From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 18 Nov 2019 16:45:10 +0100 From: Cornelia Huck Subject: Re: [PATCH V13 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework Message-ID: <20191118164510.549c097b.cohuck@redhat.com> In-Reply-To: <20191118105923.7991-7-jasowang@redhat.com> References: <20191118105923.7991-1-jasowang@redhat.com> <20191118105923.7991-7-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org List-ID: 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, alex.williamson@redhat.com, mst@redhat.com, tiwei.bie@intel.com, gregkh@linuxfoundation.org, jgg@mellanox.com, 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, eperezma@redhat.com, lulu@redhat.com, parav@mellanox.com, christophe.de.dinechin@gmail.com, kevin.tian@intel.com, stefanha@redhat.com, rdunlap@infradead.org, hch@infradead.org, aadam@redhat.com, jakub.kicinski@netronome.com, jiri@mellanox.com, jeffrey.t.kirsher@intel.com On Mon, 18 Nov 2019 18:59:23 +0800 Jason Wang wrote: [Note: I have not looked into the reworked architecture of this *at all* so far; just something that I noted...] > This sample driver creates mdev device that simulate virtio net device > over virtio mdev transport. The device is implemented through vringh > and workqueue. A device specific dma ops is to make sure HVA is used > directly as the IOVA. This should be sufficient for kernel virtio > driver to work. >=20 > Only 'virtio' type is supported right now. I plan to add 'vhost' type > on top which requires some virtual IOMMU implemented in this sample > driver. >=20 > Signed-off-by: Jason Wang > --- > MAINTAINERS | 1 + > samples/Kconfig | 10 + > samples/vfio-mdev/Makefile | 1 + > samples/vfio-mdev/mvnet_loopback.c | 690 +++++++++++++++++++++++++++++ > 4 files changed, 702 insertions(+) > create mode 100644 samples/vfio-mdev/mvnet_loopback.c >=20 > +static struct mvnet_dev { > +=09struct class=09*vd_class; > +=09struct idr=09vd_idr; > +=09struct device=09dev; > +} mvnet_dev; This structure embeds a struct device (a reference-counted structure), yet it is a static variable. This is giving a bad example to potential implementers; just allocate it dynamically. > +static void mvnet_device_release(struct device *dev) > +{ > +=09dev_dbg(dev, "mvnet: released\n"); And that also means you need a proper release function here, of course. > +}