@@ -2798,6 +2798,18 @@ static int ram_load_postcopy(QEMUFile *f)
return ret;
}
+static bool postcopy_is_advised(void)
+{
+ PostcopyState ps = postcopy_state_get();
+ return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END;
+}
+
+static bool postcopy_is_running(void)
+{
+ PostcopyState ps = postcopy_state_get();
+ return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END;
+}
+
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0, invalid_flags = 0;
@@ -2807,9 +2819,9 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
* If system is running in postcopy mode, page inserts to host memory must
* be atomic
*/
- bool postcopy_running = postcopy_state_get() >= POSTCOPY_INCOMING_LISTENING;
+ bool postcopy_running = postcopy_is_running();
/* ADVISE is earlier, it shows the source has the postcopy capability on */
- bool postcopy_advised = postcopy_state_get() >= POSTCOPY_INCOMING_ADVISE;
+ bool postcopy_advised = postcopy_is_advised();
seq_iter++;
When migrating a VM with 'migrate_set_capability postcopy-ram on' a postcopy_state is set during the process, ending up with the state POSTCOPY_INCOMING_END when the migration is over. This postcopy_state is taken into account inside ram_load to check how it will load the memory pages. This same ram_load is called when in a loadvm command. Inside ram_load, the logic to see if we're at postcopy_running state is: postcopy_running = postcopy_state_get() >= POSTCOPY_INCOMING_LISTENING postcopy_state_get() returns this enum type: typedef enum { POSTCOPY_INCOMING_NONE = 0, POSTCOPY_INCOMING_ADVISE, POSTCOPY_INCOMING_DISCARD, POSTCOPY_INCOMING_LISTENING, POSTCOPY_INCOMING_RUNNING, POSTCOPY_INCOMING_END } PostcopyState; In the case where ram_load is executed and postcopy_state is POSTCOPY_INCOMING_END, postcopy_running will be set to 'true' and ram_load will behave like a postcopy is in progress. This scenario isn't achievable in a migration but it is reproducible when executing savevm/loadvm after migrating with 'postcopy-ram on', causing loadvm to fail with Error -22: Source: (qemu) migrate_set_capability postcopy-ram on (qemu) migrate tcp:127.0.0.1:4444 Dest: (qemu) migrate_set_capability postcopy-ram on (qemu) ubuntu1704-intel login: Ubuntu 17.04 ubuntu1704-intel ttyS0 ubuntu1704-intel login: (qemu) (qemu) savevm test1 (qemu) loadvm test1 Unknown combination of migration flags: 0x4 (postcopy mode) error while loading state for instance 0x0 of device 'ram' Error -22 while loading VM state (qemu) This patch fixes this problem by changing the existing logic for postcopy_advised and postcopy_running in ram_load, making them 'false' if we're at POSTCOPY_INCOMING_END state. Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> CC: Juan Quintela <quintela@redhat.com> CC: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com> --- migration/ram.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)