Re: [PATCH v4 19/23] multifd: Add property to enable/disable zero_page

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/migration.h |  3 +++
>  hw/core/machine.c     |  4 +++-
>  migration/migration.c | 11 +++++++++++
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/migration/migration.h b/migration/migration.h
> index 8130b703eb..638cd89b6c 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -296,6 +296,8 @@ struct MigrationState {
>       * This save hostname when out-going migration starts
>       */
>      char *hostname;
> +    /* Use multifd channel to send zero pages */
> +    bool multifd_zero_pages;
>  };
>  
>  void migrate_set_state(int *state, int old_state, int new_state);
> @@ -338,6 +340,7 @@ int migrate_multifd_channels(void);
>  MultiFDCompression migrate_multifd_compression(void);
>  int migrate_multifd_zlib_level(void);
>  int migrate_multifd_zstd_level(void);
> +bool migrate_use_multifd_zero_page(void);
>  
>  int migrate_use_xbzrle(void);
>  uint64_t migrate_xbzrle_cache_size(void);
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index debcdc0e70..fc303cb707 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -37,7 +37,9 @@
>  #include "hw/virtio/virtio.h"
>  #include "hw/virtio/virtio-pci.h"
>  
> -GlobalProperty hw_compat_6_2[] = {};
> +GlobalProperty hw_compat_6_2[] = {
> +    { "migration", "multifd-zero-page", "false" },
> +};
>  const size_t hw_compat_6_2_len = G_N_ELEMENTS(hw_compat_6_2);
>  
>  GlobalProperty hw_compat_6_1[] = {
> diff --git a/migration/migration.c b/migration/migration.c
> index 0652165610..ff39f07fc5 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2502,6 +2502,15 @@ bool migrate_use_multifd(void)
>      return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
>  }
>  
> +bool migrate_use_multifd_zero_page(void)
> +{
> +    MigrationState *s;
> +
> +    s = migrate_get_current();
> +
> +    return s->multifd_zero_pages;
> +}
> +
>  bool migrate_pause_before_switchover(void)
>  {
>      MigrationState *s;
> @@ -4158,6 +4167,8 @@ static Property migration_properties[] = {
>                        clear_bitmap_shift, CLEAR_BITMAP_SHIFT_DEFAULT),
>  
>      /* Migration parameters */
> +    DEFINE_PROP_BOOL("multifd-zero-pages", MigrationState,
> +                      multifd_zero_pages, true),
>      DEFINE_PROP_UINT8("x-compress-level", MigrationState,
>                        parameters.compress_level,
>                        DEFAULT_MIGRATE_COMPRESS_LEVEL),
> -- 
> 2.34.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK