Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <1666137032-28192-1-git-send-email-si-wei.liu@oracle.com> <1666137032-28192-2-git-send-email-si-wei.liu@oracle.com>
In-Reply-To: <1666137032-28192-2-git-send-email-si-wei.liu@oracle.com>
From:   Jason Wang <jasowang@redhat.com>
Date:   Thu, 20 Oct 2022 12:38:22 +0800
Message-ID: <CACGkMEv_fKZa9qN+ytnViCdvcR4Cbr8KyT71UnWzWjrtsFMyBg@mail.gmail.com>
Subject: Re: [PATCH v2 1/4] vdpa: save vdpa_dev_set_config in struct vdpa_device
To:     Si-Wei Liu <si-wei.liu@oracle.com>
Cc:     mst@redhat.com, virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Oct 19, 2022 at 8:56 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>
> In order to allow live migration orchestration software to export the
> initial set of vdpa attributes with which the device was created, it
> will be useful if the vdpa tool can report the config on demand with
> simple query. This will ease the orchestration software implementation
> so that it doesn't have to keep track of vdpa config change, or have
> to persist vdpa attributes across failure and recovery, in fear of
> being killed due to accidental software error.
>
> This commit attempts to make struct vdpa_device contain the struct
> vdpa_dev_set_config, where all config attributes upon vdpa creation
> are carried over. Which will be used in subsequent commits.
>
> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
> ---
>  include/linux/vdpa.h | 23 +++++++++++++----------
>  1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 6d0f5e4..f1838f5 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -58,6 +58,16 @@ struct vdpa_vq_state {
>         };
>  };
>
> +struct vdpa_dev_set_config {
> +       u64 device_features;
> +       struct {
> +               u8 mac[ETH_ALEN];
> +               u16 mtu;
> +               u16 max_vq_pairs;
> +       } net;

Not for this patch but I think there should be a union container for
this structure to make it usable for other types of devices.

> +       u64 mask;
> +};
> +
>  struct vdpa_mgmt_dev;
>
>  /**
> @@ -77,6 +87,8 @@ struct vdpa_vq_state {
>   * @nvqs: maximum number of supported virtqueues
>   * @mdev: management device pointer; caller must setup when registering device as part
>   *       of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().
> + * @vdev_cfg: initial device config on vdpa creation; useful when instantiate with
> + *            the exact same config is needed.

Not a native speaker, but I guess it should be better named as "init_cfg"?

Thanks

>   */
>  struct vdpa_device {
>         struct device dev;
> @@ -91,6 +103,7 @@ struct vdpa_device {
>         struct vdpa_mgmt_dev *mdev;
>         unsigned int ngroups;
>         unsigned int nas;
> +       struct vdpa_dev_set_config vdev_cfg;
>  };
>
>  /**
> @@ -103,16 +116,6 @@ struct vdpa_iova_range {
>         u64 last;
>  };
>
> -struct vdpa_dev_set_config {
> -       u64 device_features;
> -       struct {
> -               u8 mac[ETH_ALEN];
> -               u16 mtu;
> -               u16 max_vq_pairs;
> -       } net;
> -       u64 mask;
> -};
> -
>  /**
>   * Corresponding file area for device memory mapping
>   * @file: vma->vm_file for the mapping
> --
> 1.8.3.1
>