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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DD52C433F5 for ; Thu, 5 May 2022 06:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244378AbiEEGeg (ORCPT ); Thu, 5 May 2022 02:34:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236110AbiEEGeZ (ORCPT ); Thu, 5 May 2022 02:34:25 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C2831A83F for ; Wed, 4 May 2022 23:30:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651732245; x=1683268245; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=FWdkTJQPgfah88qi8uE8TAWSXAdTDOOpVO7WtKyi8WI=; b=DrODq11zGXEEqZgmckXDhNsZn5q4UbDaS5hYOftg4Vo73VrCAOEqV0Y7 qoD0m81q1iv4q/gsv+L5mi3EstoBwfXZo1o7OJI4U8BH8OxSZcj9hDM7+ xXDjKz7xP/TWh9uOZ8HBeLLQKHoQewdLcJUV4Sztl4WtzkI/EAlGPmMC6 Vmpq5lOv27iDo5mjCWzLQ/dO6BHj8qi0T34+RgerU2Js3u8IPgI7gfvUe e7dza+m3GYHpIn2xQotdpdA2N60xk2t9+NBtkeUmv5VXhF8siF7Qkg/NE kc/HkvmBl9ZhTKGGfDpQUSH4veSfdGJ7uSG5KbQuwirV50rLDAC0gRsH6 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10337"; a="267610330" X-IronPort-AV: E=Sophos;i="5.91,200,1647327600"; d="scan'208";a="267610330" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2022 23:28:18 -0700 X-IronPort-AV: E=Sophos;i="5.91,200,1647327600"; d="scan'208";a="563093444" Received: from minhaowa-mobl.ccr.corp.intel.com (HELO [10.255.30.75]) ([10.255.30.75]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2022 23:28:12 -0700 Message-ID: Date: Thu, 5 May 2022 14:28:09 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v5 03/12] iommu: Add attach/detach_dev_pasid domain ops Content-Language: en-US To: Jean-Philippe Brucker Cc: Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Dave Jiang , Vinod Koul , Eric Auger , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20220502014842.991097-1-baolu.lu@linux.intel.com> <20220502014842.991097-4-baolu.lu@linux.intel.com> From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/5/4 02:07, Jean-Philippe Brucker wrote: > On Mon, May 02, 2022 at 09:48:33AM +0800, Lu Baolu wrote: >> Attaching an IOMMU domain to a PASID of a device is a generic operation >> for modern IOMMU drivers which support PASID-granular DMA address >> translation. Currently visible usage scenarios include (but not limited): >> >> - SVA (Shared Virtual Address) >> - kernel DMA with PASID >> - hardware-assist mediated device >> >> This adds a pair of common domain ops for this purpose and adds helpers >> to attach/detach a domain to/from a {device, PASID}. Some buses, like >> PCI, route packets without considering the PASID value. Thus a DMA target >> address with PASID might be treated as P2P if the address falls into the >> MMIO BAR of other devices in the group. To make things simple, these >> interfaces only apply to devices belonging to the singleton groups, and >> the singleton is immutable in fabric i.e. not affected by hotplug. >> >> Signed-off-by: Lu Baolu > > Reviewed-by: Jean-Philippe Brucker > > just a nit below > >> --- >> include/linux/iommu.h | 21 ++++++++++++ >> drivers/iommu/iommu.c | 76 +++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 97 insertions(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index b8ffaf2cb1d0..ab36244d4e94 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -263,6 +263,8 @@ struct iommu_ops { >> * struct iommu_domain_ops - domain specific operations >> * @attach_dev: attach an iommu domain to a device >> * @detach_dev: detach an iommu domain from a device >> + * @attach_dev_pasid: attach an iommu domain to a pasid of device >> + * @detach_dev_pasid: detach an iommu domain from a pasid of device >> * @map: map a physically contiguous memory region to an iommu domain >> * @map_pages: map a physically contiguous set of pages of the same size to >> * an iommu domain. >> @@ -283,6 +285,10 @@ struct iommu_ops { >> struct iommu_domain_ops { >> int (*attach_dev)(struct iommu_domain *domain, struct device *dev); >> void (*detach_dev)(struct iommu_domain *domain, struct device *dev); >> + int (*attach_dev_pasid)(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> + void (*detach_dev_pasid)(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> >> int (*map)(struct iommu_domain *domain, unsigned long iova, >> phys_addr_t paddr, size_t size, int prot, gfp_t gfp); >> @@ -678,6 +684,10 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); >> void iommu_group_release_dma_owner(struct iommu_group *group); >> bool iommu_group_dma_owner_claimed(struct iommu_group *group); >> >> +int iommu_attach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> +void iommu_detach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> #else /* CONFIG_IOMMU_API */ >> >> struct iommu_ops {}; >> @@ -1051,6 +1061,17 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) >> { >> return false; >> } >> + >> +static inline int iommu_attach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid) >> +{ >> + return -ENODEV; >> +} >> + >> +static inline void iommu_detach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid) >> +{ >> +} >> #endif /* CONFIG_IOMMU_API */ >> >> /** >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 29906bc16371..89c9d19ddb28 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -38,6 +38,7 @@ struct iommu_group { >> struct kobject kobj; >> struct kobject *devices_kobj; >> struct list_head devices; >> + struct xarray pasid_array; >> struct mutex mutex; >> void *iommu_data; >> void (*iommu_data_release)(void *iommu_data); >> @@ -630,6 +631,7 @@ struct iommu_group *iommu_group_alloc(void) >> mutex_init(&group->mutex); >> INIT_LIST_HEAD(&group->devices); >> INIT_LIST_HEAD(&group->entry); >> + xa_init(&group->pasid_array); >> >> ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); >> if (ret < 0) { >> @@ -3190,3 +3192,77 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group) >> return user; >> } >> EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); >> + >> +/* >> + * Use standard PCI bus topology and isolation features to check immutable >> + * singleton. Otherwise, assume the bus is static and then singleton can >> + * know from the device count in the group. >> + */ > > The comment doesn't really add anything that can't be directly understood > from the code. Yes. It's fine to remove it. Best regards, baolu