Re: how to PCI-passthrough 1 card to a DomU when another @ Dom0 uses the same driver?

["dev001" <pgngw+dev001+xen-users@f-m.fm>]

hi,

On Wed, 02 Feb 2011 15:27 -0500, "Konrad Rzeszutek Wilk"
<konrad.wilk@oracle.com> wrote:
> > cat /etc/init.d/boot.local
> >         modprobe pciback hide='(02:00.0)(03.00.0)'
> 
> Hmm, the 03.00 is incorrect. Should be 03:00.0

good catch!  yes, a typo.  and it'd been corrected.  no change in
observed behavior, tho.

> So if you look in /sys/pci .. something for 02:00.0 is there any driver
> that is using it? Or is it attached ot pciback?

i'm honestly not sure what to check, here.   what, specifically, am i
looking for?

> > i suspect this has to do with the driver not being unloadable at the
> > time of device seizure, as it's in use.
> 
> Well, the pciback.hide=(..) during bootup should have taken care of that.
> 
> Oh, unless the pciback is a _module_ at which point it would not do it.

on opensuse, iiuc it is a module

grep CONFIG_XEN_PCIDEV_BACKEND /boot/config-2.6.34.8-7-xen 
 CONFIG_XEN_PCIDEV_BACKEND=m      <--------------------
 CONFIG_XEN_PCIDEV_BACKEND_VPCI=y
 # CONFIG_XEN_PCIDEV_BACKEND_PASS is not set
 # CONFIG_XEN_PCIDEV_BACKEND_SLOT is not set
 # CONFIG_XEN_PCIDEV_BACKEND_CONTROLLER is not set

> Did you follow the rules for doing it detailed in the VT-d howto? Just
> use the pciback instead of pci-stub in it.

i'm a bit confused.  on VT-d howto, it says,

Binding Devices to pciback

  In order to pass-through devices using VT-d then need to be bound to
  pciback to ensure that they are not bound to another dom0 driver and
  this free for use by pass-through. It is possible to view this as
  hiding the device from Dom0.

...
Binding at Run-Time

As discussed in Assign_hardware_to_DomU_with_PCIBack_as_module, it is
possible to bind a device to pciback after dom0 has booted, even if it
has been bound to another device in the mean time. This method can be
used both when pciback is statically compiled into the dom0 kernel and
when it has been compiled as a module.

Binding at Module Insertion Time

As also discussed in Assign_hardware_to_DomU_with_PCIBack_as_module, it
is possible to bind a device to pciback at the time that the pciback
module is inserted. This technique is only useful if pciback has been
compiled as a module. 

and, since it's compiled as a module, at

  http://wiki.xensource.com/xenwiki/Assign_hardware_to_DomU_with_PCIBack_as_module

i "followed the rules" for method 2 ...

is that not correct?

> What happens if you 'rmmod sky2' or blacklist the sky2 driver?

perhaps i'm being thick -- what's that tell us?  i've already shown that
replacing the 'first' r8169-based card with something else allows BOTH
to-be-passed-thru pci-cards to be seized correctly.  which seems to me
to indicate that i'm set up correctly.

or no?