Steve Sistare <steven.sist...@oracle.com> writes:
> Save the mode in CPR state, so the user does not need to explicitly specify
> it for the target. Modify migrate_mode() so it returns the incoming mode on
> the target.
>
> Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
> ---
> include/migration/cpr.h | 7 +++++++
> migration/cpr.c | 23 ++++++++++++++++++++++-
> migration/migration.c | 1 +
> migration/options.c | 9 +++++++--
> 4 files changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/include/migration/cpr.h b/include/migration/cpr.h
> index 8e7e705..42b4019 100644
> --- a/include/migration/cpr.h
> +++ b/include/migration/cpr.h
> @@ -8,6 +8,13 @@
> #ifndef MIGRATION_CPR_H
> #define MIGRATION_CPR_H
>
> +#include "qapi/qapi-types-migration.h"
> +
> +#define MIG_MODE_NONE MIG_MODE__MAX
What happens when a QEMU that knows about a new mode migrates into a
QEMU that doesn't know that mode, i.e. sees it as MIG_MODE__MAX?
I'd just use -1.
> +
> +MigMode cpr_get_incoming_mode(void);
> +void cpr_set_incoming_mode(MigMode mode);
> +
> typedef int (*cpr_walk_fd_cb)(int fd);
> void cpr_save_fd(const char *name, int id, int fd);
> void cpr_delete_fd(const char *name, int id);
> diff --git a/migration/cpr.c b/migration/cpr.c
> index 313e74e..1c296c6 100644
> --- a/migration/cpr.c
> +++ b/migration/cpr.c
> @@ -21,10 +21,23 @@
> typedef QLIST_HEAD(CprFdList, CprFd) CprFdList;
>
> typedef struct CprState {
> + MigMode mode;
> CprFdList fds;
> } CprState;
>
> -static CprState cpr_state;
> +static CprState cpr_state = {
> + .mode = MIG_MODE_NONE,
> +};
> +
> +MigMode cpr_get_incoming_mode(void)
> +{
> + return cpr_state.mode;
> +}
> +
> +void cpr_set_incoming_mode(MigMode mode)
> +{
> + cpr_state.mode = mode;
> +}
>
>
> /****************************************************************************/
>
> @@ -124,11 +137,19 @@ void cpr_resave_fd(const char *name, int id, int fd)
> /*************************************************************************/
> #define CPR_STATE "CprState"
>
> +static int cpr_state_presave(void *opaque)
> +{
> + cpr_state.mode = migrate_mode();
> + return 0;
> +}
> +
> static const VMStateDescription vmstate_cpr_state = {
> .name = CPR_STATE,
> .version_id = 1,
> .minimum_version_id = 1,
> + .pre_save = cpr_state_presave,
> .fields = (VMStateField[]) {
> + VMSTATE_UINT32(mode, CprState),
> VMSTATE_QLIST_V(fds, CprState, 1, vmstate_cpr_fd, CprFd, next),
> VMSTATE_END_OF_LIST()
> }
> diff --git a/migration/migration.c b/migration/migration.c
> index e394ad7..0f47765 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -411,6 +411,7 @@ void migration_incoming_state_destroy(void)
> mis->postcopy_qemufile_dst = NULL;
> }
>
> + cpr_set_incoming_mode(MIG_MODE_NONE);
> yank_unregister_instance(MIGRATION_YANK_INSTANCE);
> }
>
> diff --git a/migration/options.c b/migration/options.c
> index 645f550..305397a 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -22,6 +22,7 @@
> #include "qapi/qmp/qnull.h"
> #include "sysemu/runstate.h"
> #include "migration/colo.h"
> +#include "migration/cpr.h"
> #include "migration/misc.h"
> #include "migration.h"
> #include "migration-stats.h"
> @@ -758,8 +759,12 @@ uint64_t migrate_max_postcopy_bandwidth(void)
>
> MigMode migrate_mode(void)
> {
> - MigrationState *s = migrate_get_current();
> - MigMode mode = s->parameters.mode;
> + MigMode mode = cpr_get_incoming_mode();
> +
> + if (mode == MIG_MODE_NONE) {
> + MigrationState *s = migrate_get_current();
> + mode = s->parameters.mode;
> + }
>
> assert(mode >= 0 && mode < MIG_MODE__MAX);
> return mode;
