There are hundreds upon hundreds of these - it looks like it's walking a large memory space, doing reads and writes, and failing every time. The graphics card gives code 43, but the problem doesn't go away even if I entirely disable enlightenments. Removing the PCIe passthrough devices gets rid of the log entries.I'm not sure what changed, but today I get a libvirt qemu log full of these messages:Hello VFIO users!Yesterday I was able to boot a Windows VM successfully with OVMF and a passed-through graphics card.
"qemu-system-x86_64: vfio_region_write(0000:01:00.0:region1+0x240c14, 0xffffffff,4) failed: Device or resource busy"
My two passed PCI devices are a GTX 980TI GPU and its HDMI audio function. They are in their own IOMMU group with their own pci bridge. The CPU is an i5-6600k.I have verified that the devices are bound to the vfio-pci driver, although I don't seem to be able to entirely stop console output from appearing on the graphics card on boot (not even with my CSM-free UEFI set to use the integrated graphics instead). There's definitely nothing like X running, and the nvidia module is unloaded in the host OS.
# virsh --version
# uname -a
Linux host 4.4.5-1-ARCH #1 SMP PREEMPT Thu Mar 10 07:38:19 CET 2016 x86_64 GNU/Linux
Removing the passed-through device fixes the issue.
What would make the vfio_region_(read|write) calls return EBUSY? I figured I'd ask here before diving into the kernel sources :-/.