On 06/03/2015 09:16 AM, Ján Tomko wrote:
> On Fri, May 29, 2015 at 03:33:37PM +0200, Peter Krempa wrote:
>> 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;
>
> ACK if you actually use the 'balloon' value to update cur_balloon here.
>
> Jan
>
Making Coverity unhappy...
3215 qemuDomainObjPrivatePtr priv = vm->privateData;
(1) Event var_decl: Declaring variable "balloon" without initializer.
Also see events: [uninit_use]
3216 unsigned long long balloon;
...
238 * recent data instead */
(9) Event cond_false: Condition "qemuDomainJobAllowed(priv,
QEMU_JOB_QUERY)", taking false branch
3239 if (qemuDomainJobAllowed(priv, QEMU_JOB_QUERY)) {
...
3258 return -1;
(10) Event if_end: End of if statement
3259 }
3260
(11) Event uninit_use: Using uninitialized value "balloon".
Also see events: [var_decl]
3261 vm->def->mem.cur_balloon = balloon;
3262
So if QEMU_JOB_QUERY is not allowed, then balloon is not initialized and
setting to cur_balloon is bad
Adding an "if (ret == 0)" prior to the setting works.
John
>> + }
>> +
>> + return 0;
>> +}
>>
>>
>> --
>> libvir-list mailing list
>> libvir-list@xxxxxxxxxx
>> https://www.redhat.com/mailman/listinfo/libvir-list
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list