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=-11.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 72336C433E7 for ; Wed, 14 Oct 2020 09:31:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00E4B20BED for ; Wed, 14 Oct 2020 09:31:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="jOGl8uO+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726323AbgJNJbg (ORCPT ); Wed, 14 Oct 2020 05:31:36 -0400 Received: from mx2.suse.de ([195.135.220.15]:36476 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725984AbgJNJbg (ORCPT ); Wed, 14 Oct 2020 05:31:36 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1602667894; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7GJdUkkNqQ2hsV+7VTbAW0Sl7Mj8Z+r8+j0SbAK2XsE=; b=jOGl8uO+C+S92shJe4Hl83nEgGrTcaBhttCvtKfFG2c/AXBAI4EGJIVyBBIjwCOryFLHAv cFH7PZtPS02eUCfjHVthz4PYAiiC8TEDuMOA+z9CHreRK3dJ4bQiD5CnsT8ggqhs+L2WqU 2TdyJJ00R+s6qoGMVD2lsc4wn0Oz7l0= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D5C74AF55; Wed, 14 Oct 2020 09:31:34 +0000 (UTC) Subject: Re: [PATCH] xen/events: don't use chip_data for legacy IRQs To: stable@vger.kernel.org Cc: Stefan Bader , Boris Ostrovsky References: <20201005061957.13509-1-jgross@suse.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: Date: Wed, 14 Oct 2020 11:31:33 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201005061957.13509-1-jgross@suse.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Any reason this has not made it into 5.4.y and older by now? This patch is fixing a real problem... Juergen On 05.10.20 08:19, Juergen Gross wrote: > Since commit c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") > Xen is using the chip_data pointer for storing IRQ specific data. When > running as a HVM domain this can result in problems for legacy IRQs, as > those might use chip_data for their own purposes. > > Use a local array for this purpose in case of legacy IRQs, avoiding the > double use. > > Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") > Signed-off-by: Juergen Gross > Tested-by: Stefan Bader > Reviewed-by: Boris Ostrovsky > Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@suse.com > --- > This is a backport for stable kernel 5.4.y and older > --- > drivers/xen/events/events_base.c | 29 +++++++++++++++++++++-------- > 1 file changed, 21 insertions(+), 8 deletions(-) > > diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c > index 55f2b834cf13..e402620b8920 100644 > --- a/drivers/xen/events/events_base.c > +++ b/drivers/xen/events/events_base.c > @@ -91,6 +91,8 @@ static bool (*pirq_needs_eoi)(unsigned irq); > /* Xen will never allocate port zero for any purpose. */ > #define VALID_EVTCHN(chn) ((chn) != 0) > > +static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY]; > + > static struct irq_chip xen_dynamic_chip; > static struct irq_chip xen_percpu_chip; > static struct irq_chip xen_pirq_chip; > @@ -155,7 +157,18 @@ int get_evtchn_to_irq(unsigned evtchn) > /* Get info for IRQ */ > struct irq_info *info_for_irq(unsigned irq) > { > - return irq_get_chip_data(irq); > + if (irq < nr_legacy_irqs()) > + return legacy_info_ptrs[irq]; > + else > + return irq_get_chip_data(irq); > +} > + > +static void set_info_for_irq(unsigned int irq, struct irq_info *info) > +{ > + if (irq < nr_legacy_irqs()) > + legacy_info_ptrs[irq] = info; > + else > + irq_set_chip_data(irq, info); > } > > /* Constructors for packed IRQ information. */ > @@ -376,7 +389,7 @@ static void xen_irq_init(unsigned irq) > info->type = IRQT_UNBOUND; > info->refcnt = -1; > > - irq_set_chip_data(irq, info); > + set_info_for_irq(irq, info); > > list_add_tail(&info->list, &xen_irq_list_head); > } > @@ -425,14 +438,14 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi) > > static void xen_free_irq(unsigned irq) > { > - struct irq_info *info = irq_get_chip_data(irq); > + struct irq_info *info = info_for_irq(irq); > > if (WARN_ON(!info)) > return; > > list_del(&info->list); > > - irq_set_chip_data(irq, NULL); > + set_info_for_irq(irq, NULL); > > WARN_ON(info->refcnt > 0); > > @@ -602,7 +615,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi); > static void __unbind_from_irq(unsigned int irq) > { > int evtchn = evtchn_from_irq(irq); > - struct irq_info *info = irq_get_chip_data(irq); > + struct irq_info *info = info_for_irq(irq); > > if (info->refcnt > 0) { > info->refcnt--; > @@ -1106,7 +1119,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, > > void unbind_from_irqhandler(unsigned int irq, void *dev_id) > { > - struct irq_info *info = irq_get_chip_data(irq); > + struct irq_info *info = info_for_irq(irq); > > if (WARN_ON(!info)) > return; > @@ -1140,7 +1153,7 @@ int evtchn_make_refcounted(unsigned int evtchn) > if (irq == -1) > return -ENOENT; > > - info = irq_get_chip_data(irq); > + info = info_for_irq(irq); > > if (!info) > return -ENOENT; > @@ -1168,7 +1181,7 @@ int evtchn_get(unsigned int evtchn) > if (irq == -1) > goto done; > > - info = irq_get_chip_data(irq); > + info = info_for_irq(irq); > > if (!info) > goto done; >