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 556EAC433DF for ; Thu, 18 Jun 2020 02:17:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 275CA20885 for ; Thu, 18 Jun 2020 02:17:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592446659; bh=ovU23r/Etbj70jTV5pACK96PBP4+CkrG2+2V3Ar5ZZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pB2kTO2GhSNn5IDybTGQvJlVfv+/cSmnS05cTxFHQ4mpVKUV3r2FiM/A8HQcJaAVX w4ZfeuCn0/GPp3Lf8IS/nS0UPJxhUB8aDBGy9goN68pbxX/cBX1nFTOM+2E6AuyapC g97L6385H5+Qdm0PlW5bQ+a5lxBM2yuvXsWq8PA4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387523AbgFRCRf (ORCPT ); Wed, 17 Jun 2020 22:17:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:51774 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730207AbgFRBTy (ORCPT ); Wed, 17 Jun 2020 21:19:54 -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 37D1221D90; Thu, 18 Jun 2020 01:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443193; bh=ovU23r/Etbj70jTV5pACK96PBP4+CkrG2+2V3Ar5ZZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e2uhbmvWyUEqBGQOfhuDOJiO5DLzDBCCWwlmwKQGOfpnCQE0kzBd2SMknNyrxyUBs X3ekBRGGCRn/XhN6G31aGK1yGz4RVWouYLhBxu7GY77bBfwJlTiARkKtGASg7F4eu2 1/q/JplJfz1TyzIEH9oSgnnvKVhI3f1bJajBhrkg= 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 5.4 154/266] vfio-pci: Mask cap zero Date: Wed, 17 Jun 2020 21:14:39 -0400 Message-Id: <20200618011631.604574-154-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618011631.604574-1-sashal@kernel.org> References: <20200618011631.604574-1-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 c4d0cf9a1ab9..d6359c37c9e5 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1460,7 +1460,12 @@ 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