Re: [PATCH v5 7/7] virtio-net: add migration support for RSS and hash report

[Dr. David Alan Gilbert]

* Yuri Benditovich (address@hidden) wrote:
> Save and restore RSS/hash report configuration.
> 
> Signed-off-by: Yuri Benditovich <address@hidden>
> ---
>  hw/net/virtio-net.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index a0614ad4e6..0b058aae9f 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -2842,6 +2842,13 @@ static int virtio_net_post_load_device(void *opaque, 
> int version_id)
>          }
>      }
>  
> +    if (n->rss_data.enabled) {
> +        trace_virtio_net_rss_enable(n->rss_data.hash_types,
> +                                    n->rss_data.indirections_len,
> +                                    sizeof(n->rss_data.key));
> +    } else {
> +        trace_virtio_net_rss_disable();
> +    }
>      return 0;
>  }
>  
> @@ -3019,6 +3026,24 @@ static const VMStateDescription 
> vmstate_virtio_net_has_vnet = {
>      },
>  };
>  
> +static const VMStateDescription vmstate_rss = {
> +    .name      = "vmstate_rss",

You need to do something to avoid breaking migration compatibility
from/to old QEMU's and from/to QEMU's on hosts without the new virtio
features.
Probably adding a .needed =   here pointing to a function that
checks 'enabled' might do it.

Dave


> +    .fields = (VMStateField[]) {
> +        VMSTATE_BOOL(enabled, VirtioNetRssData),
> +        VMSTATE_BOOL(redirect, VirtioNetRssData),
> +        VMSTATE_BOOL(populate_hash, VirtioNetRssData),
> +        VMSTATE_UINT32(hash_types, VirtioNetRssData),
> +        VMSTATE_UINT16(indirections_len, VirtioNetRssData),
> +        VMSTATE_UINT16(default_queue, VirtioNetRssData),
> +        VMSTATE_UINT8_ARRAY(key, VirtioNetRssData,
> +                            VIRTIO_NET_RSS_MAX_KEY_SIZE),
> +        VMSTATE_VARRAY_UINT16_ALLOC(indirections_table, VirtioNetRssData,
> +                                    indirections_len, 0,
> +                                    vmstate_info_uint16, uint16_t),
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
>  static const VMStateDescription vmstate_virtio_net_device = {
>      .name = "virtio-net-device",
>      .version_id = VIRTIO_NET_VM_VERSION,
> @@ -3067,6 +3092,7 @@ static const VMStateDescription 
> vmstate_virtio_net_device = {
>                           vmstate_virtio_net_tx_waiting),
>          VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
>                              has_ctrl_guest_offloads),
> +        VMSTATE_STRUCT(rss_data, VirtIONet, 1, vmstate_rss, 
> VirtioNetRssData),
>          VMSTATE_END_OF_LIST()
>     },
>  };
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK