RE: [PATCH 3/3] vp_vdpa: support feature provisioning

[Eli Cohen]

> From: Jason Wang <jasowang@xxxxxxxxxx>
> Sent: Tuesday, 20 September 2022 4:46
> To: Eli Cohen <elic@xxxxxxxxxx>
> Cc: mst@xxxxxxxxxx; si-wei.liu@xxxxxxxxxx; Parav Pandit
> <parav@xxxxxxxxxx>; wuzongyong@xxxxxxxxxxxxxxxxx;
> virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> eperezma@xxxxxxxxxx; lingshan.zhu@xxxxxxxxx; gdawar@xxxxxxxxxx;
> lulu@xxxxxxxxxx; xieyongji@xxxxxxxxxxxxx
> Subject: Re: [PATCH 3/3] vp_vdpa: support feature provisioning
> 
> On Mon, Sep 19, 2022 at 3:05 PM Eli Cohen <elic@xxxxxxxxxx> wrote:
> >
> > > From: Jason Wang <jasowang@xxxxxxxxxx>
> > > Sent: Thursday, 15 September 2022 11:51
> > > To: mst@xxxxxxxxxx; jasowang@xxxxxxxxxx
> > > Cc: Eli Cohen <elic@xxxxxxxxxx>; si-wei.liu@xxxxxxxxxx; Parav Pandit
> > > <parav@xxxxxxxxxx>; wuzongyong@xxxxxxxxxxxxxxxxx;
> > > virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > > eperezma@xxxxxxxxxx; lingshan.zhu@xxxxxxxxx; gdawar@xxxxxxxxxx;
> > > lulu@xxxxxxxxxx; xieyongji@xxxxxxxxxxxxx
> > > Subject: [PATCH 3/3] vp_vdpa: support feature provisioning
> > >
> > > This patch allows the device features to be provisioned via
> > > netlink. This is done by:
> > >
> > > 1) validating the provisioned features to be a subset of the parent
> > >    features.
> > > 2) clearing the features that is not wanted by the userspace
> > >
> > > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > > ---
> > >  drivers/vdpa/virtio_pci/vp_vdpa.c | 16 ++++++++++++++--
> > >  1 file changed, 14 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > index 04522077735b..4b28e0c95ba2 100644
> > > --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> > > @@ -17,6 +17,7 @@
> > >  #include <linux/virtio_ring.h>
> > >  #include <linux/virtio_pci.h>
> > >  #include <linux/virtio_pci_modern.h>
> > > +#include <uapi/linux/vdpa.h>
> > >
> > >  #define VP_VDPA_QUEUE_MAX 256
> > >  #define VP_VDPA_DRIVER_NAME "vp_vdpa"
> > > @@ -35,6 +36,7 @@ struct vp_vdpa {
> > >       struct virtio_pci_modern_device *mdev;
> > >       struct vp_vring *vring;
> > >       struct vdpa_callback config_cb;
> > > +     u64 device_features;
> > >       char msix_name[VP_VDPA_NAME_SIZE];
> > >       int config_irq;
> > >       int queues;
> > > @@ -66,9 +68,9 @@ static struct virtio_pci_modern_device
> > > *vp_vdpa_to_mdev(struct vp_vdpa *vp_vdpa)
> > >
> > >  static u64 vp_vdpa_get_device_features(struct vdpa_device *vdpa)
> > >  {
> > > -     struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
> > > +     struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
> > >
> > > -     return vp_modern_get_features(mdev);
> > > +     return vp_vdpa->device_features;
> > >  }
> >
> > Unrelated to this patch. Maybe put in another patch?
> 
> Actually not, since we don't want to report the features that are
> supported by the device, but the features that are provisioned via
> netlink:
> 

I see.

Reviewed-by: Eli Cohen <elic@xxxxxxxxxx>

> > > +     if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {
> > > +             if (add_config->device_features & ~device_features)
> > > +                     return -EINVAL;
> > > +             device_features &= add_config->device_features;
> > > +     }
> > > +     vp_vdpa->device_features = device_features;
> 
> Thanks
> 
> >
> > >
> > >  static int vp_vdpa_set_driver_features(struct vdpa_device *vdpa, u64
> > > features)
> > > @@ -475,6 +477,7 @@ static int vp_vdpa_dev_add(struct
> vdpa_mgmt_dev
> > > *v_mdev, const char *name,
> > >       struct pci_dev *pdev = mdev->pci_dev;
> > >       struct device *dev = &pdev->dev;
> > >       struct vp_vdpa *vp_vdpa = NULL;
> > > +     u64 device_features;
> > >       int ret, i;
> > >
> > >       vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
> > > @@ -491,6 +494,14 @@ static int vp_vdpa_dev_add(struct
> vdpa_mgmt_dev
> > > *v_mdev, const char *name,
> > >       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
> > >       vp_vdpa->mdev = mdev;
> > >
> > > +     device_features = vp_modern_get_features(mdev);
> > > +     if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {
> > > +             if (add_config->device_features & ~device_features)
> > > +                     return -EINVAL;
> > > +             device_features &= add_config->device_features;
> > > +     }
> > > +     vp_vdpa->device_features = device_features;
> > > +
> > >       ret = devm_add_action_or_reset(dev, vp_vdpa_free_irq_vectors,
> > > pdev);
> > >       if (ret) {
> > >               dev_err(&pdev->dev,
> > > @@ -599,6 +610,7 @@ static int vp_vdpa_probe(struct pci_dev *pdev,
> const
> > > struct pci_device_id *id)
> > >       mgtdev->id_table = mdev_id;
> > >       mgtdev->max_supported_vqs =
> > > vp_modern_get_num_queues(mdev);
> > >       mgtdev->supported_features = vp_modern_get_features(mdev);
> > > +     mgtdev->config_attr_mask = (1 << VDPA_ATTR_DEV_FEATURES);
> > >       pci_set_master(pdev);
> > >       pci_set_drvdata(pdev, vp_vdpa_mgtdev);
> > >
> > > --
> > > 2.25.1
> >