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=-10.1 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,USER_AGENT_GIT autolearn=unavailable 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 895F8ECE587 for ; Tue, 1 Oct 2019 16:49:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B8A220659 for ; Tue, 1 Oct 2019 16:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948541; bh=6EyxsEqBJ2oOZtJcJw9OqpnSifZ1fmKpzk8Q4zKakk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=z6XFkwNcOz5Ly4/12N1I7dHh1VoVOWQxiYJvNR7jo+zYUiRPAYhhtlvZPtwPngTTo wHOCl3ztki5tlhsn1TluGlOU12lU6ro0EV8GMJ7MjqR1NAu+ft/+1VVHpSZDuIJAW9 ihrRZrya9dgAbNqAvGOwhaUdE2hlF646bRXQpI1g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388872AbfJAQtA (ORCPT ); Tue, 1 Oct 2019 12:49:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:57608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390191AbfJAQpL (ORCPT ); Tue, 1 Oct 2019 12:45:11 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 85CCB21920; Tue, 1 Oct 2019 16:45:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948310; bh=6EyxsEqBJ2oOZtJcJw9OqpnSifZ1fmKpzk8Q4zKakk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jh/nGozf2xZ+3bl8px80Nen5boAH4hf5hBxkiWiLeBC0lYNaIZthEa6+1Q6oysM/d AEto7HSYSjrUw6fJW4ZK63y3YJ6qhKh/RZ9Xobx61IzDOYaMih/GXGZR2a/WcxMWSJ 3CQ4cq3c7NjyuJdFvYcoAR7pUZ97WlzH5PKrLx4I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Igor Druzhinin , Boris Ostrovsky , Sasha Levin Subject: [PATCH AUTOSEL 4.9 04/19] xen/pci: reserve MCFG areas earlier Date: Tue, 1 Oct 2019 12:44:50 -0400 Message-Id: <20191001164505.16708-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164505.16708-1-sashal@kernel.org> References: <20191001164505.16708-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Igor Druzhinin [ Upstream commit a4098bc6eed5e31e0391bcc068e61804c98138df ] If MCFG area is not reserved in E820, Xen by default will defer its usage until Dom0 registers it explicitly after ACPI parser recognizes it as a reserved resource in DSDT. Having it reserved in E820 is not mandatory according to "PCI Firmware Specification, rev 3.2" (par. 4.1.2) and firmware is free to keep a hole in E820 in that place. Xen doesn't know what exactly is inside this hole since it lacks full ACPI view of the platform therefore it's potentially harmful to access MCFG region without additional checks as some machines are known to provide inconsistent information on the size of the region. Now xen_mcfg_late() runs after acpi_init() which is too late as some basic PCI enumeration starts exactly there as well. Trying to register a device prior to MCFG reservation causes multiple problems with PCIe extended capability initializations in Xen (e.g. SR-IOV VF BAR sizing). There are no convenient hooks for us to subscribe to so register MCFG areas earlier upon the first invocation of xen_add_device(). It should be safe to do once since all the boot time buses must have their MCFG areas in MCFG table already and we don't support PCI bus hot-plug. Signed-off-by: Igor Druzhinin Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin --- drivers/xen/pci.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c index 7494dbeb4409c..db58aaa4dc598 100644 --- a/drivers/xen/pci.c +++ b/drivers/xen/pci.c @@ -29,6 +29,8 @@ #include "../pci/pci.h" #ifdef CONFIG_PCI_MMCONFIG #include + +static int xen_mcfg_late(void); #endif static bool __read_mostly pci_seg_supported = true; @@ -40,7 +42,18 @@ static int xen_add_device(struct device *dev) #ifdef CONFIG_PCI_IOV struct pci_dev *physfn = pci_dev->physfn; #endif - +#ifdef CONFIG_PCI_MMCONFIG + static bool pci_mcfg_reserved = false; + /* + * Reserve MCFG areas in Xen on first invocation due to this being + * potentially called from inside of acpi_init immediately after + * MCFG table has been finally parsed. + */ + if (!pci_mcfg_reserved) { + xen_mcfg_late(); + pci_mcfg_reserved = true; + } +#endif if (pci_seg_supported) { struct { struct physdev_pci_device_add add; @@ -213,7 +226,7 @@ static int __init register_xen_pci_notifier(void) arch_initcall(register_xen_pci_notifier); #ifdef CONFIG_PCI_MMCONFIG -static int __init xen_mcfg_late(void) +static int xen_mcfg_late(void) { struct pci_mmcfg_region *cfg; int rc; @@ -252,8 +265,4 @@ static int __init xen_mcfg_late(void) } return 0; } -/* - * Needs to be done after acpi_init which are subsys_initcall. - */ -subsys_initcall_sync(xen_mcfg_late); #endif -- 2.20.1