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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 B064BCA9ECF for ; Fri, 1 Nov 2019 13:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 861C020862 for ; Fri, 1 Nov 2019 13:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727744AbfKANzo (ORCPT ); Fri, 1 Nov 2019 09:55:44 -0400 Received: from mga12.intel.com ([192.55.52.136]:1155 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726622AbfKANzn (ORCPT ); Fri, 1 Nov 2019 09:55:43 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Nov 2019 06:55:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,255,1569308400"; d="scan'208";a="190964201" Received: from dpdk-virtio-tbie-2.sh.intel.com (HELO ___) ([10.67.104.74]) by orsmga007.jf.intel.com with ESMTP; 01 Nov 2019 06:55:40 -0700 Date: Fri, 1 Nov 2019 21:56:28 +0800 From: Tiwei Bie To: Jason Wang Cc: mst@redhat.com, alex.williamson@redhat.com, maxime.coquelin@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, dan.daly@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com, lingshan.zhu@intel.com Subject: Re: [PATCH v4] vhost: introduce mdev based hardware backend Message-ID: <20191101135628.GA18045@___> References: <20191031140114.25615-1-tiwei.bie@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 01, 2019 at 03:17:39PM +0800, Jason Wang wrote: > On 2019/10/31 下午10:01, Tiwei Bie wrote: > > This patch introduces a mdev based hardware vhost backend. > > This backend is built on top of the same abstraction used > > in virtio-mdev and provides a generic vhost interface for > > userspace to accelerate the virtio devices in guest. > > > > This backend is implemented as a mdev device driver on top > > of the same mdev device ops used in virtio-mdev but using > > a different mdev class id, and it will register the device > > as a VFIO device for userspace to use. Userspace can setup > > the IOMMU with the existing VFIO container/group APIs and > > then get the device fd with the device name. After getting > > the device fd of this device, userspace can use vhost ioctls > > to setup the backend. > > > > Signed-off-by: Tiwei Bie > > --- > > This patch depends on below series: > > https://lkml.org/lkml/2019/10/30/62 > > > > v3 -> v4: > > - Rebase on top of virtio-mdev series v6; > > - Some minor tweaks and improvements; > > > > v2 -> v3: > > - Fix the return value (Jason); > > - Don't cache unnecessary information in vhost-mdev (Jason); > > - Get rid of the memset in open (Jason); > > - Add comments for VHOST_SET_MEM_TABLE, ... (Jason); > > - Filter out unsupported features in vhost-mdev (Jason); > > - Add _GET_DEVICE_ID ioctl (Jason); > > - Add _GET_CONFIG/_SET_CONFIG ioctls (Jason); > > - Drop _GET_QUEUE_NUM ioctl (Jason); > > - Fix the copy-paste errors in _IOW/_IOR usage; > > - Some minor fixes and improvements; > > > > v1 -> v2: > > - Replace _SET_STATE with _SET_STATUS (MST); > > - Check status bits at each step (MST); > > - Report the max ring size and max number of queues (MST); > > - Add missing MODULE_DEVICE_TABLE (Jason); > > - Only support the network backend w/o multiqueue for now; > > - Some minor fixes and improvements; > > - Rebase on top of virtio-mdev series v4; > > > > RFC v4 -> v1: > > - Implement vhost-mdev as a mdev device driver directly and > > connect it to VFIO container/group. (Jason); > > - Pass ring addresses as GPAs/IOVAs in vhost-mdev to avoid > > meaningless HVA->GPA translations (Jason); > > > > RFC v3 -> RFC v4: > > - Build vhost-mdev on top of the same abstraction used by > > virtio-mdev (Jason); > > - Introduce vhost fd and pass VFIO fd via SET_BACKEND ioctl (MST); > > > > RFC v2 -> RFC v3: > > - Reuse vhost's ioctls instead of inventing a VFIO regions/irqs > > based vhost protocol on top of vfio-mdev (Jason); > > > > RFC v1 -> RFC v2: > > - Introduce a new VFIO device type to build a vhost protocol > > on top of vfio-mdev; > > > > drivers/vfio/mdev/mdev_core.c | 20 ++ > > drivers/vfio/mdev/mdev_private.h | 1 + > > drivers/vhost/Kconfig | 12 + > > drivers/vhost/Makefile | 3 + > > drivers/vhost/mdev.c | 556 +++++++++++++++++++++++++++++++ > > include/linux/mdev.h | 5 + > > include/uapi/linux/vhost.h | 18 + > > include/uapi/linux/vhost_types.h | 8 + > > 8 files changed, 623 insertions(+) > > create mode 100644 drivers/vhost/mdev.c > > > > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > > index 22ca589750d8..109dbac01a8f 100644 > > --- a/drivers/vfio/mdev/mdev_core.c > > +++ b/drivers/vfio/mdev/mdev_core.c > > @@ -96,6 +96,26 @@ mdev_get_virtio_ops(struct mdev_device *mdev) > > } > > EXPORT_SYMBOL(mdev_get_virtio_ops); > > +/* Specify the vhost device ops for the mdev device, this > > + * must be called during create() callback for vhost mdev device. > > + */ > > +void mdev_set_vhost_ops(struct mdev_device *mdev, > > + const struct virtio_mdev_device_ops *vhost_ops) > > +{ > > + mdev_set_class(mdev, MDEV_CLASS_ID_VHOST); > > + mdev->vhost_ops = vhost_ops; > > +} > > +EXPORT_SYMBOL(mdev_set_vhost_ops); > > + > > +/* Get the vhost device ops for the mdev device. */ > > +const struct virtio_mdev_device_ops * > > +mdev_get_vhost_ops(struct mdev_device *mdev) > > +{ > > + WARN_ON(mdev->class_id != MDEV_CLASS_ID_VHOST); > > + return mdev->vhost_ops; > > +} > > +EXPORT_SYMBOL(mdev_get_vhost_ops); > > + > > struct device *mdev_dev(struct mdev_device *mdev) > > { > > return &mdev->dev; > > diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h > > index 7b47890c34e7..5597c846e52f 100644 > > --- a/drivers/vfio/mdev/mdev_private.h > > +++ b/drivers/vfio/mdev/mdev_private.h > > @@ -40,6 +40,7 @@ struct mdev_device { > > union { > > const struct vfio_mdev_device_ops *vfio_ops; > > const struct virtio_mdev_device_ops *virtio_ops; > > + const struct virtio_mdev_device_ops *vhost_ops; > > > Any reason why virtio_ops is not used for vhost here? I don't have a strong opinion on this. Will use virtio_ops directly. > > Other looks good. Thanks! > > Thanks > >