On Mon, Sep 14, 2020 at 02:24:06PM +0000, Clint Sbisa wrote: > On Mon, Sep 14, 2020 at 11:17:26AM -0300, Jason Gunthorpe wrote: > > On Fri, Sep 11, 2020 at 09:42:25PM +0000, Clint Sbisa wrote: > > > > > There's no DMA involved with this BAR-- the driver writes a portion of the > > > packet contents in addition to the descriptors, which generally increases the > > > number of TLPs if write-combine isn't used. Furthermore, this BAR is only used > > > for writes and never for reads. > > > > You use DPDK without DMA? How does receive work? > > That was not worded well. DMA is used, but the first X bytes of the packet are > written directly to this BAR instead of being DMA'd-- the rest of the data is > DMA'd. which is back to my original question, how do you do DMA using /sys/xx/resources? Why not use VFIO like everything else? Jason
