Re: [PATCH for-5.0 v11 18/20] virtio-iommu: Support migration

[Peter Xu]

On Fri, Nov 22, 2019 at 07:29:41PM +0100, Eric Auger wrote:
> +static const VMStateDescription vmstate_virtio_iommu_device = {
> +    .name = "virtio-iommu-device",
> +    .minimum_version_id = 1,
> +    .version_id = 1,
> +    .post_load = iommu_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_GTREE_DIRECT_KEY_V(domains, VirtIOIOMMU, 1,
> +                                   &vmstate_domain, viommu_domain),
> +        VMSTATE_GTREE_DIRECT_KEY_V(endpoints, VirtIOIOMMU, 1,
> +                                   &vmstate_endpoint, viommu_endpoint),

IIUC vmstate_domain already contains all the endpoint information (in
endpoint_list of vmstate_domain), but here we migrate it twice.  I
suppose that's why now we need reconstruct_ep_domain_link() to fixup
the duplicated migration?

Then I'll instead ask whether we can skip migrating here?  Then in
post_load we simply:

  foreach(domain)
    foreach(endpoint in domain)
      g_tree_insert(s->endpoints);

It might help to avoid the reconstruct_ep_domain_link ugliness?

And besides, I also agree with Jean that the endpoint data structure
could be reused with IOMMUDevice somehow.

Thanks,

-- 
Peter Xu