On Tue, Oct 29, 2019 at 06:51:32PM +0800, Jason Wang
wrote:> On 2019/10/29 ??6:17, Tiwei Bie wrote:
> > This patch adds the network control vq support in vhost-mdev.
> > A vhost-mdev specific op is introduced to allow parent drivers
> > to handle the network control commands come from userspace.
>
> Probably work for userspace driver but not kernel driver.
Exactly. This is only for userspace.
I got your point now. In virtio-mdev kernel driver case,
the ctrl-vq can be special as well.
>
>
> >
> > Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
> > ---
> > This patch depends on below patch:
> > https://lkml.org/lkml/2019/10/29/335
> >
> > drivers/vhost/mdev.c | 37
++++++++++++++++++++++++++++++--
> > include/linux/virtio_mdev_ops.h | 10 +++++++++
> > include/uapi/linux/vhost.h | 7 ++++++
> > include/uapi/linux/vhost_types.h | 6 ++++++
> > 4 files changed, 58 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/vhost/mdev.c b/drivers/vhost/mdev.c
> > index 35b2fb33e686..c9b3eaa77405 100644
> > --- a/drivers/vhost/mdev.c
> > +++ b/drivers/vhost/mdev.c
> > @@ -47,6 +47,13 @@ enum {
> > (1ULL << VIRTIO_NET_F_HOST_UFO) |
> > (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> > (1ULL << VIRTIO_NET_F_STATUS) |
> > + (1ULL << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) |
> > + (1ULL << VIRTIO_NET_F_CTRL_VQ) |
> > + (1ULL << VIRTIO_NET_F_CTRL_RX) |
> > + (1ULL << VIRTIO_NET_F_CTRL_VLAN) |
> > + (1ULL << VIRTIO_NET_F_CTRL_RX_EXTRA) |
> > + (1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE) |
> > + (1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR) |
> > (1ULL << VIRTIO_NET_F_SPEED_DUPLEX),
> > };
> >
> > @@ -362,6 +369,29 @@ static long vhost_mdev_vring_ioctl(struct
vhost_mdev *m, unsigned int cmd,
> > return r;
> > }
> >
> > +/*
> > + * Device specific (e.g. network) ioctls.
> > + */
> > +static long vhost_mdev_dev_ioctl(struct vhost_mdev *m, unsigned int
cmd,
> > + void __user *argp)
> > +{
> > + struct mdev_device *mdev = m->mdev;
> > + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev);
> > +
> > + switch (m->virtio_id) {
> > + case VIRTIO_ID_NET:
> > + switch (cmd) {
> > + case VHOST_MDEV_NET_CTRL:
> > + if (!ops->net.ctrl)
> > + return -ENOTSUPP;
> > + return ops->net.ctrl(mdev, argp);
> > + }
> > + break;
> > + }
> > +
> > + return -ENOIOCTLCMD;
> > +}
>
> As you comment above, then vhost-mdev need device specific stuffs.
Yeah. But this device specific stuff is quite small and
simple. It's just to forward the settings between parent
and userspace. But I totally agree it would be really
great if we could avoid it in an elegant way.
>
>
> > +
> > static int vhost_mdev_open(void *device_data)
> > {
> > struct vhost_mdev *m = device_data;
> > @@ -460,8 +490,11 @@ static long vhost_mdev_unlocked_ioctl(void
*device_data,
> > * VHOST_SET_LOG_FD are not used yet.
> > */
> > r = vhost_dev_ioctl(&m->dev, cmd, argp);
> > - if (r == -ENOIOCTLCMD)
> > - r = vhost_mdev_vring_ioctl(m, cmd, argp);
> > + if (r == -ENOIOCTLCMD) {
> > + r = vhost_mdev_dev_ioctl(m, cmd, argp);
> > + if (r == -ENOIOCTLCMD)
> > + r = vhost_mdev_vring_ioctl(m, cmd, argp);
> > + }
> > }
> >
> > mutex_unlock(&m->mutex);
> > diff --git a/include/linux/virtio_mdev_ops.h
b/include/linux/virtio_mdev_ops.h
> > index d417b41f2845..622861804ebd 100644
> > --- a/include/linux/virtio_mdev_ops.h
> > +++ b/include/linux/virtio_mdev_ops.h
> > @@ -20,6 +20,8 @@ struct virtio_mdev_callback {
> > void *private;
> > };
> >
> > +struct vhost_mdev_net_ctrl;
> > +
> > /**
> > * struct vfio_mdev_device_ops - Structure to be registered for each
> > * mdev device to register the device for virtio/vhost drivers.
> > @@ -151,6 +153,14 @@ struct virtio_mdev_device_ops {
> >
> > /* Mdev device ops */
> > u64 (*get_mdev_features)(struct mdev_device *mdev);
> > +
> > + /* Vhost-mdev (MDEV_CLASS_ID_VHOST) specific ops */
> > + union {
> > + struct {
> > + int (*ctrl)(struct mdev_device *mdev,
> > + struct vhost_mdev_net_ctrl __user *ctrl);
> > + } net;
> > + };
>
> And so did device_ops. I still think we'd try out best to avoid such
thing.
I totally agree we should try our best to avoid it.
But in this case, I think it may be worth considering
as it does simplify the userspace API and the parent
driver implementation a lot..
>
> Thanks
>
>
> > };
> >
> > void mdev_set_virtio_ops(struct mdev_device *mdev,
> > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > index 061a2824a1b3..3693b2cba0c4 100644
> > --- a/include/uapi/linux/vhost.h
> > +++ b/include/uapi/linux/vhost.h
> > @@ -134,4 +134,11 @@
> > /* Get the max ring size. */
> > #define VHOST_MDEV_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16)
> >
> > +/* VHOST_MDEV device specific defines */
> > +
> > +/* Send virtio-net commands. The commands follow the same definition
> > + * of the virtio-net commands defined in virtio-spec.
> > + */
> > +#define VHOST_MDEV_NET_CTRL _IOW(VHOST_VIRTIO, 0x77, struct
vhost_mdev_net_ctrl *)
> > +
> > #endif
> > diff --git a/include/uapi/linux/vhost_types.h
b/include/uapi/linux/vhost_types.h
> > index 7b105d0b2fb9..e76b4d8e35e5 100644
> > --- a/include/uapi/linux/vhost_types.h
> > +++ b/include/uapi/linux/vhost_types.h
> > @@ -127,6 +127,12 @@ struct vhost_mdev_config {
> > __u8 buf[0];
> > };
> >
> > +struct vhost_mdev_net_ctrl {
> > + __u8 class;
> > + __u8 cmd;
> > + __u8 cmd_data[0];
> > +} __attribute__((packed));
> > +
> > /* Feature bits */
> > /* Log all write descriptors. Can be changed while device is active.
*/
> > #define VHOST_F_LOG_ALL 26
>