> -----Original Message----- > From: Xuan Zhuo [mailto:xuanzhuo@xxxxxxxxxxxxxxxxx] > Sent: Wednesday, February 21, 2024 5:53 PM > To: wangyunjian <wangyunjian@xxxxxxxxxx> > Cc: netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxxx; xudingke > <xudingke@xxxxxxxxxx>; wangyunjian <wangyunjian@xxxxxxxxxx>; > mst@xxxxxxxxxx; willemdebruijn.kernel@xxxxxxxxx; jasowang@xxxxxxxxxx; > kuba@xxxxxxxxxx; davem@xxxxxxxxxxxxx; magnus.karlsson@xxxxxxxxx > Subject: Re: [PATCH net-next 1/2] xsk: Remove non-zero 'dma_page' check in > xp_assign_dev > > On Wed, 24 Jan 2024 17:37:38 +0800, Yunjian Wang > <wangyunjian@xxxxxxxxxx> wrote: > > Now dma mappings are used by the physical NICs. However the vNIC maybe > > do not need them. So remove non-zero 'dma_page' check in > > xp_assign_dev. > > Could you tell me which one nic can work with AF_XDP without DMA? TUN will support AF_XDP Tx zero-copy, which does not require DMA mappings. Thanks > > Thanks. > > > > > > Signed-off-by: Yunjian Wang <wangyunjian@xxxxxxxxxx> > > --- > > net/xdp/xsk_buff_pool.c | 7 ------- > > 1 file changed, 7 deletions(-) > > > > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index > > 28711cc44ced..939b6e7b59ff 100644 > > --- a/net/xdp/xsk_buff_pool.c > > +++ b/net/xdp/xsk_buff_pool.c > > @@ -219,16 +219,9 @@ int xp_assign_dev(struct xsk_buff_pool *pool, > > if (err) > > goto err_unreg_pool; > > > > - if (!pool->dma_pages) { > > - WARN(1, "Driver did not DMA map zero-copy buffers"); > > - err = -EINVAL; > > - goto err_unreg_xsk; > > - } > > pool->umem->zc = true; > > return 0; > > > > -err_unreg_xsk: > > - xp_disable_drv_zc(pool); > > err_unreg_pool: > > if (!force_zc) > > err = 0; /* fallback to copy mode */ > > -- > > 2.33.0 > > > >
