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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 C9E7BC433DB for ; Wed, 24 Mar 2021 22:10:08 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 274DD61A18 for ; Wed, 24 Mar 2021 22:10:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 274DD61A18 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id E2A0360B02; Wed, 24 Mar 2021 22:10:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u8-yfEpenYf3; Wed, 24 Mar 2021 22:10:07 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTP id C7587605F7; Wed, 24 Mar 2021 22:10:06 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id A0E19C000D; Wed, 24 Mar 2021 22:10:06 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 080E2C000A for ; Wed, 24 Mar 2021 22:10:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id DC6318490B for ; Wed, 24 Mar 2021 22:10:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id caO7ZQc_22qO for ; Wed, 24 Mar 2021 22:10:04 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by smtp1.osuosl.org (Postfix) with ESMTPS id 3C478848FD for ; Wed, 24 Mar 2021 22:10:04 +0000 (UTC) IronPort-SDR: OpeULTy7JcDH/Ayje8i4z2YhKxsTm+oUJUDcgR8HkpReg7fsxov/e5TA1F4x9B1189EzMb+bXY 1YbkSa/AxvMg== X-IronPort-AV: E=McAfee;i="6000,8403,9933"; a="177913773" X-IronPort-AV: E=Sophos;i="5.81,275,1610438400"; d="scan'208";a="177913773" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2021 15:10:03 -0700 IronPort-SDR: DQZSaLihhzL2eMMuOF5/+Gq/kYGub32TVjHTLJr/fySOgtaPJemHSPHFCx7OFGJFZBYCPKhCq1 tkpDOzoJ4dTA== X-IronPort-AV: E=Sophos;i="5.81,275,1610438400"; d="scan'208";a="413927681" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2021 15:10:03 -0700 Date: Wed, 24 Mar 2021 15:12:30 -0700 From: Jacob Pan To: Jason Gunthorpe Subject: Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs Message-ID: <20210324151230.466fd47a@jacob-builder> In-Reply-To: <20210324170338.GM2356281@nvidia.com> References: <1614463286-97618-1-git-send-email-jacob.jun.pan@linux.intel.com> <1614463286-97618-6-git-send-email-jacob.jun.pan@linux.intel.com> <20210318172234.3e8c34f7@jacob-builder> <20210319124645.GP2356281@nvidia.com> <20210319135432.GT2356281@nvidia.com> <20210319112221.5123b984@jacob-builder> <20210324100246.4e6b8aa1@jacob-builder> <20210324170338.GM2356281@nvidia.com> Organization: OTC X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: Jean-Philippe Brucker , "Tian, Kevin" , Alex Williamson , Raj Ashok , Jonathan Corbet , Jean-Philippe Brucker , LKML , Dave Jiang , iommu@lists.linux-foundation.org, Li Zefan , Johannes Weiner , Tejun Heo , cgroups@vger.kernel.org, Wu Hao , David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Jason, On Wed, 24 Mar 2021 14:03:38 -0300, Jason Gunthorpe wrote: > On Wed, Mar 24, 2021 at 10:02:46AM -0700, Jacob Pan wrote: > > > Also wondering about device driver allocating auxiliary domains for > > > their private use, to do iommu_map/unmap on private PASIDs (a clean > > > replacement to super SVA, for example). Would that go through the > > > same path as /dev/ioasid and use the cgroup of current task? > > > > For the in-kernel private use, I don't think we should restrict based on > > cgroup, since there is no affinity to user processes. I also think the > > PASID allocation should just use kernel API instead of /dev/ioasid. Why > > would user space need to know the actual PASID # for device private > > domains? Maybe I missed your idea? > > There is not much in the kernel that isn't triggered by a process, I > would be careful about the idea that there is a class of users that > can consume a cgroup controlled resource without being inside the > cgroup. > > We've got into trouble before overlooking this and with something > greenfield like PASID it would be best built in to the API to prevent > a mistake. eg accepting a cgroup or process input to the allocator. > Make sense. But I think we only allow charging the current cgroup, how about I add the following to ioasid_alloc(): misc_cg = get_current_misc_cg(); ret = misc_cg_try_charge(MISC_CG_RES_IOASID, misc_cg, 1); if (ret) { put_misc_cg(misc_cg); return ret; } BTW, IOASID will be one of the resources under the proposed misc cgroup. Thanks, Jacob _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu