From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: KVM_MAX_VCPUS
Date: Wed, 17 Oct 2012 09:21:41 +0200
Message-ID: <20121017072141.GA7343@redhat.com>
References: <5079EB5B.8080102@hp.com>
 <507A242D.9070708@gmail.com>
 <20121014090825.GM16648@redhat.com>
 <507AC162.9040609@hp.com>
 <641B6FBA78EBA54CAA529D8D0E4DF811073642E0@G1W3650.americas.hpqcorp.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: "Vinod, Chegu" <chegu_vinod@hp.com>,
	Sasha Levin <levinsasha928@gmail.com>,
	KVM <kvm@vger.kernel.org>
To: "Wei, Bing (WeiBing, MCXS-SH)" <bing.wei@hp.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:60927 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751546Ab2JQHVo (ORCPT <rfc822;kvm@vger.kernel.org>);
	Wed, 17 Oct 2012 03:21:44 -0400
Content-Disposition: inline
In-Reply-To: <641B6FBA78EBA54CAA529D8D0E4DF811073642E0@G1W3650.americas.hpqcorp.net>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Wed, Oct 17, 2012 at 02:57:15AM +0000, Wei, Bing (WeiBing, MCXS-SH) wrote:
> For pCPU/core and VCPUS/logical cpu mapping, It should be 8 multiple. 254 is reasonable. Or something I miss?
> 
I am not sure what do you mean. Can you clarify?

> -----Original Message-----
> From: kvm-owner@vger.kernel.org [mailto:kvm-owner@vger.kernel.org] On Behalf Of Vinod, Chegu
> Sent: Sunday, October 14, 2012 9:43 PM
> To: Gleb Natapov
> Cc: Sasha Levin; KVM
> Subject: Re: KVM_MAX_VCPUS
> 
> On 10/14/2012 2:08 AM, Gleb Natapov wrote:
> > On Sat, Oct 13, 2012 at 10:32:13PM -0400, Sasha Levin wrote:
> >> On 10/13/2012 06:29 PM, Chegu Vinod wrote:
> >>> Hello,
> >>>
> >>> Wanted to get a clarification about KVM_MAX_VCPUS(currently set to 254)
> >>>   in kvm_host.h file. The kvm_vcpu *vcpus array is sized based on KVM_MAX_VCPUS.
> >>> (i.e. a max of 254 elements in the array).
> >>>   
> >>> An 8bit APIC id should allow for 256 ID's. Reserving one for Broadcast should
> >>> leave 255 ID's.  Is there one more ID reserved for some other purpose ? (hence
> >>> leading to KVM_MAX_VCPUS being set to 254 and not 255).
> >> Another ID goes to the IO-APIC.
> >>
> > This is not really needed on KVM. We can enlarge KVM_MAX_VCPUS to 255.
> 
> Thanks for clarification!  ( We did suspect the IO-APIC...but weren't 
> quite sure).
> 
> Vinod
> >
> > --
> > 			Gleb.
> > .
> >
> 
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
			Gleb.