ppc patch queue 2017-07-11

  * Several minor cleanups from Greg Kurz
  * Fix for migration of pseries-2.7 and earlier machine types
  * More reworking of the DRC hotplug code, fixing several problems
    though there are still more to go
  * Fixes for CPU family / alias handling on POWER9
  * Preliminary patches for POWER9 XIVE (new interrupt controller)
    support
  * Assorted other fixes

# gpg: Signature made Tue 11 Jul 2017 05:35:16 BST
# gpg:                using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.10-20170711:
  spapr: populate device tree depending on XIVE_EXPLOIT option
  spapr: introduce the XIVE_EXPLOIT option in CAS
  ppc/kvm: have the "family" CPU alias to point to TYPE_HOST_POWERPC_CPU
  spapr: Only report host/guest IOMMU page size mismatches on KVM
  spapr: fix memory hotplug error path
  target/ppc: Add debug function for radix mmu translation
  target/ppc: Refactor tcg radix mmu code
  spapr: Use unplug_request for PCI hot unplug
  spapr: Remove unnecessary differences between hotplug and coldplug paths
  spapr: Add DRC release method
  spapr: Uniform DRC reset paths
  spapr: Leave DR-indicator management to the guest
  target-ppc: SPR_BOOKE_ESR not set on FP exceptions
  spapr: fix migration to pseries machine < 2.8
  spapr: fix bogus function name in comment
  spapr: refresh "platform-specific" hcalls comment
  spapr: make spapr_populate_hotplug_cpu_dt() static
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

VFIO fixes 2017-07-10

 - Don't iterate over non-realized devices (Alex Williamson)
 - Add PCIe capability version fixup (Alex Williamson)

# gpg: Signature made Mon 10 Jul 2017 20:06:11 BST
# gpg:                using RSA key 0x239B9B6E3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>"
# gpg:                 aka "Alex Williamson <alex@shazbot.org>"
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>"
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>"
# Primary key fingerprint: 42F6 C04E 540B D1A9 9E7B  8A90 239B 9B6E 3BB0 8B22

* remotes/awilliam/tags/vfio-updates-20170710.0:
  vfio/pci: Fixup v0 PCIe capabilities
  vfio: Test realized when using VFIOGroup.device_list iterator
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

While ARM could present the xenpv machine, it does not and trying to enable
it breaks compilation.  Revert to the previous test which only looked at
$target_name, not $cpu.

Fixes: 3b6b7550Reported-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 20170711100049.20513-1-pbonzini@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

When XIVE is supported, the device tree should be populated
accordingly and the XIVE memory regions mapped to activate MMIOs.

Depending on the design we choose, we could also allocate different
ICS and ICP objects, or switch between objects. This needs to be
discussed.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

On POWER9, the Client Architecture Support (CAS) negotiation process
determines whether the guest operates in XIVE Legacy compatibility
(the former POWER8 interrupt model) or in XIVE exploitation mode (the
newer POWER9 interrupt model).

Bit 7 of Byte 23 of vector 5 is used for this purpose.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

When running KVM on POWER, we allow the user to pass "-cpu POWERx" instead
of "-cpu host". This is achieved by patching the ppc_cpu_aliases[] array
so that "POWERx" points to the CPU class with the same PVR as the host CPU.
This causes CPUs to be instantiated from this CPU class instead of the
TYPE_HOST_POWERPC_CPU class which is used with "-cpu host". These CPUs thus
miss all the KVM specific tuning from kvmppc_host_cpu_class_init().

This currently causes QEMU with "-cpu POWER9" to fail when running KVM on a
POWER9 DD1 host:

qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only
 "-cpu host" is possible
kvm_init_vcpu failed: Invalid argument

Let's have the "POWERx" alias to point to TYPE_HOST_POWERPC_CPU directly,
so that "-cpu POWERx" instantiates CPUs from the same class as "-cpu host".
Signed-off-by: NGreg Kurz <groug@kaod.org>
Tested-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We print a warning if the spapr IOMMU isn't configured to support a page
size matching the host page size backing RAM.  When that's the case we need
more complex logic to translate VFIO mappings, which is slower.

But, it's not so slow that it would be at all noticeable against the
general slowness of TCG.  So, only warn when using KVM.  This removes some
noisy and unhelpful warnings from make check on hosts with page sizes
which typically differ from those on POWER (e.g. Sparc).
Reported-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NThomas Huth <thuth@redhat.com>

QEMU shouldn't abort if spapr_add_lmbs()->spapr_drc_attach() fails.
Let's propagate the error instead, like it is done everywhere else
where spapr_drc_attach() is called.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NDaniel Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

In target/ppc/mmu-hash64.c there already exists the function
ppc_hash64_get_phys_page_debug() to get the physical (real) address for
a given effective address in hash mode.

Implement the function ppc_radix64_get_phys_page_debug() to allow a real
address to be obtained for a given effective address in radix mode.
This is used when a debugger is attached to qemu.

Previously we just had a comment saying this is unimplemented which then
fell through to the default case and caused an abort due to
unrecognised mmu model as the default had no case for the V3 mmu, which
was misleading at best.

We reuse ppc_radix64_walk_tree() which is used by the radix fault
handler since the process of walking the radix tree is identical.
Reported-by: NBalbir Singh <bsingharora@gmail.com>
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The mmu-radix64.c file implements functions to enable the radix mmu
emulation in tcg mode. There is a function ppc_radix64_walk_tree() which
performs the radix tree walk and also implicitly checks the pte
protection.

Move the protection checking of the pte from the ppc_radix64_walk_tree()
function into the caller. This means the ppc_radix64_walk_tree() function
can be used without protection checking which is useful for debugging.

ppc_radix64_walk_tree() no longer needs to take the rwx and prot variables.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

AIUI, ->unplug_request in the HotplugHandler is used for "soft"
unplug, where acknowledgement from the guest is required before
completing the unplug, whereas ->unplug is used for "hard" unplug
where qemu unilaterally removes the device, and the guest just has to
cope with its sudden absence.  For spapr we (correctly) use
->unplug_request for CPU and memory hot unplug but we use ->unplug for
PCI.

While I think it might be possible to support "hard" PCI unplug within
the PAPR model, that's not how it actually works now.  Although it's
called from ->unplug, the PCI unplug path will usually just mark the
device for removal, with completion of the unplug delayed until
userspace responds to the unplug notification. If the guest doesn't
respond as expected, that could delay the unplug completion arbitrarily
long.

To reflect that, change the PCI unplug path to be called from
->unplug_request.  We also rename spapr_phb_hot_plug_child() and
spapr_phb_hot_unplug_child() to spapr_pci_plug() and
spapr_pci_unplug_request() to more obviously reflect the callbacks they're
implementing.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

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: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

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: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

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: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>

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: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

Properly set the book E exception syndrome register when a floating
point exception occurs.

Currently on a book E processor, the POWERPC_EXCP_FP exception handler
fails to set "env->spr[SPR_BOOKE_ESR] = ESR_FP;" as required by the
book E specification.
Signed-off-by: NAaron Larson <alarson@ddci.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

since commit 5c4537bd ("spapr: Fix 2.7<->2.8 migration of PCI host bridge"),
some migration fields are forged from the new ones in spapr_pci_pre_save().

It works well, except when the number of MSI devices is 0,
because in this case the function exits immediately.

This fix moves the migration code before the exit code.

The problem can be reproduced with these commands:

source qemu-2.9:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults -S

destination qemu-2.6:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults \
                      -incoming tcp:0:4444

on the source:

    migrate tcp:localhost:4444

Destination fails with the following error:

    qemu-system-ppc64: error while loading state for
                       instance 0x0 of device 'spapr_pci'
    qemu-system-ppc64: load of migration failed: Invalid argument
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

$ git grep spapr_ppc_reset
hw/ppc/spapr.c: * as part of spapr_ppc_reset().

$ git grep ppc_spapr_reset
hw/ppc/spapr.c:static void ppc_spapr_reset(void)
hw/ppc/spapr.c:    mc->reset = ppc_spapr_reset;
hw/ppc/spapr_hcall.c:        /* If ppc_spapr_reset() did not set up a HPT
 but one is necessary
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We have more of these since the addition of KVMPPC_H_LOGICAL_MEMOP in 2012.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Since commit ff9006dd ("spapr: move spapr_core_[foo]plug() callbacks
close to machine code in spapr.c"), this function doesn't need to be extern
anymore.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Migration pull 2017-07-10

# gpg: Signature made Mon 10 Jul 2017 18:04:57 BST
# gpg:                using RSA key 0x0516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20170710a:
  migration: Make compression_threads use save/load_setup/cleanup()
  migration: Convert ram to use new load_setup()/load_cleanup()
  migration: Create load_setup()/cleanup() methods
  migration: Rename cleanup() to save_cleanup()
  migration: Rename save_live_setup() to save_setup()
  doc: update TYPE_MIGRATION documents
  doc: add item for "-M enforce-config-section"
  vl: move global property, migrate init earlier
  migration: fix handling for --only-migratable
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Once there, be consistent and use
compress_thread_{save,load}_{setup,cleanup}.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170628095228.4661-6-quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Once there, I rename ram_migration_cleanup() to ram_save_cleanup().
Notice that this is the first pass, and I only passed XBZRLE to the
new scheme.  Moved decoded_buf to inside XBZRLE struct.
As a bonus, I don't have to export xbzrle functions from ram.c.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--

loaded_data pointer was needed because called can change it (dave)
spell loaded correctly in comment (dave)
Message-Id: <20170628095228.4661-5-quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

We need to do things at load time and at cleanup time.
Signed-off-by: NJuan Quintela <quintela@redhat.com>

--

Move the printing of the error message so we can print the device
giving the error.
Add call to postcopy stuff
Message-Id: <20170628095228.4661-4-quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

We need a cleanup for loads, so we rename here to be consistent.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--

Rename htab_cleanup to htap_save_cleanup as dave suggestion
Message-Id: <20170628095228.4661-3-quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

We are going to use it now for more than save live regions.
Once there rename qemu_savevm_state_begin() to qemu_savevm_state_setup().
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170628095228.4661-2-quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

[Peter collected Eduardo's patch comment and formatted into patch]
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1499242883-2184-5-git-send-email-peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

It's never documented, and now we have one more parameter for it (which
obsoletes this one). Document it properly.
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1499396048-21657-1-git-send-email-peterx@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
  Removed 'Although now' commit message as per Eduardo's review

Currently drive_init_func() may call migrate_get_current() while the
migrate object is still not ready yet at that time. Move the migration
object init earlier, along with the global properties, right after
acceleration init.

This fixes a breakage for iotest 055, which caused an assertion failure.
Reported-by: NMax Reitz <mreitz@redhat.com>
Reported-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Tested-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Fixes: 3df663 ("migration: move only_migratable to MigrationState")
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1499242883-2184-3-git-send-email-peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

MigrateState object is not ready at that time, so we'll get an
assertion. Use qemu_global_option() instead.
Reported-by: NEduardo Habkost <ehabkost@redhat.com>
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Fixes: 3df663e5 ("migration: move only_migratable to MigrationState")
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1499242883-2184-2-git-send-email-peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Intel 82599 VFs report a PCIe capability version of 0, which is
invalid.  The earliest version of the PCIe spec used version 1.  This
causes Windows to fail startup on the device and it will be disabled
with error code 10.  Our choices are either to drop the PCIe cap on
such devices, which has the side effect of likely preventing the guest
from discovering any extended capabilities, or performing a fixup to
update the capability to the earliest valid version.  This implements
the latter.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

VFIOGroup.device_list is effectively our reference tracking mechanism
such that we can teardown a group when all of the device references
are removed.  However, we also use this list from our machine reset
handler for processing resets that affect multiple devices.  Generally
device removals are fully processed (exitfn + finalize) when this
reset handler is invoked, however if the removal is triggered via
another reset handler (piix4_reset->acpi_pcihp_reset) then the device
exitfn may run, but not finalize.  In this case we hit asserts when
we start trying to access PCI helpers since much of the PCI state of
the device is released.  To resolve this, add a pointer to the Object
DeviceState in our common base-device and skip non-realized devices
as we iterate.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

nbd patches for 2017-07-10

- Eric Blake: MAINTAINERS: Promote NBD to supported, with new maintainer
- Vladimir Sementsov-Ogievskiy: [00/10] nbd refactoring part 2

# gpg: Signature made Mon 10 Jul 2017 15:59:18 BST
# gpg:                using RSA key 0xA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2017-07-10-v2:
  nbd: use generic trace subsystem instead of TRACE macro
  nbd: refactor tracing
  nbd/server: rename clientflags var in nbd_negotiate_options
  nbd/server: fix TRACE in nbd_negotiate_send_rep_len
  nbd/client: refactor TRACE of NBD_MAGIC
  nbd/common: nbd_tls_handshake: remove extra TRACE
  nbd/server: add errp to nbd_send_reply()
  nbd/server: use errp instead of LOG
  nbd/server: refactor nbd_negotiate
  nbd/server: nbd_negotiate: return 1 on NBD_OPT_ABORT
  MAINTAINERS: Promote NBD to supported, with new maintainer
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Let NBD use the trace mechanisms already present in qemu. Now you can
use the -trace optino of qemu, or the -T/--trace option of qemu-img,
qemu-io, and qemu-nbd, to select nbd traces. For qemu, the QMP commands
trace-event-{get,set}-state can also toggle tracing on the fly.

Example:
   qemu-nbd --trace 'nbd_*' <image file> # enables all nbd traces

Recompilation with CFLAGS=-DDEBUG_NBD is no more needed, furthermore,
DEBUG_NBD macro is removed from the code.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-11-vsementsov@virtuozzo.com>
[eblake: minor tweaks to a couple of traces]
Signed-off-by: NEric Blake <eblake@redhat.com>

Reorganize traces: move, reword, add information, drop extra ones.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-10-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Rename 'clientflags' to just 'option'. This variable has nothing to do
with flags, but is a single integer representing the option requested
by the client.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-9-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Fix wrong order of TRACE arguments.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-8-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

We are going to switch from TRACE macro to trace points,
this TRACE complicates things, this patch simplifies it.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-7-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Error is propagated to the caller, TRACE is not needed.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707152918.23086-6-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707152918.23086-5-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>