Comment 3 for bug 1471583

It does sound exactly like what I'm seeing.

From http://www.gossamer-threads.com/lists/linux/kernel/2054846

"Yes. If you *re*start the VM . ... The first start (after reboot) was not a problem."

It seems clear that this problem began with kernel 3.13. I tried applying the backports ath10k to kernel 3.10, but the kernel didn't recognize it, or install put it in the wrong place or something. So I tried kernel 4.1 and the module that comes with it fails this way. From the listserv I should have thought this would be fixed by kernel 4.1, but then maybe my device is so new and this has to be device-specific?

Thanks for your instructions Alex, but I don't fully understand. I searched for an options line I could put in /etc/modprobe.d/blacklist.conf to prevent PCI bus reset for the module, but couldn't find anything. The "Unknown header type" happens very early in the boot of the guest so I don't see how fixing the guest module would help.

Maybe you're saying that I must compile the backports module with some patch in the above link and add the line you suggest? Only thing is I don't understand why the module install failed. And I don't know whether the host should have the patched ath10k module as well as the guest. Does the host need the module at all of PCI passthrough?