On 09/03/2017 13:11, Marcel Apfelbaum wrote: > On 03/09/2017 01:13 PM, Paolo Bonzini wrote: >> >> >> On 09/03/2017 00:59, Michael S. Tsirkin wrote: >>> Allow forcing a specific order of initialization on >>> devices created with -device. >>> Helpful e.g. for built-in devices such as IOMMUs which must >>> exist before all other devices. >>> >>> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> >>> --- >>> >>> Looks like we have a ton of problems because devices >>> are initialized in a random order, while we >>> really want e.g. iommu to be initialized >>> earlier than devices. >>> >>> This will be helpful for other things, e.g. >>> real hardware often is initialized in a specific order, >>> creating built-in devices for the board often >>> has to happen in a specific order, etc. >> >> In the specific case of PCI bus_master_as there is a simple workaround >> by placing a dummy container (which lets us build the AddressSpace) and >> then adding the alias region at machine_done time. >> >> This is exactly how MemoryListener is supposed to work, so I would start >> from there. >> > > Hi Paolo, > > This will certainly solve virtio-pci ordering issue, but I am not sure > it solves the vfio-pci problem. Here is a link to Alex's explanation: > > http://www.mail-archive.com/qemu-devel@nongnu.org/msg432365.html
Right, VFIO is more complicated (hence "in the specific case of PCI bus_master_as"). I answered in that thread. Paolo
