[Qemu-devel] Re: [RFC PATCH 14/20] Upgrade QEMU_FILE_VERSION from 3 to 4, and introduce qemu_savevm_state_all().

[Yoshiaki Tamura]

Anthony Liguori wrote:
> On 04/21/2010 12:57 AM, Yoshiaki Tamura wrote:
> > Make a 32bit entry after QEMU_VM_FILE_VERSION to recognize whether the
> > transfered data is QEMU_VM_FT_MODE or QEMU_VM_LIVE_MIGRATION_MODE.
>
> I'd rather you encapsulate the current protocol as opposed to extending
> it with a new version.
>
> You could also do this by just having a new -incoming option, right? All
> you really need is to indicate that this is for high frequency
> checkpointing, right?

Exactly.
I would use -incoming option.

> Regards,
>
> Anthony Liguori
>
> > Signed-off-by: Yoshiaki Tamura<address@hidden>
> > ---
> > savevm.c | 76
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> > sysemu.h | 1 +
> > 2 files changed, 75 insertions(+), 2 deletions(-)
> >
> > diff --git a/savevm.c b/savevm.c
> > index 292ae32..19b3efb 100644
> > --- a/savevm.c
> > +++ b/savevm.c
> > @@ -1402,8 +1402,10 @@ static void vmstate_save(QEMUFile *f,
> > SaveStateEntry *se)
> > }
> >
> > #define QEMU_VM_FILE_MAGIC 0x5145564d
> > -#define QEMU_VM_FILE_VERSION_COMPAT 0x00000002
> > -#define QEMU_VM_FILE_VERSION 0x00000003
> > +#define QEMU_VM_FILE_VERSION_COMPAT 0x00000003
> > +#define QEMU_VM_FILE_VERSION 0x00000004
> > +#define QEMU_VM_LIVE_MIGRATION_MODE 0x00000005
> > +#define QEMU_VM_FT_MODE 0x00000006
> >
> > #define QEMU_VM_EOF 0x00
> > #define QEMU_VM_SECTION_START 0x01
> > @@ -1425,6 +1427,12 @@ int qemu_savevm_state_begin(Monitor *mon,
> > QEMUFile *f, int blk_enable,
> >
> > qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
> > qemu_put_be32(f, QEMU_VM_FILE_VERSION);
> > +
> > + if (ft_mode) {
> > + qemu_put_be32(f, QEMU_VM_FT_MODE);
> > + } else {
> > + qemu_put_be32(f, QEMU_VM_LIVE_MIGRATION_MODE);
> > + }
> >
> > QTAILQ_FOREACH(se,&savevm_handlers, entry) {
> > int len;
> > @@ -1533,6 +1541,66 @@ int qemu_savevm_state_complete(Monitor *mon,
> > QEMUFile *f)
> > return 0;
> > }
> >
> > +int qemu_savevm_state_all(Monitor *mon, QEMUFile *f)
> > +{
> > + SaveStateEntry *se;
> > +
> > + QTAILQ_FOREACH(se,&savevm_handlers, entry) {
> > + int len;
> > +
> > + if (se->save_live_state == NULL)
> > + continue;
> > +
> > + /* Section type */
> > + qemu_put_byte(f, QEMU_VM_SECTION_START);
> > + qemu_put_be32(f, se->section_id);
> > +
> > + /* ID string */
> > + len = strlen(se->idstr);
> > + qemu_put_byte(f, len);
> > + qemu_put_buffer(f, (uint8_t *)se->idstr, len);
> > +
> > + qemu_put_be32(f, se->instance_id);
> > + qemu_put_be32(f, se->version_id);
> > + if (ft_mode == FT_INIT) {
> > + /* This is workaround. */
> > + se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
> > + } else {
> > + se->save_live_state(mon, f, QEMU_VM_SECTION_PART, se->opaque);
> > + }
> > + }
> > +
> > + ft_mode = FT_TRANSACTION;
> > + QTAILQ_FOREACH(se,&savevm_handlers, entry) {
> > + int len;
> > +
> > + if (se->save_state == NULL&& se->vmsd == NULL)
> > + continue;
> > +
> > + /* Section type */
> > + qemu_put_byte(f, QEMU_VM_SECTION_FULL);
> > + qemu_put_be32(f, se->section_id);
> > +
> > + /* ID string */
> > + len = strlen(se->idstr);
> > + qemu_put_byte(f, len);
> > + qemu_put_buffer(f, (uint8_t *)se->idstr, len);
> > +
> > + qemu_put_be32(f, se->instance_id);
> > + qemu_put_be32(f, se->version_id);
> > +
> > + vmstate_save(f, se);
> > + }
> > +
> > + qemu_put_byte(f, QEMU_VM_EOF);
> > +
> > + if (qemu_file_has_error(f))
> > + return -EIO;
> > +
> > + return 0;
> > +}
> > +
> > +
> > void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
> > {
> > SaveStateEntry *se;
> > @@ -1617,6 +1685,10 @@ int qemu_loadvm_state(QEMUFile *f, int
> > skip_header)
> > if (v != QEMU_VM_FILE_VERSION)
> > return -ENOTSUP;
> >
> > + v = qemu_get_be32(f);
> > + if (v == QEMU_VM_FT_MODE) {
> > + ft_mode = FT_INIT;
> > + }
> > }
> >
> > while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
> > diff --git a/sysemu.h b/sysemu.h
> > index 6c1441f..df314bb 100644
> > --- a/sysemu.h
> > +++ b/sysemu.h
> > @@ -67,6 +67,7 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile
> > *f, int blk_enable,
> > int shared);
> > int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f);
> > int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f);
> > +int qemu_savevm_state_all(Monitor *mon, QEMUFile *f);
> > void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f);
> > int qemu_loadvm_state(QEMUFile *f, int skip_header);