From patchwork Thu May 28 20:57:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ashok Raj X-Patchwork-Id: 11576895 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 43089739 for ; Thu, 28 May 2020 20:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 336812075F for ; Thu, 28 May 2020 20:57:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407319AbgE1U5y (ORCPT ); Thu, 28 May 2020 16:57:54 -0400 Received: from mga14.intel.com ([192.55.52.115]:34385 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406652AbgE1U5w (ORCPT ); Thu, 28 May 2020 16:57:52 -0400 IronPort-SDR: KLyWNveOuxdJQO1WWOZCqffoltcSpHa4n4GED4KHfeFuXaU7jtYdTHb6vl0CKYRv3WO8LZ0/s8 cYc10AEnGrmw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2020 13:57:51 -0700 IronPort-SDR: g97HzgpaCyP0RNtnAdIcT04mBb3TUUtTVMkD+bqeBN0v9vYO4vCsG/uu90zlloqNGBS/nnZ5Ha 1pR/6s9+n1sA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,446,1583222400"; d="scan'208";a="285292590" Received: from ssp-nc-cdi361.jf.intel.com (HELO otc-nc-03.jf.intel.com) ([10.54.39.25]) by orsmga002.jf.intel.com with ESMTP; 28 May 2020 13:57:51 -0700 From: Ashok Raj To: linux-pci@vger.kernel.org, Bjorn Helgaas , Joerg Roedel Cc: Ashok Raj , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Lu Baolu , Alex Williamson , Darrel Goeddel , Mark Scott , Romil Sharma Subject: [PATCH] PCI: Relax ACS requirement for Intel RCiEP devices. Date: Thu, 28 May 2020 13:57:42 -0700 Message-Id: <1590699462-7131-1-git-send-email-ashok.raj@intel.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org All Intel platforms guarantee that all root complex implementations must send transactions up to IOMMU for address translations. Hence for RCiEP devices that are Vendor ID Intel, can claim exception for lack of ACS support. 3.16 Root-Complex Peer to Peer Considerations When DMA remapping is enabled, peer-to-peer requests through the Root-Complex must be handled as follows: • The input address in the request is translated (through first-level, second-level or nested translation) to a host physical address (HPA). The address decoding for peer addresses must be done only on the translated HPA. Hardware implementations are free to further limit peer-to-peer accesses to specific host physical address regions (or to completely disallow peer-forwarding of translated requests). • Since address translation changes the contents (address field) of the PCI Express Transaction Layer Packet (TLP), for PCI Express peer-to-peer requests with ECRC, the Root-Complex hardware must use the new ECRC (re-computed with the translated address) if it decides to forward the TLP as a peer request. • Root-ports, and multi-function root-complex integrated endpoints, may support additional peerto-peer control features by supporting PCI Express Access Control Services (ACS) capability. Refer to ACS capability in PCI Express specifications for details. Since Linux didn't give special treatment to allow this exception, certain RCiEP MFD devices are getting grouped in a single iommu group. This doesn't permit a single device to be assigned to a guest for instance. In one vendor system: Device 14.x were grouped in a single IOMMU group. /sys/kernel/iommu_groups/5/devices/0000:00:14.0 /sys/kernel/iommu_groups/5/devices/0000:00:14.2 /sys/kernel/iommu_groups/5/devices/0000:00:14.3 After the patch: /sys/kernel/iommu_groups/5/devices/0000:00:14.0 /sys/kernel/iommu_groups/5/devices/0000:00:14.2 /sys/kernel/iommu_groups/6/devices/0000:00:14.3 <<< new group 14.0 and 14.2 are integrated devices, but legacy end points. Whereas 14.3 was a PCIe compliant RCiEP. 00:14.3 Network controller: Intel Corporation Device 9df0 (rev 30) Capabilities: [40] Express (v2) Root Complex Integrated Endpoint, MSI 00 This permits assigning this device to a guest VM. Fixes: f096c061f552 ("iommu: Rework iommu_group_get_for_pci_dev()") Signed-off-by: Ashok Raj To: Joerg Roedel To: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org Cc: iommu@lists.linux-foundation.org Cc: Lu Baolu Cc: Alex Williamson Cc: Darrel Goeddel Cc: Mark Scott , Cc: Romil Sharma Cc: Ashok Raj Reviewed-by: Alex Williamson Tested-by: Darrel Goeddel --- v2: Moved functionality from iommu to pci quirks - Alex Williamson drivers/pci/quirks.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 28c9a2409c50..63373ca0a3fe 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4682,6 +4682,20 @@ static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags) PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT); } +static int pci_quirk_rciep_acs(struct pci_dev *dev, u16 acs_flags) +{ + /* + * RCiEP's are required to allow p2p only on translated addresses. + * Refer to Intel VT-d specification Section 3.16 Root-Complex Peer + * to Peer Considerations + */ + if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END) + return -ENOTTY; + + return pci_acs_ctrl_enabled(acs_flags, + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF); +} + static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags) { /* @@ -4764,6 +4778,7 @@ static const struct pci_dev_acs_enabled { /* I219 */ { PCI_VENDOR_ID_INTEL, 0x15b7, pci_quirk_mf_endpoint_acs }, { PCI_VENDOR_ID_INTEL, 0x15b8, pci_quirk_mf_endpoint_acs }, + { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_rciep_acs }, /* QCOM QDF2xxx root ports */ { PCI_VENDOR_ID_QCOM, 0x0400, pci_quirk_qcom_rp_acs }, { PCI_VENDOR_ID_QCOM, 0x0401, pci_quirk_qcom_rp_acs },