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From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <829cb5f6-de68-9e56-106f-7311ea00e4c2@redhat.com>
Date: Mon, 5 Feb 2018 17:53:43 +0100
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Subject: Re: [Qemu-devel] [RFC] exec: eliminate ram naming issue as migration
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To: "Tan, Jianfeng" <jianfeng.tan@intel.com>, qemu-devel@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>, "Michael S . Tsirkin" <mst@redhat.com>, Maxime Coquelin <maxime.coquelin@redhat.com>

On 05/02/2018 17:44, Tan, Jianfeng wrote:
>>>
>> I understand.=C2=A0 However it's not as bad as "there's no possibility=
 at all
>> to migrate from vhost-kernel to vhost-user".=C2=A0 There are cases tha=
t are
>> more problematic: for example, there's no possibility at all to add
>> memory NUMA policy during a live migration, unless -object
>> memory-backend-* was used on the source.
>=20
> Please help me to understand: Are you saying it's always recommended to
> use -object memory-backend-* configuration even with vhost-kernel
> backend for the reason you mentioned?

Indeed---in general, there's no downside to always using -object to
start a virtual machine.  Of course when migrating a machine that was
started without -object, you need to use it on the destination too.

Paolo