Received-SPF: pass (google.com: domain of linux-kernel+bounces-96578-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Precedence: bulk
MIME-Version: 1.0
References: <20240207054701.616094-1-lulu@redhat.com> <CACGkMEtb941fJ481xtaGvjF10r_iq53FoTtmAr9jHwvqXssFrw@mail.gmail.com>
In-Reply-To: <CACGkMEtb941fJ481xtaGvjF10r_iq53FoTtmAr9jHwvqXssFrw@mail.gmail.com>
From: Cindy Lu <lulu@redhat.com>
Date: Fri, 8 Mar 2024 15:26:22 +0800
Message-ID: <CACLfguWGWPMdvXgFd0bnpW_Ej0JrhGQULpPrp4grixnb9NtH9A@mail.gmail.com>
Subject: Re: [PATCH v4 0/5] vduse: Add support for reconnection
To: Jason Wang <jasowang@redhat.com>
Cc: mst@redhat.com, xieyongji@bytedance.com, linux-kernel@vger.kernel.org, 
	maxime.coquelin@redhat.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Fri, Mar 8, 2024 at 2:08=E2=80=AFPM Jason Wang <jasowang@redhat.com> wro=
te:
>
> 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 thes=
e 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 synchron=
ize the vq info between the kernel and userspace app.
> > 2. Add a new ioctl VDUSE_DEV_GET_CONFIG. userspace app use this to get =
config 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 uA=
PI 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 defi=
ne and maintain the structure for saving reconnection information in usersp=
ace. 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
>
yes, this is also defined by the application itself. so maybe we can't
support the
cross-application reconnection
thanks
cindy
> > 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
> >
>