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=-8.3 required=3.0 tests=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, USER_AGENT_SANE_1 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 0551DC2BB55 for ; Wed, 15 Apr 2020 14:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5DA12076D for ; Wed, 15 Apr 2020 14:52:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="djamc2Oo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S371058AbgDOOwg (ORCPT ); Wed, 15 Apr 2020 10:52:36 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:59406 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S371043AbgDOOwd (ORCPT ); Wed, 15 Apr 2020 10:52:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586962351; 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=V4Hx+IN0pRdVO48Kb3j2SU1ntxZSQY+XRptloJnqRvo=; b=djamc2Ooo+0t2+lpxGoSyfiGDkkZ6cpwmjcPJ56mk/E8YSokgPme+keQGhtJZ1UOh50uF+ 1IE+lerSragKrNXQiMqA8OTIIP1yyUhUElyOjMHcwcXnMRLj6cPa/FnHXsgknGQMGCLRW2 VNTURADibp/1razxnTEynETvZnDuViM= 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-151-UJ0WusaKNHC3XykYzkbsIw-1; Wed, 15 Apr 2020 10:52:22 -0400 X-MC-Unique: UJ0WusaKNHC3XykYzkbsIw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7B39018C8C0C; Wed, 15 Apr 2020 14:52:19 +0000 (UTC) Received: from [10.36.115.53] (ovpn-115-53.ams2.redhat.com [10.36.115.53]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 807A89F9B6; Wed, 15 Apr 2020 14:52:12 +0000 (UTC) Subject: Re: [PATCH v11 01/13] iommu: Introduce attach/detach_pasid_table API To: Jacob Pan Cc: eric.auger.pro@gmail.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, joro@8bytes.org, maz@kernel.org, robin.murphy@arm.com, jean-philippe@linaro.org, zhangfei.gao@linaro.org, shameerali.kolothum.thodi@huawei.com, alex.williamson@redhat.com, yi.l.liu@intel.com, peter.maydell@linaro.org, zhangfei.gao@gmail.com, tn@semihalf.com, zhangfei.gao@foxmail.com, bbhushan2@marvell.com References: <20200414150607.28488-1-eric.auger@redhat.com> <20200414150607.28488-2-eric.auger@redhat.com> <20200414151548.658a0401@jacob-builder> From: Auger Eric Message-ID: Date: Wed, 15 Apr 2020 16:52:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20200414151548.658a0401@jacob-builder> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Jacob, On 4/15/20 12:15 AM, Jacob Pan wrote: > Hi Eric, > > There are some discussions about how to size the uAPI data. > https://lkml.org/lkml/2020/4/14/939 > > I think the problem with the current scheme is that when uAPI data gets > extended, if VFIO continue to use: > > minsz = offsetofend(struct vfio_iommu_type1_set_pasid_table, config); > if (copy_from_user(&spt, (void __user *)arg, minsz)) > > It may copy more data from user than what was setup by the user. > > So, as suggested by Alex, we could add argsz to the IOMMU uAPI struct. > So if argsz > minsz, then fail the attach_table since kernel might be > old, doesn't know about the extra data. > If argsz <= minsz, kernel can support the attach_table but must process > the data based on flags or config. So I guess we would need both an argsz _u32 + a new flag _u32 right? I am ok with that idea. Besides how will you manage for existing IOMMU UAPIs? At some point you envisionned to have a getter at iommu api level to retrieve the size of a structure for a given version, right? Thanks Eric > > Does it make sense to you? > > > On Tue, 14 Apr 2020 17:05:55 +0200 > Eric Auger wrote: > >> From: Jacob Pan >> >> In virtualization use case, when a guest is assigned >> a PCI host device, protected by a virtual IOMMU on the guest, >> the physical IOMMU must be programmed to be consistent with >> the guest mappings. If the physical IOMMU supports two >> translation stages it makes sense to program guest mappings >> onto the first stage/level (ARM/Intel terminology) while the host >> owns the stage/level 2. >> >> In that case, it is mandated to trap on guest configuration >> settings and pass those to the physical iommu driver. >> >> This patch adds a new API to the iommu subsystem that allows >> to set/unset the pasid table information. >> >> A generic iommu_pasid_table_config struct is introduced in >> a new iommu.h uapi header. This is going to be used by the VFIO >> user API. >> >> Signed-off-by: Jean-Philippe Brucker >> Signed-off-by: Liu, Yi L >> Signed-off-by: Ashok Raj >> Signed-off-by: Jacob Pan >> Signed-off-by: Eric Auger >> Reviewed-by: Jean-Philippe Brucker >> --- >> drivers/iommu/iommu.c | 19 ++++++++++++++ >> include/linux/iommu.h | 18 ++++++++++++++ >> include/uapi/linux/iommu.h | 51 >> ++++++++++++++++++++++++++++++++++++++ 3 files changed, 88 >> insertions(+) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 2b471419e26c..b71ad56f8c99 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -1723,6 +1723,25 @@ int iommu_sva_unbind_gpasid(struct >> iommu_domain *domain, struct device *dev, } >> EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); >> >> +int iommu_attach_pasid_table(struct iommu_domain *domain, >> + struct iommu_pasid_table_config *cfg) >> +{ >> + if (unlikely(!domain->ops->attach_pasid_table)) >> + return -ENODEV; >> + >> + return domain->ops->attach_pasid_table(domain, cfg); >> +} >> +EXPORT_SYMBOL_GPL(iommu_attach_pasid_table); >> + >> +void iommu_detach_pasid_table(struct iommu_domain *domain) >> +{ >> + if (unlikely(!domain->ops->detach_pasid_table)) >> + return; >> + >> + domain->ops->detach_pasid_table(domain); >> +} >> +EXPORT_SYMBOL_GPL(iommu_detach_pasid_table); >> + >> static void __iommu_detach_device(struct iommu_domain *domain, >> struct device *dev) >> { >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index 7ef8b0bda695..3e1057c3585a 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -248,6 +248,8 @@ struct iommu_iotlb_gather { >> * @cache_invalidate: invalidate translation caches >> * @sva_bind_gpasid: bind guest pasid and mm >> * @sva_unbind_gpasid: unbind guest pasid and mm >> + * @attach_pasid_table: attach a pasid table >> + * @detach_pasid_table: detach the pasid table >> * @pgsize_bitmap: bitmap of all possible supported page sizes >> * @owner: Driver module providing these ops >> */ >> @@ -307,6 +309,9 @@ struct iommu_ops { >> void *drvdata); >> void (*sva_unbind)(struct iommu_sva *handle); >> int (*sva_get_pasid)(struct iommu_sva *handle); >> + int (*attach_pasid_table)(struct iommu_domain *domain, >> + struct iommu_pasid_table_config >> *cfg); >> + void (*detach_pasid_table)(struct iommu_domain *domain); >> >> int (*page_response)(struct device *dev, >> struct iommu_fault_event *evt, >> @@ -446,6 +451,9 @@ extern int iommu_sva_bind_gpasid(struct >> iommu_domain *domain, struct device *dev, struct >> iommu_gpasid_bind_data *data); extern int >> iommu_sva_unbind_gpasid(struct iommu_domain *domain, struct device >> *dev, ioasid_t pasid); +extern int iommu_attach_pasid_table(struct >> iommu_domain *domain, >> + struct iommu_pasid_table_config >> *cfg); +extern void iommu_detach_pasid_table(struct iommu_domain >> *domain); extern struct iommu_domain *iommu_get_domain_for_dev(struct >> device *dev); extern struct iommu_domain *iommu_get_dma_domain(struct >> device *dev); extern int iommu_map(struct iommu_domain *domain, >> unsigned long iova, @@ -1048,6 +1056,16 @@ iommu_aux_get_pasid(struct >> iommu_domain *domain, struct device *dev) return -ENODEV; >> } >> >> +static inline >> +int iommu_attach_pasid_table(struct iommu_domain *domain, >> + struct iommu_pasid_table_config *cfg) >> +{ >> + return -ENODEV; >> +} >> + >> +static inline >> +void iommu_detach_pasid_table(struct iommu_domain *domain) {} >> + >> static inline struct iommu_sva * >> iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void >> *drvdata) { >> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >> index 4ad3496e5c43..8d00be10dc6d 100644 >> --- a/include/uapi/linux/iommu.h >> +++ b/include/uapi/linux/iommu.h >> @@ -321,4 +321,55 @@ struct iommu_gpasid_bind_data { >> }; >> }; >> >> +/** >> + * struct iommu_pasid_smmuv3 - ARM SMMUv3 Stream Table Entry stage 1 >> related >> + * information >> + * @version: API version of this structure >> + * @s1fmt: STE s1fmt (format of the CD table: single CD, linear table >> + * or 2-level table) >> + * @s1dss: STE s1dss (specifies the behavior when @pasid_bits != 0 >> + * and no PASID is passed along with the incoming >> transaction) >> + * @padding: reserved for future use (should be zero) >> + * >> + * The PASID table is referred to as the Context Descriptor (CD) >> table on ARM >> + * SMMUv3. Please refer to the ARM SMMU 3.x spec (ARM IHI 0070A) for >> full >> + * details. >> + */ >> +struct iommu_pasid_smmuv3 { >> +#define PASID_TABLE_SMMUV3_CFG_VERSION_1 1 >> + __u32 version; >> + __u8 s1fmt; >> + __u8 s1dss; >> + __u8 padding[2]; >> +}; >> + >> +/** >> + * struct iommu_pasid_table_config - PASID table data used to bind >> guest PASID >> + * table to the host IOMMU >> + * @version: API version to prepare for future extensions >> + * @format: format of the PASID table >> + * @base_ptr: guest physical address of the PASID table >> + * @pasid_bits: number of PASID bits used in the PASID table >> + * @config: indicates whether the guest translation stage must >> + * be translated, bypassed or aborted. >> + * @padding: reserved for future use (should be zero) >> + * @smmuv3: table information when @format is >> %IOMMU_PASID_FORMAT_SMMUV3 >> + */ >> +struct iommu_pasid_table_config { >> +#define PASID_TABLE_CFG_VERSION_1 1 >> + __u32 version; >> +#define IOMMU_PASID_FORMAT_SMMUV3 1 >> + __u32 format; >> + __u64 base_ptr; >> + __u8 pasid_bits; >> +#define IOMMU_PASID_CONFIG_TRANSLATE 1 >> +#define IOMMU_PASID_CONFIG_BYPASS 2 >> +#define IOMMU_PASID_CONFIG_ABORT 3 >> + __u8 config; >> + __u8 padding[6]; >> + union { >> + struct iommu_pasid_smmuv3 smmuv3; >> + }; >> +}; >> + >> #endif /* _UAPI_IOMMU_H */ > > [Jacob Pan] >