execute hotplug scripts from libxl v10

execute hotplug scripts from libxl v10

[Roger Pau Monne]

Hello,

As requested I've created a remote branch that contains the latest
version of my hotplug series.

Changes are available in the git repository at:
  git://xenbits.xen.org/people/royger/xen.git hotplug.v10

Roger Pau Monne (19):
     *libxl: check backend state before setting it to "closing"
      libxl: change ao_device_remove to ao_device
     *libxl: move device model creation prototypes
     *libxl: convert libxl_domain_destroy to an async op
     *libxl: move bootloader data strucutres and prototypes
      libxl: refactor disk addition to take a helper
      libxl: convert libxl__device_disk_local_attach to an async op
     *libxl: rename vifs to nics
     *libxl: convert libxl_device_disk_add to an async op
     *libxl: convert libxl_device_nic_add to an async operation
     *libxl: add option to choose who executes hotplug scripts
     *libxl: rename _IOEMU nic type to VIF_IOEMU
      libxl: set correct nic type depending on the guest
     *libxl: use libxl__xs_path_cleanup on device_destroy
     *libxl: call hotplug scripts for disk devices from libxl
     *libxl: call hotplug scripts for nic devices from libxl
      libxl: convert libxl_device_vkb_add to an async operation
      libxl: convert libxl_device_vfb_add to an async operation
      xl: main_blockdetach don't call destroy if remove succeeds

* Acked

Re: execute hotplug scripts from libxl v10

[Ian Campbell]

With this version I get a timeout when destroying an HVM guest which
uses stub domains. The timeout seems to be waiting for the stub domain's
non-primary consoles to move to state 6. I know that console 0 of a PV
domain is special (and doesn't follow the usual state machine) but this
is console 1,2 & 3 which I thought did. Perhaps Stefano can shed some
light?

I'm pretty certain this wasn't happening with the latest version of this
series I was using, which was either v8 or v9 IIRC.

Ian.


quartz:~# xl -vvv dest dHVM-1
libxl: debug: libxl.c:1262:libxl_domain_destroy: ao 0x8069688: create: how=(nil) callback=(nil) poller=0x80696c8
libxl: debug: libxl_dm.c:1228:libxl__destroy_device_model: Device Model signaled
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806b02c wpath=/local/domain/0/backend/vbd/69/768/state token=3/0: register slotnum=3
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806b24c wpath=/local/domain/0/backend/console/69/1/state token=2/1: register slotnum=2
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806b2d4 wpath=/local/domain/0/backend/console/69/2/state token=1/2: register slotnum=1
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806b35c wpath=/local/domain/0/backend/console/69/3/state token=0/3: register slotnum=0
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806b3e4 wpath=/local/domain/0/backend/vif/69/0/state token=19/4: register slotnum=19
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806ba34 wpath=/local/domain/0/backend/vbd/68/768/state token=18/5: register slotnum=18
libxl: debug: libxl_event.c:512:libxl__ev_xswatch_register: watch w=0x806bbcc wpath=/local/domain/0/backend/vif/68/0/state token=17/6: register slotnum=17
libxl: debug: libxl.c:1271:libxl_domain_destroy: ao 0x8069688: inprogress: poller=0x80696c8, flags=i
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b02c wpath=/local/domain/0/backend/vbd/69/768/state token=3/0: event epath=/local/domain/0/backend/vbd/69/768/state
libxl: debug: libxl_event.c:596:devstate_watch_callback: backend /local/domain/0/backend/vbd/69/768/state wanted state 6 ok
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806b02c wpath=/local/domain/0/backend/vbd/69/768/state token=3/0: deregister slotnum=3
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806b02c: deregister unregistered
libxl: debug: libxl_device.c:901:device_hotplug: calling hotplug script: /etc/xen/scripts/block remove
libxl: debug: libxl_event.c:426:watchfd_callback: watch epath=/local/domain/0/backend/vbd/69/768/state token=3/0: empty slot
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b24c wpath=/local/domain/0/backend/console/69/1/state token=2/1: event epath=/local/domain/0/backend/console/69/1/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/console/69/1/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b2d4 wpath=/local/domain/0/backend/console/69/2/state token=1/2: event epath=/local/domain/0/backend/console/69/2/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/console/69/2/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b35c wpath=/local/domain/0/backend/console/69/3/state token=0/3: event epath=/local/domain/0/backend/console/69/3/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/console/69/3/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b3e4 wpath=/local/domain/0/backend/vif/69/0/state token=19/4: event epath=/local/domain/0/backend/vif/69/0/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/vif/69/0/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806ba34 wpath=/local/domain/0/backend/vbd/68/768/state token=18/5: event epath=/local/domain/0/backend/vbd/68/768/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/vbd/68/768/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806bbcc wpath=/local/domain/0/backend/vif/68/0/state token=17/6: event epath=/local/domain/0/backend/vif/68/0/state
libxl: debug: libxl_event.c:600:devstate_watch_callback: backend /local/domain/0/backend/vif/68/0/state wanted state 6 still waiting state 5
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806b3e4 wpath=/local/domain/0/backend/vif/69/0/state token=19/4: event epath=/local/domain/0/backend/vif/69/0/state
libxl: debug: libxl_event.c:596:devstate_watch_callback: backend /local/domain/0/backend/vif/69/0/state wanted state 6 ok
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806b3e4 wpath=/local/domain/0/backend/vif/69/0/state token=19/4: deregister slotnum=19
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806b3e4: deregister unregistered
libxl: debug: libxl_device.c:901:device_hotplug: calling hotplug script: /etc/xen/scripts/vif-bridge offline
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806ba34 wpath=/local/domain/0/backend/vbd/68/768/state token=18/5: event epath=/local/domain/0/backend/vbd/68/768/state
libxl: debug: libxl_event.c:596:devstate_watch_callback: backend /local/domain/0/backend/vbd/68/768/state wanted state 6 ok
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806ba34 wpath=/local/domain/0/backend/vbd/68/768/state token=18/5: deregister slotnum=18
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806ba34: deregister unregistered
libxl: debug: libxl_device.c:901:device_hotplug: calling hotplug script: /etc/xen/scripts/block remove
libxl: debug: libxl_event.c:457:watchfd_callback: watch w=0x806bbcc wpath=/local/domain/0/backend/vif/68/0/state token=17/6: event epath=/local/domain/0/backend/vif/68/0/state
libxl: debug: libxl_event.c:596:devstate_watch_callback: backend /local/domain/0/backend/vif/68/0/state wanted state 6 ok
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806bbcc wpath=/local/domain/0/backend/vif/68/0/state token=17/6: deregister slotnum=17
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806bbcc: deregister unregistered
libxl: debug: libxl_device.c:901:device_hotplug: calling hotplug script: /etc/xen/scripts/vif-bridge offline
libxl: debug: libxl_xshelp.c:222:libxl__xs_path_cleanup: unable to remove path /local/domain/69/device/vif/0: No such file or directory
libxl: debug: libxl_xshelp.c:222:libxl__xs_path_cleanup: unable to remove path /local/domain/68/device/vif/0: No such file or directory
libxl: debug: libxl_event.c:614:devstate_timeout: backend /local/domain/0/backend/console/69/1/state wanted state 6  timed out
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806b24c wpath=/local/domain/0/backend/console/69/1/state token=2/1: deregister slotnum=2
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806b24c: deregister unregistered
libxl: error: libxl_device.c:843:device_backend_callback: unable to disconnect device with path /local/domain/0/backend/console/69/1
libxl: debug: libxl_xshelp.c:222:libxl__xs_path_cleanup: unable to remove path /local/domain/69/device/console/1: No such file or directory
libxl: debug: libxl_event.c:614:devstate_timeout: backend /local/domain/0/backend/console/69/2/state wanted state 6  timed out
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806b2d4 wpath=/local/domain/0/backend/console/69/2/state token=1/2: deregister slotnum=1
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806b2d4: deregister unregistered
libxl: error: libxl_device.c:843:device_backend_callback: unable to disconnect device with path /local/domain/0/backend/console/69/2
libxl: debug: libxl_xshelp.c:222:libxl__xs_path_cleanup: unable to remove path /local/domain/69/device/console/2: No such file or directory
libxl: debug: libxl_event.c:614:devstate_timeout: backend /local/domain/0/backend/console/69/3/state wanted state 6  timed out
libxl: debug: libxl_event.c:549:libxl__ev_xswatch_deregister: watch w=0x806b35c wpath=/local/domain/0/backend/console/69/3/state token=0/3: deregister slotnum=0
libxl: debug: libxl_event.c:561:libxl__ev_xswatch_deregister: watch w=0x806b35c: deregister unregistered
libxl: error: libxl_device.c:843:device_backend_callback: unable to disconnect device with path /local/domain/0/backend/console/69/3
libxl: debug: libxl_xshelp.c:222:libxl__xs_path_cleanup: unable to remove path /local/domain/69/device/console/3: No such file or directory
libxl: error: libxl.c:1462:devices_destroy_cb: libxl__devices_destroy failed for 69
libxl: debug: libxl_event.c:1434:libxl__ao_complete: ao 0x8069688: complete, rc=0
libxl: debug: libxl_event.c:1406:libxl__ao__destroy: ao 0x8069688: destroy
xc: debug: hypercall buffer: total allocations:67 total releases:67
xc: debug: hypercall buffer: current allocations:0 maximum allocations:2
xc: debug: hypercall buffer: cache current size:2
xc: debug: hypercall buffer: cache hits:64 misses:2 toobig:1

Re: execute hotplug scripts from libxl v10

[Stefano Stabellini]

On Fri, 20 Jul 2012, Ian Campbell wrote:
> With this version I get a timeout when destroying an HVM guest which
> uses stub domains. The timeout seems to be waiting for the stub domain's
> non-primary consoles to move to state 6. I know that console 0 of a PV
> domain is special (and doesn't follow the usual state machine) but this
> is console 1,2 & 3 which I thought did. Perhaps Stefano can shed some
> light?
> 
> I'm pretty certain this wasn't happening with the latest version of this
> series I was using, which was either v8 or v9 IIRC.

Reading the state machine handler in QEMU
(hw/xen_backend.c:xen_be_check_state), it looks like that QEMU is going
to set the backend state to Closing or Closed in response to the
frontend state going to Closing or Closed.
What is libxl doing exactly?