Re: [PATCH 3/4] vhost-vdpa: uAPI to stop the device

From: Eugenio Perez Martin <eperezma@redhat.com>
To: "Eugenio Pérez" <eperezma@redhat.com>,
	virtualization <virtualization@lists.linux-foundation.org>,
	"Jason Wang" <jasowang@redhat.com>,
	"kvm list" <kvm@vger.kernel.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Stefano Garzarella" <sgarzare@redhat.com>,
	Longpeng <longpeng2@huawei.com>,
	"Zhu Lingshan" <lingshan.zhu@intel.com>,
	"Martin Petrus Hubertus Habets" <martinh@xilinx.com>,
	"Harpreet Singh Anand" <hanand@xilinx.com>,
	"Si-Wei Liu" <si-wei.liu@oracle.com>,
	dinang@xilinx.com, "Eli Cohen" <elic@nvidia.com>,
	"Laurent Vivier" <lvivier@redhat.com>,
	pabloc@xilinx.com, "Dawar, Gautam" <gautam.dawar@amd.com>,
	"Xie Yongji" <xieyongji@bytedance.com>,
	"Christophe JAILLET" <christophe.jaillet@wanadoo.fr>,
	tanuj.kamde@amd.com, "Wu Zongyong" <wuzongyong@linux.alibaba.com>,
	martinpo@xilinx.com, "Cindy Lu" <lulu@redhat.com>,
	ecree.xilinx@gmail.com, "Parav Pandit" <parav@nvidia.com>,
	"Dan Carpenter" <dan.carpenter@oracle.com>,
	"Zhang Min" <zhang.min9@zte.com.cn>
Subject: Re: [PATCH 3/4] vhost-vdpa: uAPI to stop the device
Date: Mon, 23 May 2022 10:11:33 +0200	[thread overview]
Message-ID: <CAJaqyWfKXbeT5nUbBvHj4A3Ntz_YwA3OvgDeyq=D6J2cy8dRJw@mail.gmail.com> (raw)
In-Reply-To: <20220521083630.GA5298@gmail.com>

On Sat, May 21, 2022 at 10:36 AM Martin Habets <habetsm.xilinx@gmail.com> wrote:
>
> On Fri, May 20, 2022 at 07:23:24PM +0200, Eugenio Pérez wrote:
> > The ioctl adds support for stop the device from userspace.
> >
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> >  drivers/vhost/vdpa.c       | 18 ++++++++++++++++++
> >  include/uapi/linux/vhost.h |  3 +++
> >  2 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> > index a325bc259afb..da4a8c709bc1 100644
> > --- a/drivers/vhost/vdpa.c
> > +++ b/drivers/vhost/vdpa.c
> > @@ -478,6 +478,21 @@ static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
> >       return 0;
> >  }
> >
> > +static long vhost_vdpa_stop(struct vhost_vdpa *v, u32 __user *argp)
> > +{
> > +     struct vdpa_device *vdpa = v->vdpa;
> > +     const struct vdpa_config_ops *ops = vdpa->config;
> > +     int stop;
> > +
> > +     if (!ops->stop)
> > +             return -EOPNOTSUPP;
> > +
> > +     if (copy_to_user(argp, &stop, sizeof(stop)))
>
> You want to use copy_from_user() here.
>

Hi Martin,

You're right, I'll resend a new version with this fixed. Thanks!

> Martin
>
> > +             return -EFAULT;
> > +
> > +     return ops->stop(vdpa, stop);
> > +}
> > +
> >  static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> >                                  void __user *argp)
> >  {
> > @@ -649,6 +664,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
> >       case VHOST_VDPA_GET_VQS_COUNT:
> >               r = vhost_vdpa_get_vqs_count(v, argp);
> >               break;
> > +     case VHOST_STOP:
> > +             r = vhost_vdpa_stop(v, argp);
> > +             break;
> >       default:
> >               r = vhost_dev_ioctl(&v->vdev, cmd, argp);
> >               if (r == -ENOIOCTLCMD)
> > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > index cab645d4a645..e7526968ab0c 100644
> > --- a/include/uapi/linux/vhost.h
> > +++ b/include/uapi/linux/vhost.h
> > @@ -171,4 +171,7 @@
> >  #define VHOST_VDPA_SET_GROUP_ASID    _IOW(VHOST_VIRTIO, 0x7C, \
> >                                            struct vhost_vring_state)
> >
> > +/* Stop or resume a device so it does not process virtqueue requests anymore */
> > +#define VHOST_STOP                   _IOW(VHOST_VIRTIO, 0x7D, int)
> > +
> >  #endif
> > --
> > 2.27.0
>