Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [RFC] /dev/ioasid uAPI proposal
To:     Parav Pandit <parav@nvidia.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>,
        "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Alex Williamson (alex.williamson@redhat.com)" 
        <alex.williamson@redhat.com>, Jason Wang <jasowang@redhat.com>
Cc:     Eric Auger <eric.auger@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        "Raj, Ashok" <ashok.raj@intel.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>, "Wu, Hao" <hao.wu@intel.com>,
        "Jiang, Dave" <dave.jiang@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        David Gibson <david@gibson.dropbear.id.au>,
        Kirti Wankhede <kwankhede@nvidia.com>,
        Robin Murphy <robin.murphy@arm.com>
References: <MWHPR11MB1886422D4839B372C6AB245F8C239@MWHPR11MB1886.namprd11.prod.outlook.com>
 <PH0PR12MB5481C1B2249615257A461EEDDC3F9@PH0PR12MB5481.namprd12.prod.outlook.com>
From:   "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Message-ID: <06892e6a-02c9-6c25-84eb-6a4b2177b48d@metux.net>
Date:   Wed, 2 Jun 2021 10:38:51 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.10.0
MIME-Version: 1.0
In-Reply-To: <PH0PR12MB5481C1B2249615257A461EEDDC3F9@PH0PR12MB5481.namprd12.prod.outlook.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: tl
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 31.05.21 19:37, Parav Pandit wrote:

> It appears that this is only to make map ioctl faster apart from accounting.
> It doesn't have any ioasid handle input either.
> 
> In that case, can it be a new system call? Why does it have to be under /dev/ioasid?
> For example few years back such system call mpin() thought was proposed in [1].

I'm very reluctant to more syscall inflation. We already have lots of
syscalls that could have been easily done via devices or filesystems
(yes, some of them are just old Unix relics).

Syscalls don't play well w/ modules, containers, distributed systems,
etc, and need extra low-level code for most non-C languages (eg.
scripting languages).


--mtx

-- 
---
Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert
werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren
GPG/PGP-Schlüssel zu.
---
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287