On Fri, Oct 03, 2014 at 06:47:34PM +0100, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > When postcopy calls qemu_savevm_state_complete it's not really > the end of migration, so skip: > a) Finishing postcopiable iterative devices - they'll carry on > b) The termination byte on the end of the stream. > > We then also add: > qemu_savevm_state_postcopy_complete > which is called at the end of a postcopy migration to call the > complete methods on devices skipped in the _complete call.
So, we should probably rename qemu_savevm_state_complete() to reflect
the fact that it's no longer actually a completion, but just the
transition from pre-copy to post-copy phases. A good, brief name
doesn't immediately occur to me, unfortunately.
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> include/sysemu/sysemu.h | 1 +
> savevm.c | 52
> ++++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> index e7ff3d0..46665ce 100644
> --- a/include/sysemu/sysemu.h
> +++ b/include/sysemu/sysemu.h
> @@ -113,6 +113,7 @@ void qemu_savevm_state_cancel(void);
> void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
> uint64_t *res_non_postcopiable,
> uint64_t *res_postcopiable);
> +void qemu_savevm_state_postcopy_complete(QEMUFile *f);
> void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
> uint16_t len, uint8_t *data);
> void qemu_savevm_send_reqack(QEMUFile *f, uint32_t value);
> diff --git a/savevm.c b/savevm.c
> index a0cb88b..7c4541d 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -854,10 +854,51 @@ int qemu_savevm_state_iterate(QEMUFile *f)
> return ret;
> }
>
> +/*
> + * Calls the complete routines just for those devices that are postcopiable;
> + * causing the last few pages to be sent immediately and doing any associated
> + * cleanup.
> + * Note postcopy also calls the plain qemu_savevm_state_complete to complete
> + * all the other devices, but that happens at the point we switch to
> postcopy.
> + */
> +void qemu_savevm_state_postcopy_complete(QEMUFile *f)
> +{
> + SaveStateEntry *se;
> + int ret;
> +
> + QTAILQ_FOREACH(se, &savevm_handlers, entry) {
> + if (!se->ops || !se->ops->save_live_complete ||
> + !se->ops->can_postcopy) {
So, you check for the presence of a can_postcopy callback, but you
don't ever actually invoke it.
> + continue;
> + }
> + if (se->ops && se->ops->is_active) {
> + if (!se->ops->is_active(se->opaque)) {
> + continue;
> + }
> + }
> + trace_savevm_section_start(se->idstr, se->section_id);
> + /* Section type */
> + qemu_put_byte(f, QEMU_VM_SECTION_END);
> + qemu_put_be32(f, se->section_id);
> +
> + ret = se->ops->save_live_complete(f, se->opaque);
I'm wondering if it might be clearer not to overload the
save_live_complete hook, but instead allow both "execution transition"
(old complete) and "final complete" (postcopy complete) hooks
(expecting only one to be non-NULL in most cases).
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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