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 1F86EC432C2 for ; Tue, 24 Sep 2019 16:52:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5A82222C2 for ; Tue, 24 Sep 2019 16:52:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569343950; bh=ij+mSy5wxHV3v0dddhDXZrbmJdwcKRgW8kPo4Yms1JE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dLcQcqZI7conaVkOoa+7EZjBe4t+oUCTIrYeFOriMVnQgxg5zQWQgcpKv0s07jtmy CcE+9ZVaWKchn3Vn6wQD1Li9Vd/TgPzXRmNce2zVyHCtakvXnYPptbs7+CGGTNJE7L HCbQoZNzLkc1KTuqlXNEIGb7v6zpdizBKgdsZAEk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441669AbfIXQwa (ORCPT ); Tue, 24 Sep 2019 12:52:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:45472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2441568AbfIXQv6 (ORCPT ); Tue, 24 Sep 2019 12:51:58 -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 2B7AB217D9; Tue, 24 Sep 2019 16:51:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569343918; bh=ij+mSy5wxHV3v0dddhDXZrbmJdwcKRgW8kPo4Yms1JE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T+pIcQfFd8ytJB8mmRmYcUpu3B5P9fFQQxGysxIt3ytJ40wKRk+xd07BWGPwJyhQY 7IRL8PbCHy6N3Z+b4+BTRWsp4oat7aYY235TY2ZhdtV7MESP3IET502ifu1NZRaHm9 zkBKuuudFYW2nEW5vgyQyzdxyn/btHFICGalf6tA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: hexin , hexin , Liu Qi , Zhang Yu , Alex Williamson , Sasha Levin , kvm@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 13/19] vfio_pci: Restore original state on release Date: Tue, 24 Sep 2019 12:51:24 -0400 Message-Id: <20190924165130.28625-13-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190924165130.28625-1-sashal@kernel.org> References: <20190924165130.28625-1-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: 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 f9a75df2d22d1..a1a712d18e028 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -356,11 +356,20 @@ 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