Re: [libvirt] [PATCH 16/35] qemu: Add helper to update domain balloon size and refactor usage places

When qemu does not support the balloon event the current memory size needs to be queried. Since there are two places that implement the same logic, split it out into a function and reuse. --- src/qemu/qemu_domain.c | 64 ++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 3 ++ src/qemu/qemu_driver.c | 84 +++++--------------------------------------------- 3 files changed, 75 insertions(+), 76 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index db8554b..661181f 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -3182,3 +3182,67 @@ qemuDomainMachineIsI440FX(const virDomainDef *def) STRPREFIX(def->os.machine, "pc-i440") || STRPREFIX(def->os.machine, "rhel")); } + + +/** + * qemuDomainUpdateCurrentMemorySize: + * + * Updates the current balloon size from the monitor if necessary. In case when + * the balloon is not present for the domain, the function recalculates the + * maximum size to reflect possible changes. + * + * Returns 0 on success and updates vm->def->mem.cur_balloon if necessary, -1 on + * error and reports libvirt error. + */ +int +qemuDomainUpdateCurrentMemorySize(virQEMUDriverPtr driver, + virDomainObjPtr vm) +{ + qemuDomainObjPrivatePtr priv = vm->privateData; + unsigned long long balloon; + int ret = -1; + + /* inactive domain doesn't need size update */ + if (!virDomainObjIsActive(vm)) + return 0; + + /* if no balloning is available, the current size equals to the current + * full memory size */ + if (!vm->def->memballoon || + vm->def->memballoon->model == VIR_DOMAIN_MEMBALLOON_MODEL_NONE) { + vm->def->mem.cur_balloon = virDomainDefGetMemoryActual(vm->def); + return 0; + } + + /* current size is always automagically updated via the event */ + if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BALLOON_EVENT)) + return 0; + + /* here we need to ask the monitor */ + + /* Don't delay if someone's using the monitor, just use existing most + * recent data instead */ + if (qemuDomainJobAllowed(priv, QEMU_JOB_QUERY)) { + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0) + return -1; + + if (!virDomainObjIsActive(vm)) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain is not running")); + goto endjob; + } + + qemuDomainObjEnterMonitor(driver, vm); + ret = qemuMonitorGetBalloonInfo(priv->mon, &balloon); + if (qemuDomainObjExitMonitor(driver, vm) < 0) + ret = -1; + + endjob: + qemuDomainObjEndJob(driver, vm); + + if (ret < 0) + return -1;

+ } + + return 0; +}