When dump-guest-memory is requested with detach flag, after its
return, user could query its status using "query-dump" command (with
no argument). The result contains:
- status: current dump status
- completed: bytes written in the latest dump
- total: bytes to write in the latest dump
>From completed and total, we could know how much work
finished by calculating:
100.0 * completed / total (%)
Signed-off-by: Peter Xu <pet...@redhat.com>
---
dump.c | 23 +++++++++++++++++------
qapi-schema.json | 34 ++++++++++++++++++++++++++++++++--
qmp-commands.hx | 31 ++++++++++++++++++++++++++++---
3 files changed, 77 insertions(+), 11 deletions(-)
diff --git a/dump.c b/dump.c
index daa1f2c..00619c6 100644
--- a/dump.c
+++ b/dump.c
@@ -1639,11 +1639,10 @@ static void dump_process(DumpState *s, Error **errp)
create_vmcore(s, errp);
}
- if (*errp) {
- s->status = DUMP_STATUS_FAILED;
- } else {
- s->status = DUMP_STATUS_COMPLETED;
- }
+ /* make sure status is written after written_size updates */
+ smp_wmb();
+ atomic_set(&s->status,
+ ((*errp) ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
/* send DUMP_COMPLETED message (unconditionally) */
qapi_event_send_dump_completed(!!(*errp), error_get_pretty(*errp),
@@ -1660,6 +1659,18 @@ static void *dump_thread(void *data)
return NULL;
}
+DumpQueryResult *qmp_query_dump(Error **errp)
+{
+ DumpQueryResult *result = g_new(DumpQueryResult, 1);
+ DumpState *state = &dump_state_global;
+ result->status = atomic_read(&state->status);
+ /* make sure we are reading status and written_size in order */
+ smp_rmb();
+ result->completed = state->written_size;
+ result->total = state->total_size;
+ return result;
+}
+
void qmp_dump_guest_memory(bool paging, const char *file,
bool has_detach, bool detach,
bool has_begin, int64_t begin, bool has_length,
@@ -1749,7 +1760,7 @@ void qmp_dump_guest_memory(bool paging, const char *file,
begin, length, &local_err);
if (local_err) {
error_propagate(errp, local_err);
- s->status = DUMP_STATUS_FAILED;
+ atomic_set(&s->status, DUMP_STATUS_FAILED);
return;
}
diff --git a/qapi-schema.json b/qapi-schema.json
index f0d3c4a..71f6523 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2116,8 +2116,9 @@
# is the fd's name.
#
# @detach: #optional if true, QMP will return immediately rather than
-# waiting for the dump to finish. A DUMP_COMPLETED event will
-# occur at the end. (since 2.6).
+# waiting for the dump to finish. The user can track progress
+# using "query-dump". A DUMP_COMPLETED event will occur
+# at the end. (since 2.6).
#
# @begin: #optional if specified, the starting physical address.
#
@@ -2158,6 +2159,35 @@
'data': [ 'none', 'active', 'completed', 'failed' ] }
##
+# @DumpQueryResult
+#
+# The result format for 'query-dump'.
+#
+# @status: enum of @DumpStatus, which shows current dump status
+#
+# @completed: bytes written in latest dump (uncompressed)
+#
+# @total: total bytes to be written in latest dump (uncompressed)
+#
+# Since 2.6
+##
+{ 'struct': 'DumpQueryResult',
+ 'data': { 'status': 'DumpStatus',
+ 'completed': 'int',
+ 'total': 'int' } }
+
+##
+# @query-dump
+#
+# Query latest dump status.
+#
+# Returns: A @DumpStatus object showing the dump status.
+#
+# Since: 2.6
+##
+{ 'command': 'query-dump', 'returns': 'DumpQueryResult' }
+
+##
# @DumpGuestMemoryCapability:
#
# A list of the available formats for dump-guest-memory
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7b6f915..5741c0c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -858,8 +858,9 @@ Arguments:
- "protocol": destination file(started with "file:") or destination file
descriptor (started with "fd:") (json-string)
- "detach": if specified, command will return immediately rather than waiting
- for the dump completion. A DUMP_COMPLETED event will occur at
- the end. (json-bool)
+ for the dump completion. The user can track progress using
+ "query-dump" A DUMP_COMPLETED event will occur at the
+ end. (json-bool)
- "begin": the starting physical address. It's optional, and should be
specified
with length together (json-int)
- "length": the memory size, in bytes. It's optional, and should be specified
@@ -882,7 +883,7 @@ EQMP
{
.name = "query-dump-guest-memory-capability",
.args_type = "",
- .mhandler.cmd_new = qmp_marshal_query_dump_guest_memory_capability,
+ .mhandler.cmd_new = qmp_marshal_query_dump_guest_memory_capability,
},
SQMP
@@ -899,6 +900,30 @@ Example:
EQMP
+ {
+ .name = "query-dump",
+ .args_type = "",
+ .params = "",
+ .help = "query background dump status",
+ .mhandler.cmd_new = qmp_marshal_query_dump,
+ },
+
+SQMP
+query-dump
+----------
+
+Query background dump status.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "query-dump" }
+<- { "return": { "status": "active", "completed": 1024000,
+ "total": 2048000 } }
+
+EQMP
+
#if defined TARGET_S390X
{
.name = "dump-skeys",
--
2.4.3
