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 22F82C433E0 for ; Mon, 29 Jun 2020 20:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECAD32067D for ; Mon, 29 Jun 2020 20:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593462599; bh=o/qUZQFam9A5VJ5KITQFxGBldNgpWr/uOXYmmbB8AaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iHB7eP1W8y5GJ3vcuZmfsk07J23k6WtjirhCRvxRoNE8DT0q1KVRTEstozczsKm6D 7sbuTBDkcn48Mb7NWXmC3gMVVnqbtRzh5M0Ik9cULxbhhkd/uCNNmX+gq6312nt1KP RpbHtZskh4vZwa2xlhXS+coA0KXVldFqYfGurJYc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389187AbgF2U35 (ORCPT ); Mon, 29 Jun 2020 16:29:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:37042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732494AbgF2TZV (ORCPT ); Mon, 29 Jun 2020 15:25:21 -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 CC43925398; Mon, 29 Jun 2020 15:41:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593445263; bh=o/qUZQFam9A5VJ5KITQFxGBldNgpWr/uOXYmmbB8AaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wpc6pJUKGmEvGQ0IugRF3UTeb4TvsdsX9zXchdHX9V1+8c6gIInv/35JBZD24WdrU /aexJnHEQJ4XJiKobAn7TTavc7G9kGUex9+UTQw1AIg4uDX0ksnzFvfEnS4WOx2mol IR2EWjhZBHRT28WjHApetKMtjPcIDGDop1n7krL4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alex Williamson , Cornelia Huck , Sasha Levin Subject: [PATCH 4.9 044/191] vfio-pci: Mask cap zero Date: Mon, 29 Jun 2020 11:37:40 -0400 Message-Id: <20200629154007.2495120-45-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629154007.2495120-1-sashal@kernel.org> References: <20200629154007.2495120-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:39+00:00 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 608b94a0ee0e0..ef45b8f5bf510 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1461,7 +1461,12 @@ 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