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>
Bug fixes:
* memory encryption: Disable mem merge
(Dr. David Alan Gilbert)
Features:
* New EPYC CPU definitions (Babu Moger)
* Denventon-v2 CPU model (Tao Xu)
* New 'note' field on versioned CPU models (Tao Xu)
Cleanups:
* x86 CPU topology cleanups (Babu Moger)
* cpu: Use DeviceClass reset instead of a special CPUClass reset
(Peter Maydell)
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Merge remote-tracking branch 'remotes/ehabkost/tags/x86-and-machine-pull-request' into staging
x86 and machine queue for 5.0 soft freeze
Bug fixes:
* memory encryption: Disable mem merge
(Dr. David Alan Gilbert)
Features:
* New EPYC CPU definitions (Babu Moger)
* Denventon-v2 CPU model (Tao Xu)
* New 'note' field on versioned CPU models (Tao Xu)
Cleanups:
* x86 CPU topology cleanups (Babu Moger)
* cpu: Use DeviceClass reset instead of a special CPUClass reset
(Peter Maydell)
# gpg: Signature made Wed 18 Mar 2020 01:16:43 GMT
# gpg: using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg: issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF D1AA 2807 936F 984D C5A6
* remotes/ehabkost/tags/x86-and-machine-pull-request:
hw/i386: Rename apicid_from_topo_ids to x86_apicid_from_topo_ids
hw/i386: Update structures to save the number of nodes per package
hw/i386: Remove unnecessary initialization in x86_cpu_new
machine: Add SMP Sockets in CpuTopology
hw/i386: Consolidate topology functions
hw/i386: Introduce X86CPUTopoInfo to contain topology info
cpu: Use DeviceClass reset instead of a special CPUClass reset
machine/memory encryption: Disable mem merge
hw/i386: Rename X86CPUTopoInfo structure to X86CPUTopoIDs
i386: Add 2nd Generation AMD EPYC processors
i386: Add missing cpu feature bits in EPYC model
target/i386: Add new property note to versioned CPU models
target/i386: Add Denverton-v2 (no MPX) CPU model
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The CPUClass has a 'reset' method. This is a legacy from when
TYPE_CPU used not to inherit from TYPE_DEVICE. We don't need it any
more, as we can simply use the TYPE_DEVICE reset. The 'cpu_reset()'
function is kept as the API which most places use to reset a CPU; it
is now a wrapper which calls device_cold_reset() and then the
tracepoint function.
This change should not cause CPU objects to be reset more often
than they are at the moment, because:
* nobody is directly calling device_cold_reset() or
qdev_reset_all() on CPU objects
* no CPU object is on a qbus, so they will not be reset either
by somebody calling qbus_reset_all()/bus_cold_reset(), or
by the main "reset sysbus and everything in the qbus tree"
reset that most devices are reset by
Note that this does not change the need for each machine or whatever
to use qemu_register_reset() to arrange to call cpu_reset() -- that
is necessary because CPU objects are not on any qbus, so they don't
get reset when the qbus tree rooted at the sysbus bus is reset, and
this isn't being changed here.
All the changes to the files under target/ were made using the
included Coccinelle script, except:
(1) the deletion of the now-inaccurate and not terribly useful
"CPUClass::reset" comments was done with a perl one-liner afterwards:
perl -n -i -e '/ CPUClass::reset/ or print' target/*/*.c
(2) this bit of the s390 change was done by hand, because the
Coccinelle script is not sophisticated enough to handle the
parent_reset call being inside another function:
| @@ -96,8 +96,9 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
| S390CPU *cpu = S390_CPU(s);
| S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
| CPUS390XState *env = &cpu->env;
|+ DeviceState *dev = DEVICE(s);
|
|- scc->parent_reset(s);
|+ scc->parent_reset(dev);
| cpu->env.sigp_order = 0;
| s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200303100511.5498-1-peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Instead of passing a pointer to memory now just extend the GByteArray
to all the read register helpers. They can then safely append their
data through the normal way. We don't bother with this abstraction for
write registers as we have already ensured the buffer being copied
from is the correct size.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Message-Id: <20200316172155.971-15-alex.bennee@linaro.org>
Similarly to what we already do with qdev, use a helper to overload the
reset QOM methods of the parent in children classes, for clarity.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <157650847239.354886.2782881118916307978.stgit@bahia.lan>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
With the merge of notdirty handling into store_helper,
the last user of cpu->mem_io_vaddr was removed.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190709152053.16670-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Rebased onto merge commit 95a9457fd44; missed instances of qom/cpu.h
in comments replaced]
