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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 96A12C282C0 for ; Fri, 25 Jan 2019 08:55:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DB6E218D0 for ; Fri, 25 Jan 2019 08:55:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728604AbfAYIza (ORCPT ); Fri, 25 Jan 2019 03:55:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36504 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726200AbfAYIz3 (ORCPT ); Fri, 25 Jan 2019 03:55:29 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8AC58C0C49D7; Fri, 25 Jan 2019 08:55:28 +0000 (UTC) Received: from [10.36.116.147] (ovpn-116-147.ams2.redhat.com [10.36.116.147]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CEAA717563; Fri, 25 Jan 2019 08:55:21 +0000 (UTC) Subject: Re: [RFC v3 01/21] iommu: Introduce set_pasid_table API From: Auger Eric To: Jean-Philippe Brucker , eric.auger.pro@gmail.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, joro@8bytes.org, alex.williamson@redhat.com, jacob.jun.pan@linux.intel.com, yi.l.liu@linux.intel.com, will.deacon@arm.com, robin.murphy@arm.com Cc: marc.zyngier@arm.com, peter.maydell@linaro.org, kevin.tian@intel.com, ashok.raj@intel.com, christoffer.dall@arm.com References: <20190108102633.17482-1-eric.auger@redhat.com> <20190108102633.17482-2-eric.auger@redhat.com> <0203e4ce-eace-be6e-7e95-5a02c069c8e8@arm.com> Message-ID: <70ed7cbe-3e53-fcc5-00f0-47815883c530@redhat.com> Date: Fri, 25 Jan 2019 09:55:20 +0100 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: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 25 Jan 2019 08:55:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jean-Philippe, On 1/25/19 9:39 AM, Auger Eric wrote: > Hi Jean-Philippe, > > On 1/11/19 7:16 PM, Jean-Philippe Brucker wrote: >> On 08/01/2019 10:26, 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 a 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/VTD terminology) while to 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 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. We foresee at least two specializations of this struct, >>> for PASID table passing and ARM SMMUv3. >> >> Last sentence is a bit confusing. With SMMUv3 it is also used for the >> PASID table, even when it only has one entry and PASID is disabled. > OK removed >> >>> 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 >>> >>> --- >>> >>> This patch generalizes the API introduced by Jacob & co-authors in >>> https://lwn.net/Articles/754331/ >>> >>> v2 -> v3: >>> - replace unbind/bind by set_pasid_table >>> - move table pointer and pasid bits in the generic part of the struct >>> >>> v1 -> v2: >>> - restore the original pasid table name >>> - remove the struct device * parameter in the API >>> - reworked iommu_pasid_smmuv3 >>> --- >>> drivers/iommu/iommu.c | 10 ++++++++ >>> include/linux/iommu.h | 14 +++++++++++ >>> include/uapi/linux/iommu.h | 50 ++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 74 insertions(+) >>> create mode 100644 include/uapi/linux/iommu.h >>> >>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >>> index 3ed4db334341..0f2b7f1fc7c8 100644 >>> --- a/drivers/iommu/iommu.c >>> +++ b/drivers/iommu/iommu.c >>> @@ -1393,6 +1393,16 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) >>> } >>> EXPORT_SYMBOL_GPL(iommu_attach_device); >>> >>> +int iommu_set_pasid_table(struct iommu_domain *domain, >>> + struct iommu_pasid_table_config *cfg) >>> +{ >>> + if (unlikely(!domain->ops->set_pasid_table)) >>> + return -ENODEV; >>> + >>> + return domain->ops->set_pasid_table(domain, cfg); >>> +} >>> +EXPORT_SYMBOL_GPL(iommu_set_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 e90da6b6f3d1..1da2a2357ea4 100644 >>> --- a/include/linux/iommu.h >>> +++ b/include/linux/iommu.h >>> @@ -25,6 +25,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> #define IOMMU_READ (1 << 0) >>> #define IOMMU_WRITE (1 << 1) >>> @@ -184,6 +185,7 @@ struct iommu_resv_region { >>> * @domain_window_disable: Disable a particular window for a domain >>> * @of_xlate: add OF master IDs to iommu grouping >>> * @pgsize_bitmap: bitmap of all possible supported page sizes >>> + * @set_pasid_table: set pasid table >>> */ >>> struct iommu_ops { >>> bool (*capable)(enum iommu_cap); >>> @@ -226,6 +228,9 @@ struct iommu_ops { >>> int (*of_xlate)(struct device *dev, struct of_phandle_args *args); >>> bool (*is_attach_deferred)(struct iommu_domain *domain, struct device *dev); >>> >>> + int (*set_pasid_table)(struct iommu_domain *domain, >>> + struct iommu_pasid_table_config *cfg); >>> + >>> unsigned long pgsize_bitmap; >>> }; >>> >>> @@ -287,6 +292,8 @@ extern int iommu_attach_device(struct iommu_domain *domain, >>> struct device *dev); >>> extern void iommu_detach_device(struct iommu_domain *domain, >>> struct device *dev); >>> +extern int iommu_set_pasid_table(struct iommu_domain *domain, >>> + struct iommu_pasid_table_config *cfg); >>> 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, >>> @@ -696,6 +703,13 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) >>> return NULL; >>> } >>> >>> +static inline >>> +int iommu_set_pasid_table(struct iommu_domain *domain, >>> + struct iommu_pasid_table_config *cfg) >>> +{ >>> + return -ENODEV; >>> +} >>> + >>> #endif /* CONFIG_IOMMU_API */ >>> >>> #ifdef CONFIG_IOMMU_DEBUGFS >>> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >>> new file mode 100644 >>> index 000000000000..7a7cf7a3de7c >>> --- /dev/null >>> +++ b/include/uapi/linux/iommu.h >>> @@ -0,0 +1,50 @@ >>> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ >>> +/* >>> + * IOMMU user API definitions >>> + * >>> + * >>> + * This program is free software; you can redistribute it and/or modify >>> + * it under the terms of the GNU General Public License version 2 as >>> + * published by the Free Software Foundation. >> >> I don't think we need both the boilerplate and the SPDX header > OK I only kept the SPDX header. >> >>> + */ >>> + >>> +#ifndef _UAPI_IOMMU_H >>> +#define _UAPI_IOMMU_H >>> + >>> +#include >>> + >>> +/** >>> + * SMMUv3 Stream Table Entry stage 1 related information >>> + * @abort: shall the STE lead to abort >>> + * @s1fmt: STE s1fmt field as set by the guest >>> + * @s1dss: STE s1dss as set by the guest >>> + * All field names match the smmu 3.0/3.1 spec (ARM IHI 0070A) >> >> Not really the case for @abort. Could you clarify whether @abort is >> valid in combination with @bypass? >> abort corresponds to !Config[2]. In that case the spec says "report > abort to device, no event recorded". S1 bypass corresponds to > Config=0b1x0. What about removing abort in the SMMUv3 specific part and > encode the stage state in the generic part. See below proposal ... >>> + */ >>> +struct iommu_pasid_smmuv3 { >>> + __u8 abort; >>> + __u8 s1fmt; >>> + __u8 s1dss; >>> +}; >>> + >>> +/** >>> + * PASID table data used to bind guest PASID table to the host IOMMU >>> + * Note PASID table corresponds to the Context Table on ARM SMMUv3. >>> + * >>> + * @version: API version to prepare for future extensions >>> + * @format: format of the PASID table >>> + * >>> + */ >>> +struct iommu_pasid_table_config { >>> +#define PASID_TABLE_CFG_VERSION_1 1 >>> + __u32 version; >>> +#define IOMMU_PASID_FORMAT_SMMUV3 (1 << 0) >>> + __u32 format; >>> + __u64 base_ptr; >>> + __u8 pasid_bits; >>> + __u8 bypass > #define IOMMU_PASID_STREAM_ABORT (1 << 0) > #define IOMMU_PASID_STREAM_BYPASS (1 << 1) > #define IOMMU_PASID_STREAM_TRANSLATE (1 << 2) > __u8 config; Sorry for the confusion, we don't want a bitfield here as those values are exclusive. What about: struct iommu_pasid_table_config { #define PASID_TABLE_CFG_VERSION_1 1 __u32 version; #define IOMMU_PASID_FORMAT_SMMUV3 (1 << 0) __u32 format; __u64 base_ptr; __u8 pasid_bits; #define IOMMU_PASID_CONFIG_BYPASS 1 #define IOMMU_PASID_CONFIG_ABORT 2 #define IOMMU_PASID_CONFIG_TRANSLATE 3 __u8 config; __u8 padding[6]; union { struct iommu_pasid_smmuv3 smmuv3; }; }; Thanks Eric >> >> We need some padding, in case someone adds a new struct to the union >> that requires 64-byte alignment > OK >> >> And 'bypass' might not be the right name if we're making it common, >> maybe 'reset' would be clearer? Or we just need to explain that bypass >> is the initial state of a nesting domain > I will add such comment. To me the "bypass" terminology sounds clearer > than "reset" >> >> Thanks, >> Jean >> >>> + union { >>> + struct iommu_pasid_smmuv3 smmuv3; >>> + }; >>> +}; >>> + >>> +#endif /* _UAPI_IOMMU_H */ >>> >>