migration: simplify blockers
Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.
In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.
No functional change.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 402a2d6..bf1a90f 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -534,11 +534,8 @@
error_setg(&tpm_emu->migration_blocker,
"Migration disabled: TPM emulator does not support "
"migration");
- if (migrate_add_blocker(tpm_emu->migration_blocker, &err) < 0) {
+ if (migrate_add_blocker(&tpm_emu->migration_blocker, &err) < 0) {
error_report_err(err);
- error_free(tpm_emu->migration_blocker);
- tpm_emu->migration_blocker = NULL;
-
return -1;
}
}
@@ -1016,10 +1013,7 @@
qapi_free_TPMEmulatorOptions(tpm_emu->options);
- if (tpm_emu->migration_blocker) {
- migrate_del_blocker(tpm_emu->migration_blocker);
- error_free(tpm_emu->migration_blocker);
- }
+ migrate_del_blocker(&tpm_emu->migration_blocker);
tpm_sized_buffer_reset(&state_blobs->volatil);
tpm_sized_buffer_reset(&state_blobs->permanent);
diff --git a/block/parallels.c b/block/parallels.c
index 6b46623..1d695ce 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -1369,9 +1369,8 @@
bdrv_get_device_or_node_name(bs));
bdrv_graph_rdunlock_main_loop();
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_setg(errp, "Migration blocker error");
goto fail;
}
qemu_co_mutex_init(&s->lock);
@@ -1406,7 +1405,7 @@
ret = bdrv_check(bs, &res, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not repair corrupted image");
- migrate_del_blocker(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
goto fail;
}
}
@@ -1423,7 +1422,6 @@
*/
parallels_free_used_bitmap(bs);
- error_free(s->migration_blocker);
g_free(s->bat_dirty_bmap);
qemu_vfree(s->header);
return ret;
@@ -1448,8 +1446,7 @@
g_free(s->bat_dirty_bmap);
qemu_vfree(s->header);
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
static bool parallels_is_support_dirty_bitmaps(BlockDriverState *bs)
diff --git a/block/qcow.c b/block/qcow.c
index 38a1625..fdd4c83 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -307,9 +307,8 @@
bdrv_get_device_or_node_name(bs));
bdrv_graph_rdunlock_main_loop();
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail;
}
@@ -802,8 +801,7 @@
g_free(s->cluster_cache);
g_free(s->cluster_data);
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
static int coroutine_fn GRAPH_UNLOCKED
diff --git a/block/vdi.c b/block/vdi.c
index 3ed43b6..fd7e365 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -498,9 +498,8 @@
bdrv_get_device_or_node_name(bs));
bdrv_graph_rdunlock_main_loop();
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail_free_bmap;
}
@@ -988,8 +987,7 @@
qemu_vfree(s->bmap);
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
static int vdi_has_zero_init(BlockDriverState *bs)
diff --git a/block/vhdx.c b/block/vhdx.c
index 73cb214..e37f8c0 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -985,8 +985,7 @@
s->bat = NULL;
qemu_vfree(s->parent_entries);
s->parent_entries = NULL;
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
qemu_vfree(s->log.hdr);
s->log.hdr = NULL;
vhdx_region_unregister_all(s);
@@ -1097,9 +1096,8 @@
error_setg(&s->migration_blocker, "The vhdx format used by node '%s' "
"does not support live migration",
bdrv_get_device_or_node_name(bs));
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail;
}
diff --git a/block/vmdk.c b/block/vmdk.c
index 8a3b152..1335d39 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1386,9 +1386,8 @@
error_setg(&s->migration_blocker, "The vmdk format used by node '%s' "
"does not support live migration",
bdrv_get_device_or_node_name(bs));
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail;
}
@@ -2867,8 +2866,7 @@
vmdk_free_extents(bs);
g_free(s->create_type);
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
static int64_t coroutine_fn GRAPH_RDLOCK
diff --git a/block/vpc.c b/block/vpc.c
index 945847f..c30cf86 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -452,9 +452,8 @@
bdrv_get_device_or_node_name(bs));
bdrv_graph_rdunlock_main_loop();
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail;
}
@@ -1190,8 +1189,7 @@
g_free(s->pageentry_u8);
#endif
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
static QemuOptsList vpc_create_opts = {
diff --git a/block/vvfat.c b/block/vvfat.c
index b041579..266e036 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1268,9 +1268,8 @@
"The vvfat (rw) format used by node '%s' "
"does not support live migration",
bdrv_get_device_or_node_name(bs));
- ret = migrate_add_blocker(s->migration_blocker, errp);
+ ret = migrate_add_blocker(&s->migration_blocker, errp);
if (ret < 0) {
- error_free(s->migration_blocker);
goto fail;
}
}
@@ -3239,8 +3238,7 @@
g_free(s->cluster_buffer);
if (s->qcow) {
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
+ migrate_del_blocker(&s->migration_blocker);
}
}
diff --git a/dump/dump.c b/dump/dump.c
index d3578dd..d355ada 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -111,7 +111,7 @@
qemu_mutex_unlock_iothread();
}
}
- migrate_del_blocker(dump_migration_blocker);
+ migrate_del_blocker(&dump_migration_blocker);
return 0;
}
@@ -2158,7 +2158,7 @@
* Allows even for -only-migratable, but forbid migration during the
* process of dump guest memory.
*/
- if (migrate_add_blocker_internal(dump_migration_blocker, errp)) {
+ if (migrate_add_blocker_internal(&dump_migration_blocker, errp)) {
/* Remember to release the fd before passing it over to dump state */
close(fd);
return;
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 323f042..af636cf 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -406,11 +406,7 @@
* delete the migration blocker. Ideally, this
* should be hooked to transport close notification
*/
- if (pdu->s->migration_blocker) {
- migrate_del_blocker(pdu->s->migration_blocker);
- error_free(pdu->s->migration_blocker);
- pdu->s->migration_blocker = NULL;
- }
+ migrate_del_blocker(&pdu->s->migration_blocker);
}
return free_fid(pdu, fidp);
}
@@ -1505,10 +1501,8 @@
error_setg(&s->migration_blocker,
"Migration is disabled when VirtFS export path '%s' is mounted in the guest using mount_tag '%s'",
s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag);
- err = migrate_add_blocker(s->migration_blocker, NULL);
+ err = migrate_add_blocker(&s->migration_blocker, NULL);
if (err < 0) {
- error_free(s->migration_blocker);
- s->migration_blocker = NULL;
clunk_fid(s, fid);
goto out;
}
diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
index 50c5373..37af256 100644
--- a/hw/display/virtio-gpu-base.c
+++ b/hw/display/virtio-gpu-base.c
@@ -184,8 +184,7 @@
if (virtio_gpu_virgl_enabled(g->conf)) {
error_setg(&g->migration_blocker, "virgl is not yet migratable");
- if (migrate_add_blocker(g->migration_blocker, errp) < 0) {
- error_free(g->migration_blocker);
+ if (migrate_add_blocker(&g->migration_blocker, errp) < 0) {
return false;
}
}
@@ -253,10 +252,7 @@
{
VirtIOGPUBase *g = VIRTIO_GPU_BASE(qdev);
- if (g->migration_blocker) {
- migrate_del_blocker(g->migration_blocker);
- error_free(g->migration_blocker);
- }
+ migrate_del_blocker(&g->migration_blocker);
}
static void
diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index 1d58894..e0d9e51 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -516,8 +516,7 @@
if (!kvm_arm_gic_can_save_restore(s)) {
error_setg(&s->migration_blocker, "This operating system kernel does "
"not support vGICv2 migration");
- if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
- error_free(s->migration_blocker);
+ if (migrate_add_blocker(&s->migration_blocker, errp) < 0) {
return;
}
}
diff --git a/hw/intc/arm_gicv3_its_kvm.c b/hw/intc/arm_gicv3_its_kvm.c
index 7eda9fb..61c1cc7 100644
--- a/hw/intc/arm_gicv3_its_kvm.c
+++ b/hw/intc/arm_gicv3_its_kvm.c
@@ -114,8 +114,7 @@
GITS_CTLR)) {
error_setg(&s->migration_blocker, "This operating system kernel "
"does not support vITS migration");
- if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
- error_free(s->migration_blocker);
+ if (migrate_add_blocker(&s->migration_blocker, errp) < 0) {
return;
}
} else {
diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c
index 72ad916..77eb37e 100644
--- a/hw/intc/arm_gicv3_kvm.c
+++ b/hw/intc/arm_gicv3_kvm.c
@@ -878,8 +878,7 @@
GICD_CTLR)) {
error_setg(&s->migration_blocker, "This operating system kernel does "
"not support vGICv3 migration");
- if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
- error_free(s->migration_blocker);
+ if (migrate_add_blocker(&s->migration_blocker, errp) < 0) {
return;
}
}
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index d66d912..0447888 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -903,8 +903,7 @@
if (!ivshmem_is_master(s)) {
error_setg(&s->migration_blocker,
"Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
- if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
- error_free(s->migration_blocker);
+ if (migrate_add_blocker(&s->migration_blocker, errp) < 0) {
return;
}
}
@@ -922,10 +921,7 @@
IVShmemState *s = IVSHMEM_COMMON(dev);
int i;
- if (s->migration_blocker) {
- migrate_del_blocker(s->migration_blocker);
- error_free(s->migration_blocker);
- }
+ migrate_del_blocker(&s->migration_blocker);
if (memory_region_is_mapped(s->ivshmem_bar2)) {
if (!s->hostmem) {
diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c
index cc44d5e..d28ed3b 100644
--- a/hw/ppc/pef.c
+++ b/hw/ppc/pef.c
@@ -63,7 +63,7 @@
/* add migration blocker */
error_setg(&pef_mig_blocker, "PEF: Migration is not implemented");
/* NB: This can fail if --only-migratable is used */
- migrate_add_blocker(pef_mig_blocker, &error_fatal);
+ migrate_add_blocker(&pef_mig_blocker, &error_fatal);
cgs->ready = true;
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index cb84067..b25093b 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1761,7 +1761,7 @@
/* Signal all vCPUs waiting on this condition */
qemu_cond_broadcast(&spapr->fwnmi_machine_check_interlock_cond);
- migrate_del_blocker(spapr->fwnmi_migration_blocker);
+ migrate_del_blocker(&spapr->fwnmi_migration_blocker);
}
static void spapr_create_nvram(SpaprMachineState *spapr)
@@ -2937,13 +2937,6 @@
spapr_create_lmb_dr_connectors(spapr);
}
- if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI) == SPAPR_CAP_ON) {
- /* Create the error string for live migration blocker */
- error_setg(&spapr->fwnmi_migration_blocker,
- "A machine check is being handled during migration. The handler"
- "may run and log hardware error on the destination");
- }
-
if (mc->nvdimm_supported) {
spapr_create_nvdimm_dr_connectors(spapr);
}
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 4508e40..deb4641 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -920,7 +920,11 @@
* fails when running with -only-migrate. A proper interface to
* delay migration completion for a bit could avoid that.
*/
- ret = migrate_add_blocker(spapr->fwnmi_migration_blocker, NULL);
+ error_setg(&spapr->fwnmi_migration_blocker,
+ "A machine check is being handled during migration. The handler"
+ "may run and log hardware error on the destination");
+
+ ret = migrate_add_blocker(&spapr->fwnmi_migration_blocker, NULL);
if (ret == -EBUSY) {
warn_report("Received a fwnmi while migration was in progress");
}
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 7df2158..26c384b 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -496,7 +496,7 @@
spapr->fwnmi_machine_check_interlock = -1;
qemu_cond_signal(&spapr->fwnmi_machine_check_interlock_cond);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
- migrate_del_blocker(spapr->fwnmi_migration_blocker);
+ migrate_del_blocker(&spapr->fwnmi_migration_blocker);
}
static struct rtas_call {
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index 2052d72..fbc85a8 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -107,8 +107,7 @@
error_setg(&dev->migration_blocker, "%s does not support migration",
TYPE_PCI_PROXY_DEV);
- if (migrate_add_blocker(dev->migration_blocker, errp) < 0) {
- error_free(dev->migration_blocker);
+ if (migrate_add_blocker(&dev->migration_blocker, errp) < 0) {
object_unref(dev->ioc);
return;
}
@@ -134,9 +133,7 @@
qio_channel_close(dev->ioc, NULL);
}
- migrate_del_blocker(dev->migration_blocker);
-
- error_free(dev->migration_blocker);
+ migrate_del_blocker(&dev->migration_blocker);
proxy_memory_listener_deconfigure(&dev->proxy_listener);
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 2d75f21..07a5157 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -332,8 +332,7 @@
s390_pv_vm_disable();
}
ms->pv = false;
- migrate_del_blocker(pv_mig_blocker);
- error_free_or_abort(&pv_mig_blocker);
+ migrate_del_blocker(&pv_mig_blocker);
ram_block_discard_disable(false);
}
@@ -356,11 +355,10 @@
error_setg(&pv_mig_blocker,
"protected VMs are currently not migratable.");
- rc = migrate_add_blocker(pv_mig_blocker, &local_err);
+ rc = migrate_add_blocker(&pv_mig_blocker, &local_err);
if (rc) {
ram_block_discard_disable(false);
error_report_err(local_err);
- error_free_or_abort(&pv_mig_blocker);
return rc;
}
@@ -368,8 +366,7 @@
rc = s390_pv_vm_enable();
if (rc) {
ram_block_discard_disable(false);
- migrate_del_blocker(pv_mig_blocker);
- error_free_or_abort(&pv_mig_blocker);
+ migrate_del_blocker(&pv_mig_blocker);
return rc;
}
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 443f67d..14e23cc 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -208,7 +208,7 @@
"When external environment supports it (Orchestrator migrates "
"target SCSI device state or use shared storage over network), "
"set 'migratable' property to true to enable migration.");
- if (migrate_add_blocker(vsc->migration_blocker, errp) < 0) {
+ if (migrate_add_blocker(&vsc->migration_blocker, errp) < 0) {
goto free_virtio;
}
}
@@ -241,10 +241,9 @@
free_vqs:
g_free(vqs);
if (!vsc->migratable) {
- migrate_del_blocker(vsc->migration_blocker);
+ migrate_del_blocker(&vsc->migration_blocker);
}
free_virtio:
- error_free(vsc->migration_blocker);
virtio_scsi_common_unrealize(dev);
close_fd:
if (vhostfd >= 0) {
@@ -260,8 +259,7 @@
struct vhost_virtqueue *vqs = vsc->dev.vqs;
if (!vsc->migratable) {
- migrate_del_blocker(vsc->migration_blocker);
- error_free(vsc->migration_blocker);
+ migrate_del_blocker(&vsc->migration_blocker);
}
/* This will stop vhost backend. */
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 5ff5acf..d806057 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -129,11 +129,7 @@
error_setg(&multiple_devices_migration_blocker,
"Multiple VFIO devices migration is supported only if all of "
"them support P2P migration");
- ret = migrate_add_blocker(multiple_devices_migration_blocker, errp);
- if (ret < 0) {
- error_free(multiple_devices_migration_blocker);
- multiple_devices_migration_blocker = NULL;
- }
+ ret = migrate_add_blocker(&multiple_devices_migration_blocker, errp);
return ret;
}
@@ -145,9 +141,7 @@
return;
}
- migrate_del_blocker(multiple_devices_migration_blocker);
- error_free(multiple_devices_migration_blocker);
- multiple_devices_migration_blocker = NULL;
+ migrate_del_blocker(&multiple_devices_migration_blocker);
}
bool vfio_viommu_preset(VFIODevice *vbasedev)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index da43dcd..0aaad65 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -891,8 +891,6 @@
static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp)
{
- int ret;
-
if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
error_propagate(errp, err);
return -EINVAL;
@@ -901,13 +899,7 @@
vbasedev->migration_blocker = error_copy(err);
error_free(err);
- ret = migrate_add_blocker(vbasedev->migration_blocker, errp);
- if (ret < 0) {
- error_free(vbasedev->migration_blocker);
- vbasedev->migration_blocker = NULL;
- }
-
- return ret;
+ return migrate_add_blocker(&vbasedev->migration_blocker, errp);
}
/* ---------------------------------------------------------------------- */
@@ -994,9 +986,5 @@
vfio_migration_deinit(vbasedev);
}
- if (vbasedev->migration_blocker) {
- migrate_del_blocker(vbasedev->migration_blocker);
- error_free(vbasedev->migration_blocker);
- vbasedev->migration_blocker = NULL;
- }
+ migrate_del_blocker(&vbasedev->migration_blocker);
}
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 9f37206..d737671 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1527,9 +1527,8 @@
}
if (hdev->migration_blocker != NULL) {
- r = migrate_add_blocker(hdev->migration_blocker, errp);
+ r = migrate_add_blocker(&hdev->migration_blocker, errp);
if (r < 0) {
- error_free(hdev->migration_blocker);
goto fail_busyloop;
}
}
@@ -1597,10 +1596,7 @@
memory_listener_unregister(&hdev->memory_listener);
QLIST_REMOVE(hdev, entry);
}
- if (hdev->migration_blocker) {
- migrate_del_blocker(hdev->migration_blocker);
- error_free(hdev->migration_blocker);
- }
+ migrate_del_blocker(&hdev->migration_blocker);
g_free(hdev->mem);
g_free(hdev->mem_sections);
if (hdev->vhost_ops) {
diff --git a/include/migration/blocker.h b/include/migration/blocker.h
index 9cebe2b..b048f30 100644
--- a/include/migration/blocker.h
+++ b/include/migration/blocker.h
@@ -17,19 +17,23 @@
/**
* @migrate_add_blocker - prevent migration from proceeding
*
- * @reason - an error to be returned whenever migration is attempted
+ * @reasonp - address of an error to be returned whenever migration is attempted
*
* @errp - [out] The reason (if any) we cannot block migration right now.
*
* @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
+ *
+ * *@reasonp is freed and set to NULL if failure is returned.
+ * On success, the caller must not free @reasonp, except by
+ * calling migrate_del_blocker.
*/
-int migrate_add_blocker(Error *reason, Error **errp);
+int migrate_add_blocker(Error **reasonp, Error **errp);
/**
* @migrate_add_blocker_internal - prevent migration from proceeding without
* only-migrate implications
*
- * @reason - an error to be returned whenever migration is attempted
+ * @reasonp - address of an error to be returned whenever migration is attempted
*
* @errp - [out] The reason (if any) we cannot block migration right now.
*
@@ -38,14 +42,20 @@
* Some of the migration blockers can be temporary (e.g., for a few seconds),
* so it shouldn't need to conflict with "-only-migratable". For those cases,
* we can call this function rather than @migrate_add_blocker().
+ *
+ * *@reasonp is freed and set to NULL if failure is returned.
+ * On success, the caller must not free @reasonp, except by
+ * calling migrate_del_blocker.
*/
-int migrate_add_blocker_internal(Error *reason, Error **errp);
+int migrate_add_blocker_internal(Error **reasonp, Error **errp);
/**
- * @migrate_del_blocker - remove a blocking error from migration
+ * @migrate_del_blocker - remove a blocking error from migration and free it.
*
- * @reason - the error blocking migration
+ * @reasonp - address of the error blocking migration
+ *
+ * This function frees *@reasonp and sets it to NULL.
*/
-void migrate_del_blocker(Error *reason);
+void migrate_del_blocker(Error **reasonp);
#endif
diff --git a/migration/migration.c b/migration/migration.c
index 05c0b80..818b02b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1465,35 +1465,41 @@
return 0;
}
-int migrate_add_blocker_internal(Error *reason, Error **errp)
+int migrate_add_blocker_internal(Error **reasonp, Error **errp)
{
/* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */
if (runstate_check(RUN_STATE_SAVE_VM) || !migration_is_idle()) {
- error_propagate_prepend(errp, error_copy(reason),
+ error_propagate_prepend(errp, *reasonp,
"disallowing migration blocker "
"(migration/snapshot in progress) for: ");
+ *reasonp = NULL;
return -EBUSY;
}
- migration_blockers = g_slist_prepend(migration_blockers, reason);
+ migration_blockers = g_slist_prepend(migration_blockers, *reasonp);
return 0;
}
-int migrate_add_blocker(Error *reason, Error **errp)
+int migrate_add_blocker(Error **reasonp, Error **errp)
{
if (only_migratable) {
- error_propagate_prepend(errp, error_copy(reason),
+ error_propagate_prepend(errp, *reasonp,
"disallowing migration blocker "
"(--only-migratable) for: ");
+ *reasonp = NULL;
return -EACCES;
}
- return migrate_add_blocker_internal(reason, errp);
+ return migrate_add_blocker_internal(reasonp, errp);
}
-void migrate_del_blocker(Error *reason)
+void migrate_del_blocker(Error **reasonp)
{
- migration_blockers = g_slist_remove(migration_blockers, reason);
+ if (*reasonp) {
+ migration_blockers = g_slist_remove(migration_blockers, *reasonp);
+ error_free(*reasonp);
+ *reasonp = NULL;
+ }
}
void qmp_migrate_incoming(const char *uri, Error **errp)
diff --git a/stubs/migr-blocker.c b/stubs/migr-blocker.c
index 5676a2f..17a5dbf 100644
--- a/stubs/migr-blocker.c
+++ b/stubs/migr-blocker.c
@@ -1,11 +1,11 @@
#include "qemu/osdep.h"
#include "migration/blocker.h"
-int migrate_add_blocker(Error *reason, Error **errp)
+int migrate_add_blocker(Error **reasonp, Error **errp)
{
return 0;
}
-void migrate_del_blocker(Error *reason)
+void migrate_del_blocker(Error **reasonp)
{
}
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index ab72bcd..e7c054c 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1603,7 +1603,7 @@
error_setg(&hv_passthrough_mig_blocker,
"'hv-passthrough' CPU flag prevents migration, use explicit"
" set of hv-* flags instead");
- ret = migrate_add_blocker(hv_passthrough_mig_blocker, &local_err);
+ ret = migrate_add_blocker(&hv_passthrough_mig_blocker, &local_err);
if (ret < 0) {
error_report_err(local_err);
return ret;
@@ -1617,7 +1617,7 @@
" use explicit 'hv-no-nonarch-coresharing=on' instead (but"
" make sure SMT is disabled and/or that vCPUs are properly"
" pinned)");
- ret = migrate_add_blocker(hv_no_nonarch_cs_mig_blocker, &local_err);
+ ret = migrate_add_blocker(&hv_no_nonarch_cs_mig_blocker, &local_err);
if (ret < 0) {
error_report_err(local_err);
return ret;
@@ -2213,7 +2213,7 @@
error_setg(&invtsc_mig_blocker,
"State blocked by non-migratable CPU device"
" (invtsc flag)");
- r = migrate_add_blocker(invtsc_mig_blocker, &local_err);
+ r = migrate_add_blocker(&invtsc_mig_blocker, &local_err);
if (r < 0) {
error_report_err(local_err);
return r;
@@ -2271,7 +2271,7 @@
return 0;
fail:
- migrate_del_blocker(invtsc_mig_blocker);
+ migrate_del_blocker(&invtsc_mig_blocker);
return r;
}
diff --git a/target/i386/nvmm/nvmm-all.c b/target/i386/nvmm/nvmm-all.c
index fb76986..7d752bc 100644
--- a/target/i386/nvmm/nvmm-all.c
+++ b/target/i386/nvmm/nvmm-all.c
@@ -929,9 +929,8 @@
error_setg(&nvmm_migration_blocker,
"NVMM: Migration not supported");
- if (migrate_add_blocker(nvmm_migration_blocker, &local_error) < 0) {
+ if (migrate_add_blocker(&nvmm_migration_blocker, &local_error) < 0) {
error_report_err(local_error);
- error_free(nvmm_migration_blocker);
return -EINVAL;
}
}
diff --git a/target/i386/sev.c b/target/i386/sev.c
index fe2144c..9a71246 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -891,7 +891,7 @@
/* add migration blocker */
error_setg(&sev_mig_blocker,
"SEV: Migration is not implemented");
- migrate_add_blocker(sev_mig_blocker, &error_fatal);
+ migrate_add_blocker(&sev_mig_blocker, &error_fatal);
}
static void
diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index df3aba2..d29ba91 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -2160,9 +2160,8 @@
"State blocked due to non-migratable CPUID feature support,"
"dirty memory tracking support, and XSAVE/XRSTOR support");
- if (migrate_add_blocker(whpx_migration_blocker, &local_error) < 0) {
+ if (migrate_add_blocker(&whpx_migration_blocker, &local_error) < 0) {
error_report_err(local_error);
- error_free(whpx_migration_blocker);
ret = -EINVAL;
goto error;
}
diff --git a/ui/vdagent.c b/ui/vdagent.c
index 00d36a8..d8f2f95 100644
--- a/ui/vdagent.c
+++ b/ui/vdagent.c
@@ -671,7 +671,7 @@
return;
#endif
- if (migrate_add_blocker(vd->migration_blocker, errp) != 0) {
+ if (migrate_add_blocker(&vd->migration_blocker, errp) != 0) {
return;
}
@@ -924,13 +924,12 @@
{
VDAgentChardev *vd = QEMU_VDAGENT_CHARDEV(obj);
- migrate_del_blocker(vd->migration_blocker);
+ migrate_del_blocker(&vd->migration_blocker);
vdagent_disconnect(vd);
if (vd->mouse_hs) {
qemu_input_handler_unregister(vd->mouse_hs);
}
buffer_free(&vd->outbuf);
- error_free(vd->migration_blocker);
}
static const TypeInfo vdagent_chr_type_info = {
