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-rw-r--r--migration/migration.c1
-rw-r--r--migration/migration.h1
-rw-r--r--migration/postcopy-ram.c54
-rw-r--r--migration/savevm.c3
-rw-r--r--migration/trace-events2
5 files changed, 57 insertions, 4 deletions
diff --git a/migration/migration.c b/migration/migration.c
index f9c58d2511..3d3b0a5b4a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -160,6 +160,7 @@ MigrationIncomingState *migration_incoming_get_current(void)
qemu_mutex_init(&mis_current.rp_mutex);
qemu_event_init(&mis_current.main_thread_load_event, false);
qemu_sem_init(&mis_current.postcopy_pause_sem_dst, 0);
+ qemu_sem_init(&mis_current.postcopy_pause_sem_fault, 0);
init_dirty_bitmap_incoming_migration();
diff --git a/migration/migration.h b/migration/migration.h
index 32fd50e9be..4ea5949104 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -76,6 +76,7 @@ struct MigrationIncomingState {
/* notify PAUSED postcopy incoming migrations to try to continue */
QemuSemaphore postcopy_pause_sem_dst;
+ QemuSemaphore postcopy_pause_sem_fault;
};
MigrationIncomingState *migration_incoming_get_current(void);
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 8ceeaa2a93..658b750a8e 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -830,6 +830,17 @@ static void mark_postcopy_blocktime_end(uintptr_t addr)
affected_cpu);
}
+static bool postcopy_pause_fault_thread(MigrationIncomingState *mis)
+{
+ trace_postcopy_pause_fault_thread();
+
+ qemu_sem_wait(&mis->postcopy_pause_sem_fault);
+
+ trace_postcopy_pause_fault_thread_continued();
+
+ return true;
+}
+
/*
* Handle faults detected by the USERFAULT markings
*/
@@ -880,6 +891,22 @@ static void *postcopy_ram_fault_thread(void *opaque)
break;
}
+ if (!mis->to_src_file) {
+ /*
+ * Possibly someone tells us that the return path is
+ * broken already using the event. We should hold until
+ * the channel is rebuilt.
+ */
+ if (postcopy_pause_fault_thread(mis)) {
+ mis->last_rb = NULL;
+ /* Continue to read the userfaultfd */
+ } else {
+ error_report("%s: paused but don't allow to continue",
+ __func__);
+ break;
+ }
+ }
+
if (pfd[1].revents) {
uint64_t tmp64 = 0;
@@ -942,18 +969,37 @@ static void *postcopy_ram_fault_thread(void *opaque)
(uintptr_t)(msg.arg.pagefault.address),
msg.arg.pagefault.feat.ptid, rb);
+retry:
/*
* Send the request to the source - we want to request one
* of our host page sizes (which is >= TPS)
*/
if (rb != mis->last_rb) {
mis->last_rb = rb;
- migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
- rb_offset, qemu_ram_pagesize(rb));
+ ret = migrate_send_rp_req_pages(mis,
+ qemu_ram_get_idstr(rb),
+ rb_offset,
+ qemu_ram_pagesize(rb));
} else {
/* Save some space */
- migrate_send_rp_req_pages(mis, NULL,
- rb_offset, qemu_ram_pagesize(rb));
+ ret = migrate_send_rp_req_pages(mis,
+ NULL,
+ rb_offset,
+ qemu_ram_pagesize(rb));
+ }
+
+ if (ret) {
+ /* May be network failure, try to wait for recovery */
+ if (ret == -EIO && postcopy_pause_fault_thread(mis)) {
+ /* We got reconnected somehow, try to continue */
+ mis->last_rb = NULL;
+ goto retry;
+ } else {
+ /* This is a unavoidable fault */
+ error_report("%s: migrate_send_rp_req_pages() get %d",
+ __func__, ret);
+ break;
+ }
}
}
diff --git a/migration/savevm.c b/migration/savevm.c
index 8ad99b1eaa..6ee69d8283 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2083,6 +2083,9 @@ static bool postcopy_pause_incoming(MigrationIncomingState *mis)
mis->to_src_file = NULL;
qemu_mutex_unlock(&mis->rp_mutex);
+ /* Notify the fault thread for the invalidated file handle */
+ postcopy_fault_thread_notify(mis);
+
error_report("Detected IO failure for postcopy. "
"Migration paused.");
diff --git a/migration/trace-events b/migration/trace-events
index cd971bf9fe..7f836499d1 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -101,6 +101,8 @@ open_return_path_on_source_continue(void) ""
postcopy_start(void) ""
postcopy_pause_return_path(void) ""
postcopy_pause_return_path_continued(void) ""
+postcopy_pause_fault_thread(void) ""
+postcopy_pause_fault_thread_continued(void) ""
postcopy_pause_continued(void) ""
postcopy_pause_incoming(void) ""
postcopy_pause_incoming_continued(void) ""