Commit Graph

84 Commits

Author SHA1 Message Date
Markus Armbruster
15280c360e qdict qlist: Make most helper macros functions
The macro expansions of qdict_put_TYPE() and qlist_append_TYPE() need
qbool.h, qnull.h, qnum.h and qstring.h to compile.  We include qnull.h
and qnum.h in the headers, but not qbool.h and qstring.h.  Works,
because we include those wherever the macros get used.

Open-coding these helpers is of dubious value.  Turn them into
functions and drop the includes from the headers.

This cleanup makes the number of objects depending on qapi/qmp/qnum.h
from 4551 (out of 4743) to 46 in my "build everything" tree.  For
qapi/qmp/qnull.h, the number drops from 4552 to 21.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-10-armbru@redhat.com>
2018-02-09 13:52:15 +01:00
Greg Kurz
8251248394 spapr: reset DRCs after devices
A DRC with a pending unplug request releases its associated device at
machine reset time.

In the case of LMB, when all DRCs for a DIMM device have been reset,
the DIMM gets unplugged, causing guest memory to disappear. This may
be very confusing for anything still using this memory.

This is exactly what happens with vhost backends, and QEMU aborts
with:

qemu-system-ppc64: used ring relocated for ring 2
qemu-system-ppc64: qemu/hw/virtio/vhost.c:649: vhost_commit: Assertion
 `r >= 0' failed.

The issue is that each DRC registers a QEMU reset handler, and we
don't control the order in which these handlers are called (ie,
a LMB DRC will unplug a DIMM before the virtio device using the
memory on this DIMM could stop its vhost backend).

To avoid such situations, let's reset DRCs after all devices
have been reset.

Reported-by: Mallesh N. Koti <mallesh@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-11-20 10:10:56 +11:00
Michael Roth
f3f4103034 spapr_drc: pass object ownership to parent/owner
DRC objects attach themselves to an owner as a child
property. unref afterward to allow them to be finalized
when their owner is finalized.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-09-08 09:30:54 +10:00
Greg Kurz
379ae096f7 spapr_drc: add unrealize method to physical DRC class
When hot-unplugging a PHB, all its PCI DRC connectors get unrealized. This
patch adds an unrealize method to the physical DRC class, in order to undo
registrations performed in realize_physical().

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-09-08 09:30:54 +10:00
Greg Kurz
f5babeacc4 spapr_drc: use g_strdup_printf() instead of snprintf()
Passing a stack allocated buffer of arbitrary length to snprintf()
without checking the return value can cause the resultant strings
to be silently truncated.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-09-08 09:30:54 +10:00
Daniel Henrique Barboza
10f12e6450 hw/ppc: CAS reset on early device hotplug
This patch is a follow up on the discussions made in patch
"hw/ppc: disable hotplug before CAS is completed" that can be
found at [1].

At this moment, we do not support CPU/memory hotplug in early
boot stages, before CAS. When a hotplug occurs, the event is logged
in an internal RTAS event log queue and an IRQ pulse is fired. In
regular conditions, the guest handles the interrupt by executing
check_exception, fetching the generated hotplug event and enabling
the device for use.

In early boot, this IRQ isn't caught (SLOF does not handle hotplug
events), leaving the event in the rtas event log queue. If the guest
executes check_exception due to another hotplug event, the re-assertion
of the IRQ ends up de-queuing the first hotplug event as well. In short,
a device hotplugged before CAS is considered coldplugged by SLOF.
This leads to device misbehavior and, in some cases, guest kernel
Ooops when trying to unplug the device.

A proper fix would be to turn every device hotplugged before CAS
as a colplugged device. This is not trivial to do with the current
code base though - the FDT is written in the guest memory at
ppc_spapr_reset and can't be retrieved without adding extra state
(fdt_size for example) that will need to managed and migrated. Adding
the hotplugged DT in the middle of CAS negotiation via the updated DT
tree works with CPU devs, but panics the guest kernel at boot. Additional
analysis would be necessary for LMBs and PCI devices. There are
questions to be made in QEMU/SLOF/kernel level about how we can make
this change in a sustainable way.

With Linux guests, a fix would be the kernel executing check_exception
at boot time, de-queueing the events that happened in early boot and
processing them. However, even if/when the newer kernels start
fetching these events at boot time, we need to take care of older
kernels that won't be doing that.

This patch works around the situation by issuing a CAS reset if a hotplugged
device is detected during CAS:

- the DRC conditions that warrant a CAS reset is the same as those that
triggers a DRC migration - the DRC must have a device attached and
the DRC state is not equal to its ready_state. With that in mind, this
patch makes use of 'spapr_drc_needed' to determine if a CAS reset
is needed.

- In the middle of CAS negotiations, the function
'spapr_hotplugged_dev_before_cas' goes through all the DRCs to see
if there are any DRC that requires a reset, using spapr_drc_needed. If
that happens, returns '1' in 'spapr_h_cas_compose_response' which will set
spapr->cas_reboot to true, causing the machine to reboot.

No changes are made for coldplug devices.

[1] http://lists.nongnu.org/archive/html/qemu-devel/2017-08/msg02855.html

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-09-08 09:30:54 +10:00
Daniel Henrique Barboza
c618e300eb hw/ppc/spapr_drc.c: change spapr_drc_needed to use drc->dev
This patch makes a small fix in 'spapr_drc_needed' to change how we detect
if a DRC has a device attached. Previously it used dr_entity_sense for this,
which  works for physical DRCs.

However, for logical DRCs, it didn't cover the case where a logical DRC has
a drc->dev but the state is LOGICAL_UNUSABLE (e.g. a hotplugged CPU before
CAS). In this case, the dr_entity_sense of this DRC returns UNUSABLE and the
code was considering that there were no dev attached, making spapr_drc_needed
return 'false' when in fact we would like to migrate the DRC.

Changing it to check for drc->dev instead works for all DRC types.

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-09-08 09:30:54 +10:00
Bharata B Rao
188bfe1b00 spapr: Allow configure-connector to be called multiple times
In case of in-kernel memory hot unplug, when the guest is not able
to remove all the LMBs that are requested for removal, it will add back
any LMBs that have been successfully removed. The DR Connectors of
these LMBs wouldn't have been unconfigured and hence the addition of
these LMBs will result in configure-connector call being issued on
LMB DR connectors that are already in configured state. Such
configure-connector calls will fail resulting in a DIMM which is
partially unplugged.

This however worked till recently before we overhauled the DRC
implementation in QEMU. Commit 9d4c0f4f0a: "spapr: Consolidate
DRC state variables" is the first commit where this problem shows up
as per git bisect.

Ideally guest shouldn't be issuing configure-connector call on an
already configured DR connector. However for now, work around this in
QEMU by allowing configure-connector to be called multiple times for
all types of DR connectors.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
[dwg: Corrected buglet that would have initialized fdt pointers ready
 for reading on a device not present at reset]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-08-22 21:26:46 +10:00
Greg Kurz
325837ca38 spapr_drc: abort if object_property_add_child() fails
object_property_add_child() can only fail in two cases:
- the child already has a parent, which shouldn't happen since the DRC was
  allocated a few lines above
- the parent already has a child with the same name, which would mean the
  caller tries to create a DRC that already exists

In both case, this is a QEMU bug and we should abort.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-08-09 11:46:44 +10:00
Greg Kurz
bf26ae32a9 spapr_drc: fix realize and unrealize
If object_property_add_alias() returns an error in realize(), we should
propagate it to the caller and certainly not unref the DRC.

Same thing goes for unrealize(). Since object_property_del() is the last
call, we can even get rid of the intermediate Error *.

And finally, unrealize() should undo all registrations performed by
realize().

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-29 16:22:14 +10:00
Markus Armbruster
d2f95f4d48 qapi: Use QNull for a more regular visit_type_null()
Make visit_type_null() take an @obj argument like its buddies.  This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-24 13:35:11 +02:00
David Gibson
67fea71bf3 spapr: Implement DR-indicator for physical DRCs only
According to PAPR, the DR-indicator should only be valid for physical DRCs,
not logical DRCs.  At the moment we implement it for all DRCs, so restrict
it to physical ones only.

We move the state to the physical DRC subclass, which means adding some
QOM boilerplate to handle the newly distinct type.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
4445b1d27e spapr: Remove sPAPRConfigureConnectorState sub-structure
Most of the time, the state of a DRC object is contained in the single
'state' variable.  However, during the transition from UNISOLATE to
CONFIGURED state requires multiple calls to the ibm,configure-connector
RTAS call to retrieve the device tree for the attached device.  We need
some extra state to keep track of where we're up to in delivering the
device tree information to the guest.

Currently that extra state is in a sPAPRConfigureConnectorState
substructure which is only allocated when we're in the middle of the
configure connector process.  That sounds like a good idea, but the extra
state is only two integers - on many platforms that will take up the same
room as the (maybe NULL) ccs pointer even before malloc() overhead.  Plus
it's another object whose lifetime we need to manage.  In short, it's not
worth it.

So, fold the sPAPRConfigureConnectorState substructure directly into the
DRC object.

Previously the structure was allocated lazily when the configure-connector
call discovers it's not there.  Now, we need to initialize the subfields
pre-emptively, as soon as we enter UNISOLATE state.

Although it's not strictly necessary (the field values should only ever
be consulted when in UNISOLATE state), we try to keep them at -1 when in
other states, as a debugging aid.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
9d4c0f4f0a spapr: Consolidate DRC state variables
Each DRC has three fields describing its state: isolation_state,
allocation_state and configured.  At first this seems like a reasonable
representation, since its based directly on the PAPR defined
isolation-state and allocation-state indicators.  However:
  * Only a few combinations of the two fields' values are permitted
  * allocation_state isn't used at all for physical DRCs
  * The indicators are write only so they don't really have a well
    defined current value independent of each other

This replaces these variables with a single state variable, whose names
and numbers are based on the diagram in LoPAPR section 13.4.  Along with
this we add code to check the current state on various operations and make
sure the requested transition is permitted.

Strictly speaking, this makes guest visible changes to behaviour (since we
probably allowed some transitions we shouldn't have before).  However, a
hypothetical guest broken by that wasn't PAPR compliant, and probably
wouldn't have worked under PowerVM.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
f1c52354e5 spapr: Cleanups relating to DRC awaiting_release field
'awaiting_release' indicates that the host has requested an unplug of the
device attached to the DRC, but the guest has not (yet) put the device
into a state where it is safe to complete removal.

1. Rename it to 'unplug_requested' which to me at least is clearer

2. Remove the ->release_pending() method used to check this from outside
spapr_drc.c.  The method only plausibly has one implementation, so use
a plain function (spapr_drc_unplug_requested()) instead.

3. Remove it from the migration stream.  Attempting to migrate mid-unplug
is broken not just for spapr - in general management has no good way to
determine if the device should be present on the destination or not.  So,
until that's fixed, there's no point adding extra things to the stream.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
a8dc47fd82 spapr: Refactor spapr_drc_detach()
This function has two unused parameters - remove them.

It also sets awaiting_release on all paths, except one.  On that path
setting it is harmless, since it will be immediately cleared by
spapr_drc_release().  So factor it out of the if statements.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
ba50822ff8 spapr: Abort on delete failure in spapr_drc_release()
We currently ignore errors from the object_property_del() in
spapr_drc_release().  But the only way that could fail is if the property
doesn't exist, in which case it's a bug that we're in spapr_drc_release()
at all.  So change from ignoring to abort()ing on errors.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-17 15:07:05 +10:00
David Gibson
82a93a1d30 spapr: Remove 'awaiting_allocation' DRC flag
The awaiting_allocation flag in the DRC was introduced by aab9913
"spapr_drc: Prevent detach racing against attach for CPU DR", allegedly to
prevent a guest crash on racing attach and detach.  Except.. information
from the BZ actually suggests a qemu crash, not a guest crash.  And there
shouldn't be a problem here anyway: if the guest has already moved the DRC
away from UNUSABLE state, the detach would already be deferred, and if it
hadn't it should be safe to detach it (the guest should fail gracefully
when it attempts to change the allocation state).

I think this was probably just a bandaid for some other problem in the
state management.  So, remove awaiting_allocation and associated code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
Laurent Vivier
94fd9cbaa3 spapr: Treat devices added before inbound migration as coldplugged
When migrating a guest which has already had devices hotplugged,
libvirt typically starts the destination qemu with -incoming defer,
adds those hotplugged devices with qmp, then initiates the incoming
migration.

This causes problems for the management of spapr DRC state.  Because
the device is treated as hotplugged, it goes into a DRC state for a
device immediately after it's plugged, but before the guest has
acknowledged its presence.  However, chances are the guest on the
source machine *has* acknowledged the device's presence and configured
it.

If the source has fully configured the device, then DRC state won't be
sent in the migration stream: for maximum migration compatibility with
earlier versions we don't migrate DRCs in coldplug-equivalent state.
That means that the DRC effectively changes state over the migrate,
causing problems later on.

In addition, logging hotplug events for these devices isn't what we
want because a) those events should already have been issued on the
source host and b) the event queue should get wiped out by the
incoming state anyway.

In short, what we really want is to treat devices added before an
incoming migration as if they were coldplugged.

To do this, we first add a spapr_drc_hotplugged() helper which
determines if the device is hotplugged in the sense relevant for DRC
state management.  We only send hotplug events when this is true.
Second, when we add a device which isn't hotplugged in this sense, we
force a reset of the DRC state - this ensures the DRC is in a
coldplug-equivalent state (there isn't usually a system reset between
these device adds and the incoming migration).

This is based on an earlier patch by Laurent Vivier, cleaned up and
extended.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-07-17 15:07:05 +10:00
David Gibson
3579d606a0 spapr: Remove unnecessary instance_size specifications from DRC subtypes
All the DRC subtypes explicitly list instance_size in TypeInfo (all as
sizeof(sPAPRDRConnector).  This isn't necessary, since if it's not listed
it will be derived from the parent type.

Worse, this is dangerous, because if a subtype is changed in future to
have a larger structure, then subtypes of that subtype also need to have
instance_size changed, or it will lead to hard to track memory corruption
bugs.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-17 15:06:08 +10:00
David Gibson
5c1da81215 spapr: Remove unnecessary differences between hotplug and coldplug paths
spapr_drc_attach() has a 'coldplug' parameter which sets the DRC into
configured state initially, instead of the usual ISOLATED/UNUSABLE state.
It turns out this is unnecessary: although coldplugged devices do need to
be in CONFIGURED state once the guest starts, that will already be
accomplished by the reset code which will move DRCs for already plugged
devices into a coldplug equivalent state.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
2017-07-11 11:04:01 +10:00
David Gibson
6b762f29a8 spapr: Add DRC release method
At the moment, spapr_drc_release() has an ugly switch on the DRC type to
call the right, device-specific release function.  This cleans it up by
doing that via a proper QOM method.

It's still arguably an abstraction violation for the DRC code to call into
the specific device code, but one mess at a time.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
2017-07-11 11:04:01 +10:00
David Gibson
6caf3ac613 spapr: Uniform DRC reset paths
DRC objects have a regular device reset method.  However, it only gets
called in the usual way for PCI DRCs.  Because of where CPU and LMB DRCs
are in the QOM tree, their device reset method isn't automatically called.
So, the machine manually registers reset handlers to call device_reset().

This patch removes the device reset method, and instead always explicitly
registers the reset handler from realize().  This means the callers don't
have to worry about the two cases, and we always get proper resets.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2017-07-11 11:04:01 +10:00
David Gibson
f8dc29834c spapr: Leave DR-indicator management to the guest
The DR-indicator is essentially a "virtual LED" attached to a hotpluggable
device, which the guest can set to various states for the attention of
the operator or management layers.

It's mostly guest managed, except that we once-off set it to
ACTIVE/INACTIVE in the attach/detach path.  While that makes certain sense,
there's no indication in PAPR that the hypervisor should do this, and the
drmgr code on the guest side doesn't appear to need it (it will already set
the indicator to ACTIVE on hotplug, and INACTIVE on remove).

So, leave the DR-indicator entirely to the guest; the only thing we need
to do is ensure it's in a sane state on reset.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
2017-07-11 11:04:01 +10:00
David Gibson
0dfabd39d5 spapr: Clean up DRC set_isolation_state() path
There are substantial differences in the various paths through
set_isolation_state(), both for setting to ISOLATED versus UNISOLATED
state and for logical versus physical DRCs.

So, split the set_isolation_state() method into isolate() and unisolate()
methods, and give it different implementations for the two DRC types.

Factor some minimal common checks, including for valid indicator values
(which we weren't previously checking) into rtas_set_isolation_state().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-30 14:03:32 +10:00
David Gibson
617367321e spapr: Clean up DRC set_allocation_state path
The allocation-state indicator should only actually be implemented for
"logical" DRCs, not physical ones.  Factor a check for this, and also for
valid indicator state values into rtas_set_allocation_state().  Because
they don't exist for physical DRCs, there's no reason that we'd ever want
more than one method implementation, so it can just be a plain function.

In addition, the setting to USABLE and setting to UNUSABLE paths in
set_allocation_state() don't actually have much in common.  So, split the
method separate functions for each parameter value (drc_set_usable()
and drc_set_unusable()).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-30 14:03:32 +10:00
David Gibson
4f9242fc93 spapr: Make DRC reset force DRC into known state
The reset handler for DRCs attempts several state transitions which are
subject to various checks and restrictions.  But at reset time we know
there is no guest, so we can ignore most of the usual sequencing rules and
just set the DRC back to a known state.  In fact, it's safer to do so.

The existing code also has several redundant checks for
drc->awaiting_release inside a block which has already tested that.  This
patch removes those and sets the DRC to a fixed initial state based only
on whether a device is currently plugged or not.

With DRCs correctly reset to a state based on device presence, we don't
need to force state transitions as cold plugged devices are processed.
This allows us to remove all the callers of the set_*_state() methods from
outside spapr_drc.c.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-30 14:03:32 +10:00
David Gibson
9c914e5370 spapr: Split DRC release from DRC detach
spapr_drc_detach() is called when qemu generic code requests a device be
unplugged.  It makes a number of tests, which could well delay further
action until later, before actually detach the device from the DRC.

This splits out the part which actually removes the device from the DRC
into spapr_drc_release().  This will be useful for further cleanups.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-30 14:03:32 +10:00
David Gibson
307b7715d0 spapr: Eliminate DRC 'signalled' state variable
The 'signalled' field in the DRC appears to be entirely a torturous
workaround for the fact that PCI devices were started in UNISOLATED state
for unclear reasons.

1) 'signalled' is already meaningless for logical (so far, all non PCI)
DRCs.  It's always set to true (at least at any point it might be tested),
and can't be assigned any real meaning due to the way signalling works for
logical DRCs.

2) For PCI DRCs, the only time signalled would be false is when non-zero
functions of a multifunction device are hotplugged, followed by function
zero (the other way around is explicitly not permitted). In that case the
secondary function DRCs are attached, but the notification isn't sent to
the guest until function 0 is plugged.

3) signalled being false is used to allow a DRC detach to switch mode
back to ISOLATED state, which allows a secondary function to be hotplugged
then unplugged with function 0 never inserted.  Without this a secondary
function starting in UNISOLATED state couldn't be detached again without
function 0 being inserted, all the functions configured by the guest, then
sent back to ISOLATED state.

4) But now that PCI DRCs start in ISOLATED state, there's nothing to be
done.  If the guest doesn't get the notification, it won't switch the
device to UNISOLATED state, so nothing prevents it from being unplugged.
If the guest does move it to UNISOLATED state without the signal (due to
a manual drmgr call, for instance) then it really isn't safe to unplug it.

So, this patch removes the signalled variable and all code related to it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-30 14:03:32 +10:00
David Gibson
af8ad96bd0 spapr: Start hotplugged PCI devices in ISOLATED state
PCI DRCs, and only PCI DRCs, are immediately moved to UNISOLATED isolation
state once the device is attached.  This has been there from the initial
implementation, and it's not clear why.

The state diagram in PAPR 13.4 suggests PCI devices should start in
ISOLATED state until the guest moves them into UNISOLATED, and the code in
the guest-side drmgr tool seems to work that way too.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
2017-06-30 14:03:32 +10:00
Laurent Vivier
593080936a Revert "spapr: fix memory hot-unplugging"
This reverts commit fe6824d126.

Conflicts hw/ppc/spapr_drc.c, because get_index() has been renamed
spapr_get_index().

This didn't fix the problem. Once the hotplug has been started
some memory is allocated and some structures are allocated.
We don't free it when we ignore the unplug, and we can't because
they can be in use by the kernel.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-09 12:35:46 +10:00
David Gibson
7980833619 spapr: Rework DRC name handling
DRC objects have a get_name method which returns the DRC name generated
when the DRC is created.  Replace that with a fixed spapr_drc_name()
function which generates the name on the fly from other information.  This
means:
  * We get rid of a method with only one implementation, and only local
    callers
  * We don't have to carry the name string around for the lifetime of the
    DRC
  * We use information added to the class structure to generate the name
    in standard format, so we don't need an explicit switch on drc type
    any more

We also eliminate the 'name' property; it's basically useless since the
only information in it can easily be deduced from other things.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-08 14:38:27 +10:00
David Gibson
0be4e88621 spapr: Change DRC attach & detach methods to functions
DRC objects have attach & detach methods, but there's only one
implementation.  Although there are some differences in its behaviour for
different DRC types, the overall structure is the same, so while we might
want different method implementations for some parts, we're unlikely to
want them for the top-level functions.

So, replace them with direct function calls.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-08 14:38:26 +10:00
David Gibson
cd74d27e42 spapr: Clean up handling of DR-indicator
There are 3 types of "indicator" associated with hotplug in the PAPR spec
the "allocation state", "isolation state" and "DR-indicator".  The first
two are intimately tied to the various state transitions associated with
hotplug.  The DR-indicator, however, is different and simpler.

It's basically just a guest controlled variable which can be used by the
guest to flag state or problems associated with a device.  The idea is that
the hypervisor can use it to present information back on management
consoles (on some machines with PowerVM it may even control physical LEDs
on the machine case associated with the relevant device).

For that reason, there's only ever likely to be a single update
implementation so the set_indicator_state method isn't useful.  Replace it
with a direct function call.

While we're there, make some small associated cleanups:
  * PAPR doesn't use the term "indicator state", just "DR-indicator" and
the allocation state and isolation state are also considered "indicators".
Rename things to be less confusing
  * Fold set_indicator_state() and rtas_set_indicator_state() into a single
rtas_set_dr_indicator() function.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-08 14:38:26 +10:00
David Gibson
7b7258f810 spapr: Clean up RTAS set-indicator
In theory the RTAS set-indicator call can be used for a number of
"indicators" defined by PAPR.  In practice the only ones we're ever likely
to implement are those used for Dynamic Reconfiguration (i.e. hotplug).
Because of this, the current implementation determines the associated DRC
object, before dispatching based on the type of indicator.

However, this means we also need a check that we're dealing with a DR
related indicator at all, which duplicates some of the logic from the
switch further down.

Even though it means a bit of code duplication, things work out cleaner if
we delegate the DRC lookup to the individual indicator type functions -
and it also allows some further cleanups.

While we're there, remove references to "sensor", a copy/paste artefact
from the related, but distinct "get-sensor" call.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-08 14:38:26 +10:00
David Gibson
f224d35be9 spapr: Clean up DR entity sense handling
DRC classes have an entity_sense method to determine (in a specific PAPR
sense) the presence or absence of a device plugged into a DRC.  However,
we only have one implementation of the method, which explicitly tests for
different DRC types.  This changes it to instead have different method
implementations for the two cases: "logical" and "physical" DRCs.

While we're at it, the entity sense method always returns RTAS_OUT_SUCCESS,
and the interesting value is returned via pass-by-reference.  Simplify this
to directly return the value we care about

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-08 14:38:26 +10:00
David Gibson
91dcb1ffa6 spapr: Remove some non-useful properties on DRC objects
* 'connector_type' is easily derived from the 'index' property, so there's
   no point to it (it's also implicit in the QOM type of the DRC)
 * 'isolation-state', 'indicator-state' and 'allocation-state' are
   part of the transaction between qemu and guest during PAPR hotplug
   operations, and outside tools really have no business looking at it
   (especially not changing, and these were RW properties)
 * 'entity-sense' is basically just a weird PAPR encoding of whether there
   is a device connected to this DRC

Strictly speaking removing these properties is breaking the qemu interface.
However, I'm pretty sure no management tools have ever used these.  For
debugging there are better alternatives.  Therefore, I think removing these
broken interfaces is the better option.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-06 09:24:25 +10:00
David Gibson
1693ea1685 spapr: Eliminate spapr_drc_get_type_str()
This function was used in generating the device tree.  However, now that
we have different QOM types for different DRC types we can easily store
the information we need in the class structure and avoid this specialized
lookup function.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-06 09:24:21 +10:00
David Gibson
b8fdd530be spapr: Move configure-connector state into DRC
Currently the sPAPRMachineState contains a list of sPAPRConfigureConnector
structures which store intermediate state for the ibm,configure-connector
RTAS call.

This was an attempt to separate this state from the core of the DRC state.
However the configure connector process is intimately tied to the DRC
model, so there's really no point trying to have two levels of interface
here.

Moving the configure-connector state into its corresponding DRC allows
removal of a number of helpers for maintaining the anciliary list.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-06 09:24:17 +10:00
David Gibson
fbf5539718 spapr: Clean up spapr_dr_connector_by_*()
* Change names to something less ludicrously verbose
 * Now that we have QOM subclasses for the different DRC types, use a QOM
   typename instead of a PAPR type value parameter

The latter allows removal of the get_type_shift() helper.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-06 09:24:08 +10:00
David Gibson
2d33581899 spapr: Introduce DRC subclasses
Currently we only have a single QOM type for all DRCs, but lots of
places where we switch behaviour based on the DRC's PAPR defined type.
This is a poor use of our existing type system.

So, instead create QOM subclasses for each PAPR defined DRC type.  We
also introduce intermediate subclasses for physical and logical DRCs,
a division which will be useful later on.

Instead of being stored in the DRC object itself, the PAPR type is now
stored in the class structure.  There are still many places where we
switch directly on the PAPR type value, but this at least provides the
basis to start to remove those.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-06-06 09:23:46 +10:00
Greg Kurz
a32e900b8a spapr/drc: don't migrate DRC of cold-plugged CPUs and LMBs
As explained in commit 5c0139a8c2 ("spapr: fix default DRC state for
coldplugged LMBs"), guests expect cold-plugged LMBs to be pre-allocated
and unisolated. The same goes for cold-plugged CPUs.

While here, let's convert g_assert(false) to the better self documenting
g_assert_not_reached().

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-06-06 09:22:02 +10:00
David Gibson
0b55aa91c9 spapr: Make DRC get_index and get_type methods into plain functions
These two methods only have one implementation, and the spec they're
implementing means any other implementation is unlikely, verging on
impossible.

So replace them with simple functions.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-06-06 08:53:24 +10:00
David Gibson
4f65ce00ab spapr: Abolish DRC set_configured method
DRConnectorClass has a set_configured method, however:
  * There is only one implementation, and only ever likely to be one
  * There's exactly one caller, and that's (now) local
  * The implementation is very straightforward

So abolish the method entirely, and just open-code what we need.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-06-06 08:53:24 +10:00
David Gibson
88af6ea568 spapr: Abolish DRC get_fdt method
The DRConnectorClass includes a get_fdt method.  However
  * There's only one implementation, and there's only likely to ever be one
  * Both callers are local to spapr_drc
  * Each caller only uses one half of the actual implementation

So abolish get_fdt() entirely, and just open-code what we need.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-06-06 08:53:24 +10:00
David Gibson
b89b3d3929 spapr: Move DRC RTAS calls into spapr_drc.c
Currently implementations of the RTAS calls related to DRCs are in
spapr_rtas.c.  They belong better in spapr_drc.c - that way they're closer
to related code, and we'll be able to make some more things local.

spapr_rtas.c was intended to contain the RTAS infrastructure and core calls
that don't belong anywhere else, not every RTAS implementation.

Code motion only.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
2017-06-06 08:53:24 +10:00
Daniel Henrique Barboza
a50919dddf hw/ppc: migrating the DRC state of hotplugged devices
In pseries, a firmware abstraction called Dynamic Reconfiguration
Connector (DRC) is used to assign a particular dynamic resource
to the guest and provide an interface to manage configuration/removal
of the resource associated with it. In other words, DRC is the
'plugged state' of a device.

Before this patch, DRC wasn't being migrated. This causes
post-migration problems due to DRC state mismatch between source and
target. The DRC state of a device X in the source might
change, while in the target the DRC state of X is still fresh. When
migrating the guest, X will not have the same hotplugged state as it
did in the source. This means that we can't hot unplug X in the
target after migration is completed because its DRC state is not consistent.
https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1677552 is one
bug that is caused by this DRC state mismatch between source and
target.

To migrate the DRC state, we defined the VMStateDescription struct for
spapr_drc to enable the transmission of spapr_drc state in migration.
Not all the elements in the DRC state are migrated - only those
that can be modified by guest actions or device add/remove
operations:

- 'isolation_state', 'allocation_state' and 'indicator_state'
are involved in the DR state transition diagram from
PAPR+ 2.7, 13.4;

- 'configured', 'signalled', 'awaiting_release' and 'awaiting_allocation'
are needed in attaching and detaching devices;

- 'indicator_state' provides users with hardware state information.

These are the DRC elements that are migrated.

In this patch the DRC state is migrated for PCI, LMB and CPU
connector types. At this moment there is no support to migrate
DRC for the PHB (PCI Host Bridge) type.

In the 'realize' function the DRC is registered using vmstate_register,
similar to what hw/ppc/spapr_iommu.c does in 'spapr_tce_table_realize'.
This approach works because  DRCs are bus-less and do not sit
on a BusClass that implements bc->get_dev_path, so as a fallback the
VMSD gets identified via "spapr_drc"/get_index(drc).

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-25 11:31:33 +10:00
Daniel Henrique Barboza
318347234d hw/ppc: removing drc->detach_cb and drc->detach_cb_opaque
The pointer drc->detach_cb is being used as a way of informing
the detach() function inside spapr_drc.c which cb to execute. This
information can also be retrieved simply by checking drc->type and
choosing the right callback based on it. In this context, detach_cb
is redundant information that must be managed.

After the previous spapr_lmb_release change, no detach_cb_opaques
are being used by any of the three callbacks functions. This is
yet another information that is now unused and, on top of that, can't
be migrated either.

This patch makes the following changes:

- removal of detach_cb_opaque. the 'opaque' argument was removed from
the callbacks and from the detach() function of sPAPRConnectorClass. The
attribute detach_cb_opaque of sPAPRConnector was removed.

- removal of detach_cb from the detach() call. The function pointer
detach_cb of sPAPRConnector was removed. detach() now uses a
switch(drc->type) to execute the apropriate callback. To achieve this,
spapr_core_release, spapr_lmb_release and spapr_phb_remove_pci_device_cb
callbacks were made public to be visible inside detach().

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-05-25 11:31:33 +10:00
Eduardo Habkost
e90f2a8c3e qdev: Replace cannot_instantiate_with_device_add_yet with !user_creatable
cannot_instantiate_with_device_add_yet was introduced by commit
efec3dd631 to replace no_user. It was
supposed to be a temporary measure.

When it was introduced, we had 54
cannot_instantiate_with_device_add_yet=true lines in the code.
Today (3 years later) this number has not shrunk: we now have
57 cannot_instantiate_with_device_add_yet=true lines. I think it
is safe to say it is not a temporary measure, and we won't see
the flag go away soon.

Instead of a long field name that misleads people to believe it
is temporary, replace it a shorter and less misleading field:
user_creatable.

Except for code comments, changes were generated using the
following Coccinelle patch:

  @@
  expression DC;
  @@
  (
  -DC->cannot_instantiate_with_device_add_yet = false;
  +DC->user_creatable = true;
  |
  -DC->cannot_instantiate_with_device_add_yet = true;
  +DC->user_creatable = false;
  )

  @@
  typedef ObjectClass;
  expression dc;
  identifier class, data;
  @@
   static void device_class_init(ObjectClass *class, void *data)
   {
   ...
   dc->hotpluggable = true;
  +dc->user_creatable = true;
   ...
   }

  @@
  @@
   struct DeviceClass {
   ...
  -bool cannot_instantiate_with_device_add_yet;
  +bool user_creatable;
   ...
  }

  @@
  expression DC;
  @@
  (
  -!DC->cannot_instantiate_with_device_add_yet
  +DC->user_creatable
  |
  -DC->cannot_instantiate_with_device_add_yet
  +!DC->user_creatable
  )

Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Thomas Huth <thuth@redhat.com>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170503203604.31462-2-ehabkost@redhat.com>
[ehabkost: kept "TODO remove once we're there" comment]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-05-17 10:37:00 -03:00
Laurent Vivier
fe6824d126 spapr: fix memory hot-unplugging
If, once the kernel has booted, we try to remove a memory
hotplugged while the kernel was not started, QEMU crashes on
an assert:

    qemu-system-ppc64: hw/virtio/vhost.c:651:
                       vhost_commit: Assertion `r >= 0' failed.
    ...
    #4  in vhost_commit
    #5  in memory_region_transaction_commit
    #6  in pc_dimm_memory_unplug
    #7  in spapr_memory_unplug
    #8  spapr_machine_device_unplug
    #9  in hotplug_handler_unplug
    #10 in spapr_lmb_release
    #11 in detach
    #12 in set_allocation_state
    #13 in rtas_set_indicator
    ...

If we take a closer look to the guest kernel log, we can see when
we try to unplug the memory:

    pseries-hotplug-mem: Attempting to hot-add 4 LMB(s)

What happens:

    1- The kernel has ignored the memory hotplug event because
       it was not started when it was generated.

    2- When we hot-unplug the memory,
       QEMU starts to remove the memory,
            generates an hot-unplug event,
        and signals the kernel of the incoming new event

    3- as the kernel is started, on the QEMU signal, it reads
       the event list, decodes the hotplug event and tries to
       finish the hotplugging.

    4- QEMU receive the the hotplug notification while it
       is trying to hot-unplug the memory. This moves the memory
       DRC to an invalid state

This patch prevents this by not allowing to set the allocation
state to USABLE while the DRC is awaiting release.

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1432382

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-03-29 11:35:16 +11:00