From 51568d18bbfef1adce26d8cd33f3f4a4c12b1e78 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 26 Jan 2018 18:53:15 +0100 Subject: [PATCH 4/4] savevm: fail if migration blockers are present RH-Author: Dr. David Alan Gilbert Message-id: <20180126185315.2342-3-dgilbert@redhat.com> Patchwork-id: 78732 O-Subject: [RHEL7.5 qemu-kvm PATCH 2/2] savevm: fail if migration blockers are present Bugzilla: 1536883 RH-Acked-by: Peter Xu RH-Acked-by: Kevin Wolf RH-Acked-by: Miroslav Rezanina From: Greg Kurz 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] (cherry picked from commit 24f3902b088cd4f2dbebfd90527b5d81d6a050e9) dgilbert: Manual merge Signed-off-by: Amit Shah Signed-off-by: Miroslav Rezanina --- include/migration/migration.h | 1 + migration.c | 21 +++++++++++++++------ savevm.c | 2 +- 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index c99a67c..0760984 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -90,6 +90,7 @@ int migrate_fd_close(MigrationState *s); void add_migration_state_change_notifier(Notifier *notify); void remove_migration_state_change_notifier(Notifier *notify); +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.c b/migration.c index e8c5939..5591601 100644 --- a/migration.c +++ b/migration.c @@ -417,6 +417,20 @@ void migrate_del_blocker(Error *reason) migration_blockers = g_slist_remove(migration_blockers, reason); } +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) @@ -447,12 +461,7 @@ 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/savevm.c b/savevm.c index d34004e..0216df2 100644 --- a/savevm.c +++ b/savevm.c @@ -2207,7 +2207,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) .shared = 0 }; - if (qemu_savevm_state_blocked(errp)) { + if (migration_is_blocked(errp)) { return -EINVAL; } -- 1.8.3.1