Hello, I have already sent this email to qemu-discuss but I did not get a reply. https://lists.nongnu.org/archive/html/qemu-discuss/2023-09/msg00034.html Maybe someone here could help me and reply to this email or the one on qemu-discuss?
I would like to pass through PCI devices to Layer-2 VMs via Nested Virtualization. Is there current documentation for this topic somewhere? I used these parameters: -machine ...,kernel-irqchip=split -device intel-iommu With these parameters PCI pass through to L2-VMs worked fine. Now I come to the part where I get confused. https://wiki.qemu.org/Features/VT-d#With_Virtio_Devices Is this documentation relevant for PCI pass through? Do I need DMAR for virtio devices? And there is also the virtio-iommu device where I also could use the i440fx chipset. https://michael2012z.medium.com/virtio-iommu-789369049443 When adding "-device virtio-iommu-pci" pci pass through also works but I get "kvm: virtio_iommu_translate no mapping for 0x1002030f000 for sid=240" when starting qemu. What could that mean? What do these parameters "disable-legacy=on,disable-modern=off,iommu_platform=on,ats=on" actually do? When do I need them and on which virtio devices? And which device should I rather use: virtio-iommu or intel-iommu? Thanks in advance, Markus
