From patchwork Fri Jul 7 15:10:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 1804966 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=d0iyv5jP; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4QyH1z5ykzz20b8 for ; Sat, 8 Jul 2023 01:12:23 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233351AbjGGPMV (ORCPT ); Fri, 7 Jul 2023 11:12:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbjGGPMU (ORCPT ); Fri, 7 Jul 2023 11:12:20 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36EB22121 for ; Fri, 7 Jul 2023 08:11:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688742690; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/vpgghRxsUnXsE3t1IVpXcHF3Kir76KUPEpQodsytdc=; b=d0iyv5jPnpJtODScQPik/87cvsBJteCer4VzqXvU1RTFYPDABfm3BlQa5fWFRFnRM+szmq 3zcGilYPtOSQrUu/2SPaV9JyMJsk/f8HFDmVog/ZkwLJNcx80BJh+d/NjPRB6pJERDOaSX GKHkgL05vVxNRvxuPjE2oJbm2hy1FhI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-425-huiRPxb7MyqWJbXufgI7Jw-1; Fri, 07 Jul 2023 11:11:27 -0400 X-MC-Unique: huiRPxb7MyqWJbXufgI7Jw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D28691C060C9; Fri, 7 Jul 2023 15:11:26 +0000 (UTC) Received: from omen.home.shazbot.org (unknown [10.22.17.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 70FCAC09A09; Fri, 7 Jul 2023 15:11:26 +0000 (UTC) From: Alex Williamson To: bhelgaas@google.com Cc: Alex Williamson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, eric.auger@redhat.com Subject: [PATCH] PCI/VPD: Add runtime power management to sysfs interface Date: Fri, 7 Jul 2023 09:10:44 -0600 Message-Id: <20230707151044.1311544-1-alex.williamson@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Unlike default access to config space through sysfs, the vpd read and write function don't actively manage the runtime power management state of the device during access. Since commit 7ab5e10eda02 ("vfio/pci: Move the unused device into low power state with runtime PM"), the vfio-pci driver will use runtime power management and release unused devices to make use of low power states. Attempting to access VPD information in this low power state can result in incorrect information or kernel crashes depending on the system behavior. Wrap the vpd read/write bin attribute handlers in runtime PM and take into account the potential quirk to select the correct device to wake. Signed-off-by: Alex Williamson --- drivers/pci/vpd.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c index a4fc4d0690fe..81217dd4789f 100644 --- a/drivers/pci/vpd.c +++ b/drivers/pci/vpd.c @@ -275,8 +275,23 @@ static ssize_t vpd_read(struct file *filp, struct kobject *kobj, size_t count) { struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); + struct pci_dev *vpd_dev = dev; + ssize_t ret; + + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { + vpd_dev = pci_get_func0_dev(dev); + if (!vpd_dev) + return -ENODEV; + } + + pci_config_pm_runtime_get(vpd_dev); + ret = pci_read_vpd(vpd_dev, off, count, buf); + pci_config_pm_runtime_put(vpd_dev); + + if (dev != vpd_dev) + pci_dev_put(vpd_dev); - return pci_read_vpd(dev, off, count, buf); + return ret; } static ssize_t vpd_write(struct file *filp, struct kobject *kobj, @@ -284,8 +299,23 @@ static ssize_t vpd_write(struct file *filp, struct kobject *kobj, size_t count) { struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); + struct pci_dev *vpd_dev = dev; + ssize_t ret; + + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { + vpd_dev = pci_get_func0_dev(dev); + if (!vpd_dev) + return -ENODEV; + } + + pci_config_pm_runtime_get(vpd_dev); + ret = pci_write_vpd(vpd_dev, off, count, buf); + pci_config_pm_runtime_put(vpd_dev); + + if (dev != vpd_dev) + pci_dev_put(vpd_dev); - return pci_write_vpd(dev, off, count, buf); + return ret; } static BIN_ATTR(vpd, 0600, vpd_read, vpd_write, 0);