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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 A34E9CA9EBB for ; Thu, 24 Oct 2019 19:47:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 625D52166E for ; Thu, 24 Oct 2019 19:47:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FpqgupQ/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437329AbfJXTrA (ORCPT ); Thu, 24 Oct 2019 15:47:00 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:59072 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2437277AbfJXTq7 (ORCPT ); Thu, 24 Oct 2019 15:46:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571946418; 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=H9X0BtuoZ8Jvkk6PkqP3IQvdtLRJY5D+ojk6YTP+TA8=; b=FpqgupQ/bzrF9eAzPRmY49TJu08LuDdukolw0bUpkwN37ko2Ic0yX+Kdvy0TLu6/0Mr6nh Zgn4Sdwgi2pXAXL/ntjSiBjuQ1Va3XbiwtgYR+LduGrleF5DQlrto4KG1Zwoaro4zU33LU x0Cy49PUWaYaOUHmqBaQrKU6+IJyyLA= 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-251-_h2FRMZQMb62lVvm9O8R9A-1; Thu, 24 Oct 2019 15:46:54 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A3F8B107AD33; Thu, 24 Oct 2019 19:46:50 +0000 (UTC) Received: from x1.home (ovpn-118-102.phx2.redhat.com [10.3.118.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDC055C21A; Thu, 24 Oct 2019 19:46:36 +0000 (UTC) Date: Thu, 24 Oct 2019 13:46:36 -0600 From: Alex Williamson To: Jason Wang 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, cohuck@redhat.com, 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 Subject: Re: [PATCH V5 1/6] mdev: class id support Message-ID: <20191024134636.253131c5@x1.home> In-Reply-To: <38bdf762-524a-e0f1-6e9a-1102adfe8fb1@redhat.com> References: <20191023130752.18980-1-jasowang@redhat.com> <20191023130752.18980-2-jasowang@redhat.com> <20191023154204.31d74866@x1.home> <38bdf762-524a-e0f1-6e9a-1102adfe8fb1@redhat.com> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: _h2FRMZQMb62lVvm9O8R9A-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 24 Oct 2019 11:27:36 +0800 Jason Wang wrote: > On 2019/10/24 =E4=B8=8A=E5=8D=885:42, Alex Williamson wrote: > > On Wed, 23 Oct 2019 21:07:47 +0800 > > Jason Wang wrote: > > =20 > >> Mdev bus only supports vfio driver right now, so it doesn't implement > >> match method. But in the future, we may add drivers other than vfio, > >> the first driver could be virtio-mdev. This means we need to add > >> device class id support in bus match method to pair the mdev device > >> and mdev driver correctly. > >> > >> So this patch adds id_table to mdev_driver and class_id for mdev > >> device with the match method for mdev bus. > >> > >> Signed-off-by: Jason Wang > >> --- > >> .../driver-api/vfio-mediated-device.rst | 5 +++++ > >> drivers/gpu/drm/i915/gvt/kvmgt.c | 1 + > >> drivers/s390/cio/vfio_ccw_ops.c | 1 + > >> drivers/s390/crypto/vfio_ap_ops.c | 1 + > >> drivers/vfio/mdev/mdev_core.c | 18 +++++++++++++++ > >> drivers/vfio/mdev/mdev_driver.c | 22 +++++++++++++++++= ++ > >> drivers/vfio/mdev/mdev_private.h | 1 + > >> drivers/vfio/mdev/vfio_mdev.c | 6 +++++ > >> include/linux/mdev.h | 8 +++++++ > >> include/linux/mod_devicetable.h | 8 +++++++ > >> samples/vfio-mdev/mbochs.c | 1 + > >> samples/vfio-mdev/mdpy.c | 1 + > >> samples/vfio-mdev/mtty.c | 1 + > >> 13 files changed, 74 insertions(+) > >> > >> diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Docum= entation/driver-api/vfio-mediated-device.rst > >> index 25eb7d5b834b..6709413bee29 100644 > >> --- a/Documentation/driver-api/vfio-mediated-device.rst > >> +++ b/Documentation/driver-api/vfio-mediated-device.rst > >> @@ -102,12 +102,14 @@ structure to represent a mediated device's drive= r:: > >> * @probe: called when new device created > >> * @remove: called when device removed > >> * @driver: device driver structure > >> + * @id_table: the ids serviced by this driver > >> */ > >> struct mdev_driver { > >> =09 const char *name; > >> =09 int (*probe) (struct device *dev); > >> =09 void (*remove) (struct device *dev); > >> =09 struct device_driver driver; > >> +=09 const struct mdev_class_id *id_table; > >> }; > >> =20 > >> A mediated bus driver for mdev should use this structure in the func= tion calls > >> @@ -170,6 +172,9 @@ that a driver should use to unregister itself with= 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:: > >> + > >> +=09int mdev_set_class(struct mdev_device *mdev, u16 id); > >> =20 > >> 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 > >> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/g= vt/kvmgt.c > >> index 343d79c1cb7e..6420f0dbd31b 100644 > >> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c > >> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c > >> @@ -678,6 +678,7 @@ static int intel_vgpu_create(struct kobject *kobj,= struct mdev_device *mdev) > >> =09=09 dev_name(mdev_dev(mdev))); > >> =09ret =3D 0; > >> =20 > >> +=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO); > >> out: > >> =09return ret; > >> } > >> diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_c= cw_ops.c > >> index f0d71ab77c50..cf2c013ae32f 100644 > >> --- a/drivers/s390/cio/vfio_ccw_ops.c > >> +++ b/drivers/s390/cio/vfio_ccw_ops.c > >> @@ -129,6 +129,7 @@ static int vfio_ccw_mdev_create(struct kobject *ko= bj, struct mdev_device *mdev) > >> =09=09=09 private->sch->schid.ssid, > >> =09=09=09 private->sch->schid.sch_no); > >> =20 > >> +=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO); > >> =09return 0; > >> } > >> =20 > >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/v= fio_ap_ops.c > >> index 5c0f53c6dde7..07c31070afeb 100644 > >> --- a/drivers/s390/crypto/vfio_ap_ops.c > >> +++ b/drivers/s390/crypto/vfio_ap_ops.c > >> @@ -343,6 +343,7 @@ static int vfio_ap_mdev_create(struct kobject *kob= j, struct mdev_device *mdev) > >> =09list_add(&matrix_mdev->node, &matrix_dev->mdev_list); > >> =09mutex_unlock(&matrix_dev->lock); > >> =20 > >> +=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO); > >> =09return 0; > >> } > >> =20 > >> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_co= re.c > >> index b558d4cfd082..3a9c52d71b4e 100644 > >> --- a/drivers/vfio/mdev/mdev_core.c > >> +++ b/drivers/vfio/mdev/mdev_core.c > >> @@ -45,6 +45,16 @@ void mdev_set_drvdata(struct mdev_device *mdev, voi= d *data) > >> } > >> EXPORT_SYMBOL(mdev_set_drvdata); > >> =20 > >> +/* Specify the class for the mdev device, this must be called during > >> + * create() callback. > >> + */ > >> +void mdev_set_class(struct mdev_device *mdev, u16 id) > >> +{ > >> +=09WARN_ON(mdev->class_id); > >> +=09mdev->class_id =3D id; > >> +} > >> +EXPORT_SYMBOL(mdev_set_class); > >> + > >> struct device *mdev_dev(struct mdev_device *mdev) > >> { > >> =09return &mdev->dev; > >> @@ -135,6 +145,7 @@ static int mdev_device_remove_cb(struct device *de= v, void *data) > >> * mdev_register_device : Register a device > >> * @dev: device structure representing parent device. > >> * @ops: Parent device operation structure to be registered. > >> + * @id: class id. > >> * > >> * Add device to list of registered parent devices. > >> * Returns a negative value on error, otherwise 0. > >> @@ -324,6 +335,13 @@ int mdev_device_create(struct kobject *kobj, > >> =09if (ret) > >> =09=09goto ops_create_fail; > >> =20 > >> +=09if (!mdev->class_id) { > >> +=09=09ret =3D -EINVAL; > >> +=09=09WARN(1, "class id must be specified for device %s\n", > >> +=09=09 dev_name(dev)); =20 > > Nit, dev_warn(dev, "mdev vendor driver failed to specify device class\n= "); =20 >=20 >=20 > Will fix. >=20 >=20 > > =20 > >> +=09=09goto add_fail; > >> +=09} > >> + > >> =09ret =3D device_add(&mdev->dev); > >> =09if (ret) > >> =09=09goto add_fail; > >> diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_= driver.c > >> index 0d3223aee20b..319d886ffaf7 100644 > >> --- a/drivers/vfio/mdev/mdev_driver.c > >> +++ b/drivers/vfio/mdev/mdev_driver.c > >> @@ -69,8 +69,30 @@ static int mdev_remove(struct device *dev) > >> =09return 0; > >> } > >> =20 > >> +static int mdev_match(struct device *dev, struct device_driver *drv) > >> +{ > >> +=09unsigned int i; > >> +=09struct mdev_device *mdev =3D to_mdev_device(dev); > >> +=09struct mdev_driver *mdrv =3D to_mdev_driver(drv); > >> +=09const struct mdev_class_id *ids =3D mdrv->id_table; > >> + =20 > > Nit, as we start to allow new mdev bus drivers, mdev-core might want to > > protect itself from a NULL id_table, by either failing the > > mdev_register_driver() or failing the match here. I think such a > > condition would segfault as written here, but clearly we don't have > > such external drivers yet. Thanks, =20 >=20 >=20 > I'm not sure I get the point here. My understanding is that mdev-core=20 > won't try to be matched here since it was not a complete mdev device. The parent driver failing to set a type vs the parent driver failing to register with a struct mdev_driver where id_table is not null are different issues. I agree that if a vendor driver was not updated for this series that they'd never successfully create a device because the mdev-core would reject it for not setting a class, but mdev_match() is called for devices that might be created by other vendor drivers, so loading a parent driver with a null id_table potentially breaks matching for everyone. Thanks, Alex