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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E558AC5DF63 for ; Wed, 6 Nov 2019 03:50:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F0DC21D81 for ; Wed, 6 Nov 2019 03:50:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Z/WMg4st" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731134AbfKFDuE (ORCPT ); Tue, 5 Nov 2019 22:50:04 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:35008 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725768AbfKFDuE (ORCPT ); Tue, 5 Nov 2019 22:50:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573012202; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a+TaoYnSx8JQIw9cwMdJxIlkL0BV7vW8cxJKGh2NCEs=; b=Z/WMg4stfS5MAoW4W7rXmV9QknQfIkHI6Zrfm0LouZJZiODOczQhhnX90e6qXPURTlXDpW H9gW92g1Tmdo2O0mi7wFixWU7S+3h0u6a/uj+dDxtXjp8160naMb1LfMqezYEGrvlzjPqK uCXO9MFp+EYnfE3MFRGvzZu6IrDWvw0= 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-408-LCO48t2kOHqlYcbL8wcx_w-1; Tue, 05 Nov 2019 22:50:00 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CFF47107ACC3; Wed, 6 Nov 2019 03:49:55 +0000 (UTC) Received: from [10.72.12.193] (ovpn-12-193.pek2.redhat.com [10.72.12.193]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3371C600C4; Wed, 6 Nov 2019 03:48:33 +0000 (UTC) Subject: Re: [PATCH V8 3/6] mdev: introduce device specific ops To: Cornelia Huck , Alex Williamson Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, kwankhede@nvidia.com, mst@redhat.com, tiwei.bie@intel.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, maxime.coquelin@redhat.com, cunming.liang@intel.com, zhihong.wang@intel.com, rob.miller@broadcom.com, xiao.w.wang@intel.com, haotian.wang@sifive.com, zhenyuw@linux.intel.com, zhi.a.wang@intel.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, airlied@linux.ie, daniel@ffwll.ch, farman@linux.ibm.com, pasic@linux.ibm.com, sebott@linux.ibm.com, oberpar@linux.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com, borntraeger@de.ibm.com, akrowiak@linux.ibm.com, freude@linux.ibm.com, lingshan.zhu@intel.com, idos@mellanox.com, eperezma@redhat.com, lulu@redhat.com, parav@mellanox.com, christophe.de.dinechin@gmail.com, kevin.tian@intel.com, stefanha@redhat.com References: <20191105093240.5135-1-jasowang@redhat.com> <20191105093240.5135-4-jasowang@redhat.com> <20191105175025.1a620844.cohuck@redhat.com> <20191105104418.1735d800@x1.home> <20191105192851.40548978.cohuck@redhat.com> From: Jason Wang Message-ID: <42afbc46-ac7d-b4d7-9b4a-343b1400d2a8@redhat.com> Date: Wed, 6 Nov 2019 11:48:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191105192851.40548978.cohuck@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: LCO48t2kOHqlYcbL8wcx_w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/11/6 =E4=B8=8A=E5=8D=882:28, Cornelia Huck wrote: > On Tue, 5 Nov 2019 10:44:18 -0700 > Alex Williamson wrote: > >> On Tue, 5 Nov 2019 17:50:25 +0100 >> Cornelia Huck wrote: >> >>> On Tue, 5 Nov 2019 17:32:37 +0800 >>> Jason Wang wrote: >>> =20 >>>> Currently, except for the create and remove, the rest of >>>> mdev_parent_ops is designed for vfio-mdev driver only and may not help >>>> for kernel mdev driver. With the help of class id, this patch >>>> introduces device specific callbacks inside mdev_device >>>> structure. This allows different set of callback to be used by >>>> vfio-mdev and virtio-mdev. >>>> >>>> Reviewed-by: Parav Pandit >>>> Signed-off-by: Jason Wang >>>> --- >>>> .../driver-api/vfio-mediated-device.rst | 35 +++++++++---- >>>> MAINTAINERS | 1 + >>>> drivers/gpu/drm/i915/gvt/kvmgt.c | 18 ++++--- >>>> drivers/s390/cio/vfio_ccw_ops.c | 18 ++++--- >>>> drivers/s390/crypto/vfio_ap_ops.c | 14 +++-- >>>> drivers/vfio/mdev/mdev_core.c | 24 ++++++++- >>>> drivers/vfio/mdev/mdev_private.h | 5 ++ >>>> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++------- >>>> include/linux/mdev.h | 43 ++++----------- >>>> include/linux/mdev_vfio_ops.h | 52 +++++++++++++++++= ++ >>>> samples/vfio-mdev/mbochs.c | 20 ++++--- >>>> samples/vfio-mdev/mdpy.c | 20 ++++--- >>>> samples/vfio-mdev/mtty.c | 18 ++++--- >>>> 13 files changed, 206 insertions(+), 99 deletions(-) >>>> create mode 100644 include/linux/mdev_vfio_ops.h >>>> =20 >>> (...) >>> =20 >>>> @@ -172,10 +163,34 @@ that a driver should use to unregister itself wi= th the mdev core driver:: >>>> =20 >>>> =09extern void mdev_unregister_device(struct device *dev); >>>> =20 >>>> -It is also required to specify the class_id in create() callback thro= ugh:: >>>> +As multiple types of mediated devices may be supported, class id need= s >>>> +to be specified in the create callback(). This could be done >>> The brackets should probably go behind 'create'? >>> =20 >>>> +explicitly for the device that does not use on mdev bus for its >>> "for devices that do not use the mdev bus" ? >>> >>> But why wouldn't they? I feel like I've missed some discussion here :/ >> The device ops provide a route through mdev-core for known callbacks, >> which is primarily useful when we have 1:N relation between mdev bus >> driver and vendor drivers. The obvious example here is vfio-mdev, >> where we have GVT-g, vfio-ap, vfio-ccw, NVIDIA GRID, and various sample >> drivers all advertising vfio-mdev support via their class id. However, >> if we have a tightly coupled vendor driver and mdev bus driver, as the >> mlx5 support that Parav is developing, the claim is that they prefer >> not to expose any device ops and intend to interact directly with the >> mdev device. At least that's my understanding. Thanks, >> >> Alex > Ah, ok. > > So maybe use the phrasing "devices that interact with the mdev device > directly" vs "devices that use device-specific ops" instead? > > Not a strong critique, though. Will use what you suggest here. Thanks > >>>> +operation through: >>>> =20 >>>> =09int mdev_set_class(struct mdev_device *mdev, u16 id); >>>> =20 >>>> +For the device that uses on the mdev bus for its operation, the >>>> class >>> "For devices that use the mdev bus..." >>> >>> But same comment as above. >>> =20 >>>> +should provide helper function to set class id and device >>>> specific +ops. E.g for vfio-mdev devices, the function to be >>>> called is:: + >>>> +=09int mdev_set_vfio_ops(struct mdev_device *mdev, >>>> + const struct mdev_vfio_device_ops >>>> *vfio_ops); + >>>> +The class id (set by this function to MDEV_CLASS_ID_VFIO) is >>>> used to +match a device with an mdev driver via its id table. The >>>> device +specific callbacks (specified in *vfio_ops) are >>>> obtainable via +mdev_get_vfio_ops() (for use by the mdev bus >>>> driver). A vfio-mdev +device (class id MDEV_CLASS_ID_VFIO) uses >>>> the following +device-specific ops: >>>> + >>>> +* open: open callback of vfio mediated device >>>> +* close: close callback of vfio mediated device >>>> +* ioctl: ioctl callback of vfio mediated device >>>> +* read : read emulation callback >>>> +* write: write emulation callback >>>> +* mmap: mmap emulation callback >>>> + >>>> Mediated Device Management Interface Through sysfs >>>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D >>> Otherwise, looks good.