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=-10.0 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 78E04C433DF for ; Tue, 23 Jun 2020 20:10:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DC1120CC7 for ; Tue, 23 Jun 2020 20:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592943029; bh=eT5nBUH5CEcBcPKoieCysrDhqP1ryBzXBcMEC1eSKPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=B1T8ClSg6drV+hdU3DaWH3Na434fsYyQekeIZl8ikfn1q1VGLuzXibKFIov7eTEMY tbIf5r+BJ5VIuDcSIztWLi5Dy6VZN0H7eJZTjFN4eUTbmpgQOIeTnHqdsgEBHhU8eN xwkeIHVpEMscBbLhJYkkW0HScGPdLFc4x6gdSves= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388788AbgFWUK1 (ORCPT ); Tue, 23 Jun 2020 16:10:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:51434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388490AbgFWUKO (ORCPT ); Tue, 23 Jun 2020 16:10:14 -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 A931C2082F; Tue, 23 Jun 2020 20:10:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592943014; bh=eT5nBUH5CEcBcPKoieCysrDhqP1ryBzXBcMEC1eSKPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FNgMTJahMM7aqpVFitgkpqzdsmGhBduEtGJZZHAa0wgJCH51FQktmg0bl+Izr+kTn QTImKGevxsL3lvOLOyhBKPu/8KdvbxSMnFNjIVO9Z+oQ5+6ee6RGJBulqWVoLZyNqD /7ciNSLcpBI+4KyRE+7t3ARNPJmXWF3+ebGQZzoM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Cornelia Huck , Alex Williamson , Sasha Levin Subject: [PATCH 5.7 225/477] vfio-pci: Mask cap zero Date: Tue, 23 Jun 2020 21:53:42 +0200 Message-Id: <20200623195418.216892760@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alex Williamson [ Upstream commit bc138db1b96264b9c1779cf18d5a3b186aa90066 ] The PCI Code and ID Assignment Specification changed capability ID 0 from reserved to a NULL capability in the v1.1 revision. The NULL capability is defined to include only the 16-bit capability header, ie. only the ID and next pointer. Unfortunately vfio-pci creates a map of config space, where ID 0 is used to reserve the standard type 0 header. Finding an actual capability with this ID therefore results in a bogus range marked in that map and conflicts with subsequent capabilities. As this seems to be a dummy capability anyway and we already support dropping capabilities, let's hide this one rather than delving into the potentially subtle dependencies within our map. Seen on an NVIDIA Tesla T4. Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/vfio/pci/vfio_pci_config.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index 43b95f9cdaf7b..814bcbe0dd4e9 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1462,7 +1462,12 @@ static int vfio_cap_init(struct vfio_pci_device *vdev) if (ret) return ret; - if (cap <= PCI_CAP_ID_MAX) { + /* + * ID 0 is a NULL capability, conflicting with our fake + * PCI_CAP_ID_BASIC. As it has no content, consider it + * hidden for now. + */ + if (cap && cap <= PCI_CAP_ID_MAX) { len = pci_cap_length[cap]; if (len == 0xFF) { /* Variable length */ len = vfio_cap_len(vdev, cap, pos); -- 2.25.1