diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 4b5d9e5e50..ae7867a8db 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -30,6 +30,7 @@ #include "trace.h" #include "qemu/error-report.h" #include "migration/misc.h" +#include "migration/migration.h" #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" @@ -662,6 +663,18 @@ virtio_balloon_free_page_hint_notify(NotifierWithReturn *n, void *data) return 0; } + /* + * Pages hinted via qemu_guest_free_page_hint() are cleared from the dirty + * bitmap and will not get migrated, especially also not when the postcopy + * destination starts using them and requests migration from the source; the + * faulting thread will stall until postcopy migration finishes and + * all threads are woken up. Let's not start free page hinting if postcopy + * is possible. + */ + if (migrate_postcopy_ram()) { + return 0; + } + switch (pnd->reason) { case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC: virtio_balloon_free_page_stop(dev);