Re: [libvirt] [PATCHv4 01/18] blockjob: add qemu capabilities related to block jobs

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). Furthermore, qemu 1.1 will be adding 'block_job_cancel' as an asynchronous command, but an earlier implementation (that supported only the qed file format) existed which was synchronous only. If 'drive-mirror' is added in time, then we can safely use 'drive-mirror' as the witness of whether 'block_job_cancel' is synchronous or asynchronous. As of this[1] qemu email, both commands have been proposed but not yet incorporated into the tree; in fact, the implementation I tested with has changed to match this[2] email that suggested a mandatory 'full':'bool' argument rather than 'mode':'no-backing-file'. So there is a risk that qemu 1.1 will have yet another subtly different implementation. [1]https://lists.gnu.org/archive/html/qemu-devel/2012-03/msg01524.html [2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg00886.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. (qemuMonitorJSONDiskSnapshot): Fix formatting issues. --- src/qemu/qemu_capabilities.c | 3 +++ src/qemu/qemu_capabilities.h | 2 ++ src/qemu/qemu_monitor_json.c | 15 ++++++++------- 3 files changed, 13 insertions(+), 7 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_json.c b/src/qemu/qemu_monitor_json.c index d09d779..c8ed087 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -939,12 +939,14 @@ 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; @@ -3114,7 +3116,7 @@ qemuMonitorJSONDiskSnapshot(qemuMonitorPtr mon, virJSONValuePtr actions, const char *device, const char *file, const char *format, bool reuse) { - int ret; + int ret = -1; virJSONValuePtr cmd; virJSONValuePtr reply = NULL; @@ -3132,14 +3134,13 @@ qemuMonitorJSONDiskSnapshot(qemuMonitorPtr mon, virJSONValuePtr actions, if (actions) { if (virJSONValueArrayAppend(actions, cmd) < 0) { virReportOOMError(); - ret = -1; } else { ret = 0; cmd = NULL; } } else { if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0) - goto cleanup; + goto cleanup; if (qemuMonitorJSONHasError(reply, "CommandNotFound") && qemuMonitorCheckHMP(mon, "snapshot_blkdev")) {