Starting a guest with
<os>
<type arch='s390x' machine='s390-ccw-virtio-2.9'>hvm</type>
</os>
<cpu mode='host-model'/>
on an IBM z14 results in
"qemu-system-s390x: Some features requested in the CPU model are not
available in the configuration: gs"
This is because guarded storage is fenced for compat machines that did
not have guarded storage support. While this prevents future migration
abort (by not starting the guest at all), not being able to start a
"host-model" guest is very much unexpected. As it turns out, even if we
would modify libvirt to not expand the cpu model to contain "gs" for
compat machines, it cannot guarantee that a migration will succeed. For
example if the kernel changes its features (or the user has nested=1 on
one host but not on the other) the migration will fail nevertheless. So
instead of fencing "gs" for machines <= 2.9 lets allow it for all
machine types that support the CPU model. This will make "host-model"
runnable all the time, while relying on the CPU model to reject invalid
migration attempts. We also need to change the migration for guarded
storage.
Additional discussions about host-model are still pending but are out
of scope of this patch.
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Cornelia Huck <Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com>
s390-virtio-ccw.c is the sole user of s390x_new_cpu(),
so move this helper there.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1508253203-119237-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Nothing hindering us anymore from unlocking the restart code (used for
NMI).
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-29-david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This effectively enables experimental SMP support. Floating interrupts are
still a mess, so allow it but print a big warning. There also seems
to be a problem with CPU hotplug (after the main loop started).
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-27-david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[CH: changed insn-data.def as pointed out by Richard]
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
We want to use the same code base for TCG, so let's cleanly factor it
out.
The sigp mutex is currently not really needed, as everything is
protected by the iothread mutex. But this could change later, so leave
it in place and initialize it properly from common code.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-17-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
If we fail to set a proper TOD clock on the target system, this can
already result in some problematic cases. We print several warn messages
on source and target in that case.
If kvm fails to set a nonzero epoch index, then we must ultimately fail
the migration as this will result in a giant time leap backwards. This
patch lets the migration fail if we can not set the guest time on the
target.
On failure the guest will resume normally on the original host machine.
Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split failure change from epoch index change, minor fixups]
Message-Id: <20171004105751.24655-3-borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Commit e996583eb3 ("s390x/css: activate ChannelSubSys migration",
2017-07-11) was supposed to enable css migration for virtio-ccw
machines starting 2.10, but it ended up effectively enabling it
only for 2.10 as the registration of the appropriate VMStateDescription
happens in ccw_machine_2_10_instance_options which does not get
called for machines more recent than 2_10.
Let us move the corresponding chunk of code (which conditionally enables
the migration based on the value of the corresponding class property) to
ccw_init, which is called for each virtio-ccw machine instance.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reported-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20171004110109.16525-1-pasic@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Will be handy in the future.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928134609.16985-6-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Let's move it into the machine, so we trigger the IRQ after setting
ms->possible_cpus (which SCLP uses to construct the list of
online CPUs).
This also fixes a problem reported by Thomas Huth, whereby qemu can be
crashed using the none machine
qemu-s390x-softmmu -M none -monitor stdio
-> device_add qemu-s390-cpu
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928134609.16985-3-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This reverts commit d32bd032d8.
Turns out that old QEMUs always created a pci host bridge
and for many CPU models the migration from old QEMUs to new
QEMUs will fail with
qemu-system-s390x: Unknown savevm section or instance 'PCIBUS' 0
qemu-system-s390x: load of migration failed: Invalid argument
As a quick fix we will revert the commit and always create the
pci host bridge.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[fixed revert to keep the comment fixup, added a comment in the code]
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Message-Id: <20170928131831.81393-1-borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Define default CPU type in generic way in machine class_init
and let common machine code handle cpu_model parsing.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <1505998749-269631-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Now that there is only one user of cpu_s390x_create() left, make cpu
creation look like on x86.
- Perform the model/properties split and checks in s390_init_cpus()
- Parse features only once without having to remember if already parsed
- Pass only the typename to s390x_new_cpu()
- Use the typename of an existing CPU for hotplug via cpu-add
Acked-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-21-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Now that we have possible_cpus, we can get rid of the global variable
and rewrite s390_cpu_addr2state() to use it.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-20-david@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
CPU hotplug is only possible on a per core basis on s390x. So let's
add possible_cpus and wire everything up properly.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-19-david@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
device_del on a CPU will currently do nothing. Let's emit an error
telling that this is will currently not work (there is no architecture
support on s390x). Error message copied from ppc.
(qemu) device_del cpu1
device_del cpu1
CPU hot unplug not supported on this machine
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-18-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Some time ago we discussed that using "id" as property name is not the
right thing to do, as it is a reserved property for other devices and
will not work with device_add.
Switch to the term "core-id" instead, and use it as an equivalent to
"CPU address" mentioned in the PoP. There is no such thing as cpu number,
so rename env.cpu_num to env.core_id. We use "core-id" as this is the
common term to use for device_add later on (x86 and ppc).
We can get rid of cpu->id now. Keep cpu_index and env->core_id in sync.
cpu_index was already implicitly used by e.g. cpu_exists(), so keeping
both in sync seems to be the right thing to do.
cpu_index will now no longer automatically get set via
cpu_exec_realizefn(). For now, we were lucky that both implicitly stayed
in sync.
Our new cpu property "core-id" can be a static property. Range checks can
be avoided by using the correct type and the "setting after realized"
check is done implicitly.
device_add will later need the reserved "id" property. Hotplugging a CPU
on s390x will then be: "device_add host-s390-cpu,id=cpu2,core-id=2".
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-14-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Specifying more than 1 CPU (e.g. -smp 5) leads to SIGP errors (the
guest tries to bring these CPUs up but fails), because we don't support
multiple CPUs on s390x under TCG.
Let's bail out if more than 1 is specified, so we don't raise people's
hope.
Tested-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-12-david@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The only interface left, so let's properly rename it.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-5-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
It is a leftover from the days where we had still the !ccw virtio
machine. As this one is long gone, let's move everything to
s390-virtio-ccw.c.
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-4-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Let's just introduce an helper.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170818114353.13455-17-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Let's avoid any KVM stuff in s390-virtio-ccw.c. This parameter is simply
ignored.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170818114353.13455-6-david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
No need for kvm_enabled() as this function is only called from KVM and
there is no reason why it shouldn't be allowed for tcg. It is simply not
available under tcg.
Also, there is no need to check for the machine type anymore. Just like
ri_enabled(), we can directly use the stored flag, which results in
"true" for the "none" machine.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170818114353.13455-5-david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Only used in KVM and there is no reason why it shouldn't be allowed for
tcg - it is simply not available.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170818114353.13455-4-david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Don't create the s390 pci host bridge if we do not provide the zpci
facility.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
On NetBSD, where tolower() and toupper() are implemented using an
array lookup, the compiler warns if you pass a plain 'char'
to these functions:
gdbstub.c:914:13: warning: array subscript has type 'char'
This reflects the fact that toupper() and tolower() give
undefined behaviour if they are passed a value that isn't
a valid 'unsigned char' or EOF.
We have qemu_tolower() and qemu_toupper() to avoid this problem;
use them.
(The use in scsi-generic.c does not trigger the warning because
it passes a uint8_t; we switch it anyway, for consistency.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> for the s390 part.
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-id: 1500568290-7966-1-git-send-email-peter.maydell@linaro.org
Introduce guarded storage support for KVM guests on s390.
We need to enable the capability, extend machine check validity,
sigp store-additional-status-at-address, and migration.
The feature is fenced for older machine type versions.
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Add esop and esop2 features to z12 model where esop2 was originally
introduced. Disable esop and esop2 when using compatibility machine
v2.9 or earlier.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
zPCI instructions and facilities are available since IBM zEnterprise
EC12. To support z/PCI in QEMU we enable zpci, aen and ais facilities
starting with zEC12 GA1. And we always set zpci and aen bits in max cpu
model. Later they might be switched off due to applied real cpu model.
For ais bit, we only provide it in the full cpu model beginning with
zEC12 and defer its enablement in the default cpu model to a later point
in time. At the same time, disable them for 2.9 and older machines.
Because of introducing AIS facility, we could check if it's enabled to
initialize flic->ais_supported with the real value.
Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
By initializing the CPU firstly, we are able to retrieve and use the
CPU model features when initializing other subsystem or devices.
Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Turn on migration for the channel subsystem for the next machine. For
legacy machines we still have to do things the old way.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <20170711145441.33925-6-pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Currently the migration of the channel subsystem (css) is only partial
and is done by the virtio ccw proxies -- the only migratable css devices
existing at the moment.
With the current work on emulated and passthrough devices we need to
decouple the migration of the channel subsystem state from virtio ccw,
and have a separate section for it. A new section however necessarily
breaks the migration compatibility.
So let us introduce a switch at the machine class, and put it in 'off'
state for now. We will turn the switch 'on' for future machines once all
preparations are met. For compatibility machines the switch will stay
'off'.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <20170711145441.33925-3-pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We will need the machine class at machine initialization time, so the
usual way via qdev won't do. Let's cache the machine class and also use
the default values of the base machine for capability discovery.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <20170711145441.33925-2-pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Storage attributes device, like we have for storage keys.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
They are indpendent, and nowadays almost every device register things
with qdev->vmsd.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
We can replace the four remaining calls of register_savevm() by
calls to register_savevm_live(). So we can remove the function and
as we don't allocate anymore the ops pointer with g_new0()
we don't have to free it then.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The S390 virtual css support already has a mechanism to create a
virtual subchannel and provide it to the guest. However, to
pass-through subchannels to a guest, we need to introduce a new
mechanism to create the subchannel according to the real device
information. Thus we reconstruct css_create_virtual_sch to a new
css_create_sch function to handle all these cases and do allocation
and initialization of the subchannel according to the device type
and machine configuration.
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-6-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We want to support real (i.e. not virtual) channel devices
even for guests that do not support MCSS-E (where guests may
see devices from any channel subsystem image at once). As all
virtio-ccw devices are in css 0xfe (and show up in the default
css 0 for guests not activating MCSS-E), we need an option to
squash both the virtio subchannels and e.g. passed-through
subchannels from their real css (0-3, or 0 for hosts not
activating MCSS-E) into the default css. This will be
exploited in a later patch.
Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-4-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
In order to specify the LOADPARM value one may now add ",loadparm=xxx"
parameter to the "-machine s390-ccw-virtio" option.
The property setter will normalize and check the value provided much
like the way the HMC does.
The value is stored, but not used at the moment.
Initial patch from Eugene (jno) Dvurechenski.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Let's have a flic before we move on to initialize more specific
subsystems that make use of it.
Signed-off-by: Fei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Add new field to S390IPLState to store the name of the network boot
loader.
Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
The maximal number of virtqueues per device can be limited on a per
transport basis. For virtio-ccw this limit is defined by
VIRTIO_CCW_QUEUE_MAX, however the limitation used to come form the
number of adapter routes supported by flic (via notifiers).
Recently the limitation of the flic was adjusted so that it can
accommodate VIRTIO_QUEUE_MAX queues, and is in the meanwhile checked for
separately too.
Let us remove the transport specific limitation of virtio-ccw by
dropping VIRTIO_CCW_QUEUE_MAX and using VIRTIO_QUEUE_MAX instead.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Let's increase ADAPTER_ROUTES_MAX_GSI to VIRTIO_QUEUE_MAX which is the
largest demand foreseeable at the moment. Let us add a compatibility
macro for the previous machines so client code can maintain backwards
migration compatibility
To not mess up migration compatibility for virtio-ccw
VIRTIO_CCW_QUEUE_MAX is left at it's current value, and will be dropped
when virtio-ccw is converted to use the capability of the flic
introduced by this patch.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We chain our compat handler via the CCW_COMPAT macros and via the
class_init function. (e.g. ccw_machine_2_7_class_options calls
ccw_machine_2_8_class_options). As all class_init functions in that
chain call SET_MACHINE_COMPAT for their compat settings, and
SET_MACHINE_COMPAT will append there is no need to do that again.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
cpu model was merged with 2.8, it is wrong to abuse ri_allowed which
was enabled with 2.7.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
To be able to query the correct host model for the "none" machine,
let's allow runtime-instrumentation for that machine.
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Message-Id: <20160905085244.99980-21-dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We need to implement the get_dev_path method for the css bus, or
else we might end up with two different devices having the same
qdev_path.
This was noticed when adding two scsi_hd controllers: The SCSIBus
code will produce a non-unique dev_path for vmstate usage if the
parent bus does not provide the get_dev_path method.
We simply use the device's bus id, as this is unique and we won't
have any deeper hierarchy from a channel subsystem perspective
anyway.
Note that we need to disable this for older machine versions,
as this changes the migration format.
Reported-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
