From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
Create QEMU_VM_COMMAND section type for sending commands from
source to destination. These commands are not intended to convey
guest state but to control the migration process.
For use in postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
include/migration/migration.h | 1 +
include/sysemu/sysemu.h | 7 +++++++
migration/savevm.c | 46 +++++++++++++++++++++++++++++++++++++++++++
trace-events | 1 +
4 files changed, 55 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 414c5cf..8adaa45 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -34,6 +34,7 @@
#define QEMU_VM_SECTION_FULL 0x04
#define QEMU_VM_SUBSECTION 0x05
#define QEMU_VM_VMDESCRIPTION 0x06
+#define QEMU_VM_COMMAND 0x07
#define QEMU_VM_SECTION_FOOTER 0x7e
struct MigrationParams {
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 6dae2db..5869607 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -82,6 +82,11 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict);
void qemu_announce_self(void);
+/* Subcommands for QEMU_VM_COMMAND */
+enum qemu_vm_cmd {
+ MIG_CMD_INVALID = 0, /* Must be 0 */
+};
+
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params);
@@ -90,6 +95,8 @@ int qemu_savevm_state_iterate(QEMUFile *f);
void qemu_savevm_state_complete_precopy(QEMUFile *f);
void qemu_savevm_state_cancel(void);
uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
+void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
+ uint16_t len, uint8_t *data);
int qemu_loadvm_state(QEMUFile *f);
typedef enum DisplayType
diff --git a/migration/savevm.c b/migration/savevm.c
index f9168ac..7ce9d21 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -686,6 +686,23 @@ static bool check_section_footer(QEMUFile *f,
SaveStateEntry *se)
return true;
}
+/* Send a 'QEMU_VM_COMMAND' type element with the command
+ * and associated data.
+ */
+void qemu_savevm_command_send(QEMUFile *f,
+ enum qemu_vm_cmd command,
+ uint16_t len,
+ uint8_t *data)
+{
+ qemu_put_byte(f, QEMU_VM_COMMAND);
+ qemu_put_be16(f, (uint16_t)command);
+ qemu_put_be16(f, len);
+ if (len) {
+ qemu_put_buffer(f, data, len);
+ }
+ qemu_fflush(f);
+}
+
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@@ -982,6 +999,29 @@ static SaveStateEntry *find_se(const char *idstr, int
instance_id)
return NULL;
}
+/*
+ * Process an incoming 'QEMU_VM_COMMAND'
+ * negative return on error (will issue error message)
+ */
+static int loadvm_process_command(QEMUFile *f)
+{
+ uint16_t cmd;
+ uint16_t len;
+
+ cmd = qemu_get_be16(f);
+ len = qemu_get_be16(f);
+
+ trace_loadvm_process_command(cmd, len);
+ switch (cmd) {
+
+ default:
+ error_report("VM_COMMAND 0x%x unknown (len 0x%x)", cmd, len);
+ return -1;
+ }
+
+ return 0;
+}
+
struct LoadStateEntry {
QLIST_ENTRY(LoadStateEntry) entry;
SaveStateEntry *se;
@@ -1114,6 +1154,12 @@ int qemu_loadvm_state(QEMUFile *f)
goto out;
}
break;
+ case QEMU_VM_COMMAND:
+ ret = loadvm_process_command(f);
+ if (ret < 0) {
+ goto out;
+ }
+ break;
default:
error_report("Unknown savevm section type %d", section_type);
ret = -EINVAL;
diff --git a/trace-events b/trace-events
index d539528..73a65c3 100644
--- a/trace-events
+++ b/trace-events
@@ -1183,6 +1183,7 @@ virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
qemu_loadvm_state_section(unsigned int section_type) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr,
uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
+loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
savevm_section_start(const char *id, unsigned int section_id) "%s, section_id
%u"
savevm_section_end(const char *id, unsigned int section_id, int ret) "%s,
section_id %u -> %d"
savevm_state_begin(void) ""
--
2.4.3
