From e81a24a7487e502762bcd1f17dce24e8d7c35bc0 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 4 May 2016 21:44:19 +0200 Subject: [PATCH] savevm: fail if migration blockers are present QEMU has currently two ways to prevent migration to occur: - migration blocker when it depends on runtime state - VMStateDescription.unmigratable when migration is not supported at all This patch gathers all the logic into a single function to be called from both the savevm and the migrate paths. This fixes a bug with 9p, at least, where savevm would succeed and the following would happen in the guest after loadvm: $ ls /host ls: cannot access /host: Protocol error With this patch: (qemu) savevm foo Migration is disabled when VirtFS export path '/' is mounted in the guest using mount_tag 'host' Signed-off-by: Greg Kurz Reviewed-by: Paolo Bonzini Message-Id: <146239057139.11271.9011797645454781543.stgit@bahia.huguette.org> [Update subject according to Paolo's suggestion - Amit] Signed-off-by: Amit Shah (cherry picked from commit 24f3902b088cd4f2dbebfd90527b5d81d6a050e9) Signed-off-by: Michael Roth --- include/migration/migration.h | 1 + migration/migration.c | 21 +++++++++++++++------ migration/savevm.c | 2 +- 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index ac2c12c2a5..9e36a97fc5 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -210,6 +210,7 @@ int migrate_fd_close(MigrationState *s); void add_migration_state_change_notifier(Notifier *notify); void remove_migration_state_change_notifier(Notifier *notify); MigrationState *migrate_init(const MigrationParams *params); +bool migration_is_blocked(Error **errp); bool migration_in_setup(MigrationState *); bool migration_has_finished(MigrationState *); bool migration_has_failed(MigrationState *); diff --git a/migration/migration.c b/migration/migration.c index 0563b4c348..6cecc359da 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -992,6 +992,20 @@ void qmp_migrate_incoming(const char *uri, Error **errp) once = false; } +bool migration_is_blocked(Error **errp) +{ + if (qemu_savevm_state_blocked(errp)) { + return true; + } + + if (migration_blockers) { + *errp = error_copy(migration_blockers->data); + return true; + } + + return false; +} + void qmp_migrate(const char *uri, bool has_blk, bool blk, bool has_inc, bool inc, bool has_detach, bool detach, Error **errp) @@ -1014,12 +1028,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, return; } - if (qemu_savevm_state_blocked(errp)) { - return; - } - - if (migration_blockers) { - *errp = error_copy(migration_blockers->data); + if (migration_is_blocked(errp)) { return; } diff --git a/migration/savevm.c b/migration/savevm.c index 16ba443798..834664936d 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1169,7 +1169,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) MigrationState *ms = migrate_init(¶ms); ms->to_dst_file = f; - if (qemu_savevm_state_blocked(errp)) { + if (migration_is_blocked(errp)) { return -EINVAL; }