On Tue, Mar 12, 2024 at 10:10 AM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > Now, we pass multi parameters to find_vqs. These parameters > may work for transport or work for vring. > > And find_vqs has multi implements in many places: > > arch/um/drivers/virtio_uml.c > drivers/platform/mellanox/mlxbf-tmfifo.c > drivers/remoteproc/remoteproc_virtio.c > drivers/s390/virtio/virtio_ccw.c > drivers/virtio/virtio_mmio.c > drivers/virtio/virtio_pci_legacy.c > drivers/virtio/virtio_pci_modern.c > drivers/virtio/virtio_vdpa.c > > Every time, we try to add a new parameter, that is difficult. > We must change every find_vqs implement. > > One the other side, if we want to pass a parameter to vring, > we must change the call path from transport to vring. > Too many functions need to be changed. > > So it is time to refactor the find_vqs. We pass a structure > cfg to find_vqs(), that will be passed to vring by transport. > > Because the vp_modern_create_avq() use the "const char *names[]", > and the virtio_uml.c changes the name in the subsequent commit, so > change the "names" inside the virtio_vq_config from "const char *const > *names" to "const char **names". > > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > Acked-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> > Reviewed-by: Ilpo J=E4rvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> The name seems broken here. [...] > > typedef void vq_callback_t(struct virtqueue *); > > +/** > + * struct virtio_vq_config - configure for find_vqs() > + * @cfg_idx: Used by virtio core. The drivers should set this to 0. > + * During the initialization of each vq(vring setup), we need to know which > + * item in the array should be used at that time. But since the item in > + * names can be null, which causes some item of array to be skipped, we > + * cannot use vq.index as the current id. So add a cfg_idx to let vring > + * know how to get the current configuration from the array when > + * initializing vq. So this design is not good. If it is not something that the driver needs to care about, the core needs to hide it from the API. Thanks
