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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5972BC27C4F for ; Sat, 29 Jun 2024 10:45:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YBr0wMQUI9nfHEgcW87Tn7+jfpVx+jXLrJH0EYZ954o=; b=Z+pcgLaZ8+5Mbba4qSVFdBjiiX 92ZBdE8/gEwrgqyzjLGxR1oxJLU08z1z7cruheX/r8LbLOH3sSAoBaoiDAXXABF4M8dzwd1rDBnGE yDFq8DSSpFEgh3UISM5S80V9GYBhp83klHvXuaUlzO4cgbfvsltKNMAXS38bPylpcLVHkDaleDSFc TtZ3uSek8IGIzF3m80FHcafJVKMXXZzu8781xiGmHpnxtjyqOuRWizOWI6QTV88zAQVAY5LvYL/1E WTUHQGMreadLuiobf4iytn6/HWh+QPKSaviIwfEOGCWqibBK3FXWNvLlZbwfCs0jCCBEogue9IsP8 IPTxixEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sNVZg-0000000GGmP-1b1l; Sat, 29 Jun 2024 10:44:56 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sNVZU-0000000GGjQ-2ivZ for linux-arm-kernel@lists.infradead.org; Sat, 29 Jun 2024 10:44:47 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1719657882; 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: in-reply-to:in-reply-to:references:references; bh=YBr0wMQUI9nfHEgcW87Tn7+jfpVx+jXLrJH0EYZ954o=; b=nw4MLVWOk00BwhzggrZaMrhcXL2Kh+j64AG8H/iGBr9RQvByomDldI84G3tc8QkuT0uJKc JuKWG0UAs9db/0QVzkXV/K6n3ggUWczQo/SwMVpMRb0aK3hGZs1mGDAKunMoKLtpIaqVN5 K92YNbJAFDA/YNlmLdRnfejd/MZwf+4yDiZy+J/NhqWa3IdRYC9dWAZvMjSf0K0uiOPklv L+SWhkCQB5mrSIoujAC6h3KlrFM5D+BAH1M84bE4xK/YmAUNdloOEkY9++dE4vuYHLeeik jPBo2KMuo9ts18/M9C9eWSt9KT0jZ2wRVNTzp8/m3cRm01s4QycJd3tkmAxufA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1719657882; 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: in-reply-to:in-reply-to:references:references; bh=YBr0wMQUI9nfHEgcW87Tn7+jfpVx+jXLrJH0EYZ954o=; b=OcBbTenA5kOfmm/vsUhr/wkot+gSaZ5It7tkFtx+SJNb4IWB2rNQq89G4tWsxqSaCti1RQ pcjv31+K/6gJhyAw== To: Marc Zyngier Cc: Catalin Marinas , LKML , linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, anna-maria@linutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, bhelgaas@google.com, rdunlap@infradead.org, vidyas@nvidia.com, ilpo.jarvinen@linux.intel.com, apatel@ventanamicro.com, kevin.tian@intel.com, nipun.gupta@amd.com, den@valinux.co.jp, andrew@lunn.ch, gregory.clement@bootlin.com, sebastian.hesselbarth@gmail.com, gregkh@linuxfoundation.org, rafael@kernel.org, alex.williamson@redhat.com, will@kernel.org, lorenzo.pieralisi@arm.com, jgg@mellanox.com, ammarfaizi2@gnuweeb.org, robin.murphy@arm.com, lpieralisi@kernel.org, nm@ti.com, kristo@kernel.org, vkoul@kernel.org, okaya@kernel.org, agross@kernel.org, andersson@kernel.org, mark.rutland@arm.com, shameerali.kolothum.thodi@huawei.com, yuzenghui@huawei.com, shivamurthy.shastri@linutronix.de Subject: Re: [patch V4 05/21] irqchip/gic-v3-its: Provide MSI parent for PCI/MSI[-X] In-Reply-To: <86bk3khxdt.wl-maz@kernel.org> References: <20240623142137.448898081@linutronix.de> <20240623142235.024567623@linutronix.de> <87h6dcxhy0.ffs@tglx> <86ed8ghypg.wl-maz@kernel.org> <86cyo0hyc6.wl-maz@kernel.org> <86bk3khxdt.wl-maz@kernel.org> Date: Sat, 29 Jun 2024 12:44:41 +0200 Message-ID: <87ed8gxc2u.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240629_034444_837355_07D978D5 X-CRM114-Status: GOOD ( 10.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Marc! On Sat, Jun 29 2024 at 11:11, Marc Zyngier wrote: >> I have the ugly feeling that the flag is applied at the wrong level, >> or not propagated. Indeed. > Here's a possible fix. Making the masking at the ITS level optional is > not an option (haha). It is the PCI masking that is totally > superfluous and that could completely be elided. It's the right fix because ITS requires this bit to be set. Vs. PCI masking, you are right from a pure ITS point of view, but not from the PCI side. PCI can't be unmsaked until there is a valid message and we need to mask it on shutdown. It's not a run time issue at all because PCI/MSI is edge triggered so the mask/unmask dance only matters during startup, shutdown and message update. > With this hack, I can boot a GICv3+ITS guest as usual. It's not a hack. It's the proper solution. Let me fold that back and look at the other PCI conversions which probably have the same issue. Thanks for digging into this. This help is truly welcome right now. Thanks, tglx