backup: qemu: Implement metadata tracking for checkpoint APIs

A lot of this work heavily copies from the existing snapshot APIs.
What's more, this patch is (intentionally) very similar to the
checkpoint code just added in the test driver, to the point that qemu
checkpoints are not fully usable in this patch, but it at least
bisects and builds cleanly.  The separation between patches is done
because the grunt work of saving and restoring XML and tracking
relations between checkpoints is common to the test driver, while the
later patch adding integration with QMP is specific to qemu.

Also note that the interlocking to prevent checkpoints and snapshots
from existing at the same time will be a separate patch, to make it
easier to revert that restriction when we finally round out the design
for supporting interaction between the two concepts.

Signed-off-by: Eric Blake <eblake@redhat.com>

src/qemu/qemu_domain.c

@@ -56,6 +56,7 @@
 #include "logging/log_manager.h"
 #include "locking/domain_lock.h"
 #include "virdomainsnapshotobjlist.h"
+#include "virdomaincheckpointobjlist.h"
 
 #ifdef MAJOR_IN_MKDEV
 # include <sys/mkdev.h>
@@ -9138,6 +9139,37 @@ qemuDomainSnapshotWriteMetadata(virDomainObjPtr vm,
     return ret;
 }
 
+int
+qemuDomainCheckpointWriteMetadata(virDomainObjPtr vm,
+                                  virDomainMomentObjPtr checkpoint,
+                                  virCapsPtr caps,
+                                  virDomainXMLOptionPtr xmlopt,
+                                  const char *checkpointDir)
+{
+    unsigned int flags = VIR_DOMAIN_CHECKPOINT_FORMAT_SECURE;
+    virDomainCheckpointDefPtr def = virDomainCheckpointObjGetDef(checkpoint);
+    VIR_AUTOFREE(char *) newxml = NULL;
+    VIR_AUTOFREE(char *) chkDir = NULL;
+    VIR_AUTOFREE(char *) chkFile = NULL;
+
+    newxml = virDomainCheckpointDefFormat(def, caps, xmlopt, flags);
+    if (newxml == NULL)
+        return -1;
+
+    if (virAsprintf(&chkDir, "%s/%s", checkpointDir, vm->def->name) < 0)
+        return -1;
+    if (virFileMakePath(chkDir) < 0) {
+        virReportSystemError(errno, _("cannot create checkpoint directory '%s'"),
+                             chkDir);
+        return -1;
+    }
+
+    if (virAsprintf(&chkFile, "%s/%s.xml", chkDir, def->parent.name) < 0)
+        return -1;
+
+    return virXMLSaveFile(chkFile, NULL, "checkpoint-edit", newxml);
+}
+
 /* The domain is expected to be locked and inactive. Return -1 on normal
  * failure, 1 if we skipped a disk due to try_all.  */
 static int
@@ -9334,12 +9366,81 @@ qemuDomainSnapshotDiscardAllMetadata(virQEMUDriverPtr driver,
 }
 
 
+/* Discard one checkpoint (or its metadata), without reparenting any children.  */
+int
+qemuDomainCheckpointDiscard(virQEMUDriverPtr driver,
+                            virDomainObjPtr vm,
+                            virDomainMomentObjPtr chk,
+                            bool update_parent,
+                            bool metadata_only)
+{
+    virDomainMomentObjPtr parent = NULL;
+    VIR_AUTOUNREF(virQEMUDriverConfigPtr) cfg = virQEMUDriverGetConfig(driver);
+    VIR_AUTOFREE(char *) chkFile = NULL;
+
+    if (!metadata_only && !virDomainObjIsActive(vm)) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("cannot remove checkpoint from inactive domain"));
+        return -1;
+    }
+
+    if (virAsprintf(&chkFile, "%s/%s/%s.xml", cfg->checkpointDir,
+                    vm->def->name, chk->def->name) < 0)
+        return -1;
+
+    /* TODO: Implement QMP sequence to merge bitmaps */
+    parent = virDomainCheckpointFindByName(vm->checkpoints,
+                                           chk->def->parent_name);
+
+    if (chk == virDomainCheckpointGetCurrent(vm->checkpoints)) {
+        virDomainCheckpointSetCurrent(vm->checkpoints, NULL);
+        if (update_parent && parent) {
+            virDomainCheckpointSetCurrent(vm->checkpoints, parent);
+            if (qemuDomainCheckpointWriteMetadata(vm, parent, driver->caps,
+                                                  driver->xmlopt,
+                                                  cfg->checkpointDir) < 0) {
+                VIR_WARN("failed to set parent checkpoint '%s' as current",
+                         chk->def->parent_name);
+                virDomainCheckpointSetCurrent(vm->checkpoints, NULL);
+            }
+        }
+    }
+
+    if (unlink(chkFile) < 0)
+        VIR_WARN("Failed to unlink %s", chkFile);
+    if (update_parent)
+        virDomainMomentDropParent(chk);
+    virDomainCheckpointObjListRemove(vm->checkpoints, chk);
+
+    return 0;
+}
+
+int
+qemuDomainCheckpointDiscardAllMetadata(virQEMUDriverPtr driver,
+                                       virDomainObjPtr vm)
+{
+    virQEMUMomentRemove rem = {
+        .driver = driver,
+        .vm = vm,
+        .metadata_only = true,
+        .momentDiscard = qemuDomainCheckpointDiscard,
+    };
+
+    virDomainCheckpointForEach(vm->checkpoints, qemuDomainMomentDiscardAll,
+                               &rem);
+    virDomainCheckpointObjListRemoveAll(vm->checkpoints);
+
+    return rem.err;
+}
+
+
 static void
 qemuDomainRemoveInactiveCommon(virQEMUDriverPtr driver,
                                virDomainObjPtr vm)
 {
     virQEMUDriverConfigPtr cfg;
     VIR_AUTOFREE(char *) snapDir = NULL;
+    VIR_AUTOFREE(char *) chkDir = NULL;
 
     cfg = virQEMUDriverGetConfig(driver);
 
@@ -9354,6 +9455,17 @@ qemuDomainRemoveInactiveCommon(virQEMUDriverPtr driver,
     } else if (rmdir(snapDir) < 0 && errno != ENOENT) {
         VIR_WARN("unable to remove snapshot directory %s", snapDir);
     }
+    /* Remove any checkpoint metadata prior to removing the domain */
+    if (qemuDomainCheckpointDiscardAllMetadata(driver, vm) < 0) {
+        VIR_WARN("unable to remove all checkpoints for domain %s",
+                 vm->def->name);
+    } else if (virAsprintf(&chkDir, "%s/%s", cfg->checkpointDir,
+                           vm->def->name) < 0) {
+        VIR_WARN("unable to remove checkpoint directory %s/%s",
+                 cfg->checkpointDir, vm->def->name);
+    } else if (rmdir(chkDir) < 0 && errno != ENOENT) {
+        VIR_WARN("unable to remove checkpoint directory %s", chkDir);
+    }
     qemuExtDevicesCleanupHost(driver, vm->def);
 
     virObjectUnref(cfg);

src/qemu/qemu_domain.h

@@ -755,6 +755,21 @@ int qemuDomainMomentDiscardAll(void *payload,
 int qemuDomainSnapshotDiscardAllMetadata(virQEMUDriverPtr driver,
                                          virDomainObjPtr vm);
 
+int qemuDomainCheckpointWriteMetadata(virDomainObjPtr vm,
+                                      virDomainMomentObjPtr checkpoint,
+                                      virCapsPtr caps,
+                                      virDomainXMLOptionPtr xmlopt,
+                                      const char *checkpointDir);
+
+int qemuDomainCheckpointDiscard(virQEMUDriverPtr driver,
+                                virDomainObjPtr vm,
+                                virDomainMomentObjPtr chk,
+                                bool update_current,
+                                bool metadata_only);
+
+int qemuDomainCheckpointDiscardAllMetadata(virQEMUDriverPtr driver,
+                                           virDomainObjPtr vm);
+
 void qemuDomainRemoveInactive(virQEMUDriverPtr driver,
                               virDomainObjPtr vm);
 

src/qemu/qemu_driver.c

@@ -104,6 +104,7 @@
 #include "virqemu.h"
 #include "virdomainsnapshotobjlist.h"
 #include "virenum.h"
+#include "virdomaincheckpointobjlist.h"
 
 #define VIR_FROM_THIS VIR_FROM_QEMU
 
@@ -223,6 +224,40 @@ qemuSnapObjFromSnapshot(virDomainObjPtr vm,
     return qemuSnapObjFromName(vm, snapshot->name);
 }
 
+/* Looks up the domain object from checkpoint and unlocks the
+ * driver. The returned domain object is locked and ref'd and the
+ * caller must call virDomainObjEndAPI() on it. */
+static virDomainObjPtr
+qemuDomObjFromCheckpoint(virDomainCheckpointPtr checkpoint)
+{
+    return qemuDomObjFromDomain(checkpoint->domain);
+}
+
+
+/* Looks up checkpoint object from VM and name */
+static virDomainMomentObjPtr
+qemuCheckpointObjFromName(virDomainObjPtr vm,
+                          const char *name)
+{
+    virDomainMomentObjPtr chk = NULL;
+    chk = virDomainCheckpointFindByName(vm->checkpoints, name);
+    if (!chk)
+        virReportError(VIR_ERR_NO_DOMAIN_CHECKPOINT,
+                       _("no domain checkpoint with matching name '%s'"),
+                       name);
+
+    return chk;
+}
+
+
+/* Looks up checkpoint object from VM and checkpointPtr */
+static virDomainMomentObjPtr
+qemuCheckpointObjFromCheckpoint(virDomainObjPtr vm,
+                                virDomainCheckpointPtr checkpoint)
+{
+    return qemuCheckpointObjFromName(vm, checkpoint->name);
+}
+
 static int
 qemuAutostartDomain(virDomainObjPtr vm,
                     void *opaque)
@@ -526,6 +561,113 @@ qemuDomainSnapshotLoad(virDomainObjPtr vm,
 }
 
 
+static int
+qemuDomainCheckpointLoad(virDomainObjPtr vm,
+                         void *data)
+{
+    char *baseDir = (char *)data;
+    char *chkDir = NULL;
+    DIR *dir = NULL;
+    struct dirent *entry;
+    char *xmlStr;
+    char *fullpath;
+    virDomainCheckpointDefPtr def = NULL;
+    virDomainMomentObjPtr chk = NULL;
+    virDomainMomentObjPtr current = NULL;
+    unsigned int flags = VIR_DOMAIN_CHECKPOINT_PARSE_REDEFINE;
+    int ret = -1;
+    virCapsPtr caps = NULL;
+    int direrr;
+
+    virObjectLock(vm);
+    if (virAsprintf(&chkDir, "%s/%s", baseDir, vm->def->name) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Failed to allocate memory for "
+                       "checkpoint directory for domain %s"),
+                       vm->def->name);
+        goto cleanup;
+    }
+
+    if (!(caps = virQEMUDriverGetCapabilities(qemu_driver, false)))
+        goto cleanup;
+
+    VIR_INFO("Scanning for checkpoints for domain %s in %s", vm->def->name,
+             chkDir);
+
+    if (virDirOpenIfExists(&dir, chkDir) <= 0)
+        goto cleanup;
+
+    while ((direrr = virDirRead(dir, &entry, NULL)) > 0) {
+        /* NB: ignoring errors, so one malformed config doesn't
+           kill the whole process */
+        VIR_INFO("Loading checkpoint file '%s'", entry->d_name);
+
+        if (virAsprintf(&fullpath, "%s/%s", chkDir, entry->d_name) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("Failed to allocate memory for path"));
+            continue;
+        }
+
+        if (virFileReadAll(fullpath, 1024*1024*1, &xmlStr) < 0) {
+            /* Nothing we can do here, skip this one */
+            virReportSystemError(errno,
+                                 _("Failed to read checkpoint file %s"),
+                                 fullpath);
+            VIR_FREE(fullpath);
+            continue;
+        }
+
+        def = virDomainCheckpointDefParseString(xmlStr, caps,
+                                                qemu_driver->xmlopt,
+                                                flags);
+        if (!def || virDomainCheckpointAlignDisks(def) < 0) {
+            /* Nothing we can do here, skip this one */
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Failed to parse checkpoint XML from file '%s'"),
+                           fullpath);
+            VIR_FREE(fullpath);
+            VIR_FREE(xmlStr);
+            virObjectUnref(def);
+            continue;
+        }
+
+        chk = virDomainCheckpointAssignDef(vm->checkpoints, def);
+        if (chk == NULL)
+            virObjectUnref(def);
+
+        VIR_FREE(fullpath);
+        VIR_FREE(xmlStr);
+    }
+    if (direrr < 0)
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Failed to fully read directory %s"),
+                       chkDir);
+
+    if (virDomainCheckpointUpdateRelations(vm->checkpoints, &current) < 0)
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Checkpoints have inconsistent relations for domain %s"),
+                       vm->def->name);
+    virDomainCheckpointSetCurrent(vm->checkpoints, current);
+
+    /* Note that it is not practical to automatically construct
+     * checkpoints based solely on qcow2 bitmaps, since qemu does not
+     * track parent relations which we find important in our metadata.
+     * Perhaps we could double-check that our just-loaded checkpoint
+     * metadata is consistent with existing qcow2 bitmaps, but a user
+     * that changes things behind our backs deserves what happens. */
+
+    virResetLastError();
+
+    ret = 0;
+ cleanup:
+    VIR_DIR_CLOSE(dir);
+    VIR_FREE(chkDir);
+    virObjectUnref(caps);
+    virObjectUnlock(vm);
+    return ret;
+}
+
+
 static int
 qemuDomainNetsRestart(virDomainObjPtr vm,
                       void *data ATTRIBUTE_UNUSED)
@@ -912,6 +1054,10 @@ qemuStateInitialize(bool privileged,
                             qemuDomainSnapshotLoad,
                             cfg->snapshotDir);
 
+    virDomainObjListForEach(qemu_driver->domains,
+                            qemuDomainCheckpointLoad,
+                            cfg->checkpointDir);
+
     virDomainObjListForEach(qemu_driver->domains,
                             qemuDomainManagedSaveLoad,
                             qemu_driver);
@@ -7739,10 +7885,12 @@ qemuDomainUndefineFlags(virDomainPtr dom,
     char *name = NULL;
     int ret = -1;
     int nsnapshots;
+    int ncheckpoints;
     virQEMUDriverConfigPtr cfg = NULL;
 
     virCheckFlags(VIR_DOMAIN_UNDEFINE_MANAGED_SAVE |
                   VIR_DOMAIN_UNDEFINE_SNAPSHOTS_METADATA |
+                  VIR_DOMAIN_UNDEFINE_CHECKPOINTS_METADATA |
                   VIR_DOMAIN_UNDEFINE_NVRAM |
                   VIR_DOMAIN_UNDEFINE_KEEP_NVRAM, -1);
 
@@ -7782,6 +7930,19 @@ qemuDomainUndefineFlags(virDomainPtr dom,
         if (qemuDomainSnapshotDiscardAllMetadata(driver, vm) < 0)
             goto endjob;
     }
+    if (!virDomainObjIsActive(vm) &&
+        (ncheckpoints = virDomainListCheckpoints(vm->checkpoints, NULL, dom,
+                                                 NULL, flags)) > 0) {
+        if (!(flags & VIR_DOMAIN_UNDEFINE_CHECKPOINTS_METADATA)) {
+            virReportError(VIR_ERR_OPERATION_INVALID,
+                           _("cannot delete inactive domain with %d "
+                             "checkpoints"),
+                           ncheckpoints);
+            goto endjob;
+        }
+        if (qemuDomainCheckpointDiscardAllMetadata(driver, vm) < 0)
+            goto endjob;
+    }
 
     name = qemuDomainManagedSavePath(driver, vm);
     if (name == NULL)
@@ -16814,6 +16975,443 @@ qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
     return ret;
 }
 
+
+/* Called inside job lock */
+static int
+qemuDomainCheckpointPrepare(virQEMUDriverPtr driver, virCapsPtr caps,
+                            virDomainObjPtr vm,
+                            virDomainCheckpointDefPtr def)
+{
+    int ret = -1;
+    size_t i;
+    char *xml = NULL;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+
+    /* Easiest way to clone inactive portion of vm->def is via
+     * conversion in and back out of xml.  */
+    if (!(xml = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU,
+                                        true, true)) ||
+        !(def->parent.dom = virDomainDefParseString(xml, caps, driver->xmlopt, NULL,
+                                                    VIR_DOMAIN_DEF_PARSE_INACTIVE |
+                                                    VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE)))
+        goto cleanup;
+
+    if (virDomainCheckpointAlignDisks(def) < 0)
+        goto cleanup;
+
+    for (i = 0; i < def->ndisks; i++) {
+        virDomainCheckpointDiskDefPtr disk = &def->disks[i];
+
+        if (disk->type != VIR_DOMAIN_CHECKPOINT_TYPE_BITMAP)
+            continue;
+
+        if (vm->def->disks[i]->src->format != VIR_STORAGE_FILE_QCOW2) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("checkpoint for disk %s unsupported "
+                             "for storage type %s"),
+                           disk->name,
+                           virStorageFileFormatTypeToString(
+                               vm->def->disks[i]->src->format));
+            goto cleanup;
+        }
+    }
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(xml);
+    return ret;
+}
+
+
+static virDomainCheckpointPtr
+qemuDomainCheckpointCreateXML(virDomainPtr domain,
+                              const char *xmlDesc,
+                              unsigned int flags)
+{
+    virQEMUDriverPtr driver = domain->conn->privateData;
+    virDomainObjPtr vm = NULL;
+    char *xml = NULL;
+    virDomainMomentObjPtr chk = NULL;
+    virDomainCheckpointPtr checkpoint = NULL;
+    bool update_current = true;
+    bool redefine = flags & VIR_DOMAIN_CHECKPOINT_CREATE_REDEFINE;
+    unsigned int parse_flags = 0;
+    virDomainMomentObjPtr other = NULL;
+    virQEMUDriverConfigPtr cfg = NULL;
+    virCapsPtr caps = NULL;
+    VIR_AUTOUNREF(virDomainCheckpointDefPtr) def = NULL;
+
+    virCheckFlags(VIR_DOMAIN_CHECKPOINT_CREATE_REDEFINE, NULL);
+    /* TODO: VIR_DOMAIN_CHECKPOINT_CREATE_QUIESCE */
+
+    if (redefine) {
+        parse_flags |= VIR_DOMAIN_CHECKPOINT_PARSE_REDEFINE;
+        update_current = false;
+    }
+
+    if (!(vm = qemuDomObjFromDomain(domain)))
+        goto cleanup;
+
+    if (virDomainSnapshotObjListNum(vm->snapshots, NULL, 0) > 0) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("cannot create checkpoint while snapshot exists"));
+        goto cleanup;
+    }
+
+    cfg = virQEMUDriverGetConfig(driver);
+
+    if (virDomainCheckpointCreateXMLEnsureACL(domain->conn, vm->def, flags) < 0)
+        goto cleanup;
+
+    if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
+        goto cleanup;
+
+    if (qemuProcessAutoDestroyActive(driver, vm)) {
+        virReportError(VIR_ERR_OPERATION_INVALID,
+                       "%s", _("domain is marked for auto destroy"));
+        goto cleanup;
+    }
+
+    if (!virDomainObjIsActive(vm)) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("cannot create checkpoint for inactive domain"));
+        goto cleanup;
+    }
+
+    if (!(def = virDomainCheckpointDefParseString(xmlDesc, caps, driver->xmlopt,
+                                                  parse_flags)))
+        goto cleanup;
+    /* Unlike snapshots, the RNG schema already ensured a sane filename. */
+
+    /* We are going to modify the domain below. */
+    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
+        goto cleanup;
+
+    if (redefine) {
+        if (virDomainCheckpointRedefinePrep(domain, vm, &def, &chk,
+                                            driver->xmlopt,
+                                            &update_current) < 0)
+            goto endjob;
+    } else if (qemuDomainCheckpointPrepare(driver, caps, vm, def) < 0) {
+        goto endjob;
+    }
+
+    if (!chk) {
+        if (!(chk = virDomainCheckpointAssignDef(vm->checkpoints, def)))
+            goto endjob;
+
+        def = NULL;
+    }
+
+    other = virDomainCheckpointGetCurrent(vm->checkpoints);
+    if (other) {
+        if (!redefine &&
+            VIR_STRDUP(chk->def->parent_name, other->def->name) < 0)
+            goto endjob;
+        if (update_current) {
+            virDomainCheckpointSetCurrent(vm->checkpoints, NULL);
+            if (qemuDomainCheckpointWriteMetadata(vm, other,
+                                                  driver->caps, driver->xmlopt,
+                                                  cfg->checkpointDir) < 0)
+                goto endjob;
+        }
+    }
+
+    /* actually do the checkpoint */
+    if (redefine) {
+        /* XXX Should we validate that the redefined checkpoint even
+         * makes sense, such as checking that qemu-img recognizes the
+         * checkpoint bitmap name in at least one of the domain's disks?  */
+    } else {
+        /* TODO: issue QMP transaction command */
+    }
+
+    /* If we fail after this point, there's not a whole lot we can do;
+     * we've successfully created the checkpoint, so we have to go
+     * forward the best we can.
+     */
+    checkpoint = virGetDomainCheckpoint(domain, chk->def->name);
+
+ endjob:
+    if (checkpoint) {
+        if (update_current)
+            virDomainCheckpointSetCurrent(vm->checkpoints, chk);
+        if (qemuDomainCheckpointWriteMetadata(vm, chk, driver->caps,
+                                              driver->xmlopt,
+                                              cfg->checkpointDir) < 0) {
+            /* if writing of metadata fails, error out rather than trying
+             * to silently carry on without completing the checkpoint */
+            virObjectUnref(checkpoint);
+            checkpoint = NULL;
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("unable to save metadata for checkpoint %s"),
+                           chk->def->name);
+            virDomainCheckpointObjListRemove(vm->checkpoints, chk);
+        } else {
+            virDomainCheckpointLinkParent(vm->checkpoints, chk);
+        }
+    } else if (chk) {
+        virDomainCheckpointObjListRemove(vm->checkpoints, chk);
+    }
+
+    qemuDomainObjEndJob(driver, vm);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    VIR_FREE(xml);
+    virObjectUnref(caps);
+    virObjectUnref(cfg);
+    return checkpoint;
+}
+
+
+static int
+qemuDomainListAllCheckpoints(virDomainPtr domain,
+                             virDomainCheckpointPtr **chks,
+                             unsigned int flags)
+{
+    virDomainObjPtr vm = NULL;
+    int n = -1;
+
+    virCheckFlags(VIR_DOMAIN_CHECKPOINT_LIST_ROOTS |
+                  VIR_DOMAIN_CHECKPOINT_LIST_TOPOLOGICAL |
+                  VIR_DOMAIN_CHECKPOINT_FILTERS_ALL, -1);
+
+    if (!(vm = qemuDomObjFromDomain(domain)))
+        return -1;
+
+    if (virDomainListAllCheckpointsEnsureACL(domain->conn, vm->def) < 0)
+        goto cleanup;
+
+    n = virDomainListCheckpoints(vm->checkpoints, NULL, domain, chks, flags);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return n;
+}
+
+
+static int
+qemuDomainCheckpointListAllChildren(virDomainCheckpointPtr checkpoint,
+                                    virDomainCheckpointPtr **chks,
+                                    unsigned int flags)
+{
+    virDomainObjPtr vm = NULL;
+    virDomainMomentObjPtr chk = NULL;
+    int n = -1;
+
+    virCheckFlags(VIR_DOMAIN_CHECKPOINT_LIST_DESCENDANTS |
+                  VIR_DOMAIN_CHECKPOINT_LIST_TOPOLOGICAL |
+                  VIR_DOMAIN_CHECKPOINT_FILTERS_ALL, -1);
+
+    if (!(vm = qemuDomObjFromCheckpoint(checkpoint)))
+        return -1;
+
+    if (virDomainCheckpointListAllChildrenEnsureACL(checkpoint->domain->conn,
+                                                    vm->def) < 0)
+        goto cleanup;
+
+    if (!(chk = qemuCheckpointObjFromCheckpoint(vm, checkpoint)))
+        goto cleanup;
+
+    n = virDomainListCheckpoints(vm->checkpoints, chk, checkpoint->domain,
+                                 chks, flags);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return n;
+}
+
+
+static virDomainCheckpointPtr
+qemuDomainCheckpointLookupByName(virDomainPtr domain,
+                                 const char *name,
+                                 unsigned int flags)
+{
+    virDomainObjPtr vm;
+    virDomainMomentObjPtr chk = NULL;
+    virDomainCheckpointPtr checkpoint = NULL;
+
+    virCheckFlags(0, NULL);
+
+    if (!(vm = qemuDomObjFromDomain(domain)))
+        return NULL;
+
+    if (virDomainCheckpointLookupByNameEnsureACL(domain->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (!(chk = qemuCheckpointObjFromName(vm, name)))
+        goto cleanup;
+
+    checkpoint = virGetDomainCheckpoint(domain, chk->def->name);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return checkpoint;
+}
+
+
+static virDomainCheckpointPtr
+qemuDomainCheckpointGetParent(virDomainCheckpointPtr checkpoint,
+                              unsigned int flags)
+{
+    virDomainObjPtr vm;
+    virDomainMomentObjPtr chk = NULL;
+    virDomainCheckpointPtr parent = NULL;
+
+    virCheckFlags(0, NULL);
+
+    if (!(vm = qemuDomObjFromCheckpoint(checkpoint)))
+        return NULL;
+
+    if (virDomainCheckpointGetParentEnsureACL(checkpoint->domain->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (!(chk = qemuCheckpointObjFromCheckpoint(vm, checkpoint)))
+        goto cleanup;
+
+    if (!chk->def->parent_name) {
+        virReportError(VIR_ERR_NO_DOMAIN_CHECKPOINT,
+                       _("checkpoint '%s' does not have a parent"),
+                       chk->def->name);
+        goto cleanup;
+    }
+
+    parent = virGetDomainCheckpoint(checkpoint->domain, chk->def->parent_name);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return parent;
+}
+
+
+static char *
+qemuDomainCheckpointGetXMLDesc(virDomainCheckpointPtr checkpoint,
+                               unsigned int flags)
+{
+    virQEMUDriverPtr driver = checkpoint->domain->conn->privateData;
+    virDomainObjPtr vm = NULL;
+    char *xml = NULL;
+    virDomainMomentObjPtr chk = NULL;
+    virDomainCheckpointDefPtr chkdef;
+    unsigned int format_flags;
+
+    virCheckFlags(VIR_DOMAIN_CHECKPOINT_XML_SECURE |
+                  VIR_DOMAIN_CHECKPOINT_XML_NO_DOMAIN, NULL);
+
+    if (!(vm = qemuDomObjFromCheckpoint(checkpoint)))
+        return NULL;
+
+    if (virDomainCheckpointGetXMLDescEnsureACL(checkpoint->domain->conn, vm->def, flags) < 0)
+        goto cleanup;
+
+    if (!(chk = qemuCheckpointObjFromCheckpoint(vm, checkpoint)))
+        goto cleanup;
+    chkdef = virDomainCheckpointObjGetDef(chk);
+
+    format_flags = virDomainCheckpointFormatConvertXMLFlags(flags);
+    xml = virDomainCheckpointDefFormat(chkdef, driver->caps, driver->xmlopt,
+                                       format_flags);
+
+    if (flags & VIR_DOMAIN_CHECKPOINT_XML_SIZE)
+        qemuDomainObjEndJob(driver, vm);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return xml;
+}
+
+
+static int
+qemuDomainCheckpointDelete(virDomainCheckpointPtr checkpoint,
+                           unsigned int flags)
+{
+    virQEMUDriverPtr driver = checkpoint->domain->conn->privateData;
+    virDomainObjPtr vm = NULL;
+    int ret = -1;
+    virDomainMomentObjPtr chk = NULL;
+    virQEMUMomentRemove rem;
+    virQEMUMomentReparent rep;
+    bool metadata_only = !!(flags & VIR_DOMAIN_CHECKPOINT_DELETE_METADATA_ONLY);
+    virQEMUDriverConfigPtr cfg = NULL;
+
+    virCheckFlags(VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN |
+                  VIR_DOMAIN_CHECKPOINT_DELETE_METADATA_ONLY |
+                  VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN_ONLY, -1);
+
+    if (!(vm = qemuDomObjFromCheckpoint(checkpoint)))
+        return -1;
+
+    cfg = virQEMUDriverGetConfig(driver);
+
+    if (virDomainCheckpointDeleteEnsureACL(checkpoint->domain->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
+        goto cleanup;
+
+    if (!(chk = qemuCheckpointObjFromCheckpoint(vm, checkpoint)))
+        goto endjob;
+
+    if (flags & (VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN |
+                 VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN_ONLY)) {
+        rem.driver = driver;
+        rem.vm = vm;
+        rem.metadata_only = metadata_only;
+        rem.err = 0;
+        rem.current = virDomainCheckpointGetCurrent(vm->checkpoints);
+        rem.found = false;
+        rem.momentDiscard = qemuDomainCheckpointDiscard;
+        virDomainMomentForEachDescendant(chk, qemuDomainMomentDiscardAll,
+                                         &rem);
+        if (rem.err < 0)
+            goto endjob;
+        if (rem.found) {
+            virDomainCheckpointSetCurrent(vm->checkpoints, chk);
+            if (flags & VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN_ONLY) {
+                if (qemuDomainCheckpointWriteMetadata(vm, chk, driver->caps,
+                                                      driver->xmlopt,
+                                                      cfg->checkpointDir) < 0) {
+                    virReportError(VIR_ERR_INTERNAL_ERROR,
+                                   _("failed to set checkpoint '%s' as current"),
+                                   chk->def->name);
+                    virDomainCheckpointSetCurrent(vm->checkpoints, NULL);
+                    goto endjob;
+                }
+            }
+        }
+    } else if (chk->nchildren) {
+        rep.dir = cfg->checkpointDir;
+        rep.parent = chk->parent;
+        rep.vm = vm;
+        rep.err = 0;
+        rep.caps = driver->caps;
+        rep.xmlopt = driver->xmlopt;
+        rep.writeMetadata = qemuDomainCheckpointWriteMetadata;
+        virDomainMomentForEachChild(chk, qemuDomainMomentReparentChildren,
+                                    &rep);
+        if (rep.err < 0)
+            goto endjob;
+        virDomainMomentMoveChildren(chk, chk->parent);
+    }
+
+    if (flags & VIR_DOMAIN_CHECKPOINT_DELETE_CHILDREN_ONLY) {
+        virDomainMomentDropChildren(chk);
+        ret = 0;
+    } else {
+        ret = qemuDomainCheckpointDiscard(driver, vm, chk, true, metadata_only);
+    }
+
+ endjob:
+    qemuDomainObjEndJob(driver, vm);
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    virObjectUnref(cfg);
+    return ret;
+}
+
 static int qemuDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd,
                                         char **result, unsigned int flags)
 {
@@ -22557,6 +23155,14 @@ static virHypervisorDriver qemuHypervisorDriver = {
     .connectBaselineHypervisorCPU = qemuConnectBaselineHypervisorCPU, /* 4.4.0 */
     .nodeGetSEVInfo = qemuNodeGetSEVInfo, /* 4.5.0 */
     .domainGetLaunchSecurityInfo = qemuDomainGetLaunchSecurityInfo, /* 4.5.0 */
+    .domainCheckpointCreateXML = qemuDomainCheckpointCreateXML, /* 5.6.0 */
+    .domainCheckpointGetXMLDesc = qemuDomainCheckpointGetXMLDesc, /* 5.6.0 */
+
+    .domainListAllCheckpoints = qemuDomainListAllCheckpoints, /* 5.6.0 */
+    .domainCheckpointListAllChildren = qemuDomainCheckpointListAllChildren, /* 5.6.0 */
+    .domainCheckpointLookupByName = qemuDomainCheckpointLookupByName, /* 5.6.0 */
+    .domainCheckpointGetParent = qemuDomainCheckpointGetParent, /* 5.6.0 */
+    .domainCheckpointDelete = qemuDomainCheckpointDelete, /* 5.6.0 */
 };