Re: [PATCH v3 07/14] qemu: Wire up <memory/> live update

As advertised in one of previous commits, we want to be able to change 'requested-size' attribute of virtio-mem on the fly. This commit does exactly that. Changing anything else is checked for and forbidden. Once guest has changed the allocation, QEMU emits an event which we will use to track the allocation. In the next commit. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/conf/domain_conf.c | 36 ++++++++ src/conf/domain_conf.h | 4 + src/libvirt_private.syms | 1 + src/qemu/qemu_driver.c | 172 ++++++++++++++++++++++++++++++++++- src/qemu/qemu_hotplug.c | 18 ++++ src/qemu/qemu_hotplug.h | 5 + src/qemu/qemu_monitor.c | 13 +++ src/qemu/qemu_monitor.h | 5 + src/qemu/qemu_monitor_json.c | 15 +++ src/qemu/qemu_monitor_json.h | 5 + 10 files changed, 273 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index d908e95ba7..9a241ad551 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -7130,6 +7130,165 @@ qemuDomainChangeDiskLive(virDomainObj *vm, return 0; } + +static bool +qemuDomainChangeMemoryLiveValidateChange(const virDomainMemoryDef *oldDef, + const virDomainMemoryDef *newDef) +{

+ /* The only thing that is allowed to change is 'requestedsize' for virtio + * model. */

+ if (oldDef->model != newDef->model) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory model from '%s' to '%s'"), + virDomainMemoryModelTypeToString(oldDef->model), + virDomainMemoryModelTypeToString(newDef->model)); + return false; + } + + if (oldDef->access != newDef->access) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory access from '%s' to '%s'"), + virDomainMemoryAccessTypeToString(oldDef->access), + virDomainMemoryAccessTypeToString(newDef->access)); + return false; + } + + if (oldDef->discard != newDef->discard) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory discard from '%s' to '%s'"), + virTristateBoolTypeToString(oldDef->discard), + virTristateBoolTypeToString(newDef->discard)); + return false; + } + + if (!virBitmapEqual(oldDef->sourceNodes, + newDef->sourceNodes)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("cannot modify memory source nodes")); + return false; + } + + if (oldDef->pagesize != newDef->pagesize) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory pagesize from '%llu' to '%llu'"), + oldDef->pagesize, + newDef->pagesize); + return false; + } + + if (STRNEQ_NULLABLE(oldDef->nvdimmPath, newDef->nvdimmPath)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory path from '%s' to '%s'"), + NULLSTR(oldDef->nvdimmPath), + NULLSTR(newDef->nvdimmPath)); + return false; + }

+ + if (oldDef->alignsize != newDef->alignsize) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory align size from '%llu' to '%llu'"), + oldDef->alignsize, newDef->alignsize); + return false; + } + + if (oldDef->nvdimmPmem != newDef->nvdimmPmem) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory pmem from '%d' to '%d'"), + oldDef->nvdimmPmem, newDef->nvdimmPmem); + return false; + } + + if (oldDef->targetNode != newDef->targetNode) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory targetNode from '%d' to '%d'"), + oldDef->targetNode, newDef->targetNode); + return false; + } + + if (oldDef->size != newDef->size) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory size from '%llu' to '%llu'"), + oldDef->size, newDef->size); + return false; + } + + if (oldDef->labelsize != newDef->labelsize) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory label size from '%llu' to '%llu'"), + oldDef->labelsize, newDef->labelsize); + return false; + } + if (oldDef->blocksize != newDef->blocksize) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory block size from '%llu' to '%llu'"), + oldDef->blocksize, newDef->blocksize); + return false; + } + + /* requestedsize can change */ + + if (oldDef->readonly != newDef->readonly) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("cannot modify memory pmem flag")); + return false; + } + + if ((oldDef->uuid || newDef->uuid) && + !(oldDef->uuid && newDef->uuid && + memcmp(oldDef->uuid, newDef->uuid, VIR_UUID_BUFLEN) == 0)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("cannot modify memory UUID")); + return false; + } + + switch (oldDef->model) { + case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM: + break; + + case VIR_DOMAIN_MEMORY_MODEL_NONE: + case VIR_DOMAIN_MEMORY_MODEL_DIMM: + case VIR_DOMAIN_MEMORY_MODEL_NVDIMM: + case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM: + case VIR_DOMAIN_MEMORY_MODEL_LAST: + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("cannot modify memory of model '%s'"), + virDomainMemoryModelTypeToString(oldDef->model)); + return false;

+ break; + } + + return true; +} + + +static int +qemuDomainChangeMemoryLive(virQEMUDriver *driver G_GNUC_UNUSED, + virDomainObj *vm, + virDomainDeviceDef *dev) +{ + virDomainMemoryDef *newDef = dev->data.memory; + virDomainMemoryDef *oldDef = NULL; + + oldDef = virDomainMemoryFindByDeviceInfo(vm->def, &dev->data.memory->info); + if (!oldDef) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("memory '%s' not found"), dev->data.memory->info.alias);

+ return -1; + } + + if (!qemuDomainChangeMemoryLiveValidateChange(oldDef, newDef)) + return -1; + + if (qemuDomainChangeMemoryRequestedSize(driver, vm, + newDef->info.alias, + newDef->requestedsize) < 0) + return -1; + + oldDef->requestedsize = newDef->requestedsize; + return 0; +} + + static int qemuDomainUpdateDeviceLive(virDomainObj *vm, virDomainDeviceDef *dev, @@ -7171,6 +7330,18 @@ qemuDomainUpdateDeviceLive(virDomainObj *vm, ret = qemuDomainChangeNet(driver, vm, dev); break; + case VIR_DOMAIN_DEVICE_MEMORY: + oldDev.data.memory = virDomainMemoryFindByDeviceInfo(vm->def, &dev->data.memory->info); + if (oldDev.data.memory) {

+ if (virDomainDefCompatibleDevice(vm->def, dev, &oldDev, + VIR_DOMAIN_DEVICE_ACTION_UPDATE, + true) < 0) + return -1; + } + + ret = qemuDomainChangeMemoryLive(driver, vm, dev);

+ break; + case VIR_DOMAIN_DEVICE_FS: case VIR_DOMAIN_DEVICE_INPUT: case VIR_DOMAIN_DEVICE_SOUND: