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From: Peter Xu <peterx@redhat.com>
To: Thibaut Collet <thibaut.collet@6wind.com>
Cc: dev@dpdk.org, Victor Kaplansky <victork@redhat.com>
Subject: Re: [dpdk-dev] [PATCH 0/4 for 2.3] vhost-user live migration support
Date: Wed, 16 Dec 2015 10:38:03 +0800	[thread overview]
Message-ID: <20151216023803.GB20951@pxdev.xzpeter.org> (raw)
In-Reply-To: <CABUUfwPQwv4SzYynAhkKyPPpr7CGeez5L+M3aGshSR6-M6wQiQ@mail.gmail.com>

On Tue, Dec 15, 2015 at 04:07:57PM +0100, Thibaut Collet wrote:
> After a migration, to avoid netwotk outage, all interfaces of the guest
> must send a packet to update switches mapping (ideally a GARP).
> As some interfaces do not do it QEMU does it in behalf of the guest by
> sending a RARP (his RARP is not forged by the guest but by QEMU). This is
> the qemu_self_announce purpose that "spoofs" a RARP to all backend of guest
> ethernet interfaces. For vhost-user backend, QEMU can not do it directly
> and asks to the vhost-user backend to do it with the VHOST_USER_SEND_RARP
> request that contains the MAC address of the guest interface.
> 
> Thibaut.

Hi, Thibaut,

Thanks for the explaination.

Two more questions:

1. if vhost-user backend (or say, DPDK) supports GUEST_ANNOUNCE, and
   send another RARP (or say, GARP, I will use RARP as example),
   then there will be two RARP later on the line, right? (since the
   QEMU one is sent unconditionally from qemu_announce_self).

2. if the only thing vhost-user backend is to send another same RARP
   when got SEND_RARP request, why would it bother if QEMU will
   unconditionally send one? (or say, I still do not know why we
   need this SEND_RARP request, if the vhost-user backend is going
   to do the same thing again as QEMU already does)

Thanks in advance.
Peter

  parent reply	other threads:[~2015-12-16  2:38 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-11  8:26 Pavel Fedin
2015-12-11  9:49 ` Yuanhan Liu
2015-12-11 10:22   ` Pavel Fedin
2015-12-14  3:58     ` Peter Xu
2015-12-14  7:30       ` Pavel Fedin
2015-12-14  9:04         ` Peter Xu
2015-12-14  9:46           ` Pavel Fedin
2015-12-14 10:09             ` Peter Xu
2015-12-14 12:09             ` Yuanhan Liu
2015-12-14 13:00               ` Peter Xu
2015-12-14 13:21                 ` Yuanhan Liu
2015-12-14 13:28                   ` Peter Xu
2015-12-14 13:51                     ` Yuanhan Liu
2015-12-14 14:54                   ` Pavel Fedin
2015-12-15  8:23       ` Yuanhan Liu
2015-12-15  8:45         ` Pavel Fedin
2015-12-15  8:56           ` Yuanhan Liu
2015-12-15  9:04             ` Pavel Fedin
2015-12-15 10:05           ` Peter Xu
2015-12-15 11:43             ` Thibaut Collet
2015-12-15 11:47               ` Thibaut Collet
2015-12-15 12:24                 ` Pavel Fedin
2015-12-15 13:36                   ` Yuanhan Liu
2015-12-15 13:48                     ` Pavel Fedin
2015-12-15 13:59                       ` Yuanhan Liu
2015-12-15 14:58                         ` Pavel Fedin
2015-12-16  7:28                           ` Yuanhan Liu
2015-12-16 11:57                             ` Pavel Fedin
2015-12-16 12:08                               ` Yuanhan Liu
2015-12-16 12:43                                 ` Pavel Fedin
2015-12-16 13:00                                   ` Yuanhan Liu
2015-12-15 13:18                 ` Yuanhan Liu
2015-12-15 15:07                   ` Thibaut Collet
2015-12-15 15:36                     ` Pavel Fedin
2015-12-16  2:38                     ` Peter Xu [this message]
2015-12-16  2:50                       ` Yuanhan Liu
2015-12-16  7:05                       ` Pavel Fedin
2015-12-15  9:42         ` Peter Xu
  -- strict thread matches above, loose matches on Subject: below --
2015-12-02  3:43 Yuanhan Liu
2015-12-02 14:10 ` Victor Kaplansky
2015-12-02 14:33   ` Yuanhan Liu
2015-12-09  3:41 ` Xie, Huawei

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