[libvirt] [PATCH 4/6] snapshot: expose qemu commands for mirrored storage migration
Eric Blake
eblake at redhat.com
Fri Mar 23 04:17:37 UTC 2012
A snapshot-based mirrored storage migration sequence requires both the
'drive-mirror' action in 'transaction' (present if the 'drive-mirror'
standalone monitor command also exists) and the 'drive-reopen' monitor
command (it would be nice if that were also part of a 'transaction',
but the initial qemu implementation has it standalone only).
As of this[1] qemu email, both commands have been proposed but not yet
incorporated into the tree, so there is a risk that qemu 1.1 will
not have these commands, or will have something subtly different.
[1]https://lists.gnu.org/archive/html/qemu-devel/2012-03/msg01524.html
* src/qemu/qemu_capabilities.h (QEMU_CAPS_DRIVE_MIRROR)
(QEMU_CAPS_DRIVE_REOPEN): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONDriveMirror, qemuMonitorDriveReopen): New functions.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDriveMirror)
(qemuMonitorDriveReopen): Declare them.
* src/qemu/qemu_monitor.c (qemuMonitorDriveMirror)
(qemuMonitorDriveReopen): New passthroughs.
* src/qemu/qemu_monitor.h (qemuMonitorDriveMirror)
(qemuMonitorDriveReopen): Declare them.
---
src/qemu/qemu_capabilities.c | 3 ++
src/qemu/qemu_capabilities.h | 2 +
src/qemu/qemu_monitor.c | 50 ++++++++++++++++++++++++++++++
src/qemu/qemu_monitor.h | 14 ++++++++
src/qemu/qemu_monitor_json.c | 70 +++++++++++++++++++++++++++++++++++++++--
src/qemu/qemu_monitor_json.h | 21 +++++++++++-
6 files changed, 154 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 0e09d6d..1938ae4 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -156,6 +156,9 @@ VIR_ENUM_IMPL(qemuCaps, QEMU_CAPS_LAST,
"scsi-disk.channel",
"scsi-block",
"transaction",
+
+ "drive-mirror", /* 90 */
+ "drive-reopen",
);
struct qemu_feature_flags {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 78cdbe0..405bf2a 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -124,6 +124,8 @@ enum qemuCapsFlags {
QEMU_CAPS_SCSI_DISK_CHANNEL = 87, /* Is scsi-disk.channel available? */
QEMU_CAPS_SCSI_BLOCK = 88, /* -device scsi-block */
QEMU_CAPS_TRANSACTION = 89, /* transaction monitor command */
+ QEMU_CAPS_DRIVE_MIRROR = 90, /* drive-mirror monitor command */
+ QEMU_CAPS_DRIVE_REOPEN = 91, /* drive-reopen monitor command */
QEMU_CAPS_LAST, /* this must always be the last item */
};
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index bbe0f98..06d24c8 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -2652,6 +2652,32 @@ qemuMonitorDiskSnapshot(qemuMonitorPtr mon, virJSONValuePtr actions,
return ret;
}
+/* Add the drive-mirror action to a transaction. */
+int
+qemuMonitorDriveMirror(qemuMonitorPtr mon, virJSONValuePtr actions,
+ const char *device, const char *file,
+ const char *format, bool reuse)
+{
+ int ret;
+
+ VIR_DEBUG("mon=%p, actions=%p, device=%s, file=%s, format=%s, reuse=%d",
+ mon, actions, device, file, format, reuse);
+
+ if (!mon) {
+ qemuReportError(VIR_ERR_INVALID_ARG, "%s",
+ _("monitor must not be NULL"));
+ return -1;
+ }
+
+ if (mon->json)
+ ret = qemuMonitorJSONDriveMirror(mon, actions, device, file, format,
+ reuse);
+ else
+ qemuReportError(VIR_ERR_INVALID_ARG, "%s",
+ _("drive-mirror requires JSON monitor"));
+ return ret;
+}
+
/* Use the transaction QMP command to run atomic snapshot commands. */
int
qemuMonitorTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
@@ -2668,6 +2694,30 @@ qemuMonitorTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
return ret;
}
+/* Use the drive-reopen monitor command. */
+int
+qemuMonitorDriveReopen(qemuMonitorPtr mon, const char *device,
+ const char *file, const char *format)
+{
+ int ret;
+
+ VIR_DEBUG("mon=%p, device=%s, file=%s, format=%s",
+ mon, device, file, format);
+
+ if (!mon) {
+ qemuReportError(VIR_ERR_INVALID_ARG, "%s",
+ _("monitor must not be NULL"));
+ return -1;
+ }
+
+ if (mon->json)
+ ret = qemuMonitorJSONDriveReopen(mon, device, file, format);
+ else
+ qemuReportError(VIR_ERR_INVALID_ARG, "%s",
+ _("drive-reopen requires JSON monitor"));
+ return ret;
+}
+
int qemuMonitorArbitraryCommand(qemuMonitorPtr mon,
const char *cmd,
char **reply,
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 909e9ac..d213818 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -498,8 +498,22 @@ int qemuMonitorDiskSnapshot(qemuMonitorPtr mon,
const char *file,
const char *format,
bool reuse);
+int qemuMonitorDriveMirror(qemuMonitorPtr mon,
+ virJSONValuePtr actions,
+ const char *device,
+ const char *file,
+ const char *format,
+ bool reuse)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
+ ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5);
int qemuMonitorTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+int qemuMonitorDriveReopen(qemuMonitorPtr mon,
+ const char *device,
+ const char *file,
+ const char *format)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
+ ATTRIBUTE_NONNULL(4);
int qemuMonitorArbitraryCommand(qemuMonitorPtr mon,
const char *cmd,
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 0e8bcce..4338456 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -888,12 +888,14 @@ qemuMonitorJSONCheckCommands(qemuMonitorPtr mon,
if (STREQ(name, "human-monitor-command"))
*json_hmp = 1;
-
- if (STREQ(name, "system_wakeup"))
+ else if (STREQ(name, "system_wakeup"))
qemuCapsSet(qemuCaps, QEMU_CAPS_WAKEUP);
-
- if (STREQ(name, "transaction"))
+ else if (STREQ(name, "transaction"))
qemuCapsSet(qemuCaps, QEMU_CAPS_TRANSACTION);
+ else if (STREQ(name, "drive-mirror"))
+ qemuCapsSet(qemuCaps, QEMU_CAPS_DRIVE_MIRROR);
+ else if (STREQ(name, "drive-reopen"))
+ qemuCapsSet(qemuCaps, QEMU_CAPS_DRIVE_REOPEN);
}
ret = 0;
@@ -3106,6 +3108,39 @@ cleanup:
return ret;
}
+int
+qemuMonitorJSONDriveMirror(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
+ virJSONValuePtr actions,
+ const char *device, const char *file,
+ const char *format, bool reuse)
+{
+ int ret = -1;
+ virJSONValuePtr cmd;
+
+ cmd = qemuMonitorJSONMakeCommandRaw(true,
+ "drive-mirror",
+ "s:device", device,
+ "s:target", file,
+ "s:format", format,
+ "s:mode",
+ reuse ? "existing" : "absolute-paths",
+ NULL);
+ if (!cmd)
+ return -1;
+
+ if (virJSONValueArrayAppend(actions, cmd) < 0) {
+ virReportOOMError();
+ goto cleanup;
+ }
+
+ cmd = NULL;
+ ret = 0;
+
+cleanup:
+ virJSONValueFree(cmd);
+ return ret;
+}
+
/* Note that this call frees actions regardless of whether the call
* succeeds. */
int
@@ -3134,6 +3169,33 @@ cleanup:
return ret;
}
+int
+qemuMonitorJSONDriveReopen(qemuMonitorPtr mon, const char *device,
+ const char *file, const char *format)
+{
+ int ret;
+ virJSONValuePtr cmd;
+ virJSONValuePtr reply = NULL;
+
+ cmd = qemuMonitorJSONMakeCommand("drive-reopen",
+ "s:device", device,
+ "s:new-image-file", file,
+ "s:format", format,
+ NULL);
+ if (!cmd)
+ return -1;
+
+ if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
+ goto cleanup;
+
+ ret = qemuMonitorJSONCheckError(cmd, reply);
+
+cleanup:
+ virJSONValueFree(cmd);
+ virJSONValueFree(reply);
+ return ret;
+}
+
int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon,
const char *cmd_str,
char **reply_str,
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index a0f67aa..406836e 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -230,8 +230,25 @@ int qemuMonitorJSONDiskSnapshot(qemuMonitorPtr mon,
const char *device,
const char *file,
const char *format,
- bool reuse);
-int qemuMonitorJSONTransaction(qemuMonitorPtr mon, virJSONValuePtr actions);
+ bool reuse)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3)
+ ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5);
+int qemuMonitorJSONDriveMirror(qemuMonitorPtr mon,
+ virJSONValuePtr actions,
+ const char *device,
+ const char *file,
+ const char *format,
+ bool reuse)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
+ ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5);
+int qemuMonitorJSONTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+int qemuMonitorJSONDriveReopen(qemuMonitorPtr mon,
+ const char *device,
+ const char *file,
+ const char *format)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
+ ATTRIBUTE_NONNULL(4);
int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon,
const char *cmd_str,
--
1.7.7.6
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