[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH] migration: regain control of images when migration

From: Greg Kurz
Subject: [Qemu-devel] [PATCH] migration: regain control of images when migration fails to complete
Date: Wed, 18 May 2016 12:18:14 +0200
User-agent: StGit/0.17.1-dirty

We currently have an error path during migration that can cause
the source QEMU to abort:

    runstate_is_running() ----------------> true if guest is running
    bdrv_inactivate_all() ----------------> inactivate images
     ... qemu_fflush()
           socket_writev_buffer() --------> error because destination fails
         qemu_fflush() -------------------> set error on migration stream
  migration_completion() -----------------> set migrate state to FAILED
migration_thread() -----------------------> break migration loop
  vm_start() -----------------------------> restart guest with inactive

and you get:

qemu-system-ppc64: socket_writev_buffer: Got err=104 for 
/home/greg/Work/qemu/qemu-master/block/io.c:1342:bdrv_co_do_pwritev: Assertion 
`!(bs->open_flags & 0x0800)' failed.
Aborted (core dumped)

If we try postcopy with a similar scenario, we also get the writev error
message but QEMU leaves the guest paused because entered_postcopy is true.

We could possibly do the same with precopy and leave the guest paused.
But since the historical default for migration errors is to restart the
source, this patch adds a call to bdrv_invalidate_cache_all() instead.

Signed-off-by: Greg Kurz <address@hidden>
 migration/migration.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/migration/migration.c b/migration/migration.c
index 991313a8629a..5726959ddfd9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1568,8 +1568,17 @@ static void migration_completion(MigrationState *s, int 
                 ret = bdrv_inactivate_all();
             if (ret >= 0) {
+                Error *local_err = NULL;
                 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
                 qemu_savevm_state_complete_precopy(s->to_dst_file, false);
+                if (qemu_file_get_error(s->to_dst_file)) {
+                    bdrv_invalidate_cache_all(&local_err);
+                    if (local_err) {
+                        error_report_err(local_err);
+                    }
+                }

reply via email to

[Prev in Thread] Current Thread [Next in Thread]