Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 27 Jul 2023 10:54:51 +0200
From:   Stefano Garzarella <sgarzare@redhat.com>
To:     Arseniy Krasnov <avkrasnov@sberdevices.ru>
Cc:     Stefan Hajnoczi <stefanha@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Bobby Eshleman <bobby.eshleman@bytedance.com>,
        kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel@sberdevices.ru, oxffffaa@gmail.com
Subject: Re: [PATCH net-next v3 4/4] vsock/virtio: MSG_ZEROCOPY flag support
Message-ID: <p4v23nvilf45gl3snuyvypnhi3zfrmbi7qxtrdalluflt773sf@yt6tkgxiliar>
References: <20230720214245.457298-1-AVKrasnov@sberdevices.ru>
 <20230720214245.457298-5-AVKrasnov@sberdevices.ru>
 <091c067b-43a0-da7f-265f-30c8c7e62977@sberdevices.ru>
 <2k3cbz762ua3fmlben5vcm7rs624sktaltbz3ldeevwiguwk2w@klggxj5e3ueu>
 <51022d5f-5b50-b943-ad92-b06f60bef433@sberdevices.ru>
 <3d1d76c9-2fdb-3dfe-222a-b2184cf17708@sberdevices.ru>
 <o6axh6mxd6mxai2zrpax6wa25slns7ysz5xsegntskvfxl53mt@wowjgb3jazt6>
 <f020405e-86af-1b66-c5f4-9bec98298f44@sberdevices.ru>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <f020405e-86af-1b66-c5f4-9bec98298f44@sberdevices.ru>
Precedence: bulk

On Thu, Jul 27, 2023 at 11:32:00AM +0300, Arseniy Krasnov wrote:
>On 25.07.2023 15:28, Stefano Garzarella wrote:
>> On Tue, Jul 25, 2023 at 12:16:11PM +0300, Arseniy Krasnov wrote:
>>> On 25.07.2023 11:46, Arseniy Krasnov wrote:
>>>> On 25.07.2023 11:43, Stefano Garzarella wrote:
>>>>> On Fri, Jul 21, 2023 at 08:09:03AM +0300, Arseniy Krasnov wrote:

[...]

>>>>>>> +??? t = vsock_core_get_transport(info->vsk);
>>>>>>>
>>>>>>> -??????? if (msg_data_left(info->msg) == 0 &&
>>>>>>> -??????????? info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
>>>>>>> -??????????? hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
>>>>>>> +??? if (t->msgzerocopy_check_iov &&
>>>>>>> +??????? !t->msgzerocopy_check_iov(iov_iter))
>>>>>>> +??????? return false;
>>>>>
>>>>> I'd avoid adding a new transport callback used only internally in virtio
>>>>> transports.
>>>>
>>>> Ok, I see.
>>>>
>>>>>
>>>>> Usually the transport callbacks are used in af_vsock.c, if we need a
>>>>> callback just for virtio transports, maybe better to add it in struct
>>>>> virtio_vsock_pkt_info or struct virtio_vsock_sock.
>>>
>>> Hm, may be I just need to move this callback from 'struct vsock_transport' to parent 'struct virtio_transport',
>>> after 'send_pkt' callback. In this case:
>>> 1) AF_VSOCK part is not touched.
>>> 2) This callback stays in 'virtio_transport.c' and is set also in this file.
>>> ? vhost and loopback are unchanged - only 'send_pkt' still enabled in both
>>> ? files for these two transports.
>>
>> Yep, this could also work!
>>
>> Stefano
>
>Great! I'll send this implementation when this patchset for MSG_PEEK will be merged
>to net-next as both conflicts with each other.
>
>https://lore.kernel.org/netdev/20230726060150-mutt-send-email-mst@kernel.org/T/#m56f3b850361a412735616145162d2d9df25f6350

Ack!

Thanks,
Stefano