Re: [PATCH V2 RESEND 1/6] vDPA: allow userspace to query features of a vDPA device

Re: [PATCH V2 RESEND 1/6] vDPA: allow userspace to query features of a vDPA device

[Jason Wang]

On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan <lingshan.zhu@intel.com> wrote:
>
> This commit adds a new vDPA netlink attribution
> VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES. Userspace can query
> features of vDPA devices through this new attr.
>
> This commit invokes vdpa_config_ops.get_config()
> rather than vdpa_get_config_unlocked() to read
> the device config spcae, so no races in
> vdpa_set_features_unlocked()
>
> Userspace tool iproute2 example:
> $ vdpa dev config show vdpa0
> vdpa0: mac 00:e8:ca:11:be:05 link up link_announce false max_vq_pairs 4 mtu 1500
>   negotiated_features MRG_RXBUF CTRL_VQ MQ VERSION_1 ACCESS_PLATFORM
>   dev_features MTU MAC MRG_RXBUF CTRL_VQ MQ ANY_LAYOUT VERSION_1 ACCESS_PLATFORM
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> ---
>  drivers/vdpa/vdpa.c       | 17 ++++++++++++-----
>  include/uapi/linux/vdpa.h |  4 ++++
>  2 files changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index c06c02704461..2035700d6fc8 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -491,6 +491,7 @@ static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *m
>                 err = -EMSGSIZE;
>                 goto msg_err;
>         }
> +

Nit: Unnecessary changes.

>         if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
>                               mdev->supported_features, VDPA_ATTR_PAD)) {
>                 err = -EMSGSIZE;
> @@ -815,10 +816,10 @@ static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
>  static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
>  {
>         struct virtio_net_config config = {};
> -       u64 features;
> +       u64 features_device, features_driver;
>         u16 val_u16;
>
> -       vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
> +       vdev->config->get_config(vdev, 0, &config, sizeof(config));
>
>         if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac),
>                     config.mac))
> @@ -832,12 +833,18 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
>         if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
>                 return -EMSGSIZE;
>
> -       features = vdev->config->get_driver_features(vdev);
> -       if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features,
> +       features_driver = vdev->config->get_driver_features(vdev);
> +       if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
> +                             VDPA_ATTR_PAD))
> +               return -EMSGSIZE;

It looks to me that those parts were removed in patch 2. I wonder if
it's better to reorder the patch to let patch 2 come first?

Thanks

> +
> +       features_device = vdev->config->get_device_features(vdev);
> +
> +       if (nla_put_u64_64bit(msg, VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,
>                               VDPA_ATTR_PAD))
>                 return -EMSGSIZE;
>
> -       return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);
> +       return vdpa_dev_net_mq_config_fill(vdev, msg, features_driver, &config);
>  }
>
>  static int
> diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> index 25c55cab3d7c..07474183fdb3 100644
> --- a/include/uapi/linux/vdpa.h
> +++ b/include/uapi/linux/vdpa.h
> @@ -46,12 +46,16 @@ enum vdpa_attr {
>
>         VDPA_ATTR_DEV_NEGOTIATED_FEATURES,      /* u64 */
>         VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,          /* u32 */
> +       /* virtio features that are supported by the vDPA management device */
>         VDPA_ATTR_DEV_SUPPORTED_FEATURES,       /* u64 */
>
>         VDPA_ATTR_DEV_QUEUE_INDEX,              /* u32 */
>         VDPA_ATTR_DEV_VENDOR_ATTR_NAME,         /* string */
>         VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,        /* u64 */
>
> +       /* virtio features that are supported by the vDPA device */
> +       VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES,  /* u64 */
> +
>         /* new attributes must be added above here */
>         VDPA_ATTR_MAX,
>  };
> --
> 2.31.1
>

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Re: [PATCH V2 RESEND 2/6] vDPA: only report driver features if FEATURES_OK is set

[Jason Wang]

On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan <lingshan.zhu@intel.com> wrote:
>
> This commit reports driver features to user space
> only after FEATURES_OK is features negotiation is done.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> ---
>  drivers/vdpa/vdpa.c | 22 ++++++++++++++++------
>  1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 2035700d6fc8..e7765953307f 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -816,7 +816,7 @@ static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
>  static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
>  {
>         struct virtio_net_config config = {};
> -       u64 features_device, features_driver;
> +       u64 features_device;
>         u16 val_u16;
>
>         vdev->config->get_config(vdev, 0, &config, sizeof(config));
> @@ -833,11 +833,6 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
>         if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
>                 return -EMSGSIZE;
>
> -       features_driver = vdev->config->get_driver_features(vdev);
> -       if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
> -                             VDPA_ATTR_PAD))
> -               return -EMSGSIZE;
> -
>         features_device = vdev->config->get_device_features(vdev);
>
>         if (nla_put_u64_64bit(msg, VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,
> @@ -851,6 +846,8 @@ static int
>  vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
>                      int flags, struct netlink_ext_ack *extack)
>  {
> +       u64 features_driver;
> +       u8 status = 0;
>         u32 device_id;
>         void *hdr;
>         int err;
> @@ -874,6 +871,19 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid,
>                 goto msg_err;
>         }
>
> +       /* only read driver features after the feature negotiation is done */
> +       if (vdev->config->get_status)
> +               status = vdev->config->get_status(vdev);

get_status is mandatory, so I think we can remove this check.

Or if you want a strict check on the config operations, we need to do
that in __vdpa_alloc_device().

Thanks

> +
> +       if (status & VIRTIO_CONFIG_S_FEATURES_OK) {
> +               features_driver = vdev->config->get_driver_features(vdev);
> +               if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
> +                                     VDPA_ATTR_PAD)) {
> +                       err = -EMSGSIZE;
> +                       goto msg_err;
> +               }
> +       }
> +
>         switch (device_id) {
>         case VIRTIO_ID_NET:
>                 err = vdpa_dev_net_config_fill(vdev, msg);
> --
> 2.31.1
>

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Re: [PATCH V2 RESEND 3/6] vDPA: check VIRTIO_NET_F_RSS for max_virtqueue_paris's presence

[Jason Wang]

On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan <lingshan.zhu@intel.com> wrote:
>
> virtio 1.2 spec says:
> max_virtqueue_pairs only exists if VIRTIO_NET_F_MQ or
> VIRTIO_NET_F_RSS is set.
>
> So when reporint MQ to userspace, it should check both
> VIRTIO_NET_F_MQ and VIRTIO_NET_F_RSS.
>
> unused parameter struct vdpa_device *vdev is removed
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/vdpa/vdpa.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index e7765953307f..829fd4cfc038 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -800,13 +800,13 @@ static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callba
>         return msg->len;
>  }
>
> -static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
> -                                      struct sk_buff *msg, u64 features,
> +static int vdpa_dev_net_mq_config_fill(struct sk_buff *msg, u64 features,
>                                        const struct virtio_net_config *config)
>  {
>         u16 val_u16;
>
> -       if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0)
> +       if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0 &&
> +           (features & BIT_ULL(VIRTIO_NET_F_RSS)) == 0)
>                 return 0;
>
>         val_u16 = le16_to_cpu(config->max_virtqueue_pairs);
> --
> 2.31.1
>

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Re: [PATCH V2 RESEND 4/6] vDPA: check virtio device features to detect MQ

[Jason Wang]

On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan <lingshan.zhu@intel.com> wrote:
>
> vdpa_dev_net_mq_config_fill() should checks device features
> for MQ than driver features.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/vdpa/vdpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 829fd4cfc038..84a0c3877d7c 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -839,7 +839,7 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
>                               VDPA_ATTR_PAD))
>                 return -EMSGSIZE;
>
> -       return vdpa_dev_net_mq_config_fill(vdev, msg, features_driver, &config);
> +       return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
>  }
>
>  static int
> --
> 2.31.1
>

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Re: [PATCH V2 RESEND 5/6] vDPA: fix spars cast warning in vdpa_dev_net_mq_config_fill

[Jason Wang]

On Tue, Sep 27, 2022 at 11:10 AM Zhu Lingshan <lingshan.zhu@intel.com> wrote:
>
> This commit fixes spars warnings: cast to restricted __le16
> in function vdpa_dev_net_mq_config_fill()
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/vdpa/vdpa.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 84a0c3877d7c..fa7f65279f79 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -809,7 +809,8 @@ static int vdpa_dev_net_mq_config_fill(struct sk_buff *msg, u64 features,
>             (features & BIT_ULL(VIRTIO_NET_F_RSS)) == 0)
>                 return 0;
>
> -       val_u16 = le16_to_cpu(config->max_virtqueue_pairs);
> +       val_u16 = __virtio16_to_cpu(true, config->max_virtqueue_pairs);
> +
>         return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);
>  }
>
> --
> 2.31.1
>

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