Steven Sistare <steven.sist...@oracle.com> writes: > On 5/9/2024 3:14 PM, Fabiano Rosas wrote: >> Steve Sistare <steven.sist...@oracle.com> writes: >> >>> Add the only-migratable-modes option as a generalization of only-migratable. >>> Only devices that support all requested modes are allowed. >>> >>> Signed-off-by: Steve Sistare <steven.sist...@oracle.com> >>> --- >>> include/migration/misc.h | 3 +++ >>> include/sysemu/sysemu.h | 1 - >>> migration/migration-hmp-cmds.c | 26 +++++++++++++++++++++++++- >>> migration/migration.c | 22 +++++++++++++++++----- >>> migration/savevm.c | 2 +- >>> qemu-options.hx | 16 ++++++++++++++-- >>> system/globals.c | 1 - >>> system/vl.c | 13 ++++++++++++- >>> target/s390x/cpu_models.c | 4 +++- >>> 9 files changed, 75 insertions(+), 13 deletions(-) >>> >>> diff --git a/include/migration/misc.h b/include/migration/misc.h >>> index 5b963ba..3ad2cd9 100644 >>> --- a/include/migration/misc.h >>> +++ b/include/migration/misc.h >>> @@ -119,6 +119,9 @@ bool migration_incoming_postcopy_advised(void); >>> /* True if background snapshot is active */ >>> bool migration_in_bg_snapshot(void); >>> >>> +void migration_set_required_mode(MigMode mode); >>> +bool migration_mode_required(MigMode mode); >>> + >>> /* migration/block-dirty-bitmap.c */ >>> void dirty_bitmap_mig_init(void); >>> >>> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h >>> index 5b4397e..0a9c4b4 100644 >>> --- a/include/sysemu/sysemu.h >>> +++ b/include/sysemu/sysemu.h >>> @@ -8,7 +8,6 @@ >>> >>> /* vl.c */ >>> >>> -extern int only_migratable; >>> extern const char *qemu_name; >>> extern QemuUUID qemu_uuid; >>> extern bool qemu_uuid_set; >>> diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c >>> index 414c7e8..ca913b7 100644 >>> --- a/migration/migration-hmp-cmds.c >>> +++ b/migration/migration-hmp-cmds.c >>> @@ -16,6 +16,7 @@ >>> #include "qemu/osdep.h" >>> #include "block/qapi.h" >>> #include "migration/snapshot.h" >>> +#include "migration/misc.h" >>> #include "monitor/hmp.h" >>> #include "monitor/monitor.h" >>> #include "qapi/error.h" >>> @@ -33,6 +34,28 @@ >>> #include "options.h" >>> #include "migration.h" >>> >>> +static void migration_dump_modes(Monitor *mon) >>> +{ >>> + int mode, n = 0; >>> + >>> + monitor_printf(mon, "only-migratable-modes: "); >>> + >>> + for (mode = 0; mode < MIG_MODE__MAX; mode++) { >>> + if (migration_mode_required(mode)) { >>> + if (n++) { >>> + monitor_printf(mon, ","); >>> + } >>> + monitor_printf(mon, "%s", MigMode_str(mode)); >>> + } >>> + } >>> + >>> + if (!n) { >>> + monitor_printf(mon, "none\n"); >>> + } else { >>> + monitor_printf(mon, "\n"); >>> + } >>> +} >>> + >>> static void migration_global_dump(Monitor *mon) >>> { >>> MigrationState *ms = migrate_get_current(); >>> @@ -41,7 +64,7 @@ static void migration_global_dump(Monitor *mon) >>> monitor_printf(mon, "store-global-state: %s\n", >>> ms->store_global_state ? "on" : "off"); >>> monitor_printf(mon, "only-migratable: %s\n", >>> - only_migratable ? "on" : "off"); >>> + migration_mode_required(MIG_MODE_NORMAL) ? "on" : >>> "off"); >>> monitor_printf(mon, "send-configuration: %s\n", >>> ms->send_configuration ? "on" : "off"); >>> monitor_printf(mon, "send-section-footer: %s\n", >>> @@ -50,6 +73,7 @@ static void migration_global_dump(Monitor *mon) >>> ms->decompress_error_check ? "on" : "off"); >>> monitor_printf(mon, "clear-bitmap-shift: %u\n", >>> ms->clear_bitmap_shift); >>> + migration_dump_modes(mon); >>> } >>> >>> void hmp_info_migrate(Monitor *mon, const QDict *qdict) >>> diff --git a/migration/migration.c b/migration/migration.c >>> index 4984dee..5535b84 100644 >>> --- a/migration/migration.c >>> +++ b/migration/migration.c >>> @@ -1719,17 +1719,29 @@ static bool is_busy(Error **reasonp, Error **errp) >>> return false; >>> } >>> >>> -static bool is_only_migratable(Error **reasonp, Error **errp, int modes) >>> +static int migration_modes_required; >>> + >>> +void migration_set_required_mode(MigMode mode) >>> +{ >>> + migration_modes_required |= BIT(mode); >>> +} >>> + >>> +bool migration_mode_required(MigMode mode) >>> +{ >>> + return !!(migration_modes_required & BIT(mode)); >>> +} >>> + >>> +static bool modes_are_required(Error **reasonp, Error **errp, int modes) >>> { >>> ERRP_GUARD(); >>> >>> - if (only_migratable && (modes & BIT(MIG_MODE_NORMAL))) { >>> + if (migration_modes_required & modes) { >>> error_propagate_prepend(errp, *reasonp, >>> - "disallowing migration blocker " >>> - "(--only-migratable) for: "); >>> + "-only-migratable{-modes} specified, but: >>> "); >> >> extra space before 'specified' > > Will fix, thanks. > >>> *reasonp = NULL; >>> return true; >>> } >>> + >>> return false; >>> } >>> >>> @@ -1783,7 +1795,7 @@ int migrate_add_blocker_modes(Error **reasonp, Error >>> **errp, MigMode mode, ...) >>> modes = get_modes(mode, ap); >>> va_end(ap); >>> >>> - if (is_only_migratable(reasonp, errp, modes)) { >>> + if (modes_are_required(reasonp, errp, modes)) { >>> return -EACCES; >>> } else if (is_busy(reasonp, errp)) { >>> return -EBUSY; >>> diff --git a/migration/savevm.c b/migration/savevm.c >>> index 6087c3a..e53ac84 100644 >>> --- a/migration/savevm.c >>> +++ b/migration/savevm.c >>> @@ -3585,7 +3585,7 @@ void vmstate_register_ram_global(MemoryRegion *mr) >>> bool vmstate_check_only_migratable(const VMStateDescription *vmsd) >>> { >>> /* check needed if --only-migratable is specified */ >>> - if (!only_migratable) { >>> + if (!migration_mode_required(MIG_MODE_NORMAL)) { >>> return true; >>> } >>> >>> diff --git a/qemu-options.hx b/qemu-options.hx >>> index f0dfda5..946d731 100644 >>> --- a/qemu-options.hx >>> +++ b/qemu-options.hx >>> @@ -4807,8 +4807,20 @@ DEF("only-migratable", 0, >>> QEMU_OPTION_only_migratable, \ >>> "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) >>> SRST >>> ``-only-migratable`` >>> - Only allow migratable devices. Devices will not be allowed to enter >>> - an unmigratable state. >>> + Only allow devices that can migrate using normal mode. Devices will not >>> + be allowed to enter an unmigratable state. >> >> What's a "normal" mode is what people will ask. I don't think we need to >> expose this. This option never had anything to do with "modes" and I >> think we can keep it this way. See below... > > We now have a mode parameter and enum MigMode which includes normal, and is > documented in qapi. >
Alright, I take your point below. We could declare -only-migratable superseded by -only-migratable-modes then: ``-only-migratable`` Only allow devices that can migrate using normal mode. Devices will not be allowed to enter an unmigratable state. Same as -only-migratable-modes normal. Kept for backward-compatibility. >>> +ERST >>> + >>> +DEF("only-migratable-modes", HAS_ARG, QEMU_OPTION_only_migratable_modes, \ >>> + "-only-migratable-modes mode1[,...]\n" >>> + " allow only devices that are migratable using >>> mode(s)\n", >>> + QEMU_ARCH_ALL) >>> +SRST >>> +``-only-migratable-modes mode1[,...]`` >>> + Only allow devices which are migratable using all modes in the list, >>> + which guarantees that migration will not fail due to a blocker. >>> + If both only-migratable-modes and only-migratable are specified, >>> + or are specified multiple times, then the required modes accumulate. >>> ERST >>> >>> DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ >>> diff --git a/system/globals.c b/system/globals.c >>> index e353584..fdc263e 100644 >>> --- a/system/globals.c >>> +++ b/system/globals.c >>> @@ -48,7 +48,6 @@ const char *qemu_name; >>> unsigned int nb_prom_envs; >>> const char *prom_envs[MAX_PROM_ENVS]; >>> uint8_t *boot_splash_filedata; >>> -int only_migratable; /* turn it off unless user states otherwise */ >>> int icount_align_option; >>> >>> /* The bytes in qemu_uuid are in the order specified by RFC4122, _not_ in >>> the >>> diff --git a/system/vl.c b/system/vl.c >>> index b76881e..7e73be9 100644 >>> --- a/system/vl.c >>> +++ b/system/vl.c >>> @@ -3458,7 +3458,18 @@ void qemu_init(int argc, char **argv) >>> incoming = optarg; >>> break; >>> case QEMU_OPTION_only_migratable: >>> - only_migratable = 1; >>> + migration_set_required_mode(MIG_MODE_NORMAL); >> >> ...from the point of view of user intent, I think this should be >> MIG_MODE_ALL. > If only-migratable applies to all modes, then: > If a user only intends to use mode A, then a blocker for mode B will terminate > qemu. Not good. Ok, we can't know the mode before migration time, nevermind. > > Defining only-migratable to apply to normal mode is the backwards-compatible > solution. > > - Steve > >> If I have this option set I never want to see a blocker, >> period. That's not a change in behavior because the mode has to be >> explicitly selected anyway. >> >>> + break; >>> + case QEMU_OPTION_only_migratable_modes: >>> + { >>> + int i, mode; >>> + g_autofree char **words = g_strsplit(optarg, ",", -1); >>> + for (i = 0; words[i]; i++) { >>> + mode = qapi_enum_parse(&MigMode_lookup, words[i], >>> -1, >>> + &error_fatal); >>> + migration_set_required_mode(mode); >> >> This option can be used to refine the modes being considered, it should >> take precedence if both are present. >> >>> + } >>> + } >>> break; >>> case QEMU_OPTION_nodefaults: >>> has_defaults = 0; >>> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c >>> index 8ed3bb6..42ad160 100644 >>> --- a/target/s390x/cpu_models.c >>> +++ b/target/s390x/cpu_models.c >>> @@ -16,6 +16,7 @@ >>> #include "kvm/kvm_s390x.h" >>> #include "sysemu/kvm.h" >>> #include "sysemu/tcg.h" >>> +#include "migration/misc.h" >>> #include "qapi/error.h" >>> #include "qemu/error-report.h" >>> #include "qapi/visitor.h" >>> @@ -526,7 +527,8 @@ static void check_compatibility(const S390CPUModel >>> *max_model, >>> } >>> >>> #ifndef CONFIG_USER_ONLY >>> - if (only_migratable && test_bit(S390_FEAT_UNPACK, model->features)) { >>> + if (migration_mode_required(MIG_MODE_NORMAL) && >>> + test_bit(S390_FEAT_UNPACK, model->features)) { >>> error_setg(errp, "The unpack facility is not compatible with " >>> "the --only-migratable option. You must remove either " >>> "the 'unpack' facility or the --only-migratable >>> option");