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Message-ID: <1708509152.9501102-1-xuanzhuo@linux.alibaba.com>
Subject: Re: [PATCH net-next 1/2] xsk: Remove non-zero 'dma_page' check in xp_assign_dev
Date: Wed, 21 Feb 2024 17:52:32 +0800
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
To: Yunjian Wang <wangyunjian@huawei.com>
Cc: <netdev@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>,
 <kvm@vger.kernel.org>,
 <virtualization@lists.linux.dev>,
 <xudingke@huawei.com>,
 Yunjian Wang <wangyunjian@huawei.com>,
 <mst@redhat.com>,
 <willemdebruijn.kernel@gmail.com>,
 <jasowang@redhat.com>,
 <kuba@kernel.org>,
 <davem@davemloft.net>,
 <magnus.karlsson@intel.com>
References: <1706089058-1364-1-git-send-email-wangyunjian@huawei.com>
In-Reply-To: <1706089058-1364-1-git-send-email-wangyunjian@huawei.com>
Precedence: bulk

On Wed, 24 Jan 2024 17:37:38 +0800, Yunjian Wang <wangyunjian@huawei.com> 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?

Thanks.


>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
>  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
>
>