Re: [Qemu-block] [PATCH 03/17] migration: split common postcopy out of ram postcopy

[Juan Quintela]

Vladimir Sementsov-Ogievskiy <address@hidden> wrote:
> Split common postcopy staff from ram postcopy staff.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> ---
>  include/migration/migration.h |  1 +
>  migration/migration.c         | 39 +++++++++++++++++++++++++++------------
>  migration/postcopy-ram.c      |  4 +++-
>  migration/savevm.c            | 31 ++++++++++++++++++++++---------
>  4 files changed, 53 insertions(+), 22 deletions(-)
>

Hi

{
>      MigrationState *s;
> @@ -1587,9 +1592,11 @@ static int postcopy_start(MigrationState *ms, bool 
> *old_vm_running)
>       * need to tell the destination to throw any pages it's already received
>       * that are dirty
>       */
> -    if (ram_postcopy_send_discard_bitmap(ms)) {
> -        error_report("postcopy send discard bitmap failed");
> -        goto fail;
> +    if (migrate_postcopy_ram()) {
> +        if (ram_postcopy_send_discard_bitmap(ms)) {
> +            error_report("postcopy send discard bitmap failed");
> +            goto fail;
> +        }

I will have preffered that for the ram commands, to embed the
migrate_postocpy_ram() check inside them, but that is taste, and
everyone has its own O:-)

> diff --git a/migration/savevm.c b/migration/savevm.c
> index e436cb2..c8a71c8 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -73,7 +73,7 @@ static struct mig_cmd_args {
>      [MIG_CMD_INVALID]          = { .len = -1, .name = "INVALID" },
>      [MIG_CMD_OPEN_RETURN_PATH] = { .len =  0, .name = "OPEN_RETURN_PATH" },
>      [MIG_CMD_PING]             = { .len = sizeof(uint32_t), .name = "PING" },
> -    [MIG_CMD_POSTCOPY_ADVISE]  = { .len = 16, .name = "POSTCOPY_ADVISE" },
> +    [MIG_CMD_POSTCOPY_ADVISE]  = { .len = -1, .name = "POSTCOPY_ADVISE" },
>      [MIG_CMD_POSTCOPY_LISTEN]  = { .len =  0, .name = "POSTCOPY_LISTEN" },
>      [MIG_CMD_POSTCOPY_RUN]     = { .len =  0, .name = "POSTCOPY_RUN" },
>      [MIG_CMD_POSTCOPY_RAM_DISCARD] = {
> @@ -827,12 +827,17 @@ int qemu_savevm_send_packaged(QEMUFile *f, const 
> uint8_t *buf, size_t len)
>  /* Send prior to any postcopy transfer */
>  void qemu_savevm_send_postcopy_advise(QEMUFile *f)
>  {
> -    uint64_t tmp[2];
> -    tmp[0] = cpu_to_be64(getpagesize());
> -    tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
> +    if (migrate_postcopy_ram()) {
> +        uint64_t tmp[2];
> +        tmp[0] = cpu_to_be64(getpagesize());
> +        tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
>  
> -    trace_qemu_savevm_send_postcopy_advise();
> -    qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp);
> +        trace_qemu_savevm_send_postcopy_advise();
> +        qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE,
> +                                 16, (uint8_t *)tmp);
> +    } else {
> +        qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL);
> +    }
>  }
>  
>  /* Sent prior to starting the destination running in postcopy, discard pages

I haven't yet figured out why you are reusing this command with a
different number of parameters.
For this to pass, I need that Dave comment on this.

So,

Reviewed-by: Juan Quintela <address@hidden>

conditioned that Dave agrees with this.