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

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

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

readlink //sys/bus/pci/devices/0000:04:00.0/driver
../../../../bus/pci/drivers/pciback

I want you to do for 02:00.0 and see if it points to pciback before you
launch any guests. 
> 
> > > 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      <--------------------

Pfff.. sucks.
>  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
> 

.. snip..
> 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 ...
> 
Yup.
> 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

It eliminates the possiblity of the sky2 driver having ownership of
the 02:00.0. It should be assigned to the pciback driver when you launch
your guest.

> to indicate that i'm set up correctly.

I want to eliminate the possiblity of the 02:00.0 being owned by somebody
else. If it is owned by pciback, then yes it looks as if there is a bug
in either the xm tools or the pciback driver when it comes to seizing
the BDF that have the same PCI vendor:model