[Qemu-devel] Re: [PATCH 33/41] virtio-net: port to vmstate

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Dec 02, 2009 at 01:04:31PM +0100, Juan Quintela wrote:
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  hw/virtio-net.c |  148 ++++++++++++++++++++++++-------------------------------
>  1 files changed, 64 insertions(+), 84 deletions(-)
> 
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index 4434827..3a59449 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -703,6 +703,38 @@ static void virtio_net_tx_timer(void *opaque)
>      virtio_net_flush_tx(n, n->tx_vq);
>  }
> 
> +/* Restore an uint8_t from an uint32_t
> +   This is a Big hack, but it is how the old state did it.
> + */
> +
> +static int get_uint8_from_uint32(QEMUFile *f, void *pv, size_t size)
> +{
> +    uint8_t *v = pv;
> +    *v = qemu_get_be32(f);
> +    return 0;
> +}
> +
> +static void put_unused(QEMUFile *f, void *pv, size_t size)
> +{
> +    fprintf(stderr, "uint8_from_uint32 is used only for backwards compatibility.\n");

line too long

> +    fprintf(stderr, "Never should be used to write a new state.\n");
> +    exit(0);

I don't understand.  what is this dong? when
is this called? Please supply a comment.
Maybe call assert?

> +}
> +
> +static const VMStateInfo vmstate_hack_uint8_from_uint32 = {
> +    .name = "uint8_from_uint32",
> +    .get  = get_uint8_from_uint32,
> +    .put  = put_unused,
> +};
> +
> +#define VMSTATE_UINT8_HACK_TEST(_f, _s, _t)                           \
> +    VMSTATE_SINGLE_TEST(_f, _s, _t, 0, vmstate_hack_uint8_from_uint32, uint8_t)
> +
> +static bool between_4_and_8(void *opaque, int version_id)
> +{
> +    return version_id >= 4 && version_id < 8;
> +}
> +
>  static int virtio_net_post_load(void *opaque, int version_id)
>  {
>      VirtIONet *n = opaque;
> @@ -748,88 +780,37 @@ static int virtio_net_post_load(void *opaque, int version_id)
>      return 0;
>  }
> 
> -static void virtio_net_save(QEMUFile *f, void *opaque)
> -{
> -    VirtIONet *n = opaque;
> -
> -    virtio_save(&n->vdev, f);
> -
> -    qemu_put_buffer(f, n->mac, ETH_ALEN);
> -    qemu_put_be32s(f, &n->tx_timer_active);
> -    qemu_put_be32s(f, &n->mergeable_rx_bufs);
> -    qemu_put_be16s(f, &n->status);
> -    qemu_put_8s(f, &n->promisc);
> -    qemu_put_8s(f, &n->allmulti);
> -    qemu_put_be32s(f, &n->mac_table.in_use);
> -    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
> -    qemu_put_buffer(f, n->vlans, MAX_VLAN >> 3);
> -    qemu_put_be32s(f, &n->has_vnet_hdr);
> -    qemu_put_8s(f, &n->mac_table.multi_overflow);
> -    qemu_put_8s(f, &n->mac_table.uni_overflow);
> -    qemu_put_8s(f, &n->alluni);
> -    qemu_put_8s(f, &n->nomulti);
> -    qemu_put_8s(f, &n->nouni);
> -    qemu_put_8s(f, &n->nobcast);
> -    qemu_put_8s(f, &n->has_ufo);
> -}
> -
> -static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> -{
> -    VirtIONet *n = opaque;
> -
> -    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
> -        return -EINVAL;
> -
> -    virtio_load(&n->vdev, f);
> -
> -    qemu_get_buffer(f, n->mac, ETH_ALEN);
> -    qemu_get_be32s(f, &n->tx_timer_active);
> -    qemu_get_be32s(f, &n->mergeable_rx_bufs);
> -
> -    if (version_id >= 3)
> -        qemu_get_be16s(f, &n->status);
> -
> -    if (version_id >= 4) {
> -        if (version_id < 8) {
> -            n->promisc = qemu_get_be32(f);
> -            n->allmulti = qemu_get_be32(f);
> -        } else {
> -            qemu_get_8s(f, &n->promisc);
> -            qemu_get_8s(f, &n->allmulti);
> -        }
> -    }
> -
> -    if (version_id >= 5) {
> -        qemu_get_be32s(f, &n->mac_table.in_use);
> -        qemu_get_buffer(f, n->mac_table.macs,
> -                        n->mac_table.in_use * ETH_ALEN);
> -    }
> - 
> -    if (version_id >= 6)
> -        qemu_get_buffer(f, n->vlans, MAX_VLAN >> 3);
> -
> -    if (version_id >= 7) {
> -        qemu_get_be32s(f, &n->has_vnet_hdr);
> -    }
> -
> -    if (version_id >= 9) {
> -        qemu_get_8s(f, &n->mac_table.multi_overflow);
> -        qemu_get_8s(f, &n->mac_table.uni_overflow);
> -    }
> -
> -    if (version_id >= 10) {
> -        qemu_get_8s(f, &n->alluni);
> -        qemu_get_8s(f, &n->nomulti);
> -        qemu_get_8s(f, &n->nouni);
> -        qemu_get_8s(f, &n->nobcast);
> +static const VMStateDescription vmstate_virtio_net = {
> +    .name = "virtio-net",
> +    .version_id = 11,
> +    .minimum_version_id = 2,
> +    .minimum_version_id_old = 2,
> +    .post_load = virtio_net_post_load,
> +    .fields      = (VMStateField []) {
> +        VMSTATE_VIRTIO(vdev, VirtIONet),
> +        VMSTATE_BUFFER(mac, VirtIONet),
> +        VMSTATE_UINT32(tx_timer_active, VirtIONet),
> +        VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
> +        VMSTATE_UINT16_V(status, VirtIONet, 3),
> +        VMSTATE_UINT8_HACK_TEST(promisc, VirtIONet, between_4_and_8),
> +        VMSTATE_UINT8_HACK_TEST(allmulti, VirtIONet, between_4_and_8),
> +        VMSTATE_UINT8_V(promisc, VirtIONet, 8),
> +        VMSTATE_UINT8_V(allmulti, VirtIONet, 8),
> +        VMSTATE_UINT32_V(mac_table.in_use, VirtIONet, 5),
> +        VMSTATE_BUFFER_MULTIPLY(mac_table.macs, VirtIONet, 5, NULL, 0,
> +                                mac_table.in_use, ETH_ALEN),
> +        VMSTATE_BUFFER_V(vlans, VirtIONet, 6),
> +        VMSTATE_UINT32_V(has_vnet_hdr, VirtIONet, 7),
> +        VMSTATE_UINT8_V(mac_table.multi_overflow, VirtIONet, 9),
> +        VMSTATE_UINT8_V(mac_table.uni_overflow, VirtIONet, 9),
> +        VMSTATE_UINT8_V(alluni, VirtIONet, 10),
> +        VMSTATE_UINT8_V(nomulti, VirtIONet, 10),
> +        VMSTATE_UINT8_V(nouni, VirtIONet, 10),
> +        VMSTATE_UINT8_V(nobcast, VirtIONet, 10),
> +        VMSTATE_UINT8_V(has_ufo, VirtIONet, 11),
> +        VMSTATE_END_OF_LIST()
>      }
> -
> -    if (version_id >= 11) {
> -        qemu_get_8s(f, &n->has_ufo);
> -    }
> -
> -    return virtio_net_post_load(n, version_id);
> -}
> +};
> 
>  static void virtio_net_cleanup(VLANClientState *vc)
>  {
> @@ -873,8 +854,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
>      n->mergeable_rx_bufs = 0;
>      n->promisc = 1; /* for compatibility */
> 
> -    register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
> -                    virtio_net_save, virtio_net_load, n);
> +    vmstate_register(virtio_net_id++, &vmstate_virtio_net, n);
> 
>      return &n->vdev;
>  }
> @@ -885,7 +865,7 @@ void virtio_net_exit(VirtIODevice *vdev)
> 
>      qemu_purge_queued_packets(n->vc);
> 
> -    unregister_savevm("virtio-net", n);
> +    vmstate_unregister(&vmstate_virtio_net, n);
> 
>      qemu_del_timer(n->tx_timer);
>      qemu_free_timer(n->tx_timer);
> -- 
> 1.6.5.2