Now that the error path of spapr_cpu_core_realize() is just to call
idempotent spapr_cpu_core_unrealize() for rollback, no need to create
and realize the vCPUs in two separate loops.
Merge them and do them same in spapr_cpu_core_unrealize() for symmetry.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160279673321.1808373.2248221100790367912.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_cpu_core_realize() has a rollback path which partially duplicates
the code of spapr_cpu_core_unrealize().
Let's make spapr_cpu_core_unrealize() idempotent and call it instead. This
requires to:
- move the registration and unregistration of the reset handler around
but it is harmless,
- allocate the array of vCPUs with g_new0() to be able to filter out
unused slots,
- make sure to only unrealize vCPUs that have been already realized.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160279672626.1808373.14142129300586424514.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The 'sc' argument is unused. Drop it.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160279671929.1808373.10333672533575251075.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since we introduced CPU hot-unplug in sPAPR, we don't unrealize the
vCPU objects explicitly. Instead, we let QOM handle that for us under
object_property_del_all() when the CPU core object is finalized. The
only thing we do is calling cpu_remove_sync() to tear the vCPU thread
down.
This happens to work but it is ugly because:
- we call qdev_realize() but the corresponding qdev_unrealize() is
buried deep in the QOM code
- we call cpu_remove_sync() to undo qemu_init_vcpu() called by
ppc_cpu_realize() in target/ppc/translate_init.c.inc
- the CPU init and teardown paths aren't really symmetrical
The latter didn't bite us so far but a future patch that greatly
simplifies the CPU core realize path needs it to avoid a crash
in QOM.
For all these reasons, have ppc_cpu_unrealize() to undo the changes
of ppc_cpu_realize() by calling cpu_remove_sync() at the right place,
and have the sPAPR CPU core code to call qdev_unrealize().
This requires to add a missing stub because translate_init.c.inc is
also compiled for user mode.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160279671236.1808373.14732005038172874990.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When a CPU core is being removed, the machine specific data of each
CPU thread object is leaked.
Fix this by calling the dedicated helper we have for that instead of
simply unparenting the CPU object. Call it from a separate loop in
spapr_cpu_core_unrealize() for symmetry with spapr_cpu_core_realize().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160279670540.1808373.17319746576919615623.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", add a bool return value to
spapr_realize_vcpu() and use it in spapr_cpu_core_realize()
in order to get rid of the error propagation overhead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-12-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As recommended in "qapi/error.h", return true on success and false on
failure. This allows to reduce error propagation overhead in the callers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200914123505.612812-11-groug@kaod.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
PowerPC sPAPR CPUs start in the halted state, and spapr_reset_vcpu()
attempts to implement this by setting CPUState::halted to 1. But that's too
late for the case of hotplugged CPUs in a machine configure with 2 or more
threads per core.
By then, other parts of QEMU have already caused the vCPU to run in an
unitialized state a couple of times. For example, ppc_cpu_reset() calls
ppc_tlb_invalidate_all(), which ends up calling async_run_on_cpu(). This
kicks the new vCPU while it has CPUState::halted = 0, causing QEMU to issue
a KVM_RUN ioctl on the new vCPU before the guest is able to make the
start-cpu RTAS call to initialize its register state.
This problem doesn't seem to cause visible issues for regular guests, but
on a secure guest running under the Ultravisor it does. The Ultravisor
relies on being able to snoop on the start-cpu RTAS call to map vCPUs to
guests, and this issue causes it to see a stray vCPU that doesn't belong to
any guest.
Fix by setting the start-powered-off CPUState property in
spapr_create_vcpu(), which makes cpu_common_reset() initialize
CPUState::halted to 1 at an earlier moment.
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Message-Id: <20200826055535.951207-4-bauerman@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away. The previous two commits did that for sufficiently simple
cases with Coccinelle. Do it for several more manually.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-37-armbru@redhat.com>
Convert
foo(..., &err);
if (err) {
...
}
to
if (!foo(..., &err)) {
...
}
for qdev_realize(), qdev_realize_and_unref(), qbus_realize() and their
wrappers isa_realize_and_unref(), pci_realize_and_unref(),
sysbus_realize(), sysbus_realize_and_unref(), usb_realize_and_unref().
Coccinelle script:
@@
identifier fun = {
isa_realize_and_unref, pci_realize_and_unref, qbus_realize,
qdev_realize, qdev_realize_and_unref, sysbus_realize,
sysbus_realize_and_unref, usb_realize_and_unref
};
expression list args, args2;
typedef Error;
Error *err;
@@
- fun(args, &err, args2);
- if (err)
+ if (!fun(args, &err, args2))
{
...
}
Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
message "no position information". Nothing to convert there; skipped.
Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Converted manually.
A few line breaks tidied up manually.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-5-armbru@redhat.com>
All remaining conversions to qdev_realize() are for bus-less devices.
Coccinelle script:
// only correct for bus-less @dev!
@@
expression errp;
expression dev;
@@
- qdev_init_nofail(dev);
+ qdev_realize(dev, NULL, &error_fatal);
@ depends on !(file in "hw/core/qdev.c") && !(file in "hw/core/bus.c")@
expression errp;
expression dev;
symbol true;
@@
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(DEVICE(dev), NULL, errp);
@ depends on !(file in "hw/core/qdev.c") && !(file in "hw/core/bus.c")@
expression errp;
expression dev;
symbol true;
@@
- object_property_set_bool(dev, true, "realized", errp);
+ qdev_realize(DEVICE(dev), NULL, errp);
Note that Coccinelle chokes on ARMSSE typedef vs. macro in
hw/arm/armsse.c. Worked around by temporarily renaming the macro for
the spatch run.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-57-armbru@redhat.com>
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>
The only way object_property_add() can fail is when a property with
the same name already exists. Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.
Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent. Parentage is
also under program control, so this is a programming error, too.
We have a bit over 500 callers. Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.
The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.
Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call. ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.
When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.
Drop parameter @errp and assert the preconditions instead.
There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification". Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]
At the moment "pseries" starts in SLOF which only expects the FDT blob
pointer in r3. As we are going to introduce a OpenFirmware support in
QEMU, we will be booting OF clients directly and these expect a stack
pointer in r1, Linux looks at r3/r4 for the initramdisk location
(although vmlinux can find this from the device tree but zImage from
distro kernels cannot).
This extends spapr_cpu_set_entry_state() to take more registers. This
should cause no behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20200310050733.29805-2-aik@ozlabs.ru>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
For the "pseries" machine, we use "virtual hypervisor" mode where we
only model the CPU in non-hypervisor privileged mode. This means that
we need guest physical addresses within the modelled cpu to be treated
as absolute physical addresses.
We used to do that by clearing LPCR[VPM0] and setting LPCR[RMLS] to a high
limit so that the old offset based translation for guest mode applied,
which does what we need. However, POWER9 has removed support for that
translation mode, which meant we had some ugly hacks to keep it working.
We now explicitly handle this sort of translation for virtual hypervisor
mode, so the hacks aren't necessary. We don't need to set VPM0 and RMLS
from the machine type code - they're now ignored in vhyp mode. On the cpu
side we don't need to allow LPCR[RMLS] to be set on POWER9 in vhyp mode -
that was only there to allow the hack on the machine side.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
SpaprInterruptControllerClass and PnvChipClass have an intc_create() method
that calls the appropriate routine, ie. icp_create() or xive_tctx_create(),
to establish the link between the VCPU and the presenter component of the
interrupt controller during realize.
There aren't any symmetrical call to be called when the VCPU gets unrealized
though. It is assumed that object_unparent() is the only thing to do.
This is questionable because the parenting logic around the CPU and
presenter objects is really an implementation detail of the interrupt
controller. It shouldn't be open-coded in the machine code.
Fix this by adding an intc_destroy() method that undoes what was done in
intc_create(). Also NULLify the presenter pointers to avoid having
stale pointers around. This will allow to reliably check if a vCPU has
a valid presenter.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <157192724208.3146912.7254684777515287626.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
On the sPAPR machine and PowerNV machine, the interrupt presenters are
created by a machine handler at the core level and are reset
independently. This is not consistent and it raises issues when it
comes to handle hot-plugged CPUs. In that case, the presenters are not
reset. This is less of an issue in XICS, although a zero MFFR could
be a concern, but in XIVE, the OS CAM line is not set and this breaks
the presenting algorithm. The current code has workarounds which need
a global cleanup.
Extend the sPAPR IRQ backend and the PowerNV Chip class with a new
cpu_intc_reset() handler called by the CPU reset handler and remove
the XiveTCTX reset handler which is now redundant.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191022163812.330-6-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since vCPUs aren't plugged into a bus, we manually register a reset
handler for each vCPU. We also call this handler at realize time
to ensure hot plugged vCPUs are reset before being exposed to the
guest. This results in vCPUs being reset twice at machine reset.
It doesn't break anything but it is slightly suboptimal and above
all confusing.
The hotplug path in device_set_realized() already knows how to reset
a hotplugged device if the device reset handler is present. Implement
one for sPAPR CPU cores that resets all vCPUs under a core.
While here rename spapr_cpu_reset() to spapr_reset_vcpu() for
consistency with spapr_realize_vcpu() and spapr_unrealize_vcpu().
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[clg: add documentation on the reset helper usage ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191022163812.330-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This change prepares ground for future changes which will reset the
interrupt presenter in the reset handler of the sPAPR and PowerNV
cores.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191022163812.330-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This method essentially represents code which belongs to the interrupt
controller, but needs to be called on all possible intcs, rather than
just the currently active one. The "dual" version therefore calls
into the xics and xive versions confusingly.
Handle this more directly, by making it instead a method on the intc
backend, and always calling it on every backend that exists.
While we're there, streamline the error reporting a bit.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
A recent change in spapr_machine_reset() showed that resetting the compat
mode in spapr_machine_reset() for the boot vCPU and in spapr_cpu_reset()
for all other vCPUs was fragile. The fix was thus to reset the compat mode
for all vCPUs in spapr_machine_reset(), but we still have to propagate
it to hot-plugged CPUs. This is still performed from spapr_cpu_reset(),
hence resulting in ppc_set_compat() being called twice for every vCPU at
machine reset. Apart from wasting cycles, which isn't really an issue
during machine reset, this seems to indicate that spapr_cpu_reset() isn't
the best place to set the compat mode.
A natural candidate for CPU-hotplug specific code is spapr_core_plug().
Also, it sits in the same file as spapr_machine_reset() : this makes
it easier for someone who wants to know when the compat PVR is set.
Call ppc_set_compat() from there. This doesn't need to be done for
initial vCPUs since the compat PVR is 0 and spapr_machine_reset() sets
the appropriate value later. No need to do this on manually added vCPUS
on the destination QEMU during migration since the compat PVR is
part of the migrated vCPU state. Both conditions can be checked with
spapr_drc_hotplugged().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156701285312.499757.7807417667750711711.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If we a migrate P8 machine to a P9 machine, the migration fails on
destination with:
error while loading state for instance 0x1 of device 'cpu'
load of migration failed: Operation not permitted
This is caused because the compat_pvr field is only present for the first
CPU.
Originally, spapr_machine_reset() calls ppc_set_compat() to set the value
max_compat_pvr for the first cpu and this was propagated to all CPUs by
spapr_cpu_reset(). Now, as spapr_cpu_reset() is called before that, the
value is not propagated to all CPUs and the migration fails.
To fix that, propagate the new value to all CPUs in spapr_machine_reset().
Fixes: 25c9780d38 ("spapr: Reset CAS & IRQ subsystem after devices")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20190826090812.19080-1-lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
hw/boards.h pulls in almost 60 headers. The less we include it into
headers, the better. As a first step, drop superfluous inclusions,
and downgrade some more to what's actually needed. Gets rid of just
one inclusion into a header.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-23-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h. Include hw/qdev-core.h there
instead.
hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.
While there, delete a few superfluous inclusions of hw/qdev-core.h.
Touching hw/qdev-properties.h now recompiles some 1200 objects.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-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>
The processor stop status and control register (PSSCR) is used to
control the power saving facilities of the thread. The exit criterion
bit (EC) is used to specify whether the thread should be woken by any
interrupt (EC == 0) or only an interrupt enabled in the LPCR to wake the
thread (EC == 1).
The rtas facilities start-cpu and self-stop are used to transition a
vcpu between the stopped and running states. When a vcpu is stopped it
may only be started again by the start-cpu rtas call.
Currently a vcpu in the stopped state will start again whenever an
interrupt comes along due to PSSCR_EC being cleared, and while this is
architecturally correct for a hardware thread, a vcpu is expected to
only be woken by calling start-cpu. This means when performing a reboot
on a tcg machine that the secondary threads will restart while the
primary is still in slof, this is unsupported and causes call traces
like:
SLOF **********************************************************************
QEMU Starting
Build Date = Jan 14 2019 18:00:39
FW Version = git-a5b428e1c1eae703
Press "s" to enter Open Firmware.
qemu: fatal: Trying to deliver HV exception (MSR) 70 with no HV support
NIP 6d61676963313230 LR 000000003dbe0308 CTR 6d61676963313233 XER 0000000000000000 CPU#1
MSR 0000000000000000 HID0 0000000000000000 HF 0000000000000000 iidx 3 didx 3
TB 00000026 115746031956 DECR 18446744073326238463
GPR00 000000003dbe0308 000000003e669fe0 000000003dc10700 0000000000000003
GPR04 000000003dc62198 000000003dc62178 000000003dc0ea48 0000000000000030
GPR08 000000003dc621a8 0000000000000018 000000003e466008 000000003dc50700
GPR12 c00000000093a4e0 c00000003ffff300 c00000003e533f90 0000000000000000
GPR16 0000000000000000 0000000000000000 000000003e466010 000000003dc0b040
GPR20 0000000000008000 000000000000f003 0000000000000006 000000003e66a050
GPR24 000000003dc06400 000000003dc0ae70 0000000000000003 000000000000f001
GPR28 000000003e66a060 ffffffffffffffff 6d61676963313233 0000000000000028
CR 28000222 [ E L - - - E E E ] RES ffffffffffffffff
FPR00 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR04 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR08 0000000000000000 0000000000000000 0000000000000000 00000000311825e0
FPR12 00000000311825e0 0000000000000000 0000000000000000 0000000000000000
FPR16 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR20 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR24 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPR28 0000000000000000 0000000000000000 0000000000000000 0000000000000000
FPSCR 0000000000000000
SRR0 000000003dbe06b0 SRR1 0000000000080000 PVR 00000000004e1200 VRSAVE 0000000000000000
SPRG0 000000003dbe0308 SPRG1 000000003e669fe0 SPRG2 00000000000000d8 SPRG3 000000003dbe0308
SPRG4 0000000000000000 SPRG5 0000000000000000 SPRG6 0000000000000000 SPRG7 0000000000000000
HSRR0 6d61676963313230 HSRR1 0000000000000000
CFAR 000000003dbe3e64
LPCR 0000000004020008
PTCR 0000000000000000 DAR 0000000000000000 DSISR 0000000000000000
Aborted (core dumped)
To fix this, set the PSSCR_EC bit when a vcpu is stopped to disable it
from coming back online until the start-cpu rtas call is made.
Fixes: 21c0d66a9c ("target/ppc: Fix support for "STOP light" states on POWER9")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190516005744.24366-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The qemu coding standard is to use CamelCase for type and structure names,
and the pseries code follows that... sort of. There are quite a lot of
places where we bend the rules in order to preserve the capitalization of
internal acronyms like "PHB", "TCE", "DIMM" and most commonly "sPAPR".
That was a bad idea - it frequently leads to names ending up with hard to
read clusters of capital letters, and means they don't catch the eye as
type identifiers, which is kind of the point of the CamelCase convention in
the first place.
In short, keeping type identifiers look like CamelCase is more important
than preserving standard capitalization of internal "words". So, this
patch renames a heap of spapr internal type names to a more standard
CamelCase.
In addition to case changes, we also make some other identifier renames:
VIOsPAPR* -> SpaprVio*
The reverse word ordering was only ever used to mitigate the capital
cluster, so revert to the natural ordering.
VIOsPAPRVTYDevice -> SpaprVioVty
VIOsPAPRVLANDevice -> SpaprVioVlan
Brevity, since the "Device" didn't add useful information
sPAPRDRConnector -> SpaprDrc
sPAPRDRConnectorClass -> SpaprDrcClass
Brevity, and makes it clearer this is the same thing as a "DRC"
mentioned in many other places in the code
This is 100% a mechanical search-and-replace patch. It will, however,
conflict with essentially any and all outstanding patches touching the
spapr code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Next step is to remove them from under the PowerPCCPU
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Now that the 'intc' pointer is only used by the XICS interrupt mode,
let's make things clear and use a XICS type and name.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
which will be used by the machine only when the XIVE interrupt mode is
in use.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Today, the interrupt presenter is linked to a CPU using the
cpu_intc_create() method of the sPAPR IRQ backend. The resulting
object is assigned to the PowerPCCPU 'intc' pointer whatever the
interrupt mode, XICS or XIVE.
To support the 'dual' interrupt mode, we will need to distinguish
between the two presenter objects and for that, we plan to introduce a
second interrupt presenter object pointer under the PowerPCCPU. The
modifications below move the assignment of the presenter object under
the cpu_intc_create() method to prepare ground for the future changes.
Both sPAPR and PowerNV machines are impacted.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This option is used to select the interrupt controller mode (XICS or
XIVE) with which the machine will operate. XICS being the default
mode for now.
When running a machine with the XIVE interrupt mode backend, the guest
OS is required to have support for the XIVE exploitation mode. In the
case of legacy OS, the mode selected by CAS should be XICS and the OS
should fail to boot. However, QEMU could possibly detect it, terminate
the boot process and reset to stop in the SLOF firmware. This is not
yet handled.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Each interrupt mode has its own specific interrupt presenter object,
that we store under the CPU object, one for XICS and one for XIVE.
Extend the sPAPR IRQ backend with a new handler to support them both.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Set the newly added register(KVM_REG_PPC_ONLINE) to indicate if the vcpu is
online(1) or offline(0)
KVM will use this information to set the RWMR register, which controls the PURR
and SPURR accumulation.
CC: paulus@samba.org
Signed-off-by: Nikunj A Dadhania <nikunj@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We need to set cs->halted to 1 before calling ppc_set_compat. The reason
is that ppc_set_compat kicks up the new thread created to manage the
hotplugged KVM virtual CPU and the code drives directly to KVM_RUN
ioctl. When cs->halted is 1, the code:
int kvm_cpu_exec(CPUState *cpu)
...
if (kvm_arch_process_async_events(cpu)) {
atomic_set(&cpu->exit_request, 0);
return EXCP_HLT;
}
...
returns before it reaches KVM_RUN, giving time to the main thread to
finish its job. Otherwise we can fall in a deadlock because the KVM
thread will issue the KVM_RUN ioctl while the main thread is setting up
KVM registers. Depending on how these jobs are scheduled we'll end up
freezing QEMU.
The following output shows kvm_vcpu_ioctl sleeping because it cannot get
the mutex and never will.
PS: kvm_vcpu_ioctl was triggered kvm_set_one_reg - compat_pvr.
STATE: TASK_UNINTERRUPTIBLE|TASK_WAKEKILL
PID: 61564 TASK: c000003e981e0780 CPU: 48 COMMAND: "qemu-system-ppc"
#0 [c000003e982679a0] __schedule at c000000000b10a44
#1 [c000003e98267a60] schedule at c000000000b113a8
#2 [c000003e98267a90] schedule_preempt_disabled at c000000000b11910
#3 [c000003e98267ab0] __mutex_lock at c000000000b132ec
#4 [c000003e98267bc0] kvm_vcpu_ioctl at c00800000ea03140 [kvm]
#5 [c000003e98267d20] do_vfs_ioctl at c000000000407d30
#6 [c000003e98267dc0] ksys_ioctl at c000000000408674
#7 [c000003e98267e10] sys_ioctl at c0000000004086f8
#8 [c000003e98267e30] system_call at c00000000000b488
crash> struct -x kvm.vcpus 0xc000003da0000000
vcpus = {0xc000003db4880000, 0xc000003d52b80000, 0xc0000039e9c80000, 0xc000003d0e200000, 0xc000003d58280000, 0x0, 0x0, ...}
crash> struct -x kvm_vcpu.mutex.owner 0xc000003d58280000
mutex.owner = {
counter = 0xc000003a23a5c881 <- flag 1: waiters
},
crash> bt 0xc000003a23a5c880
PID: 61579 TASK: c000003a23a5c880 CPU: 9 COMMAND: "CPU 4/KVM"
(active)
crash> struct -x kvm_vcpu.mutex.wait_list 0xc000003d58280000
mutex.wait_list = {
next = 0xc000003e98267b10,
prev = 0xc000003e98267b10
},
crash> struct -x mutex_waiter.task 0xc000003e98267b10
task = 0xc000003e981e0780
The following command-line was used to reproduce the problem (note: gdb
and trace can change the results).
$ qemu-ppc/build/ppc64-softmmu/qemu-system-ppc64 -cpu host \
-enable-kvm -m 4096 \
-smp 4,maxcpus=8,sockets=1,cores=2,threads=4 \
-display none -nographic \
-drive file=disk1.qcow2,format=qcow2
...
(qemu) device_add host-spapr-cpu-core,core-id=4
[no interaction is possible after it, only SIGKILL to take the terminal
back]
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This proposal moves all the related IRQ routines of the sPAPR machine
behind a sPAPR IRQ backend interface 'spapr_irq' to prepare for future
changes. First of which will be to increase the size of the IRQ number
space, then, will follow a new backend for the POWER9 XIVE IRQ controller.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
VMStateDescription vmstate_spapr_cpu_state was added by commit
b94020268e (spapr_cpu_core: migrate per-CPU data) to migrate per-CPU
data with the required vmstate registration and unregistration calls.
However the unregistration is being done only from vcpu creation error path
and not from CPU delete path.
This causes migration to fail with the following error if migration is
attempted after a CPU unplug like this:
Unknown savevm section or instance 'spapr_cpu' 16
Additionally this leaves the source VM unresponsive after migration failure.
Fix this by ensuring the vmstate_unregister happens during CPU removal.
Fixing this becomes easier when vmstate (un)registration calls are moved to
vcpu (un)realize functions which is what this patch does.
Fixes: https://bugs.launchpad.net/qemu/+bug/1785972
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently during KVM initialization on POWER, kvm_fixup_page_sizes()
rewrites a bunch of information in the cpu state to reflect the
capabilities of the host MMU and KVM. This overwrites the information
that's already there reflecting how the TCG implementation of the MMU will
operate.
This means that we can get guest-visibly different behaviour between KVM
and TCG (and between different KVM implementations). That's bad. It also
prevents migration between KVM and TCG.
The pseries machine type now has filtering of the pagesizes it allows the
guest to use which means it can present a consistent model of the MMU
across all accelerators.
So, we can now replace kvm_fixup_page_sizes() with kvm_check_mmu() which
merely verifies that the expected cpu model can be faithfully handled by
KVM, rather than updating the cpu model to match KVM.
We call kvm_check_mmu() from the spapr cpu reset code. This is a hack:
conceptually it makes more sense where fixup_page_sizes() was - in the KVM
cpu init path. However, doing that would require moving the platform's
pagesize filtering much earlier, which would require a lot of work making
further adjustments. There wouldn't be a lot of concrete point to doing
that, since the only KVM implementation which has the awkward MMU
restrictions is KVM HV, which can only work with an spapr guest anyway.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
spapr capabilities have an apply hook to actually activate (or deactivate)
the feature in the system at reset time. However, a number of capabilities
affect the setup of cpus, and need to be applied to each of them -
including hotplugged cpus for extra complication. To make this simpler,
add an optional cpu_apply hook that is called from spapr_cpu_reset().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
QEMU implements the "Shared Processor LPAR" (SPLPAR) option, which allows
the hypervisor to time-slice a physical processor into multiple virtual
processor. The intent is to allow more guests to run, and to optimize
processor utilization.
The guest OS can cede idle VCPUs, so that their processing capacity may
be used by other VCPUs, with the H_CEDE hcall. The guest OS can also
optimize spinlocks, by confering the time-slice of a spinning VCPU to the
spinlock holder if it's currently notrunning, with the H_CONFER hcall.
Both hcalls depend on a "Virtual Processor Area" (VPA) to be registered
by the guest OS, generally during early boot. Other per-VCPU areas can
be registered: the "SLB Shadow Buffer" which allows a more efficient
dispatching of VCPUs, and the "Dispatch Trace Log Buffer" (DTL) which
is used to compute time stolen by the hypervisor. Both DTL and SLB Shadow
areas depend on the VPA to be registered.
The VPA/SLB Shadow/DTL are state that QEMU should migrate, but this doesn't
happen, for no apparent reason other than it was just never coded. This
causes the features listed above to stop working after migration, and it
breaks the logic of the H_REGISTER_VPA hcall in the destination.
The VPA is set at the guest request, ie, we don't have to migrate
it before the guest has actually set it. This patch hence adds an
"spapr_cpu/vpa" subsection to the recently introduced per-CPU machine
data migration stream.
Since DTL and SLB Shadow are optional and both depend on VPA, they get
their own subsections "spapr_cpu/vpa/slb_shadow" and "spapr_cpu/vpa/dtl"
hanging from the "spapr_cpu/vpa" subsection.
Note that this won't break migration to older QEMUs. Is is already handled
by only registering the vmstate handler for per-CPU data with newer machine
types.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
A per-CPU machine data pointer was recently added to PowerPCCPU. The
motivation is to to hide platform specific details from the core CPU
code. This per-CPU data can hold state which is relevant to the guest
though, eg, Virtual Processor Areas, and we should migrate this state.
This patch adds the plumbing so that we can migrate the per-CPU data
for PAPR guests. We only do this for newer machine types for the sake
of backward compatibility. No state is migrated for the moment: the
vmstate_spapr_cpu_state structure will be populated by subsequent
patches.
Signed-off-by: Greg Kurz <groug@kaod.org>
[dwg: Fix some trivial spelling and spacing errors]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
CPUPPCState currently contains a number of fields containing the state of
the VPA. The VPA is a PAPR specific concept covering several guest/host
shared memory areas used to communicate some information with the
hypervisor.
As a PAPR concept this is really machine specific information, although it
is per-cpu, so it doesn't really belong in the core CPU state structure.
There's also other information that's per-cpu, but platform/machine
specific. So create a (void *)machine_data in PowerPCCPU which can be
used by the machine to locate per-cpu data. Intialization, lifetime and
cleanup of machine_data is entirely up to the machine type.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
This moves some code out from spapr_cpu_core_realize() for clarity. No
functional change.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_realize_vcpu() function doesn't rollback in case of error.
This isn't a problem with coldplugged CPUs because the machine won't
start and QEMU will exit. Hotplug is a different story though: the
CPU thread is started under object_property_set_bool() and it assumes
it can access the CPU object.
If icp_create() fails, we return an error without unregistering the
reset handler for this CPU, and we let the underlying QEMU thread for
this CPU alive. Since spapr_cpu_core_realize() doesn't care to unrealize
already realized CPUs either, but happily frees all of them anyway, the
CPU thread crashes instantly:
(qemu) device_add host-spapr-cpu-core,core-id=1,id=gku
GKU: failing icp_create (cpu 0x11497fd0)
^^^^^^^^^^
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffee3feaa0 (LWP 24725)]
0x00000000104c8374 in object_dynamic_cast_assert (obj=0x11497fd0,
^^^^^^^^^^^^^^
pointer to the CPU object
623 trace_object_dynamic_cast_assert(obj ? obj->class->type->name
(gdb) p obj->class->type
$1 = (Type) 0x0
(gdb) p * obj
$2 = {class = 0x10ea9c10, free = 0x11244620,
^^^^^^^^^^
should be g_free
(gdb) p g_free
$3 = {<text variable, no debug info>} 0x7ffff282bef0 <g_free>
obj is a dangling pointer to the CPU that was just destroyed in
spapr_cpu_core_realize().
This patch adds proper rollback to both spapr_realize_vcpu() and
spapr_cpu_core_realize().
Signed-off-by: Greg Kurz <groug@kaod.org>
[dwg: Fixed a conflict due to a change in my tree]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commit 94ad93bd97 (QEMU 2.12) switched to instantiate CPUs separately
but it missed to adapt the error path accordingly. If something fails in
the CPU creation loop, then the CPU object that was just created is leaked.
The error paths in this function are a bit obfuscated, and adding
yet another label to free this CPU object makes it worse. We should
move the block of the loop to a separate function, with a proper
rollback path, but this is a bigger cleanup.
For now, let's just fix the bug by adding the missing calls to
object_unref(). This will allow easier backport to older QEMU
versions.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
