Xen users - Nov 2005 - Example PCI hiding in dom0 and direct access in domU

Hello all,
  I''m new to the list and working my way up the Xen learning curve.
This is
exciting technology and my initial experience has been very positive!!

  I''ve set up several dom0 and single domU VMs on different computers
to get
my feet wet.

  Now I''m trying to get set up an Asterisk server in a domU VM so I can
take
one of my home computers offline (and hopefully save on the electric bill.)

  I''m using a Zaptel TDM422B PCI card. That may or may not mean
something to
most people on the list, but the short of it is, it''s a PCI card that
interfaces the Asterisk Open Source PBX system to plain old telephone
service lines. I have this card working on a Debian Testing install an also
in a Debian Stable Linux system. Now I''d like to get it working inside
a Xen
virtual machine.

  Here is the grub menu.lst config in Dom0:

title Xen 2.0.7 / XenLinux 2.6
  kernel /boot/xen-2.0.7.gz dom0_mem=262144 physdev_dom0_hide=(03:01.0)
  module /boot/vmlinuz-2.6-xen0 root=/dev/hda1 ro console=tty0

Before booting with the physdev_dom0_hide parameter, lspci showed the
following information about the Zaptel PCI card:
  0000:03:01.0 Communication controller: Tiger Jet Network Inc. Tiger3XX
Modem/ISDN interface

The trouble I''m having is being able to see this card inside of a DomU
after
it is confirmed/successfully hidden from domO.

My DomU config has this line and, other than not seeing the PCI card, works
fine:
  pci = [''03,01,0'']

I''m running Xen 2.0.7 built from source using make-world. It appeared
to
grab the latest 2.6.11 kernel and patch it during the build process. The
result is Xen 2.0.7 running a 2.6.11.12-xen0 kernel.

After booting dom0, I use xm create -c asterisk to start the asterisk domU
instance. It boots fine, but it does not successfully load the wctdm module
(which I built in dom0 by setting KSRC to domU''s kernel source
location. I
also copied the /lib/modules/2.6.11.12-xenU tree into the domU file system
so it would have access to the compiled modules.)

Inside the booted domU, modprobe gives this error:

# modprobe wctdm
Zapata Telephony Interface Registered on major 196
ZT_CHANCONFIG failed on channel 1: No such device or address (6)
FATAL: Error running install command for wctdm

lspci inside of domU does not work:

# lspci
pcilib: Cannot open /sys/bus/pci/devices
pcilib: Cannot open /proc/bus/pci
lspci: Cannot find any working access method.

However, at least /proc is mounted and looks normal.


I have tried recompiling the domU kernel and changing these options to Y in
the .config:
> CONFIG_XEN_PRIVILEGED_GUEST=y
> CONFIG_XEN_PHYSDEV_ACCESS=y
(in fact, I tried all four combinations -- NN, YN, NY, YY -- none of these
allowed the card to work in domU)


Can anyone walk me through hiding a device from dom0 and getting it to work
in domU, or point out the mistakes in what I tried above?

For now, I am successfully running the card in dom0 (after undo''ing the
hiding parameter in grub and rebooting).

Thank you!
  Brian


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Brian McEntire schrieb:
> Hello all,
[...]
> # modprobe wctdm
> Zapata Telephony Interface Registered on major 196
> ZT_CHANCONFIG failed on channel 1: No such device or address (6)
> FATAL: Error running install command for wctdm
> 
> lspci inside of domU does not work:
> 
> # lspci
> pcilib: Cannot open /sys/bus/pci/devices
> pcilib: Cannot open /proc/bus/pci
> lspci: Cannot find any working access method.
Have you tried usind a Dom0 kernel for the virtual machine? In my
opinion DomU kernels don''t support real hardware access.

Regards
Robin Schroeder


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Thanks for the tip. You were right, after hiding the PCI card from DOM0, I
was then able to start another Dom0 VM and lspci showed only the Digium PCI
card.

Unfortunately, even then, Asterisk core dumps when I try to start it. One of
the messages from the dump/oops (?) is "General Protection Fault".

I''ll probably give up trying to get Asterisk to run in a VM since it is
running okay in domain0. But if anyone has made this work (with Zaptel/wctdm
modules and the Digium TDM PCI card,) I''d love to hear about it.

Thanks!


On 11/28/05, Robin Schroeder <robin@tp4.ruhr-uni-bochum.de>
wrote:
>
> Brian McEntire schrieb:
> > Hello all,
> [...]
> > # modprobe wctdm
> > Zapata Telephony Interface Registered on major 196
> > ZT_CHANCONFIG failed on channel 1: No such device or address (6)
> > FATAL: Error running install command for wctdm
> >
> > lspci inside of domU does not work:
> >
> > # lspci
> > pcilib: Cannot open /sys/bus/pci/devices
> > pcilib: Cannot open /proc/bus/pci
> > lspci: Cannot find any working access method.
>
> Have you tried usind a Dom0 kernel for the virtual machine? In my
> opinion DomU kernels don''t support real hardware access.
>
> Regards
> Robin Schroeder
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users