Specifying a balloon size more than the memory size of a guest isn't something that should be rejected when parsing the XML. Truncate the size to the maximum memory size. --- src/conf/domain_conf.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 5f74ab1..d397bca 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -3364,27 +3364,9 @@ virDomainDefPostParseInternal(virDomainDefPtr def, return -1; } - if (def->mem.cur_balloon > virDomainDefGetMemoryActual(def)) { - /* Older libvirt could get into this situation due to - * rounding; if the discrepancy is less than 4MiB, we silently - * round down, otherwise we flag the issue. */ - if (VIR_DIV_UP(def->mem.cur_balloon, 4096) > - VIR_DIV_UP(virDomainDefGetMemoryActual(def), 4096)) { - virReportError(VIR_ERR_XML_ERROR, - _("current memory '%lluk' exceeds " - "maximum '%lluk'"), - def->mem.cur_balloon, - virDomainDefGetMemoryActual(def)); - return -1; - } else { - VIR_DEBUG("Truncating current %lluk to maximum %lluk", - def->mem.cur_balloon, - virDomainDefGetMemoryActual(def)); - def->mem.cur_balloon = virDomainDefGetMemoryActual(def); - } - } else if (def->mem.cur_balloon == 0) { + if (def->mem.cur_balloon > virDomainDefGetMemoryActual(def) || + def->mem.cur_balloon == 0) def->mem.cur_balloon = virDomainDefGetMemoryActual(def); - } if ((def->mem.max_memory || def->mem.memory_slots) && !(def->mem.max_memory && def->mem.memory_slots)) { -- 2.3.5

Since libvirt doesn't call to update the new balloon size in qemu add code that will handle tweaking of the size of the current balloon statistic until qemu reports the new size using the event. --- src/qemu/qemu_driver.c | 3 +++ src/qemu/qemu_hotplug.c | 10 ++++++++++ 2 files changed, 13 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index d6e7570..187145a 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -8379,6 +8379,9 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr qemuCaps, return -1; } + if (vmdef->mem.cur_balloon == virDomainDefGetMemoryActual(vmdef)) + vmdef->mem.cur_balloon += dev->data.memory->size; + if (virDomainMemoryInsert(vmdef, dev->data.memory) < 0) return -1; dev->data.memory = NULL; diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 613b728..c3b3efb 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -1727,6 +1727,7 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver, const char *backendType; virJSONValuePtr props = NULL; virObjectEventPtr event; + bool fix_balloon = false; int id; int ret = -1; @@ -1742,6 +1743,9 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver, if (virAsprintf(&objalias, "mem%s", mem->info.alias) < 0) goto cleanup; + if (vm->def->mem.cur_balloon == virDomainDefGetMemoryActual(vm->def)) + fix_balloon = true; + if (!(devstr = qemuBuildMemoryDeviceStr(mem, vm->def, priv->qemuCaps))) goto cleanup; @@ -1780,6 +1784,10 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver, if (event) qemuDomainEventQueue(driver, event); + /* fix the balloon size if it was set to maximum */ + if (fix_balloon) + vm->def->mem.cur_balloon += mem->size; + /* mem is consumed by vm->def */ mem = NULL; @@ -2897,6 +2905,8 @@ qemuDomainRemoveMemoryDevice(virQEMUDriverPtr driver, if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0) goto error; + vm->def->mem.cur_balloon -= mem->size; + if ((idx = virDomainMemoryFindByDef(vm->def, mem)) >= 0) virDomainMemoryRemove(vm->def, idx); -- 2.3.5