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_1 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 15244C2D0A3 for ; Tue, 3 Nov 2020 13:19:07 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 479E2206B2 for ; Tue, 3 Nov 2020 13:19:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 479E2206B2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id B96FF86073; Tue, 3 Nov 2020 13:19:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ll0TYZep3XAy; Tue, 3 Nov 2020 13:19:04 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 496B085FF3; Tue, 3 Nov 2020 13:19:04 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3A5D6C088B; Tue, 3 Nov 2020 13:19:04 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 850A7C0051 for ; Tue, 3 Nov 2020 13:19:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 79198860F9 for ; Tue, 3 Nov 2020 13:19:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id F-aYus2NJk5V for ; Tue, 3 Nov 2020 13:19:01 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by whitealder.osuosl.org (Postfix) with ESMTPS id 0182786C22 for ; Tue, 3 Nov 2020 13:19:00 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id B0BA03A5; Tue, 3 Nov 2020 14:18:57 +0100 (CET) Date: Tue, 3 Nov 2020 14:18:52 +0100 From: "joro@8bytes.org" To: Jason Gunthorpe Subject: Re: (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs Message-ID: <20201103131852.GE22888@8bytes.org> References: <20201103095208.GA22888@8bytes.org> <20201103125643.GN2620339@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201103125643.GN2620339@nvidia.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: "jean-philippe@linaro.org" , "Tian, Kevin" , "Raj, Ashok" , "kvm@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "stefanha@gmail.com" , Jason Wang , "Michael S. Tsirkin" , "Sun, Yi Y" , "alex.williamson@redhat.com" , "Wu, Hao" , "Tian, Jun J" 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" On Tue, Nov 03, 2020 at 08:56:43AM -0400, Jason Gunthorpe wrote: > On Tue, Nov 03, 2020 at 10:52:09AM +0100, joro@8bytes.org wrote: > > So having said this, what is the benefit of exposing those SVA internals > > to user-space? > > Only the device use of the PASID is device specific, the actual PASID > and everything on the IOMMU side is generic. > > There is enough API there it doesn't make sense to duplicate it into > every single SVA driver. What generic things have to be done by the drivers besides allocating/deallocating PASIDs and binding an address space to it? Is there anything which isn't better handled in a kernel-internal library which drivers just use? Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu