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[Qemu-devel] [PATCH v5 26/28] migration: allow migrate_cancel to pause p
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v5 26/28] migration: allow migrate_cancel to pause postcopy |
Date: |
Tue, 5 Dec 2017 14:53:05 +0800 |
It was allowed in the past to even cancel a postcopy migration, but it
does not really make sense, and no one should be using it, since
cancelling a migration during postcopy means crashing the VM at no time.
Let's just use re-use this command as a way to pause the postcopy
migration when we detected that we are in postcopy migration. This can
be used when we want to trigger the postcopy recovery manually.
Signed-off-by: Peter Xu <address@hidden>
---
hmp-commands.hx | 8 ++++++--
migration/migration.c | 18 +++++++++++++++++-
qapi/migration.json | 3 ++-
3 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index ffcdc34652..32fdd52212 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -952,14 +952,18 @@ ETEXI
.name = "migrate_cancel",
.args_type = "",
.params = "",
- .help = "cancel the current VM migration",
+ .help = "cancel the current VM precopy migration, or "
+ "pause the migration if it's in postcopy state, "
+ "so that a postcopy recovery can be carried out later.",
.cmd = hmp_migrate_cancel,
},
STEXI
@item migrate_cancel
@findex migrate_cancel
-Cancel the current VM migration.
+If during a precopy, this command cancels the migration. If during
+postcopy, this command pauses the migration (so that a postcopy
+recovery can be carried out afterward).
ETEXI
{
diff --git a/migration/migration.c b/migration/migration.c
index 8762fad9be..0c1a783df2 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1535,7 +1535,23 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
void qmp_migrate_cancel(Error **errp)
{
- migrate_fd_cancel(migrate_get_current());
+ MigrationState *ms = migrate_get_current();
+ int ret;
+
+ if (ms->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
+ /*
+ * Cancelling a postcopy migration does not really make sense.
+ * Here instead we pause the migration only, so another
+ * recovery can take place if needed.
+ */
+ ret = qemu_file_shutdown(ms->to_dst_file);
+ if (ret) {
+ error_setg(errp, "Failed to pause migration stream.");
+ }
+ return;
+ }
+
+ migrate_fd_cancel(ms);
}
void qmp_migrate_continue(MigrationStatus state, Error **errp)
diff --git a/qapi/migration.json b/qapi/migration.json
index 5dfac0681d..e15bb516cd 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -881,7 +881,8 @@
##
# @migrate_cancel:
#
-# Cancel the current executing migration process.
+# Cancel the current executing migration process for precopy. For
+# postcopy, it'll pause the migration instead.
#
# Returns: nothing on success
#
--
2.14.3
- [Qemu-devel] [PATCH v5 16/28] migration: new message MIG_RP_MSG_RECV_BITMAP, (continued)
- [Qemu-devel] [PATCH v5 16/28] migration: new message MIG_RP_MSG_RECV_BITMAP, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 17/28] migration: new cmd MIG_CMD_POSTCOPY_RESUME, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 18/28] migration: new message MIG_RP_MSG_RESUME_ACK, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 19/28] migration: introduce SaveVMHandlers.resume_prepare, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 20/28] migration: synchronize dirty bitmap for resume, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 22/28] migration: final handshake for the resume, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 21/28] migration: setup ramstate for resume, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 23/28] migration: free SocketAddress where allocated, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 24/28] migration: init dst in migration_object_init too, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 25/28] io: let watcher of the channel run in same ctx, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 26/28] migration: allow migrate_cancel to pause postcopy,
Peter Xu <=
- [Qemu-devel] [PATCH v5 27/28] qmp/migration: new command migrate-recover, Peter Xu, 2017/12/05
- [Qemu-devel] [PATCH v5 28/28] hmp/migration: add migrate_recover command, Peter Xu, 2017/12/05
- Re: [Qemu-devel] [PATCH v5 00/28] Migration: postcopy failure recovery, Peter Xu, 2017/12/05
- Re: [Qemu-devel] [PATCH v5 00/28] Migration: postcopy failure recovery, Dr. David Alan Gilbert, 2017/12/05