[ofa-general] Infiniband with Xen

[Roland Dreier]

 > I have tried to also to passthrough the pci bridge but It doesn't work, I got that with de dmesg on my Dom0 :
 > 
 >  1297.293367] pciback: vpci: 0000:04:00.0: assign to virtual slot 0     ( this is  HCA)
 > [ 1297.295538] pciback: vpci: 0000:03:07.1: assign to virtual slot 1    ( This is eth1)
 > [ 1297.298346] pciback: vpci: 0000:03:08.0: assign to virtual slot 2     ( this is the HCA bridge)
 > [ 1298.655743] pciback 0000:03:08.0: Driver tried to write to a read-only configuration space field at offset 0x3e, size 2. This may be harmless, but if you have problems with your device:
 > [ 1298.655747] 1) see permissive attribute in sysfs
 > [ 1298.655749] 2) report problems to the xen-devel mailing list along with details of your device obtained from lspci.

Yes, the driver does set the PCI bridge back up after resetting the HCA
(to restore all the configuration values that are lost during reset).
So you need to set up Xen so that the driver is allowed to restore the
HCA and PCI bridge config space.

Also it's not clear to me from these messages whether the HCA is put
into the domU PCI topology as being under the PCI bridge -- that is
probably required for the driver to work.

 - R.