Print out the offset at which the error occured.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-Id: <20200108090348.21224-3-clg@kaod.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-Id: <20200108090348.21224-2-clg@kaod.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Pull request

# gpg: Signature made Thu 30 Jan 2020 21:38:06 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  qemu_set_log_filename: filename argument may be NULL
  hw/display/qxl.c: Use trace_event_get_state_backends()
  memory.c: Use trace_event_get_state_backends()
  docs/devel/tracing.txt: Recommend only trace_event_get_state_backends()
  Makefile: Keep trace-events-subdirs ordered
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

When support for the AHP flag was added we inexplicably only freed the
new temps in one of the two legs. Move those tcg_temp_free to the same
level as the allocation to fix that leak.

Fixes: 486624fcSigned-off-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20200131153439.26027-1-alex.bennee@linaro.org
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Pull request

# gpg: Signature made Thu 30 Jan 2020 21:31:02 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  tests/qemu-iotests: use AIOMODE with various tests
  tests/qemu-iotests: enable testing with aio options
  qemu-nbd: adds option for aio engines
  qemu-img: adds option to use aio engine for benchmarking
  qemu-io: adds option to use aio engine
  block/io_uring: adds userspace completion polling
  block: add trace events for io_uring
  block/file-posix.c: extend to use io_uring
  blockdev: adds bdrv_parse_aio to use io_uring
  util/async: add aio interfaces for io_uring
  stubs: add stubs for io_uring interface
  block/io_uring: implements interfaces for io_uring
  block/block: add BDRV flag for io_uring
  qapi/block-core: add option for io_uring
  configure: permit use of io_uring
  block/io: take bs->reqs_lock in bdrv_mark_request_serialising
  block/io: wait for serialising requests when a request becomes serialising
  block: eliminate BDRV_REQ_NO_SERIALISING
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

NULL is a valid log filename used to indicate we want to use stderr
but qemu_set_log_filename (which is called by bsd-user/main.c) was not
handling it correctly.

That also made redundant a couple of NULL checks in calling code which
have been removed.
Signed-off-by: NSalvador Fandino <salvador@qindel.com>
Message-Id: <20200123193626.19956-1-salvador@qindel.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The preferred way to test whether a trace event is enabled is to
use trace_event_get_state_backends(), because this will give the
correct answer (allowing expensive computations to be skipped)
whether the trace event is compile-time or run-time disabled.
Convert the old-style direct use of TRACE_FOO_ENABLED.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Acked-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 20200120151142.18954-4-peter.maydell@linaro.org
Message-Id: <20200120151142.18954-4-peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The preferred way to test whether a trace event is enabled is to
use trace_event_get_state_backends(), because this will give the
correct answer (allowing expensive computations to be skipped)
whether the trace event is compile-time or run-time disabled.
Convert the four old-style direct uses of TRACE_FOO_ENABLED in
memory.c.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 20200120151142.18954-3-peter.maydell@linaro.org
Message-Id: <20200120151142.18954-3-peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Instead of recommending checking the TRACE_FOO_ENABLED macro to
skip expensive computations needed only for tracing, recommend
only using trace_event_get_state_backends(). This works for both
compile-time and run-time disabling of events, and has no extra
performance impact if the event is compile-time disabled.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 20200120151142.18954-2-peter.maydell@linaro.org
Message-Id: <20200120151142.18954-2-peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Adding the same directory multiple times to trace-events-subdirs
might trigger build failures, in particular when using the LTTng
Userspace Tracer library as backend.

For example when using two times the hw/core/ directory:

    $ ./configure --enable-trace-backends=ust && make
   [...]
     CC      trace-ust-all.o
   In file included from trace-ust-all.h:13,
                    from trace-ust-all.c:13:
   trace-ust-all.h:35151:1: error: redefinition of ‘__tracepoint_cb_qemu___loader_write_rom’
   35151 | TRACEPOINT_EVENT(
         | ^~~~~~~~~~~~~~~~
   trace-ust-all.h:31791:1: note: previous definition of ‘__tracepoint_cb_qemu___loader_write_rom’ was here
   31791 | TRACEPOINT_EVENT(
         | ^~~~~~~~~~~~~~~~

To ease review and reduce likelihood of merge failures (see [*]),
keep trace-events-subdirs ordered when possible, following eb7ccb3c.

[*] https://www.mail-archive.com/qemu-devel@nongnu.org/msg671007.html
    Duplicate trace-events-subdirs entries generates duplicated
    symbols when using the LTTng Userspace Tracer library.
Reviewed-by: NDamien Hedde <damien.hedde@greensocs.com>
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200116114339.30670-1-philmd@redhat.com
Message-Id: <20200116114339.30670-1-philmd@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-16-stefanha@redhat.com
Message-Id: <20200120141858.587874-16-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-15-stefanha@redhat.com
Message-Id: <20200120141858.587874-15-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NEric Blake <eblake@redhat.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-14-stefanha@redhat.com
Message-Id: <20200120141858.587874-14-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-13-stefanha@redhat.com
Message-Id: <20200120141858.587874-13-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-12-stefanha@redhat.com
Message-Id: <20200120141858.587874-12-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-11-stefanha@redhat.com
Message-Id: <20200120141858.587874-11-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-10-stefanha@redhat.com
Message-Id: <20200120141858.587874-10-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-9-stefanha@redhat.com
Message-Id: <20200120141858.587874-9-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-8-stefanha@redhat.com
Message-Id: <20200120141858.587874-8-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-7-stefanha@redhat.com
Message-Id: <20200120141858.587874-7-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Follow linux-aio.o and stub out the block/io_uring.o APIs that will be
missing when a binary is linked with obj-util-y but without
block-util-y (e.g. vhost-user-gpu).

For example, the stubs are necessary so that a binary using util/async.o
from obj-util-y for qemu_bh_new() links successfully.  In this case
block/io_uring.o from block-util-y isn't needed and we can avoid
dragging in the block layer by linking the stubs instead.  The stub
functions never get called.
Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-6-stefanha@redhat.com
Message-Id: <20200120141858.587874-6-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Aborts when sqe fails to be set as sqes cannot be returned to the
ring. Adds slow path for short reads for older kernels
Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-5-stefanha@redhat.com
Message-Id: <20200120141858.587874-5-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-4-stefanha@redhat.com
Message-Id: <20200120141858.587874-4-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Since io_uring is the actual name of the Linux API, we use it as enum
value even though the QAPI schema conventions would prefer io-uring.
Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-3-stefanha@redhat.com
Message-Id: <20200120141858.587874-3-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NAarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-2-stefanha@redhat.com
Message-Id: <20200120141858.587874-2-stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

bdrv_mark_request_serialising is writing the overlap_offset and
overlap_bytes fields of BdrvTrackedRequest.  Take bs->reqs_lock
for the whole duration of it, and not just when waiting for
serialising requests, so that tracked_request_overlaps does not
look at a half-updated request.

The new code does not unlock/relock around retries.  This is unnecessary
because a retry is always preceded by a CoQueue wait, which already
releases and reacquires bs->reqs_lock.
Reported-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1578495356-46219-4-git-send-email-pbonzini@redhat.com
Message-Id: <1578495356-46219-4-git-send-email-pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Marking without waiting would not result in actual serialising behavior.
Thus, make a call bdrv_mark_request_serialising sufficient for
serialisation to happen.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1578495356-46219-3-git-send-email-pbonzini@redhat.com
Message-Id: <1578495356-46219-3-git-send-email-pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

It is unused since commit 00e30f05 ("block/backup: use backup-top instead
of write notifiers", 2019-10-01), drop it to simplify the code.

While at it, drop redundant assertions on flags.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1578495356-46219-2-git-send-email-pbonzini@redhat.com
Message-Id: <1578495356-46219-2-git-send-email-pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

target-arm queue:
 * hw/core/or-irq: Fix incorrect assert forbidding num-lines == MAX_OR_LINES
 * target/arm/arm-semi: Don't let the guest close stdin/stdout/stderr
 * aspeed: some minor bugfixes
 * aspeed: add eMMC controller model for AST2600 SoC
 * hw/arm/raspi: Remove obsolete use of -smp to set the soc 'enabled-cpus'
 * New 3-phase reset API for device models
 * hw/intc/arm_gicv3_kvm: Stop wrongly programming GICR_PENDBASER.PTZ bit
 * Arm KVM: stop/restart the guest counter when the VM is stopped and started

# gpg: Signature made Thu 30 Jan 2020 16:14:45 GMT
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20200130: (26 commits)
  target/arm/cpu: Add the kvm-no-adjvtime CPU property
  target/arm/kvm: Implement virtual time adjustment
  tests/arm-cpu-features: Check feature default values
  target/arm/kvm64: kvm64 cpus have timer registers
  hw/arm/virt: Add missing 5.0 options call to 4.2 options
  target/arm/kvm: trivial: Clean up header documentation
  hw/intc/arm_gicv3_kvm: Stop wrongly programming GICR_PENDBASER.PTZ bit
  hw/s390x/ipl: replace deprecated qdev_reset_all registration
  vl: replace deprecated qbus_reset_all registration
  docs/devel/reset.rst: add doc about Resettable interface
  hw/core: deprecate old reset functions and introduce new ones
  hw/core/qdev: update hotplug reset regarding resettable
  hw/core/qdev: handle parent bus change regarding resettable
  hw/core/resettable: add support for changing parent
  hw/core: add Resettable support to BusClass and DeviceClass
  hw/core: create Resettable QOM interface
  hw/core/qdev: add trace events to help with resettable transition
  add device_legacy_reset function to prepare for reset api change
  hw/arm/raspi: Remove obsolete use of -smp to set the soc 'enabled-cpus'
  misc/pca9552: Add qom set and get
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

kvm-no-adjvtime is a KVM specific CPU property and a first of its
kind. To accommodate it we also add kvm_arm_add_vcpu_properties()
and a KVM specific CPU properties description to the CPU features
document.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-7-drjones@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

When a VM is stopped (such as when it's paused) guest virtual time
should stop counting. Otherwise, when the VM is resumed it will
experience time jumps and its kernel may report soft lockups. Not
counting virtual time while the VM is stopped has the side effect
of making the guest's time appear to lag when compared with real
time, and even with time derived from the physical counter. For
this reason, this change, which is enabled by default, comes with
a KVM CPU feature allowing it to be disabled, restoring legacy
behavior.

This patch only provides the implementation of the virtual time
adjustment. A subsequent patch will provide the CPU property
allowing the change to be enabled and disabled.
Reported-by: NBijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-6-drjones@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

If we know what the default value should be then we can test for
that as well as the feature existence.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20200120101023.16030-5-drjones@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Add the missing GENERIC_TIMER feature to kvm64 cpus.

We don't currently use these registers when KVM is enabled, but it's
probably best we add the feature flag for consistency and potential
future use. There's also precedent, as we add the PMU feature flag to
KVM enabled guests, even though we don't use those registers either.

This change was originally posted as a hunk of a different, never
merged patch from Bijan Mottahedeh.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20200120101023.16030-4-drjones@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NAndrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-3-drjones@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NAndrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-2-drjones@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

If LPIs are disabled, KVM will just ignore the GICR_PENDBASER.PTZ bit when
restoring GICR_CTLR.  Setting PTZ here makes littlt sense in "reduce GIC
initialization time".

And what's worse, PTZ is generally programmed by guest to indicate to the
Redistributor whether the LPI Pending table is zero when enabling LPIs.
If migration is triggered when the PTZ has just been cleared by guest (and
before enabling LPIs), we will see PTZ==1 on the destination side, which
is not as expected.  Let's just drop this hackish userspace behavior.

Also take this chance to refine the comment a bit.

Fixes: 367b9f52 ("hw/intc/arm_gicv3_kvm: Implement get/put functions")
Signed-off-by: NZenghui Yu <yuzenghui@huawei.com>
Message-id: 20200119133051.642-1-yuzenghui@huawei.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Replace deprecated qdev_reset_all by resettable_cold_reset_fn for
the ipl registration in the main reset handlers.

This does not impact the behavior for the following reasons:
+ at this point resettable just call the old reset methods of devices
  and buses in the same order than qdev/qbus.
+ resettable handlers registered with qemu_register_reset are
  serialized; there is no interleaving.
+ eventual explicit calls to legacy reset API (device_reset or
  qdev/qbus_reset) inside this reset handler will not be masked out
  by resettable mechanism; they do not go through resettable api.
Signed-off-by: NDamien Hedde <damien.hedde@greensocs.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20200123132823.1117486-12-damien.hedde@greensocs.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Replace deprecated qbus_reset_all by resettable_cold_reset_fn for
the sysbus reset registration.

Apart for the raspi machines, this does not impact the behavior
because:
+ at this point resettable just calls the old reset methods of devices
  and buses in the same order as qdev/qbus.
+ resettable handlers registered with qemu_register_reset are
  serialized; there is no interleaving.
+ eventual explicit calls to legacy reset API (device_reset or
  qdev/qbus_reset) inside this reset handler will not be masked out
  by resettable mechanism; they do not go through resettable api.

For the raspi machines, during the sysbus reset the sd-card is not
reset twice anymore but only once. This is a consequence of switching
both sysbus reset and changing parent to resettable; it detects the
second reset is not needed. This has no impact on the state after
reset; the sd-card reset method only reset local state and query
information from the block backend.

The raspi reset change can be observed by using the following command
(reset will occurs, then do Ctrl-C to end qemu; no firmware is
given here).
qemu-system-aarch64 -M raspi3 \
    -trace resettable_phase_hold_exec \
    -trace qdev_update_parent_bus \
    -trace resettable_change_parent \
    -trace qdev_reset -trace qbus_reset

Before the patch, the qdev/qbus_reset traces show when reset method are
called. After the patch, the resettable_phase_hold_exec show when reset
method are called.

The traced reset order of the raspi3 is listed below. I've added empty
lines and the tree structure.

 +->bcm2835-peripherals reset
 |
 |       +->sd-card reset
 |   +->sd-bus reset
 +->bcm2835_gpio reset
 |      -> dev_update_parent_bus (move the sd-card on the sdhci-bus)
 |      -> resettable_change_parent
 |
 +->bcm2835-dma reset
 |
 |   +->bcm2835-sdhost-bus reset
 +->bcm2835-sdhost reset
 |
 |       +->sd-card (reset ONLY BEFORE BEFORE THE PATCH)
 |   +->sdhci-bus reset
 +->generic-sdhci reset
 |
 +->bcm2835-rng reset
 +->bcm2835-property reset
 +->bcm2835-fb reset
 +->bcm2835-mbox reset
 +->bcm2835-aux reset
 +->pl011 reset
 +->bcm2835-ic reset
 +->bcm2836-control reset
System reset

In both case, the sd-card is reset (being on bcm2835_gpio/sd-bus) then moved
to generic-sdhci/sdhci-bus by the bcm2835_gpio reset method.

Before the patch, it is then reset again being part of generic-sdhci/sdhci-bus.
After the patch, it considered again for reset but its reset method is not
called because it is already flagged as reset.
Signed-off-by: NDamien Hedde <damien.hedde@greensocs.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-11-damien.hedde@greensocs.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NDamien Hedde <damien.hedde@greensocs.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20200123132823.1117486-10-damien.hedde@greensocs.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Deprecate device_legacy_reset(), qdev_reset_all() and
qbus_reset_all() to be replaced by new functions
device_cold_reset() and bus_cold_reset() which uses resettable API.

Also introduce resettable_cold_reset_fn() which may be used as a
replacement for qdev_reset_all_fn and qbus_reset_all_fn().

Following patches will be needed to look at legacy reset call sites
and switch to resettable api. The legacy functions will be removed
when unused.
Signed-off-by: NDamien Hedde <damien.hedde@greensocs.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Tested-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-9-damien.hedde@greensocs.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>