[libvirt] [PATCH 4/6] snapshot: expose qemu commands for mirrored storage migration

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