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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 49B3BC4332E for ; Sun, 22 Mar 2020 12:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B6FE20724 for ; Sun, 22 Mar 2020 12:30:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727261AbgCVMav (ORCPT ); Sun, 22 Mar 2020 08:30:51 -0400 Received: from mga12.intel.com ([192.55.52.136]:40476 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727135AbgCVMal (ORCPT ); Sun, 22 Mar 2020 08:30:41 -0400 IronPort-SDR: V1kXPV2WSuFsHT2IqHFalK5+fskwD2ZRhcwGj+oY3N/rrmcAwL415m+tfowAZsnkok6PDfX2ax Cxk8CNOmB1Vg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2020 05:30:39 -0700 IronPort-SDR: +Ixx8tQ4PuyCq3kxQRsbUgAhz1FaTZuqouu8hIUEtDk0yK2tI91DdTh5z5zdl7vOquVcfh0Urc zBv5rD8sWLcg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,292,1580803200"; d="scan'208";a="239664402" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga008.jf.intel.com with ESMTP; 22 Mar 2020 05:30:38 -0700 From: Liu Yi L To: qemu-devel@nongnu.org, alex.williamson@redhat.com, peterx@redhat.com Cc: eric.auger@redhat.com, pbonzini@redhat.com, mst@redhat.com, david@gibson.dropbear.id.au, kevin.tian@intel.com, yi.l.liu@intel.com, jun.j.tian@intel.com, yi.y.sun@intel.com, kvm@vger.kernel.org, hao.wu@intel.com, jean-philippe@linaro.org, Jacob Pan , Yi Sun , Richard Henderson , Eduardo Habkost Subject: [PATCH v1 17/22] intel_iommu: do not pass down pasid bind for PASID #0 Date: Sun, 22 Mar 2020 05:36:14 -0700 Message-Id: <1584880579-12178-18-git-send-email-yi.l.liu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584880579-12178-1-git-send-email-yi.l.liu@intel.com> References: <1584880579-12178-1-git-send-email-yi.l.liu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org RID_PASID field was introduced in VT-d 3.0 spec, it is used for DMA requests w/o PASID in scalable mode VT-d. It is also known as IOVA. And in VT-d 3.1 spec, there is definition on it: "Implementations not supporting RID_PASID capability (ECAP_REG.RPS is 0b), use a PASID value of 0 to perform address translation for requests without PASID." This patch adds a check against the PASIDs which are going to be bound to device. For PASID #0, it is not necessary to pass down pasid bind request for it since PASID #0 is used as RID_PASID for DMA requests without pasid. Further reason is current Intel vIOMMU supports gIOVA by shadowing guest 2nd level page table. However, in future, if guest IOMMU driver uses 1st level page table to store IOVA mappings, then guest IOVA support will also be done via nested translation. When gIOVA is over FLPT, then vIOMMU should pass down the pasid bind request for PASID #0 to host, host needs to bind the guest IOVA page table to a proper PASID. e.g PASID value in RID_PASID field for PF/VF if ECAP_REG.RPS is clear or default PASID for ADI (Assignable Device Interface in Scalable IOV solution). IOVA over FLPT support on Intel VT-d: https://lkml.org/lkml/2019/9/23/297 Cc: Kevin Tian Cc: Jacob Pan Cc: Peter Xu Cc: Yi Sun Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Signed-off-by: Liu Yi L --- hw/i386/intel_iommu.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 1e0ccde..b007715 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -1886,6 +1886,16 @@ static int vtd_bind_guest_pasid(IntelIOMMUState *s, VTDBus *vtd_bus, struct iommu_gpasid_bind_data *g_bind_data; int ret = -1; + if (pasid < VTD_MIN_HPASID) { + /* + * If pasid < VTD_HPASID_MIN, this pasid is not allocated + * from host. No need to pass down the changes on it to host. + * TODO: when IOVA over FLPT is ready, this switch should be + * refined. + */ + return 0; + } + vtd_dev_icx = vtd_bus->dev_icx[devfn]; if (!vtd_dev_icx) { return -EINVAL; -- 2.7.4