Re: [PATCH v3 11/14] qemuDomainSetMemoryFlags: Take virtio-mem into consideration

The qemuDomainSetMemoryFlags() allows for memballoon (<currentMemory/>) changes for both active and inactive guests. And just before doing any change, we have to make sure that the new size is not greater than the total memory (<memory/>). However, the total memory includes not only the regular guest memory, but also sum of maximum sizes of all virtio-mems (in fact all memory devices for that matter). But virtio-mem devices are modified differently (via virDomainUpdateDevice()) and thus the upper limit for new balloon size has to be lowered. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index e376a64bee..6a9da62ded 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2433,12 +2433,28 @@ static int qemuDomainSetMemoryFlags(virDomainPtr dom, unsigned long newmem, } else { /* resize the current memory */ unsigned long oldmax = 0; + size_t i; - if (def) + if (def) { oldmax = virDomainDefGetMemoryTotal(def); + + /* While virtio-mem is regular mem from guest POV, it can't be + * modified through this API. */ + for (i = 0; i < def->nmems; i++) { + if (def->mems[i]->model == VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM) + oldmax -= def->mems[i]->size; + } + } + if (persistentDef) { - if (!oldmax || oldmax > virDomainDefGetMemoryTotal(persistentDef)) + if (!oldmax || oldmax > virDomainDefGetMemoryTotal(persistentDef)) {