Problems with PCI passthrough

[marcotte%panix.com@localhost (Brian Marcotte)]

I've been trying to use PCI passthrough to give a domU an ethernet
card. The ethernet is an Intel 559 which I grabbed for the initial
testing.

        fxp0 at pci0 dev 1 function 0: i82559 Ethernet, rev 8

NetBSD/i386 does this no matter how much ram Xen is told to use:

        xpci0 at xenbus0 id 0: Xen PCI passthrough Interface
        pci0 at xpci0 bus 10
        fxp0 at pci0 dev 1 function 0: i82559 Ethernet, rev 8
        fxp0: interrupting at irq 18, event channel 8
        xen_alloc_contig: XENMEM_decrease_reservation failed!
        fxp0: unable to allocate control data, error = 12

NetBSD/amd64 works ONLY if I tell Xen to use only 3 GB of RAM. When
using all 8 GB in the machine, it still probes correctly, but doesn't
actually move any packets. The card and switch negotiate speed and
duplex properly.

This is NetBSD-current from May 30 and Xen 3.3.1.

My questions are:

        Should this work at all on a large memory machine? I can
        buy a newer ethernet card if that is the main problem.

        Can this be made to work with NetBSD/i386?

Thanks.

--
- Brian