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 52F46C433DF for ; Thu, 18 Jun 2020 01:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22EEF22260 for ; Thu, 18 Jun 2020 01:33:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592444023; bh=P8963dETUzX8bx+UivL9M//VUnGMxCoatVm12LOeroY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TMKRlG2RCmLJ3PJrHPno6KEK6JMiaXjwTr9LoNw47y3OQmsYzJolYAMWUCcErh0M7 7BZqJ1GUj2uTXO5DLL12KnjlmTgGa0nY6HJzAEgX3rhkzcs3nIDjXeDYZiYQbhPSKo P05VeQtZK42as1VK7z0zQ/evmlF89eTmepWbfmVk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732548AbgFRBdl (ORCPT ); Wed, 17 Jun 2020 21:33:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:41310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732658AbgFRBa5 (ORCPT ); Wed, 17 Jun 2020 21:30:57 -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 4B4C520773; Thu, 18 Jun 2020 01:30:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443857; bh=P8963dETUzX8bx+UivL9M//VUnGMxCoatVm12LOeroY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q06kGMDXuWEIDj2jf0i7U7KDeeD33FH8FmysHchASxImM09QVca/5zlX2Od1UoqDD xV+LYpmFXJZcj68xdf4V0GJznlUfTzfVT4/swnG8c44cTU1MXRn8w87KfdjNshwRah NfJqr16HiHz82dxbW5NMso8LNK3KcOo6wVUuiOB8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alex Williamson , Cornelia Huck , Sasha Levin , kvm@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 40/60] vfio-pci: Mask cap zero Date: Wed, 17 Jun 2020 21:29:44 -0400 Message-Id: <20200618013004.610532-40-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618013004.610532-1-sashal@kernel.org> References: <20200618013004.610532-1-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: 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 bf65572f47a8..666b234acca0 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1405,7 +1405,12 @@ 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