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 14BB4C43387 for ; Fri, 11 Jan 2019 11:06:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9DE32177B for ; Fri, 11 Jan 2019 11:06:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732262AbfAKLGu (ORCPT ); Fri, 11 Jan 2019 06:06:50 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:53152 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730124AbfAKLGr (ORCPT ); Fri, 11 Jan 2019 06:06:47 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0381A80D; Fri, 11 Jan 2019 03:06:47 -0800 (PST) Received: from [10.1.197.78] (ostrya.cambridge.arm.com [10.1.197.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 60B843F694; Fri, 11 Jan 2019 03:06:44 -0800 (PST) Subject: Re: [RFC v3 14/21] iommu: introduce device fault data To: Jacob Pan , Eric Auger Cc: "yi.l.liu@linux.intel.com" , "kevin.tian@intel.com" , "alex.williamson@redhat.com" , "ashok.raj@intel.com" , "kvm@vger.kernel.org" , "peter.maydell@linaro.org" , Will Deacon , "linux-kernel@vger.kernel.org" , Christoffer Dall , Marc Zyngier , "iommu@lists.linux-foundation.org" , Robin Murphy , "kvmarm@lists.cs.columbia.edu" , "eric.auger.pro@gmail.com" References: <20190108102633.17482-1-eric.auger@redhat.com> <20190108102633.17482-15-eric.auger@redhat.com> <20190110104544.26f3bcb1@jacob-builder> From: Jean-Philippe Brucker Message-ID: <63a19100-c3dd-9dbd-b37a-9dfbe254459e@arm.com> Date: Fri, 11 Jan 2019 11:06:29 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20190110104544.26f3bcb1@jacob-builder> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/01/2019 18:45, Jacob Pan wrote: > On Tue, 8 Jan 2019 11:26:26 +0100 > Eric Auger wrote: > >> From: Jacob Pan >> >> Device faults detected by IOMMU can be reported outside IOMMU >> subsystem for further processing. This patch intends to provide >> a generic device fault data such that device drivers can be >> communicated with IOMMU faults without model specific knowledge. >> >> The proposed format is the result of discussion at: >> https://lkml.org/lkml/2017/11/10/291 >> Part of the code is based on Jean-Philippe Brucker's patchset >> (https://patchwork.kernel.org/patch/9989315/). >> >> The assumption is that model specific IOMMU driver can filter and >> handle most of the internal faults if the cause is within IOMMU driver >> control. Therefore, the fault reasons can be reported are grouped >> and generalized based common specifications such as PCI ATS. >> >> Signed-off-by: Jacob Pan >> Signed-off-by: Jean-Philippe Brucker >> Signed-off-by: Liu, Yi L >> Signed-off-by: Ashok Raj >> Signed-off-by: Eric Auger >> [moved part of the iommu_fault_event struct in the uapi, enriched >> the fault reasons to be able to map unrecoverable SMMUv3 errors] >> --- >> include/linux/iommu.h | 55 ++++++++++++++++++++++++- >> include/uapi/linux/iommu.h | 83 >> ++++++++++++++++++++++++++++++++++++++ 2 files changed, 136 >> insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index 244c1a3d5989..1dedc2d247c2 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -49,13 +49,17 @@ struct bus_type; >> struct device; >> struct iommu_domain; >> struct notifier_block; >> +struct iommu_fault_event; >> >> /* iommu fault flags */ >> -#define IOMMU_FAULT_READ 0x0 >> -#define IOMMU_FAULT_WRITE 0x1 >> +#define IOMMU_FAULT_READ (1 << 0) >> +#define IOMMU_FAULT_WRITE (1 << 1) >> +#define IOMMU_FAULT_EXEC (1 << 2) >> +#define IOMMU_FAULT_PRIV (1 << 3) >> >> typedef int (*iommu_fault_handler_t)(struct iommu_domain *, >> struct device *, unsigned long, int, void *); >> +typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault_event *, >> void *); >> struct iommu_domain_geometry { >> dma_addr_t aperture_start; /* First address that can be >> mapped */ @@ -255,6 +259,52 @@ struct iommu_device { >> struct device *dev; >> }; >> >> +/** >> + * struct iommu_fault_event - Generic per device fault data >> + * >> + * - PCI and non-PCI devices >> + * - Recoverable faults (e.g. page request), information based on >> PCI ATS >> + * and PASID spec. >> + * - Un-recoverable faults of device interest >> + * - DMA remapping and IRQ remapping faults >> + * >> + * @fault: fault descriptor >> + * @device_private: if present, uniquely identify device-specific >> + * private data for an individual page request. >> + * @iommu_private: used by the IOMMU driver for storing >> fault-specific >> + * data. Users should not modify this field before >> + * sending the fault response. >> + */ >> +struct iommu_fault_event { >> + struct iommu_fault fault; >> + u64 device_private; > I think we want to move device_private to uapi since it gets injected > into the guest, then returned by guest in case of page response. For > VT-d we also need 128 bits of private data. VT-d spec. 7.7.1 Ah, I didn't notice the format changed in VT-d rev3. On that topic, how do we manage future extensions to the iommu_fault struct? Should we add ~48 bytes of padding after device_private, along with some flags telling which field is valid, or deal with it using a structure version like we do for the invalidate and bind structs? In the first case, iommu_fault wouldn't fit in a 64-byte cacheline anymore, but I'm not sure we care. > For exception tracking (e.g. unanswered page request), I can add timer > and list info later when I include PRQ. sounds ok? >> + u64 iommu_private; [...] >> +/** >> + * struct iommu_fault - Generic fault data >> + * >> + * @type contains fault type >> + * @reason fault reasons if relevant outside IOMMU driver. >> + * IOMMU driver internal faults are not reported. >> + * @addr: tells the offending page address >> + * @fetch_addr: tells the address that caused an abort, if any >> + * @pasid: contains process address space ID, used in shared virtual >> memory >> + * @page_req_group_id: page request group index >> + * @last_req: last request in a page request group >> + * @pasid_valid: indicates if the PRQ has a valid PASID >> + * @prot: page access protection flag: >> + * IOMMU_FAULT_READ, IOMMU_FAULT_WRITE >> + */ >> + >> +struct iommu_fault { >> + __u32 type; /* enum iommu_fault_type */ >> + __u32 reason; /* enum iommu_fault_reason */ >> + __u64 addr; >> + __u64 fetch_addr; >> + __u32 pasid; >> + __u32 page_req_group_id; >> + __u32 last_req; >> + __u32 pasid_valid; >> + __u32 prot; >> + __u32 access; What does @access contain? Can it be squashed into @prot? Thanks, Jean > relocated to uapi, Yi can you confirm? > __u64 device_private[2]; > >> +}; >> #endif /* _UAPI_IOMMU_H */ > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu >