From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40139) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bCoy0-0003Na-OM for qemu-devel@nongnu.org; Tue, 14 Jun 2016 10:05:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bCoxz-0005XD-Nf for qemu-devel@nongnu.org; Tue, 14 Jun 2016 10:05:20 -0400 References: <1465580427-13596-1-git-send-email-drjones@redhat.com> <1465580427-13596-7-git-send-email-drjones@redhat.com> <20160613203529.6ln7dlgnrcgda5x4@hawk.localdomain> <60ee196d-0292-3fb4-5d59-68c2d742eaa4@redhat.com> <20160614113904.2u5qvf7kasv5hact@hawk.localdomain> <20160614140329.6oz6mzlgs4gswjls@hawk.localdomain> From: Paolo Bonzini Message-ID: <587c43df-c1f3-38ed-e241-f7f7654cd173@redhat.com> Date: Tue, 14 Jun 2016 16:05:07 +0200 MIME-Version: 1.0 In-Reply-To: <20160614140329.6oz6mzlgs4gswjls@hawk.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC 06/16] vl: move smp parsing to machine pre_init List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Jones Cc: peter.maydell@linaro.org, ehabkost@redhat.com, qemu-devel@nongnu.org, agraf@suse.de, qemu-arm@nongnu.org, qemu-ppc@nongnu.org, dgibson@redhat.com, imammedo@redhat.com, david@gibson.dropbear.id.au On 14/06/2016 16:03, Andrew Jones wrote: > However, I just chatted with Igor, and he says cpu hotplug operates > on logical processors, and thus it's fine to talk about hotplugging > threads. Even real hardware does this. Real hardware will plug a > socket full of threads, but then the firmware may keep most of them > disabled until they're "hotplugged". So, I think the value of cpus > can be anything. Even the useless value of zero. Fair enough! > I'd keep =0 allowed. In most cases it just means =1, same as if the > property wasn't input. In some cases, cpus,maxcpus it creates a > useless machine, but maybe could accelerate QEMU runs for the purpose > of probing? Eh, it probably adds more complication than necessary... > Considering cpus should mean logical processors, I think that can > have any value on (0, maxcpus] Ok. The machine can warn if necessary. Paolo