Re: [Qemu-devel] [PATCH V8 15/17] filter-rewriter: handle checkpoint and failover event

[Jason Wang]

On 2018年06月03日 13:05, Zhang Chen wrote:
> After one round of checkpoint, the states between PVM and SVM
> become consistent, so it is unnecessary to adjust the sequence
> of net packets for old connections, besides, while failover
> happens, filter-rewriter needs to check if it still needs to
> adjust sequence of net packets.
>
> Signed-off-by: zhanghailiang <address@hidden>
> Signed-off-by: Zhang Chen <address@hidden>
> ---
>   migration/colo.c      | 13 +++++++++++++
>   net/filter-rewriter.c | 40 ++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 53 insertions(+)
>
> diff --git a/migration/colo.c b/migration/colo.c
> index 442471e088..0bff21d9e5 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -31,6 +31,7 @@
>   #include "qapi/qapi-events-migration.h"
>   #include "qapi/qmp/qerror.h"
>   #include "sysemu/cpus.h"
> +#include "net/filter.h"
>   
>   static bool vmstate_loading;
>   static Notifier packets_compare_notifier;
> @@ -82,6 +83,11 @@ static void secondary_vm_do_failover(void)
>       if (local_err) {
>           error_report_err(local_err);
>       }
> +    /* Notify all filters of all NIC to do checkpoint */
> +    colo_notify_filters_event(COLO_EVENT_FAILOVER, &local_err);
> +    if (local_err) {
> +        error_report_err(local_err);
> +    }
>   
>       if (!autostart) {
>           error_report("\"-S\" qemu option will be ignored in secondary side");
> @@ -800,6 +806,13 @@ void *colo_process_incoming_thread(void *opaque)
>               goto out;
>           }
>   
> +        /* Notify all filters of all NIC to do checkpoint */
> +        colo_notify_filters_event(COLO_EVENT_CHECKPOINT, &local_err);
> +        if (local_err) {
> +            qemu_mutex_unlock_iothread();
> +            goto out;
> +        }
> +

I think the above should belong to another patch.

>           vmstate_loading = false;
>           vm_start();
>           trace_colo_vm_state_change("stop", "run");
> diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
> index 0909a9a8af..f3c306cc89 100644
> --- a/net/filter-rewriter.c
> +++ b/net/filter-rewriter.c
> @@ -20,6 +20,8 @@
>   #include "qemu/main-loop.h"
>   #include "qemu/iov.h"
>   #include "net/checksum.h"
> +#include "net/colo.h"
> +#include "migration/colo.h"
>   
>   #define FILTER_COLO_REWRITER(obj) \
>       OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER)
> @@ -277,6 +279,43 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState 
> *nf,
>       return 0;
>   }
>   
> +static void reset_seq_offset(gpointer key, gpointer value, gpointer user_data)
> +{
> +    Connection *conn = (Connection *)value;
> +
> +    conn->offset = 0;
> +}
> +
> +static gboolean offset_is_nonzero(gpointer key,
> +                                  gpointer value,
> +                                  gpointer user_data)
> +{
> +    Connection *conn = (Connection *)value;
> +
> +    return conn->offset ? true : false;
> +}
> +
> +static void colo_rewriter_handle_event(NetFilterState *nf, int event,
> +                                       Error **errp)
> +{
> +    RewriterState *rs = FILTER_COLO_REWRITER(nf);
> +
> +    switch (event) {
> +    case COLO_EVENT_CHECKPOINT:
> +        g_hash_table_foreach(rs->connection_track_table,
> +                            reset_seq_offset, NULL);
> +        break;
> +    case COLO_EVENT_FAILOVER:
> +        if (!g_hash_table_find(rs->connection_track_table,
> +                              offset_is_nonzero, NULL)) {
> +            object_property_set_str(OBJECT(nf), "off", "status", errp);
> +        }

I may miss something but I think rewriter should not be turned off even 
after failover?

Thanks

> +        break;
> +    default:
> +        break;
> +    }
> +}
> +
>   static void colo_rewriter_cleanup(NetFilterState *nf)
>   {
>       RewriterState *s = FILTER_COLO_REWRITER(nf);
> @@ -332,6 +371,7 @@ static void colo_rewriter_class_init(ObjectClass *oc, void 
> *data)
>       nfc->setup = colo_rewriter_setup;
>       nfc->cleanup = colo_rewriter_cleanup;
>       nfc->receive_iov = colo_rewriter_receive_iov;
> +    nfc->handle_event = colo_rewriter_handle_event;
>   }
>   
>   static const TypeInfo colo_rewriter_info = {