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From: Jason Wang <jasowang@redhat.com>
Date: Fri, 8 Mar 2024 14:07:46 +0800
Message-ID: <CACGkMEtb941fJ481xtaGvjF10r_iq53FoTtmAr9jHwvqXssFrw@mail.gmail.com>
Subject: Re: [PATCH v4 0/5] vduse: Add support for reconnection
To: Cindy Lu <lulu@redhat.com>
Cc: mst@redhat.com, xieyongji@bytedance.com, linux-kernel@vger.kernel.org, 
	maxime.coquelin@redhat.com
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On Wed, Feb 7, 2024 at 1:47=E2=80=AFPM Cindy Lu <lulu@redhat.com> wrote:
>
> Here is the reconnect support in vduse,
>
> Kernel will allocate pages for reconnection.
> Userspace needs to use mmap to map the memory to userspace and use these =
pages to
> save the reconnect information.
>
> test passd in vduse+dpdk-testpmd
>
> change in V2
> 1. Address the comments from v1
> 2. Add the document for reconnect process
>
> change in V3
> 1. Move the vdpa_vq_state to the uAPI.  vduse will use this to synchroniz=
e the vq info between the kernel and userspace app.
> 2. Add a new ioctl VDUSE_DEV_GET_CONFIG. userspace app use this to get co=
nfig space
> 3. Rewrite the commit message.
> 4. Only save the address for the page address and remove the index.
> 5. remove the ioctl VDUSE_GET_RECONNECT_INFO, userspace app will use uAPI=
 VDUSE_RECONNCT_MMAP_SIZE to mmap
> 6. Rewrite the document for the reconnect process to make it clearer.
>
> change in v4
> 1. Change the number of map pages to VQ numbers. UserSpace APP can define=
 and maintain the structure for saving reconnection information in userspac=
e. The kernel will not maintain this information.

So this means the structure (e.g inflight descriptors) are application
specific, we can't do cross application reconnection?

Thanks

> 2. Rewrite the document for the reconnect process to make it clearer.
> 3. add the new ioctl for VDUSE_DEV_GET_CONFIG/VDUSE_DEV_GET_STATUS
>
> Cindy Lu (5):
>   vduse: Add new ioctl VDUSE_DEV_GET_CONFIG
>   vduse: Add new ioctl VDUSE_DEV_GET_STATUS
>   vduse: Add function to get/free the pages for reconnection
>   vduse: Add file operation for mmap
>   Documentation: Add reconnect process for VDUSE
>
>  Documentation/userspace-api/vduse.rst |  32 +++++++
>  drivers/vdpa/vdpa_user/vduse_dev.c    | 125 ++++++++++++++++++++++++++
>  include/uapi/linux/vduse.h            |   5 ++
>  3 files changed, 162 insertions(+)
>
> --
> 2.43.0
>