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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 93139CA9EA3 for ; Fri, 18 Oct 2019 07:35:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 681F921925 for ; Fri, 18 Oct 2019 07:35:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389722AbfJRHfQ (ORCPT ); Fri, 18 Oct 2019 03:35:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55966 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728706AbfJRHfQ (ORCPT ); Fri, 18 Oct 2019 03:35:16 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A678F10DCC96; Fri, 18 Oct 2019 07:35:14 +0000 (UTC) Received: from [10.72.12.183] (ovpn-12-183.pek2.redhat.com [10.72.12.183]) by smtp.corp.redhat.com (Postfix) with ESMTP id A27C960600; Fri, 18 Oct 2019 07:34:48 +0000 (UTC) Subject: Re: [PATCH V4 3/6] mdev: introduce device specific ops To: Cornelia Huck 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, alex.williamson@redhat.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: <20191017104836.32464-1-jasowang@redhat.com> <20191017104836.32464-4-jasowang@redhat.com> <20191017170755.15506ada.cohuck@redhat.com> From: Jason Wang Message-ID: Date: Fri, 18 Oct 2019 15:34:44 +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: <20191017170755.15506ada.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Fri, 18 Oct 2019 07:35:15 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/10/17 下午11:07, Cornelia Huck wrote: > On Thu, 17 Oct 2019 18:48:33 +0800 > Jason Wang wrote: > >> 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. >> >> Signed-off-by: Jason Wang >> --- >> .../driver-api/vfio-mediated-device.rst | 25 +++++---- >> 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 | 18 +++++-- >> drivers/vfio/mdev/mdev_private.h | 1 + >> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++------- >> include/linux/mdev.h | 45 ++++------------ >> include/linux/vfio_mdev.h | 52 +++++++++++++++++++ >> samples/vfio-mdev/mbochs.c | 20 ++++--- >> samples/vfio-mdev/mdpy.c | 20 ++++--- >> samples/vfio-mdev/mtty.c | 18 ++++--- >> 13 files changed, 184 insertions(+), 103 deletions(-) >> create mode 100644 include/linux/vfio_mdev.h >> >> diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst >> index f9a78d75a67a..0cca84d19603 100644 >> --- a/Documentation/driver-api/vfio-mediated-device.rst >> +++ b/Documentation/driver-api/vfio-mediated-device.rst >> @@ -152,11 +152,22 @@ callbacks per mdev parent device, per mdev type, or any other categorization. >> Vendor drivers are expected to be fully asynchronous in this respect or >> provide their own internal resource protection.) >> >> -The callbacks in the mdev_parent_ops structure are as follows: >> - >> -* open: open callback of mediated device >> -* close: close callback of mediated device >> -* ioctl: ioctl callback of mediated device >> +As multiple types of mediated devices may be supported, the device >> +must set up the class id and the device specific callbacks in create() > s/in create()/in the create()/ Will fix. > >> +callback. E.g for vfio-mdev device it needs to be done through: > "Each class provides a helper function to do so; e.g. for vfio-mdev > devices, the function to be called is:" > > ? This looks better. > >> + >> + int mdev_set_vfio_ops(struct mdev_device *mdev, >> + const struct vfio_mdev_ops *vfio_ops); >> + >> +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device > "(set by this helper function to MDEV_CLASS_ID_VFIO)" ? Yes. >> +with an mdev driver via its id table. The device specific callbacks >> +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by > "(specified in *vfio_ops by the caller)" ? Yes. >> +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 >> @@ -167,10 +178,6 @@ register itself with the mdev core driver:: >> extern int mdev_register_device(struct device *dev, >> const struct mdev_parent_ops *ops); >> >> -It is also required to specify the class_id in create() callback through:: >> - >> - int mdev_set_class(struct mdev_device *mdev, u16 id); >> - > I'm wondering if this patch set should start out with introducing > helper functions already (i.e. don't introduce mdev_set_class(), but > start out with mdev_set_class_vfio() which will gain the *vfio_ops > argument in this patch.) I think it doesn't harm to keep it as is since in patch 1 we introduce class_id and bus match method based on that without device ops there.  But if you stick I can change. Thanks > >> However, the mdev_parent_ops structure is not required in the function call >> that a driver should use to unregister itself with the mdev core driver:: >> > (...) > >> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c >> index 3a9c52d71b4e..d0f3113c8071 100644 >> --- a/drivers/vfio/mdev/mdev_core.c >> +++ b/drivers/vfio/mdev/mdev_core.c >> @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data) >> } >> EXPORT_SYMBOL(mdev_set_drvdata); >> >> -/* Specify the class for the mdev device, this must be called during >> - * create() callback. >> +/* Specify the VFIO device ops for the mdev device, this >> + * must be called during create() callback for VFIO mdev device. >> */ > /* > * Specify the mdev device to be a VFIO mdev device, and set the > * VFIO devices ops for it. This must be called from the create() > * callback for VFIO mdev devices. > */ > > ? > >> -void mdev_set_class(struct mdev_device *mdev, u16 id) >> +void mdev_set_vfio_ops(struct mdev_device *mdev, >> + const struct vfio_mdev_device_ops *vfio_ops) >> { >> WARN_ON(mdev->class_id); >> - mdev->class_id = id; >> + mdev->class_id = MDEV_CLASS_ID_VFIO; >> + mdev->device_ops = vfio_ops; >> } >> -EXPORT_SYMBOL(mdev_set_class); >> +EXPORT_SYMBOL(mdev_set_vfio_ops); >> + >> +const void *mdev_get_dev_ops(struct mdev_device *mdev) >> +{ >> + return mdev->device_ops; >> +} >> +EXPORT_SYMBOL(mdev_get_dev_ops); >> >> struct device *mdev_dev(struct mdev_device *mdev) >> { > (...) > > The code change looks good to me; I'm just wondering if we should > introduce mdev_set_class() at all (see above).