Re: [PATCH PROTOTYPE 1/6] memory: Introduce sparse RAM handler for memory regions

[Peter Xu <peterx@redhat.com>]

On Thu, Sep 24, 2020 at 06:04:18PM +0200, David Hildenbrand wrote:
> +static inline void memory_region_set_sparse_ram_handler(MemoryRegion *mr,
> +                                                        SparseRAMHandler *srh)
> +{
> +    g_assert(memory_region_is_ram(mr));

Nit: Maybe assert mr->srh==NULL here?  If sparse ram handler is exclusive,
which afaiu, is a yes.

> +    mr->srh = srh;
> +}
> +
> +static inline void memory_region_register_sparse_ram_notifier(MemoryRegion *mr,
> +                                                           SparseRAMNotifier *n)
> +{
> +    SparseRAMHandler *srh = memory_region_get_sparse_ram_handler(mr);
> +    SparseRAMHandlerClass *srhc = SPARSE_RAM_HANDLER_GET_CLASS(srh);
> +
> +    srhc->register_listener(srh, mr, n);

I feel like you need to check srhc!=NULL first or vfio may start crash without
virtio-mem...  Same question to the other ones (at least unregister).

-- 
Peter Xu