Devices may have component devices and buses.
Device realization may fail. Realization is recursive: a device's
realize() method realizes its components, and device_set_realized()
realizes its buses (which should in turn realize the devices on that
bus, except bus_set_realized() doesn't implement that, yet).
When realization of a component or bus fails, we need to roll back:
unrealize everything we realized so far. If any of these unrealizes
failed, the device would be left in an inconsistent state. Must not
happen.
device_set_realized() lets it happen: it ignores errors in the roll
back code starting at label child_realize_fail.
Since realization is recursive, unrealization must be recursive, too.
But how could a partly failed unrealize be rolled back? We'd have to
re-realize, which can fail. This design is fundamentally broken.
device_set_realized() does not roll back at all. Instead, it keeps
unrealizing, ignoring further errors.
It can screw up even for a device with no buses: if the lone
dc->unrealize() fails, it still unregisters vmstate, and calls
listeners' unrealize() callback.
bus_set_realized() does not roll back either. Instead, it stops
unrealizing.
Fortunately, no unrealize method can fail, as we'll see below.
To fix the design error, drop parameter @errp from all the unrealize
methods.
Any unrealize method that uses @errp now needs an update. This leads
us to unrealize() methods that can fail. Merely passing it to another
unrealize method cannot cause failure, though. Here are the ones that
do other things with @errp:
* virtio_serial_device_unrealize()
Fails when qbus_set_hotplug_handler() fails, but still does all the
other work. On failure, the device would stay realized with its
resources completely gone. Oops. Can't happen, because
qbus_set_hotplug_handler() can't actually fail here. Pass
&error_abort to qbus_set_hotplug_handler() instead.
* hw/ppc/spapr_drc.c's unrealize()
Fails when object_property_del() fails, but all the other work is
already done. On failure, the device would stay realized with its
vmstate registration gone. Oops. Can't happen, because
object_property_del() can't actually fail here. Pass &error_abort
to object_property_del() instead.
* spapr_phb_unrealize()
Fails and bails out when remove_drcs() fails, but other work is
already done. On failure, the device would stay realized with some
of its resources gone. Oops. remove_drcs() fails only when
chassis_from_bus()'s object_property_get_uint() fails, and it can't
here. Pass &error_abort to remove_drcs() instead.
Therefore, no unrealize method can fail before this patch.
device_set_realized()'s recursive unrealization via bus uses
object_property_set_bool(). Can't drop @errp there, so pass
&error_abort.
We similarly unrealize with object_property_set_bool() elsewhere,
always ignoring errors. Pass &error_abort instead.
Several unrealize methods no longer handle errors from other unrealize
methods: virtio_9p_device_unrealize(),
virtio_input_device_unrealize(), scsi_qdev_unrealize(), ...
Much of the deleted error handling looks wrong anyway.
One unrealize methods no longer ignore such errors:
usb_ehci_pci_exit().
Several realize methods no longer ignore errors when rolling back:
v9fs_device_realize_common(), pci_qdev_unrealize(),
spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(),
virtio_device_realize().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-17-armbru@redhat.com>
In my "build everything" tree, changing migration/vmstate.h triggers a
recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
hw/hw.h supposedly includes it for convenience. Several other headers
include it just to get VMStateDescription. The previous commit made
that unnecessary.
Include migration/vmstate.h only where it's still needed. Touching it
now recompiles only some 1600 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-16-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing sysemu/reset.h triggers a
recompile of some 2600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
The main culprit is hw/hw.h, which supposedly includes it for
convenience.
Include sysemu/reset.h only where it's needed. Touching it now
recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-9-armbru@redhat.com>
We already have enum that enumerates all the actions that a
watchdog can take when hitting its timeout: WatchdogAction.
Use that instead of inventing our own.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <ce2790634e6a1b3b6cf90462399d17bad83f0290.1504771369.git.mprivozn@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
QEMU currently aborts when the user tries to hot-unplug a diag288
device:
$ qemu-system-s390x -nographic -nodefaults -S -monitor stdio
QEMU 2.9.92 monitor - type 'help' for more information
(qemu) device_add diag288,id=x
(qemu) device_del x
**
ERROR:qemu/qdev-monitor.c:872:qdev_unplug: assertion failed: (hotplug_ctrl)
Aborted (core dumped)
The device is not designed as hot-pluggable (it should only be used
via the "-watchdog" parameter), so let's simply remove the possibility
to hotplug it to prevent that users can run into this ugly situation.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1502892528-22618-1-git-send-email-thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This patch replaces get_ticks_per_sec() calls with the macro
NANOSECONDS_PER_SECOND. Also, as there are no callers, get_ticks_per_sec()
is then removed. This replacement improves the readability and
understandability of code.
For example,
timer_mod(fdctrl->result_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (get_ticks_per_sec() / 50));
NANOSECONDS_PER_SECOND makes it obvious that qemu_clock_get_ns
matches the unit of the expression on the right side of the plus.
Signed-off-by: Rutuja Shah <rutu.shah.26@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When configured to inject an NMI, watchdog_perform_action() may cause
the BQL to be temporarily relinquished (inject_nmi() → ... →
s390_nmi() → s390_cpu_restart() → run_on_cpu()). When the guest issues
diag 288 again in response to the NMI, the diag 288 operation will
race against wdt_diag288_reset(). Depending on scheduler behaviour,
wdt_diag288_reset() may be run after the guest issued a diag 288
Init. As a result, we will cancel the timer the guest just set up. The
effect observed by the guest is that a second expiry does not trigger
the watchdog action and diag 288 Change operations fail.
Fix this by resetting the timer _before_ invoking the action.
Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1453832250-766-8-git-send-email-peter.maydell@linaro.org
If the watchdog expires and the guest is not notified (NONE, DEBUG, PAUSE),
we must not reset the watchdog device, otherwise watchdog_ping() and
watchdog_stop() will fail when triggered by the guest. This reset behavior
matches to the z/VM behavior when a custom command is to be executed
on expiry.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Bo Tu <tubo@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The diag288 watchdog is no sysbus device, therefore it doesn't get
triggered on resets automatically using dc->reset.
Let's register the reset handler manually, so we get correctly notified
again when a system reset was requested. Also reset the watchdog on
subsystem resets that don't trigger a full system reset.
Signed-off-by: Xu Wang <gesaint@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Add vmstate structure to keep state and data during migration.
Signed-off-by: Xu Wang <gesaint@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch introduces a new diag288 watchdog device that will, just like
other watchdogs, monitor a guest and take corresponding actions when it
detects that the guest is not responding.
diag288 is s390x specific. The wiring to s390x KVM will be done in
separate patches.
Signed-off-by: Xu Wang <gesaint@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split out qemu-option.hx base changes]
