From patchwork Tue Sep 10 08:19:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 11138905 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0E7E51395 for ; Tue, 10 Sep 2019 08:20:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA00221A4C for ; Tue, 10 Sep 2019 08:20:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406732AbfIJIUE (ORCPT ); Tue, 10 Sep 2019 04:20:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54330 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731155AbfIJIUE (ORCPT ); Tue, 10 Sep 2019 04:20:04 -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 026D55859E; Tue, 10 Sep 2019 08:20:03 +0000 (UTC) Received: from jason-ThinkPad-X1-Carbon-6th.redhat.com (ovpn-12-188.pek2.redhat.com [10.72.12.188]) by smtp.corp.redhat.com (Postfix) with ESMTP id 449B56092F; Tue, 10 Sep 2019 08:19:49 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com, cohuck@redhat.com, tiwei.bie@intel.com, maxime.coquelin@redhat.com, cunming.liang@intel.com, zhihong.wang@intel.com, rob.miller@broadcom.com, idos@mellanox.com, xiao.w.wang@intel.com, haotian.wang@sifive.com Subject: [RFC PATCH 0/4] mdev based hardware virtio offloading support Date: Tue, 10 Sep 2019 16:19:31 +0800 Message-Id: <20190910081935.30516-1-jasowang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 10 Sep 2019 08:20:03 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi all: There are hardware that can do virtio datapath offloading while having its own control path. This path tries to implement a mdev based unified API to support using kernel virtio driver to drive those devices. This is done by introducing a new mdev transport for virtio (virtio_mdev) and register itself as a new kind of mdev driver. Then it provides a unified way for kernel virtio driver to talk with mdev device implementation. Though the series only contain kernel driver support, the goal is to make the transport generic enough to support userspace drivers. This means vhost-mdev[1] could be built on top as well by resuing the transport. A sample driver is also implemented which simulate a virito-net loopback ethernet device on top of vringh + workqueue. This could be used as a reference implementation for real hardware driver. Notes: - Some of the key transport command for vhost-mdev(userspace driver) is not introduced. This includes: 1) set/get virtqueue state (idx etc), this could be simply done by introducing new transport command 2) dirty pages tracking, could be simply done by introducing new transport command 3) set/get device internal state, this requires more thought, of course we can introduce device specific transport command, but it would be better to have a unified API - Current mdev_parent_ops assumes all pointers are userspace pointer, this block the kernel driver, this series just abuse those as kernel pointer and this could be addressed by inventing new parent_ops. - For quick POC, mdev transport was just derived from virtio-MMIO, I'm pretty sure it has lots of space to be optimized, please share your thought. Please review. [1] https://lkml.org/lkml/2019/8/28/35 Jason Wang (4): vringh: fix copy direction of vringh_iov_push_kern() mdev: introduce helper to set per device dma ops virtio: introudce a mdev based transport docs: Sample driver to demonstrate how to implement virtio-mdev framework drivers/vfio/mdev/Kconfig | 7 + drivers/vfio/mdev/Makefile | 1 + drivers/vfio/mdev/mdev_core.c | 7 + drivers/vfio/mdev/virtio_mdev.c | 500 ++++++++++++++++++++ drivers/vhost/vringh.c | 8 +- include/linux/mdev.h | 2 + include/uapi/linux/virtio_mdev.h | 131 ++++++ samples/Kconfig | 7 + samples/vfio-mdev/Makefile | 1 + samples/vfio-mdev/mvnet.c | 766 +++++++++++++++++++++++++++++++ 10 files changed, 1429 insertions(+), 1 deletion(-) create mode 100644 drivers/vfio/mdev/virtio_mdev.c create mode 100644 include/uapi/linux/virtio_mdev.h create mode 100644 samples/vfio-mdev/mvnet.c