Re: 4.2 kernel 3.5 USB PCI Passthrough

["Pasi Kärkkäinen" <pasik@iki.fi>]

On Tue, Sep 25, 2012 at 09:09:57AM +0200, Andi Reinbrech wrote:
> Hi Xenners,
> 
> I have been using 4.2 for a very long time now, and recently (since
> upgrading to rc2), I've had some strange issues cropping up:
> 
> None of my disk images boot with xl create;  I have moved the
> important ones to LVM disks, since phy: boots fine.  I have hacked
> some of the xen code to make this work (but forgot which hack got it
> working, it has to do with the caching modes in the file open calls
> - I will double check and get back to the list).  My qemu disks are
> always reported as 0mb-sized volumes in the BIOS screen when this
> bug manifests itself.  Neither raw nor qcow2 images work.
>

I think there was fixes/changes to Xen qemu-dm caching modes
during the late 4.2-rc's. 
 
> When I upgraded to kernel 3.5, my USB PCI passthrough stopped
> working.  The secondary VGA passthrough still works fine, just the
> USB host controller that is passed through gets claimed by xen, but
> the guest cannot load drivers for the controller.  I.e. the guest
> (Windoze 7) sees it in device manager, but the device fails to
> activate.
> 

Any errors in dom0 dmesg or in xen dmesg? 

> Last night I upgraded to the latest 3.5.4 in the fc17 repo, and the
> USB issue was still there.  The weird thing though, is that it seems
> that my raw images magically started booting.  I still need to
> investigate this, in more detail to make sure I'm not mixing up
> versions and get conclusive results.
> 

Did you upgrade Xen to 4.2.0 final at the same time? 

> Apologies, this post is not too detailed and contains too many
> "maybes", but I though there may be a simple answer that someone
> else had stumbled across the same issues recently.
> 
> I will compile rc3 later on and run decent comparisons on both
> kernels, as well as raw and LVM machines.
> 

You probably should post a different thread for each problem..

-- Pasi