Re: PCI passthrough problem

["Phil (list)" <pbpublist@gmail.com>]

On Thu, 2015-10-01 at 08:32 -0400, Mauricio Tavares wrote:
> On Thu, Oct 1, 2015 at 3:27 AM, Phil (list) <pbpublist@gmail.com>
> wrote:
> > If this isn't the right place to ask, any pointers to the correct
> > place
> > are appreciated...
> > 
> > I'm trying to see if I can get PCI passthrough working for a video
> > capture card (Hauppauge Colossus 1x PCIe) under a Windows XP guest
> > (32
> > -bit).  Things appear to be somewhat working (Windows is seeing the
> > device, the drivers successfully installed, and device manager
> > indicates everything is working) however when I fire up the capture
> > application, it is not able to find the device despite Windows
> > recognizing it (no errors, it just doesn't 'see' any installed
> > capture
> > devices).  There is also a secondary capture/viewer application
> > that
> > won't even install due to not being able to find a capture card. 
> >  Since
> > that wasn't the behavior when running it natively under Windows,
> > I'm
> > assuming that the issue is related to PCI passthrough but it's
> > difficult to be certain since I'm not seeing any errors beyond the
> > capture applications not being able to find the device.
> > 
>       I think you need to find out if the problem follows the
> program,
> the card, or the passthrough thingie. For instance, is there any
> other
> program you can run to see if it sees the card? If you can't think of
> anything, you could run a, say, ubuntu/fedora livecd (start you vm
> client and tell it to boot from iso) and see if it can see and use
> the
> card.
> 

I only have the two capture apps that came with the card as I don't
really use Windows for much other than this card anymore.

To try to verify that everything is fine from a hardware / Windows
driver standpoint: I took a spare drive and performed a bare metal Win
XP install, installed the drivers, and then the capture software (i.e.
the same sequence and software versions as I used in the VM) and
everything works properly (i.e. both capture applications were able to
detect and use the capture card as expected).   Other than using a
different hard drive, all other system hardware was identical.  So that
would seem to rule out everything from the hardware through to the
Windows applications and leave it back in the realm of kvm/PCI
passthrough.

Unfortunately, no Linux drivers exist for this card (i.e. the reason
I'm attempting to use it under Windows in a VM) so any other Linux
distro would have about the same level of support in that it would
recognize that the PCI card exists but then not be able to do anything
with it.  If you're thinking that there is a problem with version of
kvm in Debian, I would be open to trying another distro if that would
help troubleshoot it.  I'm also reasonably comfortable navigating
around kvm, it's the PCI passthrough functionality that is new to me.

> > Some details on my setup: i7-2600 running on a Q77 motherboard with
> > VT
> > -d enabled in bios.  I'm running Debian Linux (testing) with qemu
> > -kvm
> > 1:2.4+dfsg-3 and am passing intel_iommu=on as a kernel parameter on
> > boot.  These are the main details I can think of to share, but if
> > there
> > is any additional info that would be useful, please let me know and
> > I'll be happy to provide it.
> > 
> > Having read through a few different posts around the 'net on how to
> > do
> > PCI passthrough (pretty much everything I've found was discussing
> > GPUs,
> > and almost always on a different distro), the only thing that jumps
> > out
> > as a potential problem is that the card in question does not appear
> > to
> > support FLR.  However, I'm not clear if that's an absolute
> > requirement
> > for PCI passthrough or something that is specific to GPU support?
> >  Beyond that, I'm at a loss as to what the issue could be...
> > 
> > Thanks,
> > Phil
> > --
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