[pve-devel] CPU and Memory hot add

Mon Feb 17 10:22:45 CET 2014

Am 17.02.2014 10:16, schrieb Alexandre DERUMIER:
>>> yeah I've already added them but when I try to add a dimm I always get adding memory 'hotplug' disabled 
> 
> Do you have also updated seabios ?

i could fix the "error" by using

-m 2048,slots=32,maxmem=64G

instead of

-m 2048,slots=32,maxmem=65536

seems it wants a XG value for maxmem.

Now adding memory and adding a new dimm device does not give an error
anymore but there's also nothing happending inside the guest.

I applied:
http://patchwork.ozlabs.org/patch/292614/

and have then done
make bios in the rom directory of qemu

Stefan

> 
> ----- Mail original ----- 
> 
> De: "Stefan Priebe - Profihost AG" <s.priebe at profihost.ag> 
> À: "Alexandre DERUMIER" <aderumier at odiso.com> 
> Cc: pve-devel at pve.proxmox.com 
> Envoyé: Lundi 17 Février 2014 06:44:02 
> Objet: Re: [pve-devel] CPU and Memory hot add 
> 
> 
> Am 17.02.2014 um 06:15 schrieb Alexandre DERUMIER <aderumier at odiso.com>: 
> 
>>>> No they don't ;-) here an output of a running vm adding more memory: 
>>
>> Could be interesting to see if they use acpi hotplug. 
>> If yes, they should have somewhere an udev rules for memory hotplug. (and cpu hotplug too) 
>>
>> something like:" 
>> " 
>> # Hotplug physical memory 
>> SUBSYSTEM=="memory", ACTION=="add", TEST=="state", ATTR{state}=="offline", \ 
>> ATTR{state}="online" 
>> " 
>>
>> maybe can you try to remove the udev rules, reboot, try to change memory size, and see if it's working or not 
> 
> Yes these rules exist and they use acpi hot plug. 
> 
>>
>> last qemu memory acpi hotplug v7 patches are here 
>> http://qemu.11.n7.nabble.com/PATCH-00-27-RFC-v7-ACPI-memory-hotplug-td234477.html 
>>
>> Don't known about the stability, but maybe can you try them ? 
> 
> Yeah I've already added them but when I try to add a dimm I always get adding memory 'hotplug' disabled 
> 
> But I don't know why. 
> 
> Stefan 
> 
>>
>> ----- Mail original ----- 
>>
>> De: "Stefan Priebe" <s.priebe at profihost.ag> 
>> À: "Alexandre DERUMIER" <aderumier at odiso.com> 
>> Cc: pve-devel at pve.proxmox.com 
>> Envoyé: Dimanche 16 Février 2014 21:55:47 
>> Objet: Re: [pve-devel] CPU and Memory hot add 
>>
>>
>> Am 15.02.2014 13:59, schrieb Alexandre DERUMIER: 
>>> cpu hot add is already implemented. (even in proxmox ;) 
>>> https://git.proxmox.com/?p=qemu-server.git;a=commit;h=838776ab650f0593b48c234070c1a189fdbd72c7 
>>>
>>> cpu hot del is not yet implemented. (but they are some prelimary patches in the qemu mailing list) 
>>>
>>> memory hotplug is not yet implemented. (should be ok for next qemu 2.0 release I think) 
>>>
>>> But maybe they are cheating, like I do : just use ballonning with a fixed size ? 
>>
>> No they don't ;-) here an output of a running vm adding more memory: 
>>
>> [ 356.984360] Hotplug Mem Device 
>> [ 356.985973] init_memory_mapping: 0000000040000000-0000000080000000 
>> [ 356.986070] 0040000000 - 0080000000 page 1G 
>> [ 356.988604] [ffffea0001000000-ffffea00011fffff] PMD -> 
>> [ffff88003ce00000-ffff88003cffffff] on node 0 
>> [ 356.997027] [ffffea0001200000-ffffea00013fffff] PMD -> 
>> [ffff88003c800000-ffff88003c9fffff] on node 0 
>> [ 356.998495] [ffffea0001400000-ffffea00015fffff] PMD -> 
>> [ffff88003c600000-ffff88003c7fffff] on node 0 
>> [ 357.000084] [ffffea0001600000-ffffea00017fffff] PMD -> 
>> [ffff88003b000000-ffff88003b1fffff] on node 0 
>> [ 357.001459] [ffffea0001800000-ffffea00019fffff] PMD -> 
>> [ffff880034c00000-ffff880034dfffff] on node 0 
>> [ 357.004401] [ffffea0001a00000-ffffea0001dfffff] PMD -> 
>> [ffff88003c000000-ffff88003c3fffff] on node 0 
>> [ 357.007038] Hotplug Mem Device 
>> [ 357.024941] Built 1 zonelists in Node order, mobility grouping on. 
>> Total pages: 273785 
>> [ 357.024941] Policy zone: Normal 
>> [ 357.038623] init_memory_mapping: 0000000080000000-00000000c0000000 
>> [ 357.038636] 0080000000 - 00c0000000 page 1G 
>> [ 357.038782] [ffffea0001e00000-ffffea0001ffffff] PMD -> 
>> [ffff88003b400000-ffff88003b5fffff] on node 0 
>> [ 357.040088] [ffffea0002000000-ffffea00021fffff] PMD -> 
>> [ffff880047e00000-ffff880047ffffff] on node 0 
>> [ 357.040756] [ffffea0002200000-ffffea00025fffff] PMD -> 
>> [ffff88007fc00000-ffff88007fffffff] on node 0 
>> [ 357.044036] [ffffea0002600000-ffffea00029fffff] PMD -> 
>> [ffff88007f800000-ffff88007fbfffff] on node 0 
>> [ 357.062995] [ffffea0002a00000-ffffea0002dfffff] PMD -> 
>> [ffff88007f400000-ffff88007f7fffff] on node 0 
>> [ 357.072594] Hotplug Mem Device 
>> [ 357.119388] init_memory_mapping: 0000000100000000-0000000140000000 
>> [ 357.119388] 0100000000 - 0140000000 page 1G 
>> [ 357.121941] [ffffea0002e00000-ffffea00041fffff] PMD -> 
>> [ffff88007f000000-ffff88007f3fffff] on node 0 
>> [ 357.125199] [ffffea0004200000-ffffea00045fffff] PMD -> 
>> [ffff880087800000-ffff880087bfffff] on node 0 
>> [ 357.128890] [ffffea0004600000-ffffea00049fffff] PMD -> 
>> [ffff880087400000-ffff8800877fffff] on node 0 
>> [ 357.132014] [ffffea0004a00000-ffffea0004dfffff] PMD -> 
>> [ffff880087000000-ffff8800873fffff] on node 0 
>> [ 357.135378] Hotplug Mem Device 
>> [ 357.170010] init_memory_mapping: 0000000140000000-0000000180000000 
>> [ 357.170010] 0140000000 - 0180000000 page 1G 
>> [ 357.170174] [ffffea0004e00000-ffffea00051fffff] PMD -> 
>> [ffff880086c00000-ffff880086ffffff] on node 0 
>> [ 357.172473] [ffffea0005200000-ffffea00055fffff] PMD -> 
>> [ffff880127c00000-ffff880127ffffff] on node 0 
>> [ 357.175795] [ffffea0005600000-ffffea00059fffff] PMD -> 
>> [ffff880127800000-ffff880127bfffff] on node 0 
>> [ 357.180010] [ffffea0005a00000-ffffea0005dfffff] PMD -> 
>> [ffff880127400000-ffff8801277fffff] on node 0 
>> [ 357.195142] Hotplug Mem Device 
>> [ 357.195409] init_memory_mapping: 0000000180000000-00000001c0000000 
>> [ 357.195409] 0180000000 - 01c0000000 page 1G 
>> [ 357.197770] [ffffea0005e00000-ffffea00061fffff] PMD -> 
>> [ffff880127000000-ffff8801273fffff] on node 0 
>> [ 357.199525] [ffffea0006200000-ffffea00063fffff] PMD -> 
>> [ffff880137e00000-ffff880137ffffff] on node 0 
>> [ 357.202982] [ffffea0006400000-ffffea00067fffff] PMD -> 
>> [ffff880137800000-ffff880137bfffff] on node 0 
>> [ 357.206225] [ffffea0006800000-ffffea0006bfffff] PMD -> 
>> [ffff880137400000-ffff8801377fffff] on node 0 
>> [ 357.210314] Hotplug Mem Device 
>> [ 357.280089] init_memory_mapping: 00000001c0000000-0000000200000000 
>> [ 357.280089] 01c0000000 - 0200000000 page 1G 
>> [ 357.280295] [ffffea0006c00000-ffffea0006ffffff] PMD -> 
>> [ffff880137000000-ffff8801373fffff] on node 0 
>> [ 357.280898] [ffffea0007000000-ffffea00073fffff] PMD -> 
>> [ffff8801b7c00000-ffff8801b7ffffff] on node 0 
>> [ 357.284138] [ffffea0007400000-ffffea00077fffff] PMD -> 
>> [ffff8801b7800000-ffff8801b7bfffff] on node 0 
>> [ 357.290084] [ffffea0007800000-ffffea0007bfffff] PMD -> 
>> [ffff8801b7400000-ffff8801b77fffff] on node 0 
>>
>> Stefan 
>>
>>>
>>> ----- Mail original ----- 
>>>
>>> De: "Stefan Priebe" <s.priebe at profihost.ag> 
>>> À: pve-devel at pve.proxmox.com 
>>> Envoyé: Vendredi 14 Février 2014 21:18:47 
>>> Objet: [pve-devel] CPU and Memory hot add 
>>>
>>> Hi, 
>>>
>>> while browsing the web, i found profitbricks, which is active in germany 
>>> and the us (http://www.profitbricks.com/technical-info). 
>>>
>>> They use KVM and offer memory and cpu hot add on the fly? Anybody an 
>>> idea how this works if kvm does not already support it? 
>>>
>>> Greets, 
>>> Stefan 
>>> _______________________________________________ 
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>>>