PCI device passthrough for FreeDOS guests

[Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>]

Hi,

I want to trace the PCI device accesses (config space, I/O ports, memory
BARs) of a DOS application (EEPROM flasher) and it seems KVM can help
with this.
The current plan is to install KVM, use FreeDOS as a guest, activate
passthrough for the PCI device I'm interested in and log the accesses
somehow.

Possible problems I'd have to solve:
- According to
http://www.linux-kvm.org/wiki/images/d/d0/KvmForum2008$kdf2008_14.pdf
PCI device passthrough needs a CPU with VT-d/IOMMU support.
- http://www.linux-kvm.org/page/TODO says passthrough won't work for
conventional PCI devices (I assume a PCI graphics card is such a device).
- http://www.linux-kvm.org/page/TODO says passthrough won't work for
devices without Function Level Reset (FLR).
- http://www.linux-kvm.org/page/TODO says VT support for real mode is
not good, so FreeDOS might be a problem.
- The KVM wiki does not mention how to get PCI passthrough working.
- No idea if logging of PCI accesses is possible with KVM or if I have
to use helper tools for that.

Any insights/hints are appreciated. If KVM is the wrong tool for my
task, please point me in the right direction.

Please CC me as I'm not subscribed to the list. Thanks.

Regards,
Carl-Daniel

P.S. The linux-kvm.org wiki returns zero results if you search the wiki
text for "PCI", but a Google search finds quite a few pages mentioning
PCI. Is there a bug in the seach function?