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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 E95A4C2D0DB for ; Wed, 22 Jan 2020 10:44:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B25A824689 for ; Wed, 22 Jan 2020 10:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579689850; bh=U7baVMUBD0atkOvxVpY1i6OsBGZBdoYk6vMsLlamq5I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=jza7Fs4Qk5G98eH5D9XL7k+IdcMJLnDRh0qdLrgJlX4Vj1N1ALHo/BWksePXzbfK8 esdbjl4AGYp+P0Jj8c7N4vJvWCEPhLcJ0aeFVbDmo57RNJ7qBCTkJSQuOQUox4+N5y P12Lkc0CIvtvyb9Xv2UU7o174lM0utLbwBKz7LAw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729235AbgAVKoJ (ORCPT ); Wed, 22 Jan 2020 05:44:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:60936 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726094AbgAVKoJ (ORCPT ); Wed, 22 Jan 2020 05:44:09 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5FA0224688; Wed, 22 Jan 2020 10:44:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579689848; bh=U7baVMUBD0atkOvxVpY1i6OsBGZBdoYk6vMsLlamq5I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZXkWgPRYXC9AKBrp3Hlil++Z4lNFiEZjUjC/mAdr53vbH1Wtz8Z2quRd0RSkznGf0 x8pQmO3goBhNl8wI7rTYrajTkOSfJXw0i+olU0Wb/ZD+Lm1lphPJtg9gDwREphdoRI WtwfN8MwqWIKnFv52fFI/Pcmwl9nOYFGbILW9ojY= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1iuDUU-000ipx-AG; Wed, 22 Jan 2020 10:44:06 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 22 Jan 2020 10:44:06 +0000 From: Marc Zyngier To: Zenghui Yu Cc: kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, tglx@linutronix.de, jason@lakedaemon.net, wanghaibin.wang@huawei.com Subject: Re: [PATCH] irqchip/gic-v3-its: Don't confuse get_vlpi_map() by writing DB config In-Reply-To: <20200122085609.658-1-yuzenghui@huawei.com> References: <20200122085609.658-1-yuzenghui@huawei.com> Message-ID: <4aaaad3ae7367c5c932c430e18550d9e@kernel.org> X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.8 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: yuzenghui@huawei.com, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, tglx@linutronix.de, jason@lakedaemon.net, wanghaibin.wang@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Zenghui, Thanks for this. On 2020-01-22 08:56, Zenghui Yu wrote: > When we're writing config for the doorbell interrupt, get_vlpi_map() > will > get confused by doorbell's d->parent_data hack and find the wrong > its_dev > as chip data and the wrong event. > > Fix this issue by making sure no doorbells will be involved before > invoking > get_vlpi_map(), which restore some of the logic in lpi_write_config(). > > Fixes: c1d4d5cd203c ("irqchip/gic-v3-its: Add its_vlpi_map helpers") > Signed-off-by: Zenghui Yu > --- > > This is based on mainline and can't be directly applied to the current > irqchip-next. > > drivers/irqchip/irq-gic-v3-its.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c > b/drivers/irqchip/irq-gic-v3-its.c > index e05673bcd52b..cc8a4fcbd6d6 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -1181,12 +1181,13 @@ static struct its_vlpi_map > *get_vlpi_map(struct irq_data *d) > > static void lpi_write_config(struct irq_data *d, u8 clr, u8 set) > { > - struct its_vlpi_map *map = get_vlpi_map(d); > irq_hw_number_t hwirq; > void *va; > u8 *cfg; > > - if (map) { > + if (irqd_is_forwarded_to_vcpu(d)) { > + struct its_vlpi_map *map = get_vlpi_map(d); > + > va = page_address(map->vm->vprop_page); > hwirq = map->vintid; Shouldn't we fix get_vlpi_map() instead? Something like (untested): diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index e05673bcd52b..b704214390c0 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1170,13 +1170,14 @@ static void its_send_vclear(struct its_device *dev, u32 event_id) */ static struct its_vlpi_map *get_vlpi_map(struct irq_data *d) { - struct its_device *its_dev = irq_data_get_irq_chip_data(d); - u32 event = its_get_event_id(d); + if (irqd_is_forwarded_to_vcpu(d)) { + struct its_device *its_dev = irq_data_get_irq_chip_data(d); + u32 event = its_get_event_id(d); - if (!irqd_is_forwarded_to_vcpu(d)) - return NULL; + return dev_event_to_vlpi_map(its_dev, event); + } - return dev_event_to_vlpi_map(its_dev, event); + return NULL; } static void lpi_write_config(struct irq_data *d, u8 clr, u8 set) Or am I missing the actual problem? Overall, I'm starting to hate that ->parent hack as it's been the source of a number of bugs. The main issue is that the VPE hierarchy is missing one level (it has no ITS domain, and goes directly from the VPE domain to the low-level GIC domain). It means we end-up special-casing things, and that's never good... M. -- Jazz is not dead. It just smells funny...