[GIT PULL 1/8] migration: add migration_guest_ram_loading() helper

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

From: "Denis V. Lunev" <den@openvz.org>

Operations that read guest RAM (dump-guest-memory, memsave, pmemsave)
must refuse to run while the destination of a migration is still
receiving that RAM: during precopy it is incomplete, and during postcopy
a read faults the page in from the source. Provide a single predicate
they can share instead of open-coding the runstate and postcopy checks.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20260619101834.228432-2-den@openvz.org>
---
 include/migration/misc.h | 3 +++
 migration/migration.c    | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/include/migration/misc.h b/include/migration/misc.h
index 3159a5e53c3..d3d6e1f50d1 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -117,6 +117,9 @@ void migration_file_set_error(int ret, Error *err);
 /* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */
 bool migration_in_incoming_postcopy(void);
 
+/* True while the destination still receives guest RAM (precopy or postcopy) */
+bool migration_guest_ram_loading(void);
+
 /* True if incoming migration entered POSTCOPY_INCOMING_ADVISE */
 bool migration_incoming_postcopy_advised(void);
 
diff --git a/migration/migration.c b/migration/migration.c
index 278cad502ae..0f56432d903 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1643,6 +1643,12 @@ bool migration_in_incoming_postcopy(void)
     return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END;
 }
 
+bool migration_guest_ram_loading(void)
+{
+    return runstate_check(RUN_STATE_INMIGRATE) ||
+           migration_in_incoming_postcopy();
+}
+
 bool migration_incoming_postcopy_advised(void)
 {
     PostcopyState ps = postcopy_state_get();

-- 
2.54.0