Re: [PATCH 1/4] [kvm-autotest] cgroup-kvm: add_*_drive / rm_drive

["Lukáš Doktor" <ldoktor@redhat.com>]

I thought about that. But pci_add is not much stable and it's not 
supported in QMP (as far as I read) with a note that this way is buggy 
and should be rewritten completely. So I placed it here to let it 
develop and then I can move it into utils.

Regards,
Lukáš

Dne 10.10.2011 12:26, Jiri Zupka napsal(a):
> This is useful function. This function can be in kvm utils.
>
> ----- Original Message -----
>> * functions for adding and removal of drive to vm using host-file or
>>     host-scsi_debug device.
>>
>> Signed-off-by: Lukas Doktor<ldoktor@redhat.com>
>> ---
>>   client/tests/kvm/tests/cgroup.py |  125
>>   ++++++++++++++++++++++++++++++++-----
>>   1 files changed, 108 insertions(+), 17 deletions(-)
>>
>> diff --git a/client/tests/kvm/tests/cgroup.py
>> b/client/tests/kvm/tests/cgroup.py
>> index b9a10ea..d6418b5 100644
>> --- a/client/tests/kvm/tests/cgroup.py
>> +++ b/client/tests/kvm/tests/cgroup.py
>> @@ -17,6 +17,108 @@ def run_cgroup(test, params, env):
>>       vms = None
>>       tests = None
>>
>> +    # Func
>> +    def get_device_driver():
>> +        """
>> +        Discovers the used block device driver {ide, scsi,
>> virtio_blk}
>> +        @return: Used block device driver {ide, scsi, virtio}
>> +        """
>> +        if test.tagged_testname.count('virtio_blk'):
>> +            return "virtio"
>> +        elif test.tagged_testname.count('scsi'):
>> +            return "scsi"
>> +        else:
>> +            return "ide"
>> +
>> +
>> +    def add_file_drive(vm, driver=get_device_driver(),
>> host_file=None):
>> +        """
>> +        Hot-add a drive based on file to a vm
>> +        @param vm: Desired VM
>> +        @param driver: which driver should be used (default: same as
>> in test)
>> +        @param host_file: Which file on host is the image (default:
>> create new)
>> +        @return: Tupple(ret_file, device)
>> +                    ret_file: created file handler (None if not
>> created)
>> +                    device: PCI id of the virtual disk
>> +        """
>> +        if not host_file:
>> +            host_file =
>> tempfile.NamedTemporaryFile(prefix="cgroup-disk-",
>> +                                               suffix=".iso")
>> +            utils.system("dd if=/dev/zero of=%s bs=1M count=8
>> &>/dev/null"
>> +                         % (host_file.name))
>> +            ret_file = host_file
>> +        else:
>> +            ret_file = None
>> +
>> +        out = vm.monitor.cmd("pci_add auto storage
>> file=%s,if=%s,snapshot=off,"
>> +                             "cache=off" % (host_file.name, driver))
>> +        dev = re.search(r'OK domain (\d+), bus (\d+), slot (\d+),
>> function \d+',
>> +                        out)
>> +        if not dev:
>> +            raise error.TestFail("Can't add device(%s, %s, %s): %s"
>> % (vm,
>> +                                                host_file.name,
>> driver, out))
>> +        device = "%s:%s:%s" % dev.groups()
>> +        return (ret_file, device)
>> +
>> +
>> +    def add_scsi_drive(vm, driver=get_device_driver(),
>> host_file=None):
>> +        """
>> +        Hot-add a drive based on scsi_debug device to a vm
>> +        @param vm: Desired VM
>> +        @param driver: which driver should be used (default: same as
>> in test)
>> +        @param host_file: Which dev on host is the image (default:
>> create new)
>> +        @return: Tupple(ret_file, device)
>> +                    ret_file: string of the created dev (None if not
>> created)
>> +                    device: PCI id of the virtual disk
>> +        """
>> +        if not host_file:
>> +            if utils.system_output("lsmod | grep scsi_debug -c") ==
>> 0:
>> +                utils.system("modprobe scsi_debug dev_size_mb=8
>> add_host=0")
>> +            utils.system("echo 1>
>> /sys/bus/pseudo/drivers/scsi_debug/add_host")
>> +            host_file = utils.system_output("ls /dev/sd* | tail -n
>> 1")
>> +            # Enable idling in scsi_debug drive
>> +            utils.system("echo 1>  /sys/block/%s/queue/rotational" %
>> host_file)
>> +            ret_file = host_file
>> +        else:
>> +            # Don't remove this device during cleanup
>> +            # Reenable idling in scsi_debug drive (in case it's not)
>> +            utils.system("echo 1>  /sys/block/%s/queue/rotational" %
>> host_file)
>> +            ret_file = None
>> +
>> +        out = vm.monitor.cmd("pci_add auto storage
>> file=%s,if=%s,snapshot=off,"
>> +                             "cache=off" % (host_file, driver))
>> +        dev = re.search(r'OK domain (\d+), bus (\d+), slot (\d+),
>> function \d+',
>> +                        out)
>> +        if not dev:
>> +            raise error.TestFail("Can't add device(%s, %s, %s): %s"
>> % (vm,
>> +                                                        host_file,
>> driver, out))
>> +        device = "%s:%s:%s" % dev.groups()
>> +        return (ret_file, device)
>> +
>> +
>> +    def rm_drive(vm, host_file, device):
>> +        """
>> +        Remove drive from vm and device on disk
>> +        ! beware to remove scsi devices in reverse order !
>> +        """
>> +        vm.monitor.cmd("pci_del %s" % device)
>> +
>> +        if isinstance(host_file, file):     # file
>> +            host_file.close()
>> +        elif isinstance(host_file, str):    # scsi device
>> +            utils.system("echo -1>
>> /sys/bus/pseudo/drivers/scsi_debug/add_host")
>> +        else:        # custom file, do nothing
>> +            pass
>> +
>> +    def get_all_pids(ppid):
>> +        """
>> +        Get all PIDs of children/threads of parent ppid
>> +        param ppid: parent PID
>> +        return: list of PIDs of all children/threads of ppid
>> +        """
>> +        return (utils.system_output("ps -L --ppid=%d -o lwp" % ppid)
>> +
>>                                                         .split('\n')[1:])
>> +
>>       # Tests
>>       class _TestBlkioBandwidth:
>>           """
>> @@ -46,9 +148,8 @@ def run_cgroup(test, params, env):
>>               """
>>               err = ""
>>               try:
>> -                for i in range (2):
>> -                    vms[i].monitor.cmd("pci_del %s" %
>> self.devices[i])
>> -                    self.files[i].close()
>> +                for i in range(1, -1, -1):
>> +                    rm_drive(vms[i], self.files[i], self.devices[i])
>>               except Exception, failure_detail:
>>                   err += "\nCan't remove PCI drive: %s" %
>>                   failure_detail
>>               try:
>> @@ -89,8 +190,7 @@ def run_cgroup(test, params, env):
>>                   if blkio.set_cgroup(self.vms[i].get_shell_pid(),
>>                   pwd[i]):
>>                       raise error.TestError("Could not set cgroup")
>>                   # Move all existing threads into cgroup
>> -                for tmp in utils.system_output("ps -L --ppid=%d -o
>> lwp"
>> -                                %
>> self.vms[i].get_shell_pid()).split('\n')[1:]:
>> +                for tmp in
>> get_all_pids(self.vms[i].get_shell_pid()):
>>                       if blkio.set_cgroup(int(tmp), pwd[i]):
>>                           raise error.TestError("Could not set
>>                           cgroup")
>>               if self.blkio.set_property("blkio.weight", 100, pwd[0]):
>> @@ -101,18 +201,9 @@ def run_cgroup(test, params, env):
>>               # Add dummy drives
>>               # TODO: implement also using QMP.
>>               for i in range(2):
>> -                self.files.append(tempfile.NamedTemporaryFile(
>> -                                        prefix="cgroup-disk-",
>> -                                        suffix=".iso"))
>> -                utils.system("dd if=/dev/zero of=%s bs=1M count=10
>> &>/dev/null"
>> -                             % (self.files[i].name))
>> -                out = vms[i].monitor.cmd("pci_add auto storage
>> file=%s,"
>> -                                "if=virtio,snapshot=off,cache=off"
>> -                                % (self.files[i].name))
>> -                out = re.search(r'OK domain (\d+), bus (\d+), slot
>> (\d+), '
>> -                                 'function \d+', out).groups()
>> -                self.devices.append("%s:%s:%s" % out)
>> -
>> +                (host_file, device) = add_file_drive(vms[i],
>> "virtio")
>> +                self.files.append(host_file)
>> +                self.devices.append(device)
>>
>>           def run(self):
>>               """
>> --
>> 1.7.6.2
>>
>> --
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