Re: [Qemu-devel] [PATCH 4/5] Disable XBZRLE during migrate to file if it is active

[Paolo Bonzini]

> XBZRLE is not effective when migrating to file.
> 
> Disabling it automatically will remove the need to update the
> command line to allow loading a guest from a file that was in XBZRLE
> format.

What about savevm?

Paolo

> Signed-off-by: Orit Wasserman <address@hidden>
> ---
>  include/migration/migration.h | 1 +
>  migration-exec.c              | 6 ++++++
>  migration.c                   | 9 +++++++++
>  3 files changed, 16 insertions(+)
> 
> diff --git a/include/migration/migration.h
> b/include/migration/migration.h
> index a8c9639..8577a0f 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -129,6 +129,7 @@ int xbzrle_encode_buffer(uint8_t *old_buf,
> uint8_t *new_buf, int slen,
>  int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int
>  dlen);
>  
>  int migrate_use_xbzrle(void);
> +void migrate_disable_xbzrle(void);
>  int64_t migrate_xbzrle_cache_size(void);
>  
>  int64_t xbzrle_cache_resize(int64_t new_size);
> diff --git a/migration-exec.c b/migration-exec.c
> index a051a6e..98ba41a 100644
> --- a/migration-exec.c
> +++ b/migration-exec.c
> @@ -61,6 +61,12 @@ void exec_start_outgoing_migration(MigrationState
> *s, const char *command, Error
>  {
>      FILE *f;
>  
> +    /* there is no point in using XBZRLE when migrating to file */
> +    if (migrate_use_xbzrle()) {
> +        DPRINTF("XBZRLE active during migrate to file -
> disabling\n");
> +        migrate_disable_xbzrle();
> +    }
> +
>      f = popen(command, "w");
>      if (f == NULL) {
>          error_setg_errno(errp, errno, "failed to popen the migration
>          target");
> diff --git a/migration.c b/migration.c
> index 77c1971..e32635e 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -510,6 +510,15 @@ int migrate_use_xbzrle(void)
>      return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
>  }
>  
> +void migrate_disable_xbzrle(void)
> +{
> +    MigrationState *s;
> +
> +    s = migrate_get_current();
> +
> +    s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE] = false;
> +}
> +
>  int64_t migrate_xbzrle_cache_size(void)
>  {
>      MigrationState *s;
> --
> 1.7.11.7
> 
>