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Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm"
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm" |
Date: |
Tue, 16 Jul 2013 12:31:46 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 |
Il 16/07/2013 12:19, Igor Mammedov ha scritto:
> On Tue, 16 Jul 2013 08:19:48 +0200
> Paolo Bonzini <address@hidden> wrote:
>
>> Il 16/07/2013 03:27, Hu Tao ha scritto:
>>>> I think it's the same. One "-numa mem" option = one "-device dimm"
>>>> option; both define one range. Unused memory ranges may remain if you
>>>> stumble upon a unusable range such as the PCI window. For example two
>>>> "-numa mem,size=2G" options would allocate memory from 0 to 2G and from
>>>> 4 to 6G.
>>>
>>> So we can drop -dimm if we agree on -numa mem?
>>
>> Yes, the point of the "-numa mem" proposal was to avoid the concept of a
>> "partially initialized device" that you had for DIMMs.
> I've though -numa mem was for mapping initial memory to numa nodes.
> It seem wrong to use it for representing dimm device and also limiting
> possible hotplugged regions to specified at startup ranges.
It's not for DIMM devices, it is for reserving areas of the address
space for hot-plugged RAM. DIMM hotplug is done with "device_add dimm"
(and you can also use "-numa mem,populated=no,... -device dimm,..." to
start a VM with hot-unpluggable memory).
> we can leave -numa for initial memory mapping and manage of the mapping
> of hotpluggable regions with -device dimm,node=X,size=Y.
>
> It that case command line -device dimm will provide a fully initialized
> dimm device usable at startup (but hot-unplugable) and
> (monitor) device_add dimm,,node=X,size=Y
> would serve hot-plug case.
>
> That way arbitrary sized dimm could be hot-pluged without specifying them
> at startup, like it's done on bare-metal.
But the memory ranges need to be specified at startup in the ACPI
tables, and that's what "-numa mem" is for.
> In addition command line -device would be used in migration case to describe
> already hot-plugged dimms on target.
Yep.
Paolo
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", (continued)
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Vasilis Liaskovitis, 2013/07/15
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Paolo Bonzini, 2013/07/15
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Vasilis Liaskovitis, 2013/07/15
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Hu Tao, 2013/07/15
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Paolo Bonzini, 2013/07/16
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Hu Tao, 2013/07/16
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Igor Mammedov, 2013/07/16
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Igor Mammedov, 2013/07/16
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm",
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Igor Mammedov, 2013/07/16
- Re: [Qemu-devel] [PATCH v5 05/14] vl: handle "-device dimm", Paolo Bonzini, 2013/07/16