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=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 E6AF7C63798 for ; Thu, 22 Jul 2021 14:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C486E6100C for ; Thu, 22 Jul 2021 14:42:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232371AbhGVOB4 (ORCPT ); Thu, 22 Jul 2021 10:01:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:57027 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232396AbhGVOB4 (ORCPT ); Thu, 22 Jul 2021 10:01:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626964950; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Kw6CRwUqzdaXdrl+GoUqts83hcJHaySlHaJXBWUbRA8=; b=ggHsOqYmK6EZn8ITs7DU1KO0Qvyyb1xW5CkcCcu10xsjAYb52QFOhWvK1HFXa54DfEuzk/ JPCJN6AjayrWckhCLefMluwuZG1ZdkO2H8/AVIwzLDoISLai1wVzUOBCre0Uvf1dVapI+0 xCjbxEPBbpDRoyZhzJGxRvzSnSk5HSU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-453-h11GFaXVNSK1F2Q3vQ8VlA-1; Thu, 22 Jul 2021 10:42:26 -0400 X-MC-Unique: h11GFaXVNSK1F2Q3vQ8VlA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C201107ACF5; Thu, 22 Jul 2021 14:42:22 +0000 (UTC) Received: from localhost (ovpn-112-132.ams2.redhat.com [10.36.112.132]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E891210016DB; Thu, 22 Jul 2021 14:42:11 +0000 (UTC) From: Cornelia Huck To: Jason Gunthorpe , David Airlie , Tony Krowiak , Alex Williamson , Christian Borntraeger , Jonathan Corbet , Daniel Vetter , Diana Craciun , dri-devel@lists.freedesktop.org, Eric Auger , Eric Farman , Harald Freudenberger , Vasily Gorbik , Heiko Carstens , intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, Jani Nikula , Jason Herne , Joonas Lahtinen , kvm@vger.kernel.org, Kirti Wankhede , linux-doc@vger.kernel.org, linux-s390@vger.kernel.org, Matthew Rosato , Peter Oberparleiter , Halil Pasic , Rodrigo Vivi , Vineeth Vijayan , Zhi Wang Cc: "Raj, Ashok" , Christoph Hellwig , Leon Romanovsky , Max Gurtovoy , Yishai Hadas , Zhenyu Wang Subject: Re: [PATCH v2 04/14] vfio: Provide better generic support for open/release vfio_device_ops In-Reply-To: <4-v2-b6a5582525c9+ff96-vfio_reflck_jgg@nvidia.com> Organization: Red Hat GmbH References: <4-v2-b6a5582525c9+ff96-vfio_reflck_jgg@nvidia.com> User-Agent: Notmuch/0.32.1 (https://notmuchmail.org) Date: Thu, 22 Jul 2021 16:42:10 +0200 Message-ID: <87bl6u76m5.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Jul 20 2021, Jason Gunthorpe wrote: > Currently the driver ops have an open/release pair that is called once > each time a device FD is opened or closed. Add an additional set of > open/close_device() ops which are called when the device FD is opened for > the first time and closed for the last time. > > An analysis shows that all of the drivers require this semantic. Some are > open coding it as part of their reflck implementation, and some are just > buggy and miss it completely. > > To retain the current semantics PCI and FSL depend on, introduce the idea > of a "device set" which is a grouping of vfio_device's that share the same > lock around opening. > > The device set is established by providing a 'set_id' pointer. All > vfio_device's that provide the same pointer will be joined to the same > singleton memory and lock across the whole set. This effectively replaces > the oddly named reflck. > > After conversion the set_id will be sourced from: > - A struct device from a fsl_mc_device (fsl) > - A struct pci_slot (pci) > - A struct pci_bus (pci) > - The struct vfio_device (everything) > > The design ensures that the above pointers are live as long as the > vfio_device is registered, so they form reliable unique keys to group > vfio_devices into sets. > > This implementation uses xarray instead of searching through the driver > core structures, which simplifies the somewhat tricky locking in this > area. > > Following patches convert all the drivers. > > Signed-off-by: Yishai Hadas > Signed-off-by: Jason Gunthorpe > --- > drivers/vfio/mdev/vfio_mdev.c | 22 +++++ > drivers/vfio/vfio.c | 146 +++++++++++++++++++++++++++++----- > include/linux/mdev.h | 2 + > include/linux/vfio.h | 19 +++++ > 4 files changed, 167 insertions(+), 22 deletions(-) Reviewed-by: Cornelia Huck