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From:   "Jiang Wang ." <jiang.wang@bytedance.com>
Date:   Tue, 13 Apr 2021 15:32:57 -0700
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Subject: Re: [RFC] vsock: add multiple transports support for dgram
To:     Jorgen Hansen <jhansen@vmware.com>
Cc:     "virtualization@lists.linux-foundation.org" 
        <virtualization@lists.linux-foundation.org>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        "cong.wang@bytedance.com" <cong.wang@bytedance.com>,
        "duanxiongchun@bytedance.com" <duanxiongchun@bytedance.com>,
        "xieyongji@bytedance.com" <xieyongji@bytedance.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Stefano Garzarella <sgarzare@redhat.com>,
        Colin Ian King <colin.king@canonical.com>,
        Norbert Slusarek <nslusarek@gmx.net>,
        Andra Paraschiv <andraprs@amazon.com>,
        Alexander Popov <alex.popov@linux.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Tue, Apr 13, 2021 at 2:02 AM Jorgen Hansen <jhansen@vmware.com> wrote:
>
>
>
> > On 7 Apr 2021, at 20:25, Jiang Wang . <jiang.wang@bytedance.com> wrote:
> >
> > On Wed, Apr 7, 2021 at 2:51 AM Jorgen Hansen <jhansen@vmware.com> wrote=
:
> >>
> >>
> >>> On 6 Apr 2021, at 20:31, Jiang Wang <jiang.wang@bytedance.com> wrote:
> >>>
> >>> From: "jiang.wang" <jiang.wang@bytedance.com>
> >>>
> >>> Currently, only VMCI supports dgram sockets. To supported
> >>> nested VM use case, this patch removes transport_dgram and
> >>> uses transport_g2h and transport_h2g for dgram too.
> >>
> >> Could you provide some background for introducing this change - are yo=
u
> >> looking at introducing datagrams for a different transport? VMCI datag=
rams
> >> already support the nested use case,
> >
> > Yes, I am trying to introduce datagram for virtio transport. I wrote a
> > spec patch for
> > virtio dgram support and also a code patch, but the code patch is still=
 WIP.
>
> Oh ok. Cool. I must have missed the spec patch - could you provide a refe=
rence to
> it?

Sure. here is the link:
https://lists.linuxfoundation.org/pipermail/virtualization/2021-April/05354=
3.html

> > When I wrote this commit message, I was thinking nested VM is the same =
as
> > multiple transport support. But now, I realize they are different.
> > Nested VMs may use
> > the same virtualization layer(KVM on KVM), or different virtualization =
layers
> > (KVM on ESXi). Thanks for letting me know that VMCI already supported n=
ested
> > use cases. I think you mean VMCI on VMCI, right?
>
> Right, only VMCI on VMCI.

Got it. thanks.

> I=E2=80=99ll respond to Stefano=E2=80=99s email for the rest of the discu=
ssion.
>
> Thanks,
> Jorgen