[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Qemu-arm] VCPU hotplug on KVM/ARM
From: |
Marc Zyngier |
Subject: |
Re: [Qemu-devel] [Qemu-arm] VCPU hotplug on KVM/ARM |
Date: |
Wed, 7 Mar 2018 12:47:39 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 |
On 01/03/18 13:32, David Hildenbrand wrote:
> On 01.03.2018 11:05, Peter Maydell wrote:
>> On 1 March 2018 at 09:50, Igor Mammedov <address@hidden> wrote:
>>> In QEMU on x86 (and I think ppc, s390 as well), we create vCPUs on demand.>>
>>> It would be nice if ARM would be able to do that too,
>>> so that it could take advantage of the same code.
>>
>> It's not clear to me how that would work, given that for
>> instance the interrupt controller wants to know up-front
>> how many CPUs it has to deal with.
>>
>
> So how is cpu hotplug handled in HW? Or doesn't it even exist there?
I don't know of any physical system offering that facility.
> (we have max_cpus for the interrupt controller, but not sure if that is
> what we want)
We'd need something along those lines. Each CPU has a notional point to
point link to the interrupt controller (to the redistributor, to be
precise), and this entity must pre-exist.
Thanks,
M.
--
Jazz is not dead. It just smells funny...