Re: [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.

[Stefan Weil]

Am 10.11.2015 um 15:25 schrieb Juan Quintela:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> The state of the postcopy process is managed via a series of messages;
>    * Add wrappers and handlers for sending/receiving these messages
>    * Add state variable that track the current state of postcopy
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> Reviewed-by: Amit Shah <address@hidden>
> Reviewed-by: Juan Quintela <address@hidden>
> Signed-off-by: Juan Quintela <address@hidden>
> ---
>  include/migration/migration.h |  27 +++++
>  include/sysemu/sysemu.h       |  19 ++++
>  migration/migration.c         |  20 ++++
>  migration/savevm.c            | 254 
> ++++++++++++++++++++++++++++++++++++++++++
>  trace-events                  |  10 ++
>  5 files changed, 330 insertions(+)
>
[...]
> diff --git a/migration/savevm.c b/migration/savevm.c
[...]
> +    if (remote_hps != getpagesize())  {
> +        /*
> +         * Some combinations of mismatch are probably possible but it gets
> +         * a bit more complicated.  In particular we need to place whole
> +         * host pages on the dest at once, and we need to ensure that we
> +         * handle dirtying to make sure we never end up sending part of
> +         * a hostpage on it's own.
> +         */
> +        error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
> +                     (int)remote_hps, getpagesize());

This statement introduces a new warning when compiling for
Windows where getpagesize() returns a size_t. I'll send a patch
to change that definition to return an int value.

Is there a special reason why a type cast was used here
instead of using PRIu64? See also the format string below.

Regards
Stefan


> +        return -1;
> +    }
> +
> +    remote_tps = qemu_get_be64(mis->from_src_file);
> +    if (remote_tps != (1ul << qemu_target_page_bits())) {
> +        /*
> +         * Again, some differences could be dealt with, but for now keep it
> +         * simple.
> +         */
> +        error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
> +                     (int)remote_tps, 1 << qemu_target_page_bits());
>