Re: [Qemu-devel] [PATCH 0/4] Support more than 255 cpus

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2014-05-15 09:16, Li, ZhenHua wrote:
> Kernel's kvm support is not here.
> x2APIC is needed, I will try to do that later.

x2APIC emulation can wait if KVM support is there. But we need at least
one of them before starting to think about raising the limit.

Jan

PS: Please don't top-post.

> 
> On 05/13/2014 06:53 PM, Jan Kiszka wrote:
>> On 2014-05-13 09:09, Li, Zhen-Hua wrote:
>>> From: "Li, ZhenHua" <zhen-hual@hp.com>
>>>
>>> These series patches are trying to make Qemu support more than 255 CPUs.
>>> The max cpu number changed to 4096.
>>>
>>>   Support more than 255 cpus: ACPI and APIC defines
>>>   Support more than 255 cpus: max_cpus to 4096
>>>   Support more than 255 cpus: max cpumask bit to 4096
>>>   Support more than 255 cpus: runtime chec
>>>
>>>   include/hw/acpi/cpu_hotplug_defs.h | 4 ++--
>>>   include/hw/i386/apic_internal.h    | 2 +-
>>>   include/hw/i386/pc.h | 2 +-
>>>   include/sysemu/sysemu.h | 2 +-
>>>   hw/i386/acpi-build.c | 8 ++++----
>> Don't we need x2APIC support to provide >255 CPUs? Where so you enforce
>> this, i.e. keep the restriction to 255 CPUs when we are not in KVM mode
>> with in-kernel APIC (the emulate APIC lacks x2APIC mode, unfortunately)?
>> But, wait, KVM only supports up to 255 VCPUs. So what are you
>> targeting at?
>>
>> Jan
>>
> 

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