git pull" in ioemu-remote, and the behaviour
has changed.  Now with a vfb it seems to hang forever: the domain
appears to boot, but there's no console output, and it doesn't seem to
have brought up its network.  There's nothing on the vfb either. 
/local/domain/$DOMID/serial/0/tty has /dev/pts/1, which the xenconsole
process has open.

If I remove the vfb in the config, it works as expected.

    J

Re: vfb console inhibiting Xen console?

[Stefano Stabellini]

On Fri, 3 Jul 2009, Jeremy Fitzhardinge wrote:
> On 07/03/09 04:38, Stefano Stabellini wrote:
> > Yes, you can.
> > Check that /local/domain/$DOMID/serial/0/tty exists and contains the
> > tty path in dom0.
> > If you specify vfb in your config file then qemu provides the console
> > backend and creates that node on xenstore that specify the tty device
> > path.
> > I just tried to start a pv guest with a vfb and didn't have any problem
> > connecting to the console, maybe you don't have an updated qemu tree?
> >   
> 
> I can never tell whether the versions match up or not.  I did a clean
> build and it appeared to do some git pulling.
> 
> But I just did an specific "git pull" in ioemu-remote, and the behaviour
> has changed.  Now with a vfb it seems to hang forever: the domain
> appears to boot, but there's no console output, and it doesn't seem to
> have brought up its network.  There's nothing on the vfb either. 
> /local/domain/$DOMID/serial/0/tty has /dev/pts/1, which the xenconsole
> process has open.
> 
> If I remove the vfb in the config, it works as expected.

What are the command line options to qemu in dom0?
Is fbcon loaded in the guest?
Could you please also send me the qemu log
(/var/log/xen/qemu-dm-$DOMID.log)?