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Message-ID: <e7005e49-54fd-92c7-d6a5-7b69bccbc254@sberdevices.ru>
Date:   Mon, 22 May 2023 16:15:26 +0300
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Subject: Re: [RFC PATCH v3 04/17] vsock/virtio: non-linear skb handling for
 tap
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To:     Simon Horman <simon.horman@corigine.com>
CC:     Stefan Hajnoczi <stefanha@redhat.com>,
        Stefano Garzarella <sgarzare@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>
References: <20230522073950.3574171-1-AVKrasnov@sberdevices.ru>
 <20230522073950.3574171-5-AVKrasnov@sberdevices.ru>
 <ZGtqijZSCbAsS5D3@corigine.com>
From:   Arseniy Krasnov <avkrasnov@sberdevices.ru>
In-Reply-To: <ZGtqijZSCbAsS5D3@corigine.com>
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Precedence: bulk


On 22.05.2023 16:13, Simon Horman wrote:
> On Mon, May 22, 2023 at 10:39:37AM +0300, Arseniy Krasnov wrote:
>> For tap device new skb is created and data from the current skb is
>> copied to it. This adds copying data from non-linear skb to new
>> the skb.
>>
>> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
>> ---
>>  net/vmw_vsock/virtio_transport_common.c | 31 ++++++++++++++++++++++---
>>  1 file changed, 28 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>> index 16effa8d55d2..9854f48a0544 100644
>> --- a/net/vmw_vsock/virtio_transport_common.c
>> +++ b/net/vmw_vsock/virtio_transport_common.c
>> @@ -106,6 +106,27 @@ virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
>>  	return NULL;
>>  }
>>  
>> +static void virtio_transport_copy_nonlinear_skb(struct sk_buff *skb,
>> +						void *dst,
>> +						size_t len)
>> +{
>> +	struct iov_iter iov_iter = { 0 };
>> +	struct iovec iovec;
>> +	size_t to_copy;
>> +
>> +	iovec.iov_base = dst;
> 
> Hi Arseniy,
> 
> Sparse seems unhappy about this.
> Though, TBH, I'm unsure what should be done about it.
> 
> .../virtio_transport_common.c:117:24: warning: incorrect type in assignment (different address spaces)
> .../virtio_transport_common.c:117:24:    expected void [noderef] __user *iov_base
> .../virtio_transport_common.c:117:24:    got void *dst
> 
Got it, i'll check how to resolve this problem!

Thanks!
> 
> ...