Re: [libvirt] [PATCHv2 08/15] blockjob: expose qemu commands for mirrored storage migration

From: "Eric Blake" <eblake(a)redhat.com&gt; To: libvir-list(a)redhat.com Cc: pbonzini(a)redhat.com, fsimonce(a)redhat.com Sent: Friday, April 6, 2012 6:36:54 AM Subject: [PATCHv2 08/15] blockjob: expose qemu commands for mirrored storage migration The new block copy 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 | 23 +++++++++++++ src/qemu/qemu_monitor_json.c | 74 +++++++++++++++++++++++++++++++++++++++-- src/qemu/qemu_monitor_json.h | 21 +++++++++++- 6 files changed, 167 insertions(+), 6 deletions(-)

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index e1a8d4c..f33bed8 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -2685,6 +2685,32 @@ 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, int mode) +{ + int ret; + + VIR_DEBUG("mon=%p, actions=%p, device=%s, file=%s, format=%s, mode=%o", + mon, actions, device, file, format, mode); + + 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, + mode); + 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) @@ -2701,6 +2727,30 @@ 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,