+Cc more people to start a discussion about a potential DMA API. If you think it is interesting, we can start a fresh discussion thread.
07/04/2021 10:26, Thomas Monjalon: > 07/04/2021 09:47, Maxime Coquelin: > > > > On 3/17/21 6:40 AM, Cheng Jiang wrote: > > > We use ioat ring space for determining if ioat callbacks can enqueue a > > > packet to ioat device. But there is one slot can't be used in ioat > > > ring due to the ioat driver design, so we need to reduce one slot in > > > ioat ring to prevent ring size mismatch in ioat callbacks. [...] > > > --- a/examples/vhost/ioat.c > > > +++ b/examples/vhost/ioat.c > > > @@ -113,7 +113,7 @@ open_ioat(const char *value) > > > goto out; > > > } > > > rte_rawdev_start(dev_id); > > > - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; > > > + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; > > > > That really comforts me in thinking we need a generic abstraction for > > DMA devices. How is the application developer supposed to know that > > the DMA driver has such weird limitations? > > Having a generic DMA API may be interesting. > Do you know any other HW candidate for such an API? > Do you think rte_memcpy can be used as a SW driver?
