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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 E6D28C433E2 for ; Fri, 11 Sep 2020 19:39:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A908E214F1 for ; Fri, 11 Sep 2020 19:39:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dx0vpN/l" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725902AbgIKTjK (ORCPT ); Fri, 11 Sep 2020 15:39:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21872 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgIKTjI (ORCPT ); Fri, 11 Sep 2020 15:39:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599853146; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XkONE/g0FLpiBamkrJndr/ZIJkzwsHn+tlSk2RJm3GY=; b=dx0vpN/lMZvssfUSPlJBWlQ4paQwJThQX+5rRkbkY19DSbr108vS7KKBqev9tqoUMd2Frl Fs7D+QCnAfjLAu9j2zMvxTkJee1v1zr3drQF1EM/asH3dQQll8oXf5CD+WX563cHwuV+vg 8GbvmPMbZ+PT9SL2ugDZ+3S5Ds5ArnY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-39-ArsGl1IMO6KvtIClzxqg5A-1; Fri, 11 Sep 2020 15:39:04 -0400 X-MC-Unique: ArsGl1IMO6KvtIClzxqg5A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2A81181CAFF; Fri, 11 Sep 2020 19:39:02 +0000 (UTC) Received: from w520.home (ovpn-112-71.phx2.redhat.com [10.3.112.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3F79E60C04; Fri, 11 Sep 2020 19:38:55 +0000 (UTC) Date: Fri, 11 Sep 2020 13:38:54 -0600 From: Alex Williamson To: Liu Yi L Cc: eric.auger@redhat.com, baolu.lu@linux.intel.com, joro@8bytes.org, kevin.tian@intel.com, jacob.jun.pan@linux.intel.com, ashok.raj@intel.com, jun.j.tian@intel.com, yi.y.sun@intel.com, jean-philippe@linaro.org, peterx@redhat.com, jasowang@redhat.com, hao.wu@intel.com, stefanha@gmail.com, iommu@lists.linux-foundation.org, kvm@vger.kernel.org Subject: Re: [PATCH v7 01/16] iommu: Report domain nesting info Message-ID: <20200911133854.0e6a919c@w520.home> In-Reply-To: <1599734733-6431-2-git-send-email-yi.l.liu@intel.com> References: <1599734733-6431-1-git-send-email-yi.l.liu@intel.com> <1599734733-6431-2-git-send-email-yi.l.liu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 10 Sep 2020 03:45:18 -0700 Liu Yi L wrote: > IOMMUs that support nesting translation needs report the capability info > to userspace. It gives information about requirements the userspace needs > to implement plus other features characterizing the physical implementation. > > This patch introduces a new IOMMU UAPI struct that gives information about > the nesting capabilities and features. This struct is supposed to be returned > by iommu_domain_get_attr() with DOMAIN_ATTR_NESTING attribute parameter, with > one domain whose type has been set to DOMAIN_ATTR_NESTING. > > Cc: Kevin Tian > CC: Jacob Pan > Cc: Alex Williamson > Cc: Eric Auger > Cc: Jean-Philippe Brucker > Cc: Joerg Roedel > Cc: Lu Baolu > Signed-off-by: Liu Yi L > Signed-off-by: Jacob Pan > --- > v6 -> v7: > *) rephrase the commit message, replace the @data[] field in struct > iommu_nesting_info with union per comments from Eric Auger. > > v5 -> v6: > *) rephrase the feature notes per comments from Eric Auger. > *) rename @size of struct iommu_nesting_info to @argsz. > > v4 -> v5: > *) address comments from Eric Auger. > > v3 -> v4: > *) split the SMMU driver changes to be a separate patch > *) move the @addr_width and @pasid_bits from vendor specific > part to generic part. > *) tweak the description for the @features field of struct > iommu_nesting_info. > *) add description on the @data[] field of struct iommu_nesting_info > > v2 -> v3: > *) remvoe cap/ecap_mask in iommu_nesting_info. > *) reuse DOMAIN_ATTR_NESTING to get nesting info. > *) return an empty iommu_nesting_info for SMMU drivers per Jean' > suggestion. > --- > include/uapi/linux/iommu.h | 76 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > index 1ebc23d..ff987e4 100644 > --- a/include/uapi/linux/iommu.h > +++ b/include/uapi/linux/iommu.h > @@ -341,4 +341,80 @@ struct iommu_gpasid_bind_data { > } vendor; > }; > > +/* > + * struct iommu_nesting_info_vtd - Intel VT-d specific nesting info. > + * > + * @flags: VT-d specific flags. Currently reserved for future > + * extension. must be set to 0. > + * @cap_reg: Describe basic capabilities as defined in VT-d capability > + * register. > + * @ecap_reg: Describe the extended capabilities as defined in VT-d > + * extended capability register. > + */ > +struct iommu_nesting_info_vtd { > + __u32 flags; > + __u64 cap_reg; > + __u64 ecap_reg; > +}; The vendor union has 8-byte alignment, so flags here will be 8-byte aligned, followed by a compiler dependent gap before the 8-byte fields. We should fill that gap with padding to make it deterministic for userspace. Thanks, Alex > + > +/* > + * struct iommu_nesting_info - Information for nesting-capable IOMMU. > + * userspace should check it before using > + * nesting capability. > + * > + * @argsz: size of the whole structure. > + * @flags: currently reserved for future extension. must set to 0. > + * @format: PASID table entry format, the same definition as struct > + * iommu_gpasid_bind_data @format. > + * @features: supported nesting features. > + * @addr_width: The output addr width of first level/stage translation > + * @pasid_bits: Maximum supported PASID bits, 0 represents no PASID > + * support. > + * @vendor: vendor specific data, structure type can be deduced from > + * @format field. > + * > + * +===============+======================================================+ > + * | feature | Notes | > + * +===============+======================================================+ > + * | SYSWIDE_PASID | IOMMU vendor driver sets it to mandate userspace | > + * | | to allocate PASID from kernel. All PASID allocation | > + * | | free must be mediated through the IOMMU UAPI. | > + * +---------------+------------------------------------------------------+ > + * | BIND_PGTBL | IOMMU vendor driver sets it to mandate userspace to | > + * | | bind the first level/stage page table to associated | > + * | | PASID (either the one specified in bind request or | > + * | | the default PASID of iommu domain), through IOMMU | > + * | | UAPI. | > + * +---------------+------------------------------------------------------+ > + * | CACHE_INVLD | IOMMU vendor driver sets it to mandate userspace to | > + * | | explicitly invalidate the IOMMU cache through IOMMU | > + * | | UAPI according to vendor-specific requirement when | > + * | | changing the 1st level/stage page table. | > + * +---------------+------------------------------------------------------+ > + * > + * data struct types defined for @format: > + * +================================+=====================================+ > + * | @format | data struct | > + * +================================+=====================================+ > + * | IOMMU_PASID_FORMAT_INTEL_VTD | struct iommu_nesting_info_vtd | > + * +--------------------------------+-------------------------------------+ > + * > + */ > +struct iommu_nesting_info { > + __u32 argsz; > + __u32 flags; > + __u32 format; > +#define IOMMU_NESTING_FEAT_SYSWIDE_PASID (1 << 0) > +#define IOMMU_NESTING_FEAT_BIND_PGTBL (1 << 1) > +#define IOMMU_NESTING_FEAT_CACHE_INVLD (1 << 2) > + __u32 features; > + __u16 addr_width; > + __u16 pasid_bits; > + __u8 padding[12]; > + /* Vendor specific data */ > + union { > + struct iommu_nesting_info_vtd vtd; > + } vendor; > +}; > + > #endif /* _UAPI_IOMMU_H */