Re: [libvirt] [PATCH v7 18/23] backup: qemu: Implement metadata tracking for checkpoint APIs

A lot of this work heavily copies from the existing snapshot APIs. The interaction with qemu during create/delete still needs to be implemented, but this takes care of all the libvirt metadata (saving and restoring XML, and tracking the relations between multiple checkpoints). Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/qemu/qemu_block.h | 3 + src/qemu/qemu_conf.h | 2 + src/qemu/qemu_domain.h | 15 + src/qemu/qemu_block.c | 12 + src/qemu/qemu_conf.c | 5 + src/qemu/qemu_domain.c | 133 +++++++ src/qemu/qemu_driver.c | 843 +++++++++++++++++++++++++++++++++++++++++ 7 files changed, 1013 insertions(+)

+static char * +qemuDomainCheckpointGetXMLDesc(virDomainCheckpointPtr checkpoint, + unsigned int flags) +{ + virQEMUDriverPtr driver = checkpoint->domain->conn->privateData; + virDomainObjPtr vm = NULL; + char *xml = NULL; + virDomainMomentObjPtr chk = NULL; + qemuDomainObjPrivatePtr priv; + int rc; + size_t i; + virDomainCheckpointDefPtr chkdef; + + virCheckFlags(VIR_DOMAIN_CHECKPOINT_XML_SECURE | + VIR_DOMAIN_CHECKPOINT_XML_NO_DOMAIN | + VIR_DOMAIN_CHECKPOINT_XML_SIZE, NULL); + + if (!(vm = qemuDomObjFromCheckpoint(checkpoint))) + return NULL; + + if (virDomainCheckpointGetXMLDescEnsureACL(checkpoint->domain->conn, vm->def, flags) < 0) + goto cleanup; + + if (!(chk = qemuCheckObjFromCheckpoint(vm, 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];