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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 12331C4360C for ; Sun, 6 Oct 2019 17:19:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDF7C217F9 for ; Sun, 6 Oct 2019 17:19:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382378; bh=RlYKxXdLi0iG8jA3nBMsToaPxsGq9Tnp4BjvMwYQlnw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nLrsFEDKviXUUK8rjoxxfnYOlX2PxMZ1sL9IiiWc8ltmVzDXEi37IDyGQJLne6/4f gMpNb0gaRtwwoNaiJmyHj4PBa8Bq0sX2nJYtb4v1Ys6BSNDxMnZqR07MsC4Yf4YjeI CDSU3yqJTcgHRn2mj1vF0edTroXgPEcNurA08+Ho= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726798AbfJFRTf (ORCPT ); Sun, 6 Oct 2019 13:19:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:44412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726508AbfJFRTc (ORCPT ); Sun, 6 Oct 2019 13:19:32 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 CADFA2077B; Sun, 6 Oct 2019 17:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382371; bh=RlYKxXdLi0iG8jA3nBMsToaPxsGq9Tnp4BjvMwYQlnw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZFEOiwU8DE/P0n2l0WaK5YqBzdw62p/zr17AARSvIPgmVmnD4X2UDey5acI/amTp8 +f5zx8e+Sdssex08q3uXYA/+ZsqX3GqKvYGC63FhAVUB77p/Mg0TBLdtQqRzvt6AZg GI6iy6gDzGvraGP2fVJqcpx5uKm+mBmb5fBuBHS4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, hexin , Liu Qi , Zhang Yu , Alex Williamson , Sasha Levin Subject: [PATCH 4.4 11/36] vfio_pci: Restore original state on release Date: Sun, 6 Oct 2019 19:18:53 +0200 Message-Id: <20191006171048.918067947@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171038.266461022@linuxfoundation.org> References: <20191006171038.266461022@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: hexin [ Upstream commit 92c8026854c25093946e0d7fe536fd9eac440f06 ] vfio_pci_enable() saves the device's initial configuration information with the intent that it is restored in vfio_pci_disable(). However, the commit referenced in Fixes: below replaced the call to __pci_reset_function_locked(), which is not wrapped in a state save and restore, with pci_try_reset_function(), which overwrites the restored device state with the current state before applying it to the device. Reinstate use of __pci_reset_function_locked() to return to the desired behavior. Fixes: 890ed578df82 ("vfio-pci: Use pci "try" reset interface") Signed-off-by: hexin Signed-off-by: Liu Qi Signed-off-by: Zhang Yu Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/vfio/pci/vfio_pci.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 47b229fa5e8ec..4b62eb3b59233 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -221,11 +221,20 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); /* - * Try to reset the device. The success of this is dependent on - * being able to lock the device, which is not always possible. + * Try to get the locks ourselves to prevent a deadlock. The + * success of this is dependent on being able to lock the device, + * which is not always possible. + * We can not use the "try" reset interface here, which will + * overwrite the previously restored configuration information. */ - if (vdev->reset_works && !pci_try_reset_function(pdev)) - vdev->needs_reset = false; + if (vdev->reset_works && pci_cfg_access_trylock(pdev)) { + if (device_trylock(&pdev->dev)) { + if (!__pci_reset_function_locked(pdev)) + vdev->needs_reset = false; + device_unlock(&pdev->dev); + } + pci_cfg_access_unlock(pdev); + } pci_restore_state(pdev); out: -- 2.20.1