Re: [Qemu-devel] [PATCH v11 8/9] Add set_cachesize command

[Juan Quintela <quintela@redhat.com>]

Orit Wasserman <owasserm@redhat.com> wrote:
> Change XBZRLE cache size in bytes (the size should be a power of 2).
> If XBZRLE cache size is too small there will be many cache miss.
>
> Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
> Signed-off-by: Petter Svard <petters@cs.umu.se>
> Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
> Signed-off-by: Orit Wasserman <owasserm@redhat.com>

> +void qmp_migrate_set_cachesize(int64_t value, Error **errp)
> +{
> +    MigrationState *s = migrate_get_current();
> +
> +    /* Check for truncation */
> +    if (value != (size_t)value) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
> +                  "exceeding address space");
> +        return;
> +    }
> +
> +    value = MIN(UINT64_MAX, value);

This looks fishy to say the least.  value is signed.  Is there any way
that UINT64_MAX is going to be smaller than value?