From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B04BC432C0 for ; Wed, 27 Nov 2019 06:04:07 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C65120684 for ; Wed, 27 Nov 2019 06:04:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="cHwZ/Qgy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C65120684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33282 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iZqQo-0002IH-7P for qemu-devel@archiver.kernel.org; Wed, 27 Nov 2019 01:04:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:43917) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iZqPy-0001As-2X for qemu-devel@nongnu.org; Wed, 27 Nov 2019 01:03:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iZqPw-0003Vp-FH for qemu-devel@nongnu.org; Wed, 27 Nov 2019 01:03:13 -0500 Received: from bilbo.ozlabs.org ([203.11.71.1]:52135 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iZqPv-0003Iq-5T; Wed, 27 Nov 2019 01:03:12 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 47N9DV71QDz9sSw; Wed, 27 Nov 2019 17:03:06 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1574834586; bh=sgcHE5ZixYgXaifxhnowhHGFrJYbvzsjfjBUkTPjnpA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cHwZ/Qgyq0NufxEGktCjda+CyLe2Kma3zCDzHYShyWa73y8Im9vWLqEVLYSpLixgp Eqtb7pe4s6+vikxOk6EE9ziu2Lzz3sNypuNWKQ2nAQ9zsCwoeUPbuVbwn7tmI7CSJ7 LXGGvmeozaAovSgGr0zdUgqr2pO6QaqoIr92aRFc= Date: Wed, 27 Nov 2019 16:41:50 +1100 From: David Gibson To: Greg Kurz Subject: Re: [for-5.0 PATCH v2 0/4] spapr: Use less XIVE HW resources in KVM Message-ID: <20191127054150.GT5582@umbus.fritz.box> References: <157478677206.67101.11965554900825793694.stgit@bahia.tlslab.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="RWwYAm6PHzOoZjya" Content-Disposition: inline In-Reply-To: <157478677206.67101.11965554900825793694.stgit@bahia.tlslab.ibm.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 203.11.71.1 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-ppc@nongnu.org, =?iso-8859-1?Q?C=E9dric?= Le Goater , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --RWwYAm6PHzOoZjya Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Nov 26, 2019 at 05:46:12PM +0100, Greg Kurz wrote: > On POWER9 systems, the XICS-on-XIVE and XIVE KVM devices currently > allocate a bunch of VPs in the XIVE HW to accomodate the highest > VCPU id that may be possibly used in a VM. This limits the number > of VMs that can run with an in-kernel interrupt controller to 63 > per POWER9 chip, irrespectively of its number of HW threads, eg. > up to 96 on a POWER9 Nimbus socket. This is an unfortunate waste > of scarce HW resources since a typical VM doesn't need that much > VPs to run. >=20 > This series exploits new attributes of the XICS-on-XIVE and XIVE > KVM devices that allow userspace to tune the numbers of VPs it > really needs. Support for this attributes has just reached linux > mainline. >=20 > In combination with recent commit 29cb4187497d "spapr: Set VSMT to > smp_threads by default" which makes VCPU ids contiguous, it is > possible to start more than 200 VMs instead of 127 on an AC922 > system (two sockets, 144 HW threads). >=20 > Changes in v2: > - add an nr_servers argument to the activate() handler instead of > a QOM property for XIVE and a XICSFabric method for XICS-on-XIVE. > - even if the last two patches haven't changed much, the code base > itself has, so I've deliberately dropped Cedric's R-b tags Applied to ppc-for-5.0, thanks. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --RWwYAm6PHzOoZjya Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAl3eDJsACgkQbDjKyiDZ s5Ix4BAAlewqDT7GSyOO8JOM2Ace14C31doT+b9Qq4s5XTlWWFJEZMneIGMCN0O/ Qw6xu+u5y7kQGNod6QhtEdZdaUNARZEzrBGUe7NiIS2u6uhLabeYIUklg5qC5ije M7dFe1wl/Q/Oj7d666kimcOMoZyvkCSerIGaBD47v2FkOgC1szLKpdZb2Gzpz604 7+hHlpi6/KwsYcNOsc+Ij9rjsx1lbnBwle/u3TdeJTtVSi4+G40FZYFwkq1L9Wfa ids+hPmaSfkr4XGn1weqB3EpjlPuDFG2HgYrzopEkgq108QbfQTgQOeIYKwl2aky 1ft2qjk//3y5gm3MVwVZnah0wUYA/81+uv95h55wUnctLWzRvkUArkvphI4chzWh B62RMyM4zyAG8gMy9y0jPCsHXfoyRNEzpIhat3m3Rm4oN1OkKmFXt5HapRfH2C7I ELZIAmrRmIXVIdOuwiaVrDItJU+bWYOBSgdlkWdBooSpjI1sQElW7Nzq6oPS2hkj f9KvKV7WL2+LsCEs9w4HOUjGDPG5FXfMqEe3vdO203SHlGN6FSGXtAmbxwDxJNI6 gffByKxmYS7QVwGrfz77+JKnnJwK+Q0XUuALxTbmHXUHpWgXWorWW55CBNLoV3RN n0qqIgvX4d7dpHlNuZuWp1Pd2SO4pE2ogSFvbgK3gmBxWgfV3qs= =DpCL -----END PGP SIGNATURE----- --RWwYAm6PHzOoZjya--