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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DF96C433F5 for ; Tue, 16 Nov 2021 14:51:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56C1461A6C for ; Tue, 16 Nov 2021 14:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237742AbhKPOyA convert rfc822-to-8bit (ORCPT ); Tue, 16 Nov 2021 09:54:00 -0500 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:46413 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237658AbhKPOx3 (ORCPT ); Tue, 16 Nov 2021 09:53:29 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-66-xtADflvUPhaqRyR5uYC8sg-1; Tue, 16 Nov 2021 09:50:24 -0500 X-MC-Unique: xtADflvUPhaqRyR5uYC8sg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7C2D31B18BC0; Tue, 16 Nov 2021 14:50:23 +0000 (UTC) Received: from bahia (unknown [10.39.192.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0DCFC5E272; Tue, 16 Nov 2021 14:50:21 +0000 (UTC) Date: Tue, 16 Nov 2021 15:50:20 +0100 From: Greg Kurz To: =?UTF-8?B?Q8OpZHJpYw==?= Le Goater Cc: , Michael Ellerman , Marc Zyngier , Subject: Re: [PATCH] powerpc/xive: Change IRQ domain to a tree domain Message-ID: <20211116155020.653abb3f@bahia> In-Reply-To: References: <20211116134022.420412-1-clg@kaod.org> <20211116152343.782c687c@bahia> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, 16 Nov 2021 15:49:13 +0100 Cédric Le Goater wrote: > On 11/16/21 15:23, Greg Kurz wrote: > > On Tue, 16 Nov 2021 14:40:22 +0100 > > Cédric Le Goater wrote: > > > >> Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains > >> exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the > >> 'nomap' domains still in use under the powerpc arch. With this new > >> flag, the revmap_tree of the IRQ domain is not used anymore. This > >> change broke the support of shared LSIs [1] in the XIVE driver because > >> it was relying on a lookup in the revmap_tree to query previously > >> mapped interrupts. Linux now creates two distinct IRQ mappings on the > >> same HW IRQ which can lead to unexpected behavior in the drivers. > >> > >> The XIVE IRQ domain is not a direct mapping domain and its HW IRQ > >> interrupt number space is rather large : 1M/socket on POWER9 and > >> POWER10, change the XIVE driver to use a 'tree' domain type instead. > >> > >> [1] For instance, a linux KVM guest with virtio-rng and virtio-balloon > >> devices. > >> > >> Cc: Marc Zyngier > >> Cc: stable@vger.kernel.org # v5.14+ > >> Fixes: 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") > >> Signed-off-by: Cédric Le Goater > >> --- > >> > > > > Tested-by: Greg Kurz > > > > with a KVM guest + virtio-rng + virtio-balloon on a POWER9 host. > > Did you test on a 5.14 backport or mainline ? > I've tested on a 5.14 backport only. > I am asking because a large change adding support for MSI domains > to XIVE was merged in 5.15. > > Thanks, > > C. > > > > > >> Marc, > >> > >> The Fixes tag is there because the patch in question revealed that > >> something was broken in XIVE. genirq is not in cause. However, I > >> don't know for PS3 and Cell. May be less critical for now. > >> > >> arch/powerpc/sysdev/xive/common.c | 3 +-- > >> arch/powerpc/sysdev/xive/Kconfig | 1 - > >> 2 files changed, 1 insertion(+), 3 deletions(-) > >> > >> diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c > >> index fed6fd16c8f4..9d0f0fe25598 100644 > >> --- a/arch/powerpc/sysdev/xive/common.c > >> +++ b/arch/powerpc/sysdev/xive/common.c > >> @@ -1536,8 +1536,7 @@ static const struct irq_domain_ops xive_irq_domain_ops = { > >> > >> static void __init xive_init_host(struct device_node *np) > >> { > >> - xive_irq_domain = irq_domain_add_nomap(np, XIVE_MAX_IRQ, > >> - &xive_irq_domain_ops, NULL); > >> + xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL); > >> if (WARN_ON(xive_irq_domain == NULL)) > >> return; > >> irq_set_default_host(xive_irq_domain); > >> diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig > >> index 97796c6b63f0..785c292d104b 100644 > >> --- a/arch/powerpc/sysdev/xive/Kconfig > >> +++ b/arch/powerpc/sysdev/xive/Kconfig > >> @@ -3,7 +3,6 @@ config PPC_XIVE > >> bool > >> select PPC_SMP_MUXED_IPI > >> select HARDIRQS_SW_RESEND > >> - select IRQ_DOMAIN_NOMAP > >> > >> config PPC_XIVE_NATIVE > >> bool > > >