I've been having trouble getting virtio (in legacy mode) working with the multi-process model. The latest issue is as follows:
- The primary process calls vtpci_init() with a struct rte_pci_device that's only valid in that process - For legacy mode vtpci_init() calls rte_eal_pci_ioport() with that pci device and a the struct rte_pci_ioport that's in shared memory - The secondary processes will of course not call vtpci_init() - When a secondary process tries to notify the vqueue in either the the RX or TX path, it will do so via the shared memory ioport. - When rte_eal_pci_ioport_write() tries to dispatch the ioport to the right place, it'll need to access the PCI device. But that's a garbage pointer in the context of this process. (Usually it's still pointing to some allocated memory, so you don't even get a segfault but the ioport write is just silently aborted). - This causes the queues to stall, unless the primary process happens to notify them as well for some reason. Is there a clean solution? My current workaround is to allocate rte_pci_device structs in shared memory rather than the heap. (Though all processes still have their own copy). But that requires rearranging the initialization order in rte_eal_init() to delay the PCI init, and I'm guessing there's a good reason for the current order. -- Juho Snellman
