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Subject: Re: [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace
To:     Yongji Xie <elohimes@gmail.com>,
        Liu Xiaodong <xiaodong.liu@intel.com>
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From:   Jason Wang <jasowang@redhat.com>
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Date:   Tue, 29 Jun 2021 12:12:57 +0800
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在 2021/6/28 下午6:32, Yongji Xie 写道:
>> The large barrier is bounce-buffer mapping: SPDK requires hugepages
>> for NVMe over PCIe and RDMA, so take some preallcoated hugepages to
>> map as bounce buffer is necessary. Or it's hard to avoid an extra
>> memcpy from bounce-buffer to hugepage.
>> If you can add an option to map hugepages as bounce-buffer,
>> then SPDK could also be a potential user of vduse.
>>
> I think we can support registering user space memory for bounce-buffer
> use like XDP does. But this needs to pin the pages, so I didn't
> consider it in this initial version.
>

Note that userspace should be unaware of the existence of the bounce buffer.

So we need to think carefully of mmap() vs umem registering.

Thanks