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Date:   Mon, 17 Apr 2023 11:56:10 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc:     Christoph Hellwig <hch@infradead.org>, netdev@vger.kernel.org,
        =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>,
        Magnus Karlsson <magnus.karlsson@intel.com>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        Jonathan Lemon <jonathan.lemon@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>, bpf@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        Jason Wang <jasowang@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Gerd Hoffmann <kraxel@redhat.com>
Subject: Re: [PATCH net-next] xsk: introduce xsk_dma_ops
Message-ID: <20230417115610.7763a87c@kernel.org>
In-Reply-To: <1681711081.378984-2-xuanzhuo@linux.alibaba.com>
References: <20230417032750.7086-1-xuanzhuo@linux.alibaba.com>
        <ZDzKAD2SNe1q/XA6@infradead.org>
        <1681711081.378984-2-xuanzhuo@linux.alibaba.com>
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On Mon, 17 Apr 2023 13:58:01 +0800 Xuan Zhuo wrote:
> On Sun, 16 Apr 2023 21:24:32 -0700, Christoph Hellwig <hch@infradead.org> wrote:
> > On Mon, Apr 17, 2023 at 11:27:50AM +0800, Xuan Zhuo wrote:  
> > > The purpose of this patch is to allow driver pass the own dma_ops to
> > > xsk.  
> >
> > Drivers have no business passing around dma_ops, or even knowing about
> > them.  
> 
> May misunderstand, here the "dma_ops" is not the "dma_ops" of DMA API.
> 
> I mean the callbacks for xsk to do dma.
> 
> Maybe, I should rename it in the next version.

Would you mind explaining this a bit more to folks like me who are not
familiar with VirtIO?  DMA API is supposed to hide the DMA mapping
details from the stack, why is it not sufficient here.