def config_feature_memory_backing(test, vmxml, **kwargs):
"""
Config libvirt VM XML to influence how virtual memory pages are backed
by host pages.
:param vmxml: VMXML instance
:param kwargs: Function keywords
:return: Corresponding feature flag in qem cmdline
"""
# Both 'nosharepages' and 'locked' are supported since 1.0.6
if not libvirt_version.version_compare(1, 0, 6):
test.cancel("Element is not supported in current" " libvirt version")
qemu_flags = []
no_sharepages = "yes" == kwargs.get("nosharepages", "no")
locked = "yes" == kwargs.get("locked", "no")
if no_sharepages:
# On RHEL6, the flag is 'redhat-disable-KSM'
# On RHEL7 & Fedora, the flag is 'mem-merge=off'
qemu_flags.append(['mem-merge=off', 'redhat-disable-KSM'])
if locked:
qemu_flags.append("mlock=on")
memtune_xml = vm_xml.VMMemTuneXML()
memtune_xml.hard_limit = vmxml.max_mem * 4
vmxml.memtune = memtune_xml
vmxml.sync()
try:
vm_xml.VMXML.set_memoryBacking_tag(vmxml.vm_name,
hpgs=False,
nosp=no_sharepages,
locked=locked)
logging.debug("xml updated to %s", vmxml.xmltreefile)
except Exception as detail:
logging.error("Update VM XML fail: %s", detail)
return qemu_flags
def run_test_memorybacking(case):
"""
Test memory backing cases
:param case: test case
"""
if case == 'no_numa':
# Verify <access mode='shared'/> is ignored
# if no NUMA nodes are configured
if libvirt_version.version_compare(7, 0, 0) or\
not libvirt_version.version_compare(5, 0, 0):
test.cancel('This case is not supported by current libvirt.')
access_mode = params.get('access_mode')
# Setup memoryBacking
mem_backing = vm_xml.VMMemBackingXML()
mem_backing.access_mode = access_mode
hugepages = vm_xml.VMHugepagesXML()
mem_backing.hugepages = hugepages
vmxml.mb = mem_backing
logging.debug('membacking xml is: %s', mem_backing)
vmxml.xmltreefile.write()
# Define xml
cmd_result = virsh.define(vmxml.xml, debug=True)
check_result(cmd_result, status_error, error_msg)
if case == 'mem_lock':
# Allow use mlock without hard limit
hard_limit = params.get('hard_limit')
hard_limit_unit = params.get('hard_limit_unit', 'KiB')
mem_backing = vm_xml.VMMemBackingXML()
mem_backing.locked = True
vmxml.mb = mem_backing
if hard_limit:
mem_tune = vm_xml.VMMemTuneXML()
mem_tune.hard_limit = int(hard_limit)
mem_tune.hard_limit_unit = hard_limit_unit
vmxml.memtune = mem_tune
vmxml.sync()
vm.start()
output = process.run('prlimit -p `pidof qemu-kvm`',
shell=True,
verbose=True).stdout_text
if not re.search(expect_msg, output):
test.fail('Not found expected content "%s" in output.' %
expect_msg)