From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 22 Apr 2016 15:48:50 +0200 (CEST) Received: from mx1.redhat.com ([209.132.183.28]:39594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27026343AbcDVNssicPHE (ORCPT ); Fri, 22 Apr 2016 15:48:48 +0200 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 840BB8111C; Fri, 22 Apr 2016 13:48:42 +0000 (UTC) Received: from potion (dhcp-1-215.brq.redhat.com [10.34.1.215]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u3MDmcgk009670; Fri, 22 Apr 2016 09:48:39 -0400 Received: by potion (sSMTP sendmail emulation); Fri, 22 Apr 2016 15:48:38 +0200 Date: Fri, 22 Apr 2016 15:48:38 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Igor Mammedov Cc: Greg Kurz , Paolo Bonzini , james.hogan@imgtec.com, mingo@redhat.com, linux-mips@linux-mips.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David Hildenbrand , qemu-ppc@nongnu.org, Cornelia Huck , Paul Mackerras , David Gibson Subject: Re: [PATCH v4 2/2] KVM: move vcpu id checking to archs Message-ID: <20160422134837.GA30844@potion> References: <146124809455.32509.15232948272580716135.stgit@bahia.huguette.org> <146124811255.32509.17679765789502091772.stgit@bahia.huguette.org> <20160421160018.GA31953@potion> <20160421184500.6cb5fd8a@bahia.huguette.org> <20160421173611.GB30356@potion> <20160422112538.41b23a9d@bahia.huguette.org> <20160422131957.6419a696@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20160422131957.6419a696@nial.brq.redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 53203 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: rkrcmar@redhat.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 2016-04-22 13:19+0200, Igor Mammedov: > On Fri, 22 Apr 2016 11:25:38 +0200 > Greg Kurz wrote: >> On Thu, 21 Apr 2016 19:36:11 +0200 >> Radim Krčmář wrote: >> > 2016-04-21 18:45+0200, Greg Kurz: >> > > On Thu, 21 Apr 2016 18:00:19 +0200 >> > > Radim Krčmář wrote: >> > >> 2016-04-21 16:20+0200, Greg Kurz: >[...] >> > > maybe later >> > > if we have other scenarios where vcpu ids need to cross the limit ? >> > >> > x86 is going to have that soon too -- vcpu_id will be able to range from >> > 0 to 2^32-1 (or 2^31), but MAX_CPUS related data structures probably >> > won't be improved to actually scale, so MAX_CPUS will remain lower. >> > > That's not true, x86 is going to stick with KVM_MAX_VCPUS/qemu's max_cpus, > the only thing that is going to change is that max supported APIC ID > value will be in range 0 to 2^32-1 vs current 8bit one > and since APIC ID is not vcpu_id so it won't affect vcpu_id. I wish it wasn't. vcpu_id is the initial APIC ID -- at least the spec says so and KVM code behaves like that (QEMU does too). It doesn't have to be so, though, KVM_SET_LAPIC provides the interface to set APIC ID. We'd decouple these two and change some related things. (And add yet another cap for that? :]) I'll see what would be really needed, thanks.