Re: multi-core VMM

G.R.
Wed, 09 Jan 2013 09:04:39 -0000

Well, I can''t agree.
HW provide features and SW use it. Otherwise, HW feature is just a vain.

PS: please keep the list CCed so that people are aware of the
discussion. Probably they have something to share on this topic.

On Wed, Jan 9, 2013 at 1:37 PM, ZHANG Zhi <zhizhang@smu.edu.sg>
wrote:
> I think it''s the hardware''s business, namely the Intel or
AMD, not the hyperviosr''s business. Xen does not have to consider such
an issue.
>
> Re:
> I think that''s possible, you can check the cpupool related command
in the xl manpage.
>
> But I have a similar question -- In CPU like i7, 8 logical cores are not
fully equivalent.
> They are hyper-threading over CMP. The two HT cores from a single physical
core are contending for pipeline resource. In linux kernel, there is specific
scheduler optimization for this case.
> My question is that how XEN hypervisor handle this? Will such HT info be
available to the VM?
> I guess there may be some different depend on whether you bind VCPU to host
core or not.
>
> Also, is there any different for dom0 && domU in this aspect?
>
> Thanks,
> Timothy
>
> On Wed, Dec 19, 2012 at 2:20 PM, ZHANG Zhi <zhizhang@smu.edu.sg>
wrote:
>> Hi, list,
>>
>> A VMM provides a VMCS for each VM. How does the VMM assign system
>> resources for each VM? For example, in a multi-core environment, how
>> can I enable the VMM to run, say, on a two-core intel''s
processor
>> while I am able to force a VM to execute only on a specific core upon
>> initializing the Guest OS ? that is to say, how I can assure the VM to
>> believe that there is only one physical core running on this machine?
>>
>> What should I do? Is it possible to assign a core when VMM starts a
>> new VM after the VMM is booted ?
>>
>>    Thanks a lot!
>>
>>
>>
>>
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>>