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 E038BC433E1 for ; Thu, 18 Jun 2020 01:50:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B316B21941 for ; Thu, 18 Jun 2020 01:50:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592445050; bh=eRjf+cH66X240ZxJWU85UNzRiBGQvPd8fyerJQuc2vY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iFaBawjll3rV3h329K2n0Flk9TQaynTinomMM4MRbBlgoY/VsCD6dUcUxgsKxIvkK wciVl5YzN90QvZtjc0owk0TVtpwSUCpH4mYJsWbovDAaZElouhDzBhJbKG3xP3bv9O sAf4MG4dymwPL5MVdYvhHz48eh1I2FSkXoa+8ctA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731849AbgFRB1V (ORCPT ); Wed, 17 Jun 2020 21:27:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:35440 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731840AbgFRB1U (ORCPT ); Wed, 17 Jun 2020 21:27:20 -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 E4A3C20B1F; Thu, 18 Jun 2020 01:27:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443639; bh=eRjf+cH66X240ZxJWU85UNzRiBGQvPd8fyerJQuc2vY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EHFDT+JLw1rxruu/IBHeKUga0GQNEJEO1mTCTsZF0DYAzLJw5s8KjnUgAt+cMTpKq Sbk0eSvsb4MZBYzn102uvnSkyjk7oc9gMZR8CJZPCuWAh3eJxuHavDiribx5OTiZH1 6JB8EZ3PGrjPyXycI9CfXPDORYuhz/586dZqZKd0= 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 4.14 062/108] vfio-pci: Mask cap zero Date: Wed, 17 Jun 2020 21:25:14 -0400 Message-Id: <20200618012600.608744-62-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618012600.608744-1-sashal@kernel.org> References: <20200618012600.608744-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 c2d300bc37f6..36bc8f104e42 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1464,7 +1464,12 @@ 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