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 F14D5C43334 for ; Mon, 27 Jun 2022 13:04:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234331AbiF0NEw (ORCPT ); Mon, 27 Jun 2022 09:04:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234467AbiF0NEg (ORCPT ); Mon, 27 Jun 2022 09:04:36 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC4D81115E for ; Mon, 27 Jun 2022 06:04:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656335041; x=1687871041; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=pvt1FnCHqt1/XWnPYD13BBulCVA6oKyVYSxAmRYprsc=; b=PMmxpXtHAE7quvc3kgcYlCK0mbRB60OPGYe895lPdnRtXANeANQp4vCJ v8GyEL2+/gFm1WOb06+MSxfjSUDvWgRXk9F1bKme3FPwOVSQIJ8D8o/pI kplBcBA2R5yBD6xg9XiC9JJMD6AvkIQBxtqF7xAa9XrEc/NFLzuRascN6 ChRVvuMbuI0RWceJTPMxFEv2vKc2RFFYTC2R1OrRiQu7qou1iWJTxIynL HOb5kQiaOZTaAkhPLFY4Nm2FSdGluQqfnuv5P0/xjIxM0A/uaWtb6m2ik ZEmpPgZquA3haAhUP8cBtNZzTmrWhDjDsagMgql0y5UGbAbuCjyQVGuab A==; X-IronPort-AV: E=McAfee;i="6400,9594,10390"; a="261857377" X-IronPort-AV: E=Sophos;i="5.92,226,1650956400"; d="scan'208";a="261857377" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 06:03:59 -0700 X-IronPort-AV: E=Sophos;i="5.92,226,1650956400"; d="scan'208";a="646418348" Received: from zhaohaif-mobl1.ccr.corp.intel.com (HELO [10.254.210.224]) ([10.254.210.224]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 06:03:55 -0700 Message-ID: Date: Mon, 27 Jun 2022 21:03:52 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v9 10/11] iommu: Per-domain I/O page fault handling To: Lu Baolu , Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Dave Jiang , Vinod Koul Cc: Eric Auger , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Jean-Philippe Brucker References: <20220621144353.17547-1-baolu.lu@linux.intel.com> <20220621144353.17547-11-baolu.lu@linux.intel.com> From: Ethan Zhao In-Reply-To: <20220621144353.17547-11-baolu.lu@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, 在 2022/6/21 22:43, Lu Baolu 写道: > Tweak the I/O page fault handling framework to route the page faults to > the domain and call the page fault handler retrieved from the domain. > This makes the I/O page fault handling framework possible to serve more > usage scenarios as long as they have an IOMMU domain and install a page > fault handler in it. Some unused functions are also removed to avoid > dead code. > > The iommu_get_domain_for_dev_pasid() which retrieves attached domain > for a {device, PASID} pair is used. It will be used by the page fault > handling framework which knows {device, PASID} reported from the iommu > driver. We have a guarantee that the SVA domain doesn't go away during > IOPF handling, because unbind() waits for pending faults with > iopf_queue_flush_dev() before freeing the domain. Hence, there's no need > to synchronize life cycle of the iommu domains between the unbind() and > the interrupt threads. > > Signed-off-by: Lu Baolu > Reviewed-by: Jean-Philippe Brucker > --- > drivers/iommu/io-pgfault.c | 64 +++++--------------------------------- > 1 file changed, 7 insertions(+), 57 deletions(-) > > diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c > index aee9e033012f..4f24ec703479 100644 > --- a/drivers/iommu/io-pgfault.c > +++ b/drivers/iommu/io-pgfault.c > @@ -69,69 +69,18 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf, > return iommu_page_response(dev, &resp); > } > > -static enum iommu_page_response_code > -iopf_handle_single(struct iopf_fault *iopf) > -{ > - vm_fault_t ret; > - struct mm_struct *mm; > - struct vm_area_struct *vma; > - unsigned int access_flags = 0; > - unsigned int fault_flags = FAULT_FLAG_REMOTE; > - struct iommu_fault_page_request *prm = &iopf->fault.prm; > - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; > - > - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) > - return status; > - > - mm = iommu_sva_find(prm->pasid); > - if (IS_ERR_OR_NULL(mm)) > - return status; > - > - mmap_read_lock(mm); > - > - vma = find_extend_vma(mm, prm->addr); > - if (!vma) > - /* Unmapped area */ > - goto out_put_mm; > - > - if (prm->perm & IOMMU_FAULT_PERM_READ) > - access_flags |= VM_READ; > - > - if (prm->perm & IOMMU_FAULT_PERM_WRITE) { > - access_flags |= VM_WRITE; > - fault_flags |= FAULT_FLAG_WRITE; > - } > - > - if (prm->perm & IOMMU_FAULT_PERM_EXEC) { > - access_flags |= VM_EXEC; > - fault_flags |= FAULT_FLAG_INSTRUCTION; > - } > - > - if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) > - fault_flags |= FAULT_FLAG_USER; > - > - if (access_flags & ~vma->vm_flags) > - /* Access fault */ > - goto out_put_mm; > - > - ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); > - status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : > - IOMMU_PAGE_RESP_SUCCESS; > - > -out_put_mm: > - mmap_read_unlock(mm); > - mmput(mm); > - > - return status; > -} > - Once the iopf_handle_single() is removed, the name of iopf_handle_group() looks a little weired and confused, does this group mean the iommu group (domain) ? while I take some minutes to look into the code, oh, means a batch / list / queue  of iopfs , and iopf_handle_group() becomes a generic iopf_handler() . Doe it make sense to revise the names of iopf_handle_group(), iopf_complete_group,  iopf_group in this patch set ? Thanks, Ethan > static void iopf_handle_group(struct work_struct *work) > { > struct iopf_group *group; > + struct iommu_domain *domain; > struct iopf_fault *iopf, *next; > enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS; > > group = container_of(work, struct iopf_group, work); > + domain = iommu_get_domain_for_dev_pasid(group->dev, > + group->last_fault.fault.prm.pasid); > + if (!domain || !domain->iopf_handler) > + status = IOMMU_PAGE_RESP_INVALID; > > list_for_each_entry_safe(iopf, next, &group->faults, list) { > /* > @@ -139,7 +88,8 @@ static void iopf_handle_group(struct work_struct *work) > * faults in the group if there is an error. > */ > if (status == IOMMU_PAGE_RESP_SUCCESS) > - status = iopf_handle_single(iopf); > + status = domain->iopf_handler(&iopf->fault, > + domain->fault_data); > > if (!(iopf->fault.prm.flags & > IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) -- "firm, enduring, strong, and long-lived"