Re: [libvirt] [PATCH 13/13] backup: qemu: Implement VIR_DOMAIN_CHECKPOINT_XML_SIZE flag

Once a checkpoint has been created, it is desirable to estimate the size of the disk delta that is represented between the checkpoint and the current operation. To do this, we have to scrape information out of QMP query-block on a request from the user. --- src/qemu/qemu_monitor.h | 4 ++ src/qemu/qemu_monitor_json.h | 3 ++ src/qemu/qemu_driver.c | 56 +++++++++++++++++++++++++- src/qemu/qemu_monitor.c | 11 ++++++ src/qemu/qemu_monitor_json.c | 76 ++++++++++++++++++++++++++++++++++++ 5 files changed, 149 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 0cdb2dd1e2..585a0203eb 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c

@@ -17399,9 +17403,59 @@ qemuDomainCheckpointGetXMLDesc(virDomainCheckpointPtr checkpoint, goto cleanup; chkdef = virDomainCheckpointObjGetDef(chk); + if (flags & VIR_DOMAIN_CHECKPOINT_XML_SIZE) { + /* TODO: for non-current checkpoint, this requires a QMP sequence per + disk, since the stat of one bitmap in isolation is too low, + and merely adding bitmap sizes may be too high: + block-dirty-bitmap-create tmp + for each bitmap from checkpoint to current: + add bitmap to src_list + block-dirty-bitmap-merge dst=tmp src_list + query-block and read tmp size + block-dirty-bitmap-remove tmp + So for now, go with simpler query-blocks only for current. + */ + if (virDomainCheckpointGetCurrent(vm->checkpoints) != chk) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("cannot compute size for non-current checkpoint '%s'"), + checkpoint->name); + goto cleanup; + } + + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0) + goto cleanup; + + if (virDomainObjCheckActive(vm) < 0) + goto endjob; + + if (qemuBlockNodeNamesDetect(driver, vm, QEMU_ASYNC_JOB_NONE) < 0) + goto endjob;

+ + /* TODO: Shouldn't need to recompute node names. */

+ for (i = 0; i < chkdef->ndisks; i++) { + virDomainCheckpointDiskDef *disk = &chkdef->disks[i]; + + if (disk->type != VIR_DOMAIN_CHECKPOINT_TYPE_BITMAP) + continue; + VIR_FREE(chk->def->dom->disks[disk->idx]->src->nodeformat);

+ if (VIR_STRDUP(chk->def->dom->disks[disk->idx]->src->nodeformat, + qemuBlockNodeLookup(vm, disk->name)) < 0) + goto endjob; + } + + priv = vm->privateData; + qemuDomainObjEnterMonitor(driver, vm); + rc = qemuMonitorUpdateCheckpointSize(priv->mon, chkdef); + if (qemuDomainObjExitMonitor(driver, vm) < 0)

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 2dcd65d86f..4c232105c2 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -2760,6 +2760,82 @@ int qemuMonitorJSONBlockResize(qemuMonitorPtr mon, return ret; } +int qemuMonitorJSONUpdateCheckpointSize(qemuMonitorPtr mon, + virDomainCheckpointDefPtr chk) +{ + int ret = -1; + size_t i, j; + virJSONValuePtr devices; + + if (!(devices = qemuMonitorJSONQueryBlock(mon))) + return -1;

+ + for (i = 0; i < virJSONValueArraySize(devices); i++) { + virJSONValuePtr dev = virJSONValueArrayGet(devices, i); + virJSONValuePtr inserted; + virJSONValuePtr bitmaps = NULL; + const char *node; + virDomainCheckpointDiskDefPtr disk; + + if (!(dev = qemuMonitorJSONGetBlockDev(devices, i))) + goto cleanup;