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

[Eli Cohen]

> 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?

> 
>  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