Hello, i am trying to pass through a graphic card to a guest within a guest. So far i can see a text console within the target vm which says "radeon: ring 0 test failed", so it times out in radeon_vce_ring_test function. I am using qemu 2.8.50 at revision 0f6bcf68a99efdc531b209551f2b760b0bdcc554.
The relevant lowermost host arguments are: -machine pc-q35-2.8,accel=kvm,kernel-irqchip=split -device intel-iommu,intremap=on,eim=on If i dont set the x-vga flag for the passed through device in the lowermost host the VM within the VM does not reset(?) the device during shutdown and the screen freezes. If i do, the screen goes black and no signal is going to the screen anymore and i can restart the target VM without the whole machine freezing. (one has to set CONFIG_VFIO_PCI_VGA=y in the kernel of the first VM, or call pci_register_vga to get this) Also with irqchip=split the first vm cannot shutdown gracefully and crashes during shutdown. I also can see some IRTE vector and trigger mode inconsistencies, can they cause this? Or are there some quirks to be done to get this going? If anybody could lead me into the right direction or if there is work going on in this field i would be more than glad to help testing. Thank you in advance