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 71E44C4161F for ; Thu, 4 Mar 2021 01:09:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B5AF64E99 for ; Thu, 4 Mar 2021 01:09:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357004AbhCDBF0 (ORCPT ); Wed, 3 Mar 2021 20:05:26 -0500 Received: from mga01.intel.com ([192.55.52.88]:47696 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1452876AbhCDAi7 (ORCPT ); Wed, 3 Mar 2021 19:38:59 -0500 IronPort-SDR: r/+4kTZ10ybl6ojVDgReLQmZX9Pv0I6DfZ+aSzz64MPqwpzK4oL8qfbVjqgNa27u3zr56ng078 QFMOBflaTFFQ== X-IronPort-AV: E=McAfee;i="6000,8403,9912"; a="207000391" X-IronPort-AV: E=Sophos;i="5.81,220,1610438400"; d="scan'208";a="207000391" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2021 15:59:49 -0800 IronPort-SDR: +vxitPST2B82Q3t1Wscr0o0o+AAEVJudR9cF6VlNUJofp/U3LMOqwUGZhjDEiq/KHp0TECf9+y t8/bPNCml/tQ== X-IronPort-AV: E=Sophos;i="5.81,220,1610438400"; d="scan'208";a="445479939" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2021 15:59:49 -0800 Date: Wed, 3 Mar 2021 16:02:05 -0800 From: Jacob Pan To: Tejun Heo Cc: LKML , Joerg Roedel , Lu Baolu , David Woodhouse , iommu@lists.linux-foundation.org, cgroups@vger.kernel.org, Johannes Weiner , Jean-Philippe Brucker , Alex Williamson , Eric Auger , Jason Gunthorpe , Jonathan Corbet , Raj Ashok , "Tian, Kevin" , Yi Liu , Wu Hao , Dave Jiang , jacob.jun.pan@linux.intel.com Subject: Re: [RFC PATCH 15/18] cgroup: Introduce ioasids controller Message-ID: <20210303160205.151d114e@jacob-builder> In-Reply-To: <20210303131726.7a8cb169@jacob-builder> References: <1614463286-97618-1-git-send-email-jacob.jun.pan@linux.intel.com> <1614463286-97618-16-git-send-email-jacob.jun.pan@linux.intel.com> <20210303131726.7a8cb169@jacob-builder> Organization: OTC X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacob, On Wed, 3 Mar 2021 13:17:26 -0800, Jacob Pan wrote: > Hi Tejun, > > On Wed, 3 Mar 2021 10:44:28 -0500, Tejun Heo wrote: > > > On Sat, Feb 27, 2021 at 02:01:23PM -0800, Jacob Pan wrote: > > > IOASIDs are used to associate DMA requests with virtual address > > > spaces. They are a system-wide limited resource made available to the > > > userspace applications. Let it be VMs or user-space device drivers. > > > > > > This RFC patch introduces a cgroup controller to address the following > > > problems: > > > 1. Some user applications exhaust all the available IOASIDs thus > > > depriving others of the same host. > > > 2. System admins need to provision VMs based on their needs for > > > IOASIDs, e.g. the number of VMs with assigned devices that perform > > > DMA requests with PASID. > > > > Please take a look at the proposed misc controller: > > > > http://lkml.kernel.org/r/20210302081705.1990283-2-vipinsh@google.com > > > > Would that fit your bill? > The interface definitely can be reused. But IOASID has a different > behavior in terms of migration and ownership checking. I guess SEV key > IDs are not tied to a process whereas IOASIDs are. Perhaps this can be > solved by adding > + .can_attach = ioasids_can_attach, > + .cancel_attach = ioasids_cancel_attach, > Let me give it a try and come back. > While I am trying to fit the IOASIDs cgroup in to the misc cgroup proposal. I'd like to have a direction check on whether this idea of using cgroup for IOASID/PASID resource management is viable. Alex/Jason/Jean and everyone, your feedback is much appreciated. > Thanks for the pointer. > > Jacob > > > > > Thanks. > > > > > Thanks, > > Jacob Thanks, Jacob