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 A4BF4C433EF for ; Sun, 24 Jul 2022 14:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231475AbiGXOE7 (ORCPT ); Sun, 24 Jul 2022 10:04:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229450AbiGXOE5 (ORCPT ); Sun, 24 Jul 2022 10:04:57 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E372112621 for ; Sun, 24 Jul 2022 07:04:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658671496; x=1690207496; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=4SB7MknA24m1jUG2lvk0lBvwcZyqcGj7Lokl0Nv3fhk=; b=CxlLKRZl99+3Tk8lXzRN8gTj9VR0K4IV5HGgc2MH4tUHuB6JVWYTb+iO pApM9ph5uDQYs4/gTw9+B0V0aVjbcRDc/arlmAGHYR7SYOSZE3FRb9FVL G6pH/h9Pb70oef5rtJZGJN/+DXGBLHvtR4CpIjSRBCGfW+JwuQ/INiZxf 2yqcuhxPETTIyiOHYdvEjtlx57GUwFXMfzr3wxpj6Jcp9mAVhELUVTi3r j7qL15YlfjuHs5zyVSInps/yHFDsCyxXJmiU6gEu3OQpik1lgko8H4PVM gCKPebPN+sEZnfxTdAPlDHMu3tiJViZnn+EmDVhvuHREc8vSesy5iGIAs Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10417"; a="267320782" X-IronPort-AV: E=Sophos;i="5.93,190,1654585200"; d="scan'208";a="267320782" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jul 2022 07:04:56 -0700 X-IronPort-AV: E=Sophos;i="5.93,190,1654585200"; d="scan'208";a="657820532" Received: from zjiang1-mobl.ccr.corp.intel.com (HELO [10.249.170.155]) ([10.249.170.155]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jul 2022 07:04:52 -0700 Message-ID: <487b533a-b289-eee7-0bd8-3be36c6e00e3@linux.intel.com> Date: Sun, 24 Jul 2022 22:04:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Cc: baolu.lu@linux.intel.com, Joerg Roedel , 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 , Zhangfei Gao , Zhu Tony , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Jean-Philippe Brucker Subject: Re: [PATCH v10 10/12] iommu: Prepare IOMMU domain for IOPF Content-Language: en-US To: Jason Gunthorpe References: <20220705050710.2887204-1-baolu.lu@linux.intel.com> <20220705050710.2887204-11-baolu.lu@linux.intel.com> <20220723143334.GJ79279@nvidia.com> From: Baolu Lu In-Reply-To: <20220723143334.GJ79279@nvidia.com> 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 2022/7/23 22:33, Jason Gunthorpe wrote: > On Tue, Jul 05, 2022 at 01:07:08PM +0800, Lu Baolu wrote: >> This adds some mechanisms around the iommu_domain so that the I/O page >> fault handling framework could route a page fault to the domain and >> call the fault handler from it. >> >> Add pointers to the page fault handler and its private data in struct >> iommu_domain. The fault handler will be called with the private data >> as a parameter once a page fault is routed to the domain. Any kernel >> component which owns an iommu domain could install handler and its >> private parameter so that the page fault could be further routed and >> handled. >> >> This also prepares the SVA implementation to be the first consumer of >> the per-domain page fault handling model. The I/O page fault handler >> for SVA is copied to the SVA file with mmget_not_zero() added before >> mmap_read_lock(). >> >> Suggested-by: Jean-Philippe Brucker >> Signed-off-by: Lu Baolu >> Reviewed-by: Jean-Philippe Brucker >> Tested-by: Zhangfei Gao >> Tested-by: Tony Zhu >> --- >> include/linux/iommu.h | 3 ++ >> drivers/iommu/iommu-sva-lib.h | 8 +++++ >> drivers/iommu/io-pgfault.c | 7 +++++ >> drivers/iommu/iommu-sva-lib.c | 58 +++++++++++++++++++++++++++++++++++ >> drivers/iommu/iommu.c | 4 +++ >> 5 files changed, 80 insertions(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index ae0cfca064e6..47610f21d451 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -105,6 +105,9 @@ struct iommu_domain { >> unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ >> struct iommu_domain_geometry geometry; >> struct iommu_dma_cookie *iova_cookie; >> + enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault, >> + void *data); >> + void *fault_data; >> union { >> struct { >> iommu_fault_handler_t handler; > > Why do we need two falut callbacks? The only difference is that one is > recoverable and the other is not, right? > > Can we run both down the same op? The iommu_fault_handler_t is for report_iommu_fault() which could be replaced with the newer iommu_report_device_fault(). https://lore.kernel.org/linux-iommu/Yo4Nw9QyllT1RZbd@myrica/ > >> +/* >> + * I/O page fault handler for SVA >> + */ >> +enum iommu_page_response_code >> +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) >> +{ >> + vm_fault_t ret; >> + struct vm_area_struct *vma; >> + struct mm_struct *mm = data; >> + unsigned int access_flags = 0; >> + unsigned int fault_flags = FAULT_FLAG_REMOTE; >> + struct iommu_fault_page_request *prm = &fault->prm; >> + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; >> + >> + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) >> + return status; >> + >> + if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm)) > > Do not use IS_ERR_ON_NULL. mm should never be null here since the > fault handler should have been removed from the domain before the > fault_data is changed. Yes. Updated. Best regards, baolu