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dom0/qvm-block: automatically choose frontend device (#419)

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This commit is contained in:
Marek Marczykowski 2012-02-14 20:57:43 +01:00
parent 1683a0b815
commit 05e89d82fb
1 changed files with 22 additions and 4 deletions
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26
dom0/qvm-core/qubesutils.py
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@ -158,6 +158,19 @@ def block_name_to_devid(name):
(major, minor) = block_name_to_majorminor(name) (major, minor) = block_name_to_majorminor(name)
return major << 8 | minor return major << 8 | minor
def block_find_unused_frontend(vm = None):
assert vm is not None
assert vm.is_running()
vbd_list = xs.ls('', '/local/domain/%d/device/vbd' % vm.xid)
# xvd* devices
major = 202
# prefer xvdi
for minor in range(8*16,254,16)+range(0,8*16,16):
if str(major << 8 | minor) not in vbd_list:
return block_devid_to_name(major << 8 | minor)
return None
def block_list(vm = None): def block_list(vm = None):
device_re = re.compile(r"^[a-z0-9]{1,8}$") device_re = re.compile(r"^[a-z0-9]{1,8}$")
# FIXME: any better idea of desc_re? # FIXME: any better idea of desc_re?
@ -235,16 +248,21 @@ def block_check_attached(backend_vm, device, backend_xid = None):
return {"xid":int(vm_xid), "frontend": frontend, "devid": int(devid), "vm": vm_name} return {"xid":int(vm_xid), "frontend": frontend, "devid": int(devid), "vm": vm_name}
return None return None
def block_attach(vm, backend_vm, device, frontend="xvdi", mode="w", auto_detach=False): def block_attach(vm, backend_vm, device, frontend=None, mode="w", auto_detach=False):
if not vm.is_running(): if not vm.is_running():
raise QubesException("VM %s not running" % vm.name) raise QubesException("VM %s not running" % vm.name)
if not backend_vm.is_running(): if not backend_vm.is_running():
raise QubesException("VM %s not running" % backend_vm.name) raise QubesException("VM %s not running" % backend_vm.name)
# Check if any device attached at this frontend if frontend is None:
if xs.read('', '/local/domain/%d/device/vbd/%d/state' % (vm.xid, block_name_to_devid(frontend))) == '4': frontend = block_find_unused_frontend(vm)
raise QubesException("Frontend %s busy in VM %s, detach it first" % (frontend, vm.name)) if frontend is None:
raise QubesException("No unused frontend found")
else:
# Check if any device attached at this frontend
if xs.read('', '/local/domain/%d/device/vbd/%d/state' % (vm.xid, block_name_to_devid(frontend))) == '4':
raise QubesException("Frontend %s busy in VM %s, detach it first" % (frontend, vm.name))
# Check if this device is attached to some domain # Check if this device is attached to some domain
attached_vm = block_check_attached(backend_vm, device) attached_vm = block_check_attached(backend_vm, device)