def get_runtime_properties(self):
xendom = XendDomain.instance()
dominfo = xendom.get_vm_by_uuid(self.VM)
try:
device_dict = {}
for device_sxp in dominfo.getDeviceSxprs('vscsi'):
target_dev = None
for dev in device_sxp[1][0][1]:
vdev = sxp.child_value(dev, 'v-dev')
if vdev == self.virtual_HCTL:
target_dev = dev
break
if target_dev is None:
continue
dev_dict = {}
for info in target_dev[1:]:
dev_dict[info[0]] = info[1]
device_dict['dev'] = dev_dict
for info in device_sxp[1][1:]:
device_dict[info[0]] = info[1]
return device_dict
except Exception, exn:
log.exception(exn)
return {}
def pool_list(cls, names):
sxprs = []
try:
node = XendNode.instance()
xd = XendDomain.instance()
pools = cls.get_all_records()
for (pool_uuid, pool_vals) in pools.items():
if pool_vals['name_label'] in names or len(names) == 0:
# conv host_cpu refs to cpu number
cpus = [
node.get_host_cpu_field(cpu_ref, 'number')
for cpu_ref in pool_vals['host_CPUs']
]
cpus.sort()
pool_vals['host_CPU_numbers'] = cpus
# query VMs names. Take in account, that a VM
# returned by get_all_records could be destroy, now
vm_names = [
vm.getName() for vm in map(
xd.get_vm_by_uuid, pool_vals['started_VMs']) if vm
]
pool_vals['started_VM_names'] = vm_names
pool_vals['auto_power_on'] = int(
pool_vals['auto_power_on'])
sxprs += [[pool_uuid] + map2sxp(pool_vals)]
except XendAPIError, ex:
raise VmError(ex.get_api_error())
def get_runtime_properties(self):
xendom = XendDomain.instance()
dominfo = xendom.get_vm_by_uuid(self.VM)
try:
device_dict = {}
for device_sxp in dominfo.getDeviceSxprs('vscsi'):
target_dev = None
for dev in device_sxp[1][0][1]:
vdev = sxp.child_value(dev, 'v-dev')
if vdev == self.virtual_HCTL:
target_dev = dev
break
if target_dev is None:
continue
dev_dict = {}
for info in target_dev[1:]:
dev_dict[info[0]] = info[1]
device_dict['dev'] = dev_dict
for info in device_sxp[1][1:]:
device_dict[info[0]] = info[1]
return device_dict
except Exception, exn:
log.exception(exn)
return {}
def destroy(self):
xendom = XendDomain.instance()
dom = xendom.get_vm_by_uuid(self.get_VM())
if not dom:
raise InvalidHandleError("VM", self.get_VM())
XendTask.log_progress(0, 100, \
dom.destroy_dscsi_HBA, \
self.get_uuid())
def destroy(self):
xendom = XendDomain.instance()
dom = xendom.get_vm_by_uuid(self.get_VM())
if not dom:
raise InvalidHandleError("VM", self.get_VM())
XendTask.log_progress(0, 100, \
dom.destroy_dscsi, \
self.get_uuid())
def get_VIFs(self):
result = []
vms = XendDomain.instance().get_all_vms()
for vm in vms:
vifs = vm.get_vifs()
for vif in vifs:
vif_cfg = vm.get_dev_xenapi_config('vif', vif)
if vif_cfg.get('network') == self.get_uuid():
result.append(vif)
return result
def get_VIFs(self):
result = []
vms = XendDomain.instance().get_all_vms()
for vm in vms:
vifs = vm.get_vifs()
for vif in vifs:
vif_cfg = vm.get_dev_xenapi_config('vif', vif)
if vif_cfg.get('network') == self.get_uuid():
result.append(vif)
return result
def pool_migrate(cls, domname, poolname):
dom = XendDomain.instance()
pool = cls.lookup_pool(poolname)
if not pool:
raise VmError('unknown pool %s' % poolname)
dominfo = dom.domain_lookup_nr(domname)
if not dominfo:
raise VmError('unknown domain %s' % domname)
domid = dominfo.getDomid()
if domid is not None:
if domid == 0:
raise VmError('could not move Domain-0')
try:
cls.move_domain(pool.get_uuid(), domid)
except Exception, ex:
raise VmError('could not move domain')
def pool_migrate(cls, domname, poolname):
dom = XendDomain.instance()
pool = cls.lookup_pool(poolname)
if not pool:
raise VmError('unknown pool %s' % poolname)
dominfo = dom.domain_lookup_nr(domname)
if not dominfo:
raise VmError('unknown domain %s' % domname)
domid = dominfo.getDomid()
if domid is not None:
if domid == 0:
raise VmError('could not move Domain-0')
try:
cls.move_domain(pool.get_uuid(), domid)
except Exception, ex:
raise VmError('could not move domain')
def get_started_VMs(self):
""" Query all VMs currently assigned to pool.
@return: ref of all VMs assigned to pool; if pool is not active,
an empty list will be returned
@rtype: list of str
"""
if self.get_activated():
# search VMs related to this pool
pool_id = self.query_pool_id()
started_VMs = [ vm.get_uuid()
for vm in XendDomain.instance().list('all')
if vm.get_cpu_pool() == pool_id ]
else:
# pool not active, so it couldn't have any started VMs
started_VMs = []
return started_VMs
def get_started_VMs(self):
""" Query all VMs currently assigned to pool.
@return: ref of all VMs assigned to pool; if pool is not active,
an empty list will be returned
@rtype: list of str
"""
if self.get_activated():
# search VMs related to this pool
pool_id = self.query_pool_id()
started_VMs = [
vm.get_uuid() for vm in XendDomain.instance().list('all')
if vm.get_cpu_pool() == pool_id
]
else:
# pool not active, so it couldn't have any started VMs
started_VMs = []
return started_VMs
def create(self, dscsi_struct):
# Check if VM is valid
xendom = XendDomain.instance()
if not xendom.is_valid_vm(dscsi_struct['VM']):
raise InvalidHandleError('VM', dscsi_struct['VM'])
dom = xendom.get_vm_by_uuid(dscsi_struct['VM'])
# Check if PSCSI is valid
xennode = XendNode.instance()
pscsi_uuid = xennode.get_pscsi_by_uuid(dscsi_struct['PSCSI'])
if not pscsi_uuid:
raise InvalidHandleError('PSCSI', dscsi_struct['PSCSI'])
# Assign PSCSI to VM
try:
dscsi_ref = XendTask.log_progress(0, 100, \
dom.create_dscsi, \
dscsi_struct)
except XendError, e:
log.exception("Error in create_dscsi")
raise
def create(self, dscsi_struct):
# Check if VM is valid
xendom = XendDomain.instance()
if not xendom.is_valid_vm(dscsi_struct['VM']):
raise InvalidHandleError('VM', dscsi_struct['VM'])
dom = xendom.get_vm_by_uuid(dscsi_struct['VM'])
# Check if PSCSI is valid
xennode = XendNode.instance()
pscsi_uuid = xennode.get_pscsi_by_uuid(dscsi_struct['PSCSI'])
if not pscsi_uuid:
raise InvalidHandleError('PSCSI', dscsi_struct['PSCSI'])
# Assign PSCSI to VM
try:
dscsi_ref = XendTask.log_progress(0, 100, \
dom.create_dscsi, \
dscsi_struct)
except XendError, e:
log.exception("Error in create_dscsi")
raise
def create(self, dpci_struct):
# Check if VM is valid
xendom = XendDomain.instance()
if not xendom.is_valid_vm(dpci_struct['VM']):
raise InvalidHandleError('VM', dpci_struct['VM'])
dom = xendom.get_vm_by_uuid(dpci_struct['VM'])
# Check if PPCI is valid
xennode = XendNode.instance()
ppci_uuid = xennode.get_ppci_by_uuid(dpci_struct['PPCI'])
if not ppci_uuid:
raise InvalidHandleError('PPCI', dpci_struct['PPCI'])
for existing_dpci in XendAPIStore.get_all('DPCI'):
if ppci_uuid == existing_dpci.get_PPCI():
raise DirectPCIError("Device is in use")
# Assign PPCI to VM
try:
dpci_ref = XendTask.log_progress(0, 100, dom.create_dpci,
dpci_struct)
except XendError, e:
raise DirectPCIError("Failed to assign device")
def create(self, dpci_struct):
# Check if VM is valid
xendom = XendDomain.instance()
if not xendom.is_valid_vm(dpci_struct['VM']):
raise InvalidHandleError('VM', dpci_struct['VM'])
dom = xendom.get_vm_by_uuid(dpci_struct['VM'])
# Check if PPCI is valid
xennode = XendNode.instance()
ppci_uuid = xennode.get_ppci_by_uuid(dpci_struct['PPCI'])
if not ppci_uuid:
raise InvalidHandleError('PPCI', dpci_struct['PPCI'])
for existing_dpci in XendAPIStore.get_all('DPCI'):
if ppci_uuid == existing_dpci.get_PPCI():
raise DirectPCIError("Device is in use")
# Assign PPCI to VM
try:
dpci_ref = XendTask.log_progress(0, 100, dom.create_dpci,
dpci_struct)
except XendError, e:
raise DirectPCIError("Failed to assign device")
def pool_list(cls, names):
sxprs = []
try:
node = XendNode.instance()
xd = XendDomain.instance()
pools = cls.get_all_records()
for (pool_uuid, pool_vals) in pools.items():
if pool_vals['name_label'] in names or len(names) == 0:
# conv host_cpu refs to cpu number
cpus = [ node.get_host_cpu_field(cpu_ref, 'number')
for cpu_ref in pool_vals['host_CPUs'] ]
cpus.sort()
pool_vals['host_CPU_numbers'] = cpus
# query VMs names. Take in account, that a VM
# returned by get_all_records could be destroy, now
vm_names = [ vm.getName()
for vm in map(xd.get_vm_by_uuid,
pool_vals['started_VMs'])
if vm ]
pool_vals['started_VM_names'] = vm_names
pool_vals['auto_power_on'] = int(pool_vals['auto_power_on'])
sxprs += [[pool_uuid] + map2sxp(pool_vals)]
except XendAPIError, ex:
raise VmError(ex.get_api_error())
except Exception, exn:
log.exception("Can't create directory '/var/lib/xen'")
raise XendError("Can't create directory '/var/lib/xen'")
write_exact(fd, SIGNATURE, "could not write guest state file: signature")
sxprep = dominfo.sxpr()
if node > -1:
insert_after(sxprep,'vcpus',['node', str(node)])
for device_sxp in sxp.children(sxprep, 'device'):
backend = sxp.child(device_sxp[1], 'backend')
if backend == None:
continue
bkdominfo = XendDomain.instance().domain_lookup_nr(backend[1])
if bkdominfo == None:
raise XendError("Could not find backend: %s" % backend[1])
if bkdominfo.getDomid() == XendDomain.DOM0_ID:
# Skip for compatibility of checkpoint data format
continue
backend[1] = bkdominfo.getName()
config = sxp.to_string(sxprep)
#log.debug('xendcheckpoint config: %s' % config)
domain_name = dominfo.getName()
# Rename the domain temporarily, so that we don't get a name clash if this
# domain is migrating (live or non-live) to the local host. Doing such a
# thing is useful for debugging.
def free(need_mem, dominfo):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_ballooning
# is False, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
# stop tmem from absorbing any more memory (must THAW when done!)
xc.tmem_control(0,TMEMC_FREEZE,-1, 0, 0, "")
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
total_mem = physinfo['total_memory']
if dom0_ballooning:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
freeable_mem = free_mem + scrub_mem
if freeable_mem < need_mem and need_mem < max_free_mem:
# flush memory from tmem to scrub_mem and reobtain physinfo
need_tmem_kb = need_mem - freeable_mem
tmem_kb = xc.tmem_control(0,TMEMC_FLUSH,-1, need_tmem_kb, 0, "")
log.debug("Balloon: tmem relinquished %d KiB of %d KiB requested.",
tmem_kb, need_tmem_kb)
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
# Check whethercurrent machine is a numa system and the new
# created hvm has all its vcpus in the same node, if all the
# conditions above are fit. We will wait until all the pages
# in scrub list are freed (if waiting time go beyond 20s,
# we will stop waiting it.)
if physinfo['nr_nodes'] > 1 and retries == 0:
oldnode = -1
waitscrub = 1
vcpus = dominfo.info['cpus'][0]
for vcpu in vcpus:
nodenum = 0
for node in physinfo['node_to_cpu']:
for cpu in node:
if vcpu == cpu:
if oldnode == -1:
oldnode = nodenum
elif oldnode != nodenum:
waitscrub = 0
nodenum = nodenum + 1
if waitscrub == 1 and scrub_mem > 0:
log.debug("wait for scrub %s", scrub_mem)
while scrub_mem > 0 and retries < rlimit:
time.sleep(sleep_time)
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
retries += 1
sleep_time += SLEEP_TIME_GROWTH
log.debug("scrub for %d times", retries)
retries = 0
sleep_time = SLEEP_TIME_GROWTH
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
if free_mem >= need_mem:
log.debug("Balloon: %d KiB free; need %d; done.",
free_mem, need_mem)
return
if retries == 0:
rlimit += ((need_mem - free_mem)/1024/1024) * RETRY_LIMIT_INCR
log.debug("Balloon: %d KiB free; %d to scrub; need %d; retries: %d.",
free_mem, scrub_mem, need_mem, rlimit)
if dom0_ballooning:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if (new_alloc >= dom0_min_mem and
new_alloc != last_new_alloc):
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.",
new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if not dom0_ballooning:
raise VmError(('Not enough free memory and enable-dom0-ballooning '
'is False, so I cannot release any more. '
'I need %d KiB but only have %d.') %
(need_mem, free_mem))
elif new_alloc < dom0_min_mem:
raise VmError(
('I need %d KiB, but dom0_min_mem is %d and shrinking to '
'%d KiB would leave only %d KiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + scrub_mem + dom0_alloc - dom0_min_mem))
else:
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
dom0.setMemoryTarget(dom0_start_alloc_mb)
raise VmError(
('Not enough memory is available, and dom0 cannot'
' be shrunk any further'))
finally:
# allow tmem to accept pages again
xc.tmem_control(0,TMEMC_THAW,-1, 0, 0, "")
del xc
def free(need_mem, dominfo):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_ballooning
# is False, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
memory_pool = MemoryPool.instance()
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
guest_size = 0
hvm = dominfo.info.is_hvm()
if memory_pool.is_enabled() and dominfo.domid:
if not hvm :
if need_mem <= 4 * 1024:
guest_size = 32
else:
guest_size = dominfo.image.getBitSize()
if guest_size == 32:
dom0_ballooning = 0
else: #no ballooning as memory pool enabled
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
mem_need_balloon = 0
left_memory_pool = 0
mem_target = 0
untouched_memory_pool = 0
real_need_mem = need_mem
# stop tmem from absorbing any more memory (must THAW when done!)
xc.tmem_control(0,TMEMC_FREEZE,-1, 0, 0, 0, "")
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
total_mem = physinfo['total_memory']
if memory_pool.is_enabled() and dominfo.domid:
if guest_size != 32 or hvm:
if need_mem > 4 * 1024:
dominfo.alloc_mem = need_mem
left_memory_pool = memory_pool.get_left_memory()
if need_mem > left_memory_pool:
dominfo.alloc_mem = 0
raise VmError(('Not enough free memory'
' so I cannot release any more. '
'I need %d KiB but only have %d in the pool.') %
(need_mem, memory_pool.get_left_memory()))
else:
untouched_memory_pool = memory_pool.get_untouched_memory()
if (left_memory_pool - untouched_memory_pool) > need_mem:
dom0_ballooning = 0
else:
mem_need_balloon = need_mem - left_memory_pool + untouched_memory_pool
need_mem = free_mem + scrub_mem + mem_need_balloon
if dom0_ballooning:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
freeable_mem = free_mem + scrub_mem
if freeable_mem < need_mem and need_mem < max_free_mem:
# flush memory from tmem to scrub_mem and reobtain physinfo
need_tmem_kb = need_mem - freeable_mem
tmem_kb = xc.tmem_control(0,TMEMC_FLUSH,-1, need_tmem_kb, 0, 0, "")
log.debug("Balloon: tmem relinquished %d KiB of %d KiB requested.",
tmem_kb, need_tmem_kb)
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
if free_mem >= need_mem:
if (guest_size != 32 or hvm) and dominfo.domid:
memory_pool.decrease_untouched_memory(mem_need_balloon)
memory_pool.decrease_memory(real_need_mem)
else:
log.debug("Balloon: %d KiB free; need %d; done.",
free_mem, need_mem)
return
if retries == 0:
rlimit += ((need_mem - free_mem)/1024/1024) * RETRY_LIMIT_INCR
log.debug("Balloon: %d KiB free; %d to scrub; need %d; retries: %d.",
free_mem, scrub_mem, need_mem, rlimit)
if dom0_ballooning:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if (new_alloc >= dom0_min_mem and
new_alloc != last_new_alloc):
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.",
new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if not dom0_ballooning:
dominfo.alloc_mem = 0
raise VmError(('Not enough free memory and enable-dom0-ballooning '
'is False, so I cannot release any more. '
'I need %d KiB but only have %d.') %
(need_mem, free_mem))
elif new_alloc < dom0_min_mem:
dominfo.alloc_mem = 0
raise VmError(
('I need %d KiB, but dom0_min_mem is %d and shrinking to '
'%d KiB would leave only %d KiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + scrub_mem + dom0_alloc - dom0_min_mem))
else:
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
dom0.setMemoryTarget(dom0_start_alloc_mb)
dominfo.alloc_mem = 0
raise VmError(
('Not enough memory is available, and dom0 cannot'
' be shrunk any further'))
finally:
# allow tmem to accept pages again
xc.tmem_control(0,TMEMC_THAW,-1, 0, 0, 0, "")
del xc
def free(need_mem):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_min_mem
# is 0, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
total_mem = physinfo['total_memory']
if dom0_min_mem > 0:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
if free_mem >= need_mem:
log.debug("Balloon: %d KiB free; need %d; done.", free_mem,
need_mem)
return
if retries == 0:
rlimit += (
(need_mem - free_mem) / 1024 / 1024) * RETRY_LIMIT_INCR
log.debug(
"Balloon: %d KiB free; %d to scrub; need %d; retries: %d.",
free_mem, scrub_mem, need_mem, rlimit)
if dom0_min_mem > 0:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if (new_alloc >= dom0_min_mem
and new_alloc != last_new_alloc):
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.",
new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if dom0_min_mem == 0:
raise VmError(('Not enough free memory and dom0_min_mem is 0, so '
'I cannot release any more. I need %d KiB but '
'only have %d.') % (need_mem, free_mem))
elif new_alloc < dom0_min_mem:
raise VmError(
('I need %d KiB, but dom0_min_mem is %d and shrinking to '
'%d KiB would leave only %d KiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + scrub_mem + dom0_alloc - dom0_min_mem))
else:
dom0.setMemoryTarget(dom0_start_alloc_mb)
raise VmError(('Not enough memory is available, and dom0 cannot'
' be shrunk any further'))
finally:
del xc
def free(need_mem, dominfo):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_ballooning
# is False, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
memory_pool = MemoryPool.instance()
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
guest_size = 0
hvm = dominfo.info.is_hvm()
if memory_pool.is_enabled() and dominfo.domid:
if not hvm:
if need_mem <= 4 * 1024:
guest_size = 32
else:
guest_size = dominfo.image.getBitSize()
if guest_size == 32:
dom0_ballooning = 0
else: #no ballooning as memory pool enabled
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
mem_need_balloon = 0
left_memory_pool = 0
mem_target = 0
untouched_memory_pool = 0
real_need_mem = need_mem
# stop tmem from absorbing any more memory (must THAW when done!)
xc.tmem_control(0, TMEMC_FREEZE, -1, 0, 0, 0, "")
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
total_mem = physinfo['total_memory']
if memory_pool.is_enabled() and dominfo.domid:
if guest_size != 32 or hvm:
if need_mem > 4 * 1024:
dominfo.alloc_mem = need_mem
left_memory_pool = memory_pool.get_left_memory()
if need_mem > left_memory_pool:
dominfo.alloc_mem = 0
raise VmError(
('Not enough free memory'
' so I cannot release any more. '
'I need %d KiB but only have %d in the pool.') %
(need_mem, memory_pool.get_left_memory()))
else:
untouched_memory_pool = memory_pool.get_untouched_memory()
if (left_memory_pool - untouched_memory_pool) > need_mem:
dom0_ballooning = 0
else:
mem_need_balloon = need_mem - left_memory_pool + untouched_memory_pool
need_mem = free_mem + scrub_mem + mem_need_balloon
if dom0_ballooning:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
freeable_mem = free_mem + scrub_mem
if freeable_mem < need_mem and need_mem < max_free_mem:
# flush memory from tmem to scrub_mem and reobtain physinfo
need_tmem_kb = need_mem - freeable_mem
tmem_kb = xc.tmem_control(0, TMEMC_FLUSH, -1, need_tmem_kb, 0, 0,
"")
log.debug("Balloon: tmem relinquished %d KiB of %d KiB requested.",
tmem_kb, need_tmem_kb)
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
if free_mem >= need_mem:
if (guest_size != 32 or hvm) and dominfo.domid:
memory_pool.decrease_untouched_memory(mem_need_balloon)
memory_pool.decrease_memory(real_need_mem)
else:
log.debug("Balloon: %d KiB free; need %d; done.", free_mem,
need_mem)
return
if retries == 0:
rlimit += (
(need_mem - free_mem) / 1024 / 1024) * RETRY_LIMIT_INCR
log.debug(
"Balloon: %d KiB free; %d to scrub; need %d; retries: %d.",
free_mem, scrub_mem, need_mem, rlimit)
if dom0_ballooning:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if (new_alloc >= dom0_min_mem
and new_alloc != last_new_alloc):
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.",
new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if not dom0_ballooning:
dominfo.alloc_mem = 0
raise VmError(
('Not enough free memory and enable-dom0-ballooning '
'is False, so I cannot release any more. '
'I need %d KiB but only have %d.') % (need_mem, free_mem))
elif new_alloc < dom0_min_mem:
dominfo.alloc_mem = 0
raise VmError(
('I need %d KiB, but dom0_min_mem is %d and shrinking to '
'%d KiB would leave only %d KiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + scrub_mem + dom0_alloc - dom0_min_mem))
else:
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
dom0.setMemoryTarget(dom0_start_alloc_mb)
dominfo.alloc_mem = 0
raise VmError(('Not enough memory is available, and dom0 cannot'
' be shrunk any further'))
finally:
# allow tmem to accept pages again
xc.tmem_control(0, TMEMC_THAW, -1, 0, 0, 0, "")
del xc
def free(need_mem, dominfo):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_ballooning
# is False, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_ballooning = xoptions.get_enable_dom0_ballooning()
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo["free_memory"]
scrub_mem = physinfo["scrub_memory"]
total_mem = physinfo["total_memory"]
if dom0_ballooning:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
# Check whethercurrent machine is a numa system and the new
# created hvm has all its vcpus in the same node, if all the
# conditions above are fit. We will wait until all the pages
# in scrub list are freed (if waiting time go beyond 20s,
# we will stop waiting it.)
if physinfo["nr_nodes"] > 1 and retries == 0:
oldnode = -1
waitscrub = 1
vcpus = dominfo.info["cpus"][0]
for vcpu in vcpus:
nodenum = 0
for node in physinfo["node_to_cpu"]:
for cpu in node:
if vcpu == cpu:
if oldnode == -1:
oldnode = nodenum
elif oldnode != nodenum:
waitscrub = 0
nodenum = nodenum + 1
if waitscrub == 1 and scrub_mem > 0:
log.debug("wait for scrub %s", scrub_mem)
while scrub_mem > 0 and retries < rlimit:
time.sleep(sleep_time)
physinfo = xc.physinfo()
free_mem = physinfo["free_memory"]
scrub_mem = physinfo["scrub_memory"]
retries += 1
sleep_time += SLEEP_TIME_GROWTH
log.debug("scrub for %d times", retries)
retries = 0
sleep_time = SLEEP_TIME_GROWTH
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo["free_memory"]
scrub_mem = physinfo["scrub_memory"]
if free_mem >= need_mem:
log.debug("Balloon: %d KiB free; need %d; done.", free_mem, need_mem)
return
if retries == 0:
rlimit += ((need_mem - free_mem) / 1024 / 1024) * RETRY_LIMIT_INCR
log.debug(
"Balloon: %d KiB free; %d to scrub; need %d; retries: %d.", free_mem, scrub_mem, need_mem, rlimit
)
if dom0_ballooning:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if new_alloc >= dom0_min_mem and new_alloc != last_new_alloc:
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.", new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if not dom0_ballooning:
raise VmError(
(
"Not enough free memory and enable-dom0-ballooning "
"is False, so I cannot release any more. "
"I need %d KiB but only have %d."
)
% (need_mem, free_mem)
)
elif new_alloc < dom0_min_mem:
raise VmError(
("I need %d KiB, but dom0_min_mem is %d and shrinking to " "%d KiB would leave only %d KiB free.")
% (need_mem, dom0_min_mem, dom0_min_mem, free_mem + scrub_mem + dom0_alloc - dom0_min_mem)
)
else:
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
dom0.setMemoryTarget(dom0_start_alloc_mb)
raise VmError(("Not enough memory is available, and dom0 cannot" " be shrunk any further"))
finally:
del xc
def free(required):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. No matter where
# we expect the free memory to come from, therefore, we need to wait for
# it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_min_mem
# is 0, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
need_mem = (required + 1023) / 1024 + BALLOON_OUT_SLACK
xroot = XendRoot.instance()
xc = xen.lowlevel.xc.xc()
try:
dom0_min_mem = xroot.get_dom0_min_mem()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
last_new_alloc = None
while retries < RETRY_LIMIT:
free_mem = xc.physinfo()['free_memory']
if free_mem >= need_mem:
log.debug("Balloon: free %d; need %d; done.", free_mem,
need_mem)
return
if retries == 0:
log.debug("Balloon: free %d; need %d.", free_mem, need_mem)
if dom0_min_mem > 0:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem)
if (new_alloc >= dom0_min_mem and
new_alloc != last_new_alloc):
log.debug("Balloon: setting dom0 target to %d.",
new_alloc)
dom0 = XendDomain.instance().privilegedDomain()
dom0.setMemoryTarget(new_alloc)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning.
time.sleep(sleep_time)
retries += 1
sleep_time += SLEEP_TIME_GROWTH
# Not enough memory; diagnose the problem.
if dom0_min_mem == 0:
raise VmError(('Not enough free memory and dom0_min_mem is 0, so '
'I cannot release any more. I need %d MiB but '
'only have %d.') %
(need_mem, free_mem))
elif new_alloc < dom0_min_mem:
raise VmError(
('I need %d MiB, but dom0_min_mem is %d and shrinking to '
'%d MiB would leave only %d MiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + dom0_alloc - dom0_min_mem))
else:
raise VmError('The privileged domain did not balloon!')
finally:
del xc
def free(need_mem):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. Such memory
# does, however, need to be accounted for when calculating how much dom0
# needs to balloon. No matter where we expect the free memory to come
# from, we need to wait for it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_min_mem
# is 0, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
xoptions = XendOptions.instance()
dom0 = XendDomain.instance().privilegedDomain()
xc = xen.lowlevel.xc.xc()
dom0_start_alloc_mb = get_dom0_current_alloc() / 1024
try:
dom0_min_mem = xoptions.get_dom0_min_mem() * 1024
dom0_alloc = get_dom0_current_alloc()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
new_alloc = 0
last_new_alloc = None
last_free = None
rlimit = RETRY_LIMIT
# If unreasonable memory size is required, we give up waiting
# for ballooning or scrubbing, as if had retried.
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
total_mem = physinfo['total_memory']
if dom0_min_mem > 0:
max_free_mem = total_mem - dom0_min_mem
else:
max_free_mem = total_mem - dom0_alloc
if need_mem >= max_free_mem:
retries = rlimit
while retries < rlimit:
physinfo = xc.physinfo()
free_mem = physinfo['free_memory']
scrub_mem = physinfo['scrub_memory']
if free_mem >= need_mem:
log.debug("Balloon: %d KiB free; need %d; done.",
free_mem, need_mem)
return
if retries == 0:
rlimit += ((need_mem - free_mem)/1024/1024) * RETRY_LIMIT_INCR
log.debug("Balloon: %d KiB free; %d to scrub; need %d; retries: %d.",
free_mem, scrub_mem, need_mem, rlimit)
if dom0_min_mem > 0:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem - scrub_mem)
if free_mem + scrub_mem >= need_mem:
if last_new_alloc == None:
log.debug("Balloon: waiting on scrubbing")
last_new_alloc = dom0_alloc
else:
if (new_alloc >= dom0_min_mem and
new_alloc != last_new_alloc):
new_alloc_mb = new_alloc / 1024 # Round down
log.debug("Balloon: setting dom0 target to %d MiB.",
new_alloc_mb)
dom0.setMemoryTarget(new_alloc_mb)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning or scrubbing.
time.sleep(sleep_time)
if retries < 2 * RETRY_LIMIT:
sleep_time += SLEEP_TIME_GROWTH
if last_free != None and last_free >= free_mem + scrub_mem:
retries += 1
last_free = free_mem + scrub_mem
# Not enough memory; diagnose the problem.
if dom0_min_mem == 0:
raise VmError(('Not enough free memory and dom0_min_mem is 0, so '
'I cannot release any more. I need %d KiB but '
'only have %d.') %
(need_mem, free_mem))
elif new_alloc < dom0_min_mem:
raise VmError(
('I need %d KiB, but dom0_min_mem is %d and shrinking to '
'%d KiB would leave only %d KiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + scrub_mem + dom0_alloc - dom0_min_mem))
else:
dom0.setMemoryTarget(dom0_start_alloc_mb)
raise VmError(
('Not enough memory is available, and dom0 cannot'
' be shrunk any further'))
finally:
del xc
def free(required):
"""Balloon out memory from the privileged domain so that there is the
specified required amount (in KiB) free.
"""
# We check whether there is enough free memory, and if not, instruct dom0
# to balloon out to free some up. Memory freed by a destroyed domain may
# not appear in the free_memory field immediately, because it needs to be
# scrubbed before it can be released to the free list, which is done
# asynchronously by Xen; ballooning is asynchronous also. No matter where
# we expect the free memory to come from, therefore, we need to wait for
# it to become available.
#
# We are not allowed to balloon below dom0_min_mem, or if dom0_min_mem
# is 0, we cannot balloon at all. Memory can still become available
# through a rebooting domain, however.
#
# Eventually, we time out (presumably because there really isn't enough
# free memory).
#
# We don't want to set the memory target (triggering a watch) when that
# has already been done, but we do want to respond to changing memory
# usage, so we recheck the required alloc each time around the loop, but
# track the last used value so that we don't trigger too many watches.
need_mem = (required + 1023) / 1024 + BALLOON_OUT_SLACK
xroot = XendRoot.instance()
xc = xen.lowlevel.xc.xc()
try:
dom0_min_mem = xroot.get_dom0_min_mem()
retries = 0
sleep_time = SLEEP_TIME_GROWTH
last_new_alloc = None
while retries < RETRY_LIMIT:
free_mem = xc.physinfo()['free_memory']
if free_mem >= need_mem:
log.debug("Balloon: free %d; need %d; done.", free_mem,
need_mem)
return
if retries == 0:
log.debug("Balloon: free %d; need %d.", free_mem, need_mem)
if dom0_min_mem > 0:
dom0_alloc = get_dom0_current_alloc()
new_alloc = dom0_alloc - (need_mem - free_mem)
if (new_alloc >= dom0_min_mem and new_alloc != last_new_alloc):
log.debug("Balloon: setting dom0 target to %d.", new_alloc)
dom0 = XendDomain.instance().privilegedDomain()
dom0.setMemoryTarget(new_alloc)
last_new_alloc = new_alloc
# Continue to retry, waiting for ballooning.
time.sleep(sleep_time)
retries += 1
sleep_time += SLEEP_TIME_GROWTH
# Not enough memory; diagnose the problem.
if dom0_min_mem == 0:
raise VmError(('Not enough free memory and dom0_min_mem is 0, so '
'I cannot release any more. I need %d MiB but '
'only have %d.') % (need_mem, free_mem))
elif new_alloc < dom0_min_mem:
raise VmError(
('I need %d MiB, but dom0_min_mem is %d and shrinking to '
'%d MiB would leave only %d MiB free.') %
(need_mem, dom0_min_mem, dom0_min_mem,
free_mem + dom0_alloc - dom0_min_mem))
else:
raise VmError('The privileged domain did not balloon!')
finally:
del xc