PCI pass through vs. slot

PCI pass through vs. slot

[ron minnich]

I am a bit confused on the PCI stuff.

PASSTHRU-- does this mean that pcifront is not needed? Or only that
the PCI is not limited as it is with slot.

In general, none of the docs are getting me anywhere with xen 3.0.3.
Example: I run this:
  echo -n 0000:2:0.1>/sys/bus/pci/drivers/pciback/new_slot
  echo -n 0000:2:0.0>/sys/bus/pci/drivers/pciback/new_slot
  echo -n bind 0000:2:0.0 > /sys/bus/pci/drivers/pciback/bind
  echo -n bind 0000:2:0.1 > /sys/bus/pci/drivers/pciback/bind


It fails in one of two ways. If there is a driver present for that
device, the driver symlink has a value, and it seems that it can not
be changed to "pciback".

if there is no driver present, there is no driver symlink, and xen
seems not be be able to set it. So the domain can not be started.

Any good writeups on PCI passthrough? I need Plan 9 to have raw access
toa device.

ron

Re: PCI pass through vs. slot

[Keir Fraser]

On 5/12/06 6:41 pm, "ron minnich" <rminnich@gmail.com> wrote:

> I am a bit confused on the PCI stuff.
> 
> PASSTHRU-- does this mean that pcifront is not needed? Or only that
> the PCI is not limited as it is with slot.

No, it means that the device address (bus,slot,fn) is 'passed through'
unmodified to pcifront, with no remapping. You still need pcifront!

 -- Keir