Re: [PATCH v4 15/18] virtio-mem: Update state to match bitmap as soon as it's been migrated

["Maciej S. Szmigiero" <mail@xxxxxxxxxxxxxxxxxxxxx>]

On 26.09.2023 20:57, David Hildenbrand wrote:
> It's cleaner and future-proof to just have other state that depends on the
> bitmap state to be updated as soon as possible when restoring the bitmap.
>
> So factor out informing RamDiscardListener into a functon and call it in
> case of early migration right after we restored the bitmap.
>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>   hw/virtio/virtio-mem.c | 26 +++++++++++++++++++++-----
>   1 file changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index 0b0e6c5090..0cf47df9cf 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -984,9 +984,8 @@ static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
>                                                  virtio_mem_discard_range_cb);
>   }
>   
> -static int virtio_mem_post_load(void *opaque, int version_id)
> +static int virtio_mem_post_load_bitmap(VirtIOMEM *vmem)
>   {
> -    VirtIOMEM *vmem = VIRTIO_MEM(opaque);
>       RamDiscardListener *rdl;
>       int ret;
>   
> @@ -1001,6 +1000,20 @@ static int virtio_mem_post_load(void *opaque, int version_id)
>               return ret;
>           }
>       }
> +    return 0;
> +}
> +
> +static int virtio_mem_post_load(void *opaque, int version_id)
> +{
> +    VirtIOMEM *vmem = VIRTIO_MEM(opaque);
> +    int ret;
> +
> +    if (!vmem->early_migration) {
> +        ret = virtio_mem_post_load_bitmap(vmem);
> +        if (ret) {
> +            return ret;
> +        }
> +    }
>   
>       /*
>        * If shared RAM is migrated using the file content and not using QEMU,
> @@ -1043,7 +1056,7 @@ static int virtio_mem_post_load_early(void *opaque, int version_id)
>       int ret;
>   
>       if (!vmem->prealloc) {
> -        return 0;
> +        goto post_load_bitmap;
>       }
>   
>       /*
> @@ -1051,7 +1064,7 @@ static int virtio_mem_post_load_early(void *opaque, int version_id)
>        * don't mess with preallocation and postcopy.
>        */
>       if (migrate_ram_is_ignored(rb)) {
> -        return 0;
> +        goto post_load_bitmap;
>       }
>   
>       /*
> @@ -1084,7 +1097,10 @@ static int virtio_mem_post_load_early(void *opaque, int version_id)
>               return -EBUSY;
>           }
>       }
> -    return 0;
> +
> +post_load_bitmap:
> +    /* Finally, update any other state to be consistent with the new bitmap. */
> +    return virtio_mem_post_load_bitmap(vmem);
>   }
>   
>   typedef struct VirtIOMEMMigSanityChecks {


Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@xxxxxxxxxx>

Thanks,
Maciej