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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 81D75C433E5 for ; Fri, 21 Aug 2020 01:39:38 +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 4DD9A2075E for ; Fri, 21 Aug 2020 01:39:38 +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="dnox/6fk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4DD9A2075E 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]:53948 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k8w1p-0003tp-Ev for qemu-devel@archiver.kernel.org; Thu, 20 Aug 2020 21:39:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42670) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8w0k-0002zl-Br; Thu, 20 Aug 2020 21:38:31 -0400 Received: from ozlabs.org ([203.11.71.1]:51945) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8w0h-0003CI-QE; Thu, 20 Aug 2020 21:38:30 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4BXkgD6Fsbz9sTR; Fri, 21 Aug 2020 11:38:16 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1597973896; bh=d6evanwXgBG4IPliJsRhqkIUyNzNEyBUO0d7EazVANI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dnox/6fkFo5XlX69C8HBD541rPCo7/e7tr+R3WgXlZoysJVj+Suxq9bzInIi0M8Ek nz8N23J2vbhGe1W3d2JbF4UHyytU/ooZbpgCDzPEczF51jy56tC77RANoKSMfwGUOd o6ml7Y+bOFRtlWezENMmb9+lHMQq475ultksP+1g= Date: Fri, 21 Aug 2020 11:38:07 +1000 From: David Gibson To: =?iso-8859-1?Q?C=E9dric?= Le Goater Subject: Re: [PATCH v2 0/4] spapr/xive: Allocate vCPU IPIs from the vCPU contexts Message-ID: <20200821013807.GV271315@yekko.fritz.box> References: <20200820134547.2355743-1-clg@kaod.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="G9m07da55tKJni3T" Content-Disposition: inline In-Reply-To: <20200820134547.2355743-1-clg@kaod.org> Received-SPF: pass client-ip=203.11.71.1; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/20 20:03:50 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -9 X-Spam_score: -1.0 X-Spam_bar: - X-Spam_report: (-1.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=no autolearn_force=no X-Spam_action: no action 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-devel@nongnu.org, qemu-ppc@nongnu.org, Satheesh Rajendran , Greg Kurz , Gustavo Romero Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --G9m07da55tKJni3T Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 20, 2020 at 03:45:43PM +0200, C=E9dric Le Goater wrote: > Hello, >=20 >=20 > When QEMU switches to the XIVE interrupt mode, it creates all the > guest interrupts at the level of the KVM device. These interrupts are > backed by real HW interrupts from the IPI interrupt pool of the XIVE > controller. >=20 > Currently, this is done from the QEMU main thread, which results in > allocating all interrupts from the chip on which QEMU is running. IPIs > are not distributed across the system and the load is not well > balanced across the interrupt controllers. >=20 > Change the vCPU IPI allocation to run from the vCPU context. The > associated XIVE IPI interrupt will be allocated on the chip on which > the vCPU is running and improve distribution of the IPIs in the system. > When the vCPUs are pinned, this will make the IPI local to the chip of > the vCPU. It will reduce rerouting between interrupt controllers and > gives better performance. >=20 >=20 > I did some basic migration testing with the 'dual' and 'xive' modes, > also tried CPU hoplug. I haven't tried migration with older pseries > machine. LGTM, applied to ppc-for-5.2. --=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 --G9m07da55tKJni3T Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAl8/JX0ACgkQbDjKyiDZ s5LXhxAAtzI5norZqEs9I5qk657PW3Rr3sCOLs//Nyl3LZYICqHy5DwhxZXteAKZ hWav26NFXXN879C9+hjPP7RqsN4d9IzW/IXNuptLN1n+gSA1wkfFBtUU8KoIYh2y tvQ6IlGRCyWmjRZ86mUOQDgti8TM14n3a4NeW7xhBPD1NCf8PY+fj2ZKQmlJ4nQ1 mMomIzbO7W6XNVfAGM1hZmaMQbCM46CHWdiqlW70R8bcnQhCfCk+g4cnWwzHo2lY ui7zyD66jSdqjuSxSyFgh8zKV2N/APQwIgrsdqYcMK8//9VEe9IEaVgGhTZiZcX9 8ERZ6rrLG2kha/tk3pOLZmSFgam4BrZaWoCFA6qjeX+R5rheipyPoKSfZ6yG7Yll DdGpignYvT4LGE5IXwmVQ6izhGgpZf+JRrRKSmq/NDxodnt7De8WyyfZI/hu5b/9 rwzzwOcRZoOkyd88JHJ9waNJZv4yCa9WY9mFusFcGbt0dUXTKeOq7tQCqEU8GfGo bTrmYxufhzMML2ZCjDWY64ozdPQT2yrK0hVPRAm3sZ9tjhXNidCeb+v3HvJ0iSWF Vv32Devl6N5O+ZstMZca9arNpvae1+i9943WlF6akaQXeHSaZZHPb0AuntrJAQkO vdidDlTgMWeBgzhMkQt4ShYAufMOkiQDAsl3qCUKUt5LK6Wv3GU= =6cBF -----END PGP SIGNATURE----- --G9m07da55tKJni3T--