The GDateTime APIs provided by GLib avoid portability pitfalls, such
as some platforms where 'struct timeval.tv_sec' field is still 'long'
instead of 'time_t'. When combined with automatic cleanup, GDateTime
often results in simpler code too.
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.
We still have several references to the old file, so let's fix them
with the following command:
sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Per xHCI spec v1.2 chapter 4.17.5 page 296:
If MSI or MSI-X interrupts are enabled, Interrupt Pending (IP)
shall be cleared automatically when the PCI dword write generated
by the interrupt assertion is complete.
Currently QEMU does not clear the IP flag in the MSI / MSI-X mode.
This causes subsequent spurious interrupt to be delivered to guests.
To solve this, we change the xhci intr_raise() hook routine to have
a bool return value that is passed to its caller (the xhci core),
with true indicating that IP should be self-cleared.
Fixes: 62c6ae04cf ("xhci: Initial xHCI implementation")
Fixes: 4c47f80063 ("xhci: add msix support")
Signed-off-by: Ruimei Yan <ruimei.yan@windriver.com>
[bmeng: move IP clear codes from xhci pci to xhci core]
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Message-Id: <20210521024224.2277634-2-bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
At present MSI / MSI-X interrupts are triggered regardless of the
irq level. We should have checked the level to determine whether
the interrupt needs to be delivered.
The level check logic was present in early versions of the xhci
model, but got dropped later by a rework of interrupt handling
under commit 4c4abe7cc9 ("xhci: rework interrupt handling").
Fixes: 4c4abe7cc9 ("xhci: rework interrupt handling")
Signed-off-by: Ruimei Yan <ruimei.yan@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Message-Id: <20210521024224.2277634-1-bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Target lm32 was deprecated in commit d849800512, v5.2.0. See there
for rationale.
Some of its code lives on in device models derived from milkymist
ones: hw/char/digic-uart.c and hw/display/bcm2835_fb.c.
Cc: Michael Walle <michael@walle.cc>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210503084034.3804963-2-armbru@redhat.com>
Acked-by: Michael Walle <michael@walle.cc>
[Trivial conflicts resolved, reST markup fixed]
usb-host and usb-redirect try to batch bulk transfers by combining many
small usb packets into a single, large transfer request, to reduce the
overhead and improve performance.
This patch adds a size limit of 1 MiB for those combined packets to
restrict the host resources the guest can bind that way.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210503132915.2335822-6-kraxel@redhat.com>
If the Kconfig 'USB' value is not selected, it is pointless to
build the USB core components. Add a stub for the HMP commands
and usbdevice_create() which is called by usb_device_add in
softmmu/vl.c.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210424224110.3442424-3-f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Many files include qemu/log.h without needing it. Remove the superfluous
include statements.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210328054833.2351597-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Many files include hw/irq.h without needing it. Remove the superfluous
include statements.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210327050236.2232347-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Many files include hw/sysbus.h without needing it. Remove the superfluous
include statements.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210327082804.2259480-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
QEMU crashes with certain targets when trying to show the help
output of EHCI devices:
$ ./qemu-system-aarch64 -device ich9-usb-ehci1,help
qemu-system-aarch64: ../../devel/qemu/softmmu/physmem.c:1154: phys_section_add:
Assertion `map->sections_nb < TARGET_PAGE_SIZE' failed.
Aborted (core dumped)
This happens because the device is doing things at "instance_init" time
that should be done at "realize" time instead. So move the related code
to the realize() function instead. (NB: This now also matches the
memory_region_del_subregion() calls which are done in usb_ehci_unrealize(),
and not during finalize()).
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210326095155.1994604-1-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
When building with --enable-sanitizers we get:
Direct leak of 32 byte(s) in 2 object(s) allocated from:
#0 0x5618479ec7cf in malloc (qemu-system-aarch64+0x233b7cf)
#1 0x7f675745f958 in g_malloc (/lib64/libglib-2.0.so.0+0x58958)
#2 0x561847f02ca2 in usb_packet_init hw/usb/core.c:531:5
#3 0x561848df4df4 in usb_ehci_init hw/usb/hcd-ehci.c:2575:5
#4 0x561847c119ac in ehci_sysbus_init hw/usb/hcd-ehci-sysbus.c:73:5
#5 0x56184a5bdab8 in object_init_with_type qom/object.c:375:9
#6 0x56184a5bd955 in object_init_with_type qom/object.c:371:9
#7 0x56184a5a2bda in object_initialize_with_type qom/object.c:517:5
#8 0x56184a5a24d5 in object_initialize qom/object.c:536:5
#9 0x56184a5a2f6c in object_initialize_child_with_propsv qom/object.c:566:5
#10 0x56184a5a2e60 in object_initialize_child_with_props qom/object.c:549:10
#11 0x56184a5a3a1e in object_initialize_child_internal qom/object.c:603:5
#12 0x561849542d18 in npcm7xx_init hw/arm/npcm7xx.c:427:5
Similarly to commit d710e1e7bd ("usb: ehci: fix memory leak in
ehci"), fix by calling usb_ehci_finalize() to free the USBPacket.
Fixes: 7341ea075c
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210323183701.281152-1-f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
"-usbdevice ccid" was not documented and -usbdevice itself was marked
as deprecated before QEMU v6.0. And searching for "-usbdevice ccid"
in the internet does not show any useful results, so likely nobody
was using the ccid device via the -usbdevice option. Remove it now.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210311092829.1479051-1-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Stale data in csw (specifically residue) can confuse the state machine
and allows the guest trigger an assert(). So clear csw on reset to
avoid this happening in case the guest resets the device in the middle
of a request.
Buglink: https://bugs.launchpad.net/qemu/+bug/1523811
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210312094954.796799-1-kraxel@redhat.com>
Add new kconfig symbols so usb-storage and usb-bot can
be enabled or disabled individually at build time.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210312090425.772900-5-kraxel@redhat.com>
In preparation for splitting the usb-storage.c file move
declarations to the new usb/msd.h header file.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210312090425.772900-2-kraxel@redhat.com>
Extract the VT82C686 PCI UHCI function into a new unit so
it is only build when the VT82C686 south bridge is selected.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210309190802.830969-4-f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Extract generic UHCI prototypes into a new "hcd-uhci.h" local
header so we can reuse them in other units.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210309190802.830969-3-f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
When trying to remove the -usbdevice option, there were complaints that
"-usbdevice braille" is still a very useful shortcut for some people.
Thus we never remove this option. Since it's not such a big burden to
keep it around, and it's also convenient in the sense that you don't
have to worry to enable a host controller explicitly with this option,
we should remove it from he deprecation list again.
However, there is one exception: "-usbdevice audio" should go away, since
audio devices without "audiodev=..." parameter are also on the deprecation
list and you cannot use "-usbdevice audio" with "audiodev".
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210310173323.1422754-4-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
No device needs them anymore and in fact they're undocumented.
Remove the code. The only change in behavior is that "-usbdevice
braille:hello" now reports an error, which is a bugfix.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210310173323.1422754-2-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This property was only required for the pc-1.0 and earlier machine
types. Since these have been removed now, we can delete the property
as well.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210302120152.118042-1-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The 'running' argument from VMChangeStateHandler does not require
other value than 0 / 1. Make it a plain boolean.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210111152020.1422021-3-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
An assorted set of spelling fixes in various places.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210309111510.79495-1-mjt@msgid.tls.msk.ru>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The command complete callback has a SCSIRequest as the first argument,
and the status field of that structure is identical to the 'status'
argument. So drop the argument from the callback.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Message-Id: <20201116184041.60465-3-hare@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The category of the u2f-passthru device is not set, put it into the 'misc'
category.
Signed-off-by: Gan Qixin <ganqixin@huawei.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20201130083630.2520597-10-ganqixin@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Without that wireshark complains about invalid control setup data
for non-control transfers.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210216144939.841873-1-kraxel@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
In order to keep track of the alternate setting that should be used for
a given interface, the USBDevice struct keeps an array of alternate
setting values, which is indexed by the interface number. In
usb_host_set_interface, when this array is updated, usb_host_ep_update
is called as a result. However, when usb_host_ep_update accesses the
active libusb_config_descriptor, it indexes udev->altsetting with the
loop variable, rather than the interface number.
With the simple trace backend enable, this behavior can be seen:
[...]
usb_xhci_xfer_start 0.440 pid=1215 xfer=0x5596a4b85930 slotid=0x1 epid=0x1 streamid=0x0
usb_packet_state_change 1.703 pid=1215 bus=0x1 port=b'1' ep=0x0 p=0x5596a4b85938 o=b'undef' n=b'setup'
usb_host_req_control 2.269 pid=1215 bus=0x1 addr=0x5 p=0x5596a4b85938 req=0x10b value=0x1 index=0xd
usb_host_set_interface 0.449 pid=1215 bus=0x1 addr=0x5 interface=0xd alt=0x1
usb_host_parse_config 2542.648 pid=1215 bus=0x1 addr=0x5 value=0x2 active=0x1
usb_host_parse_interface 1.804 pid=1215 bus=0x1 addr=0x5 num=0xc alt=0x0 active=0x1
usb_host_parse_endpoint 2.012 pid=1215 bus=0x1 addr=0x5 ep=0x2 dir=b'in' type=b'int' active=0x1
usb_host_parse_interface 1.598 pid=1215 bus=0x1 addr=0x5 num=0xd alt=0x0 active=0x1
usb_host_req_emulated 3.593 pid=1215 bus=0x1 addr=0x5 p=0x5596a4b85938 status=0x0
usb_packet_state_change 2.550 pid=1215 bus=0x1 port=b'1' ep=0x0 p=0x5596a4b85938 o=b'setup' n=b'complete'
usb_xhci_xfer_success 4.298 pid=1215 xfer=0x5596a4b85930 bytes=0x0
[...]
In particular, it is seen that although usb_host_set_interface sets the
alternate setting of interface 0xd to 0x1, usb_host_ep_update uses 0x0
as the alternate setting due to using the incorrect index to
udev->altsetting.
Fix this problem by getting the interface number from the active
libusb_config_descriptor, and then using that as the index to
udev->altsetting.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Message-Id: <20210201213021.500277-1-rosbrookn@ainfosec.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Currently, blk_is_read_only() tells whether a given BlockBackend can
only be used in read-only mode because its root node is read-only. Some
callers actually try to answer a slightly different question: Is the
BlockBackend configured to be writable, by taking write permissions on
the root node?
This can differ, for example, for CD-ROM devices which don't take write
permissions, but may be backed by a writable image file. scsi-cd allows
write requests to the drive if blk_is_read_only() returns false.
However, the write request will immediately run into an assertion
failure because the write permission is missing.
This patch introduces separate functions for both questions.
blk_supports_write_perm() answers the question whether the block
node/image file can support writable devices, whereas blk_is_writable()
tells whether the BlockBackend is currently configured to be writable.
All calls of blk_is_read_only() are converted to one of the two new
functions.
Fixes: https://bugs.launchpad.net/bugs/1906693
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210118123448.307825-2-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Handle host superspeedplus (usb 3.1+) devices like superspeed (usb 3.0)
devices. That is enough to get them handled properly by xhci. They show
up as superspeed devices inside the guest, but should be able to actually
run at higher speeds.
Reported-by: Angel Pagan <Angel.Pagan@stratus.com>
Tested-by: Angel Pagan <Angel.Pagan@stratus.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210121150832.3564097-1-kraxel@redhat.com>
Log all traffic of a specific usb device to a pcap file for later
inspection. File format is compatible with linux usb monitor.
Usage:
qemu -device usb-${somedevice},pcap=file.pcap
wireshark file.pcap
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210119194452.2148048-1-kraxel@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We are not ready to handle additional CDB data.
If a guest sends a packet with such additional data,
report the command parameter as not supported.
Specify a size (of 1 byte) for the add_cdb member we
are not using, to fix the following warning:
usb/dev-uas.c:157:31: error: field 'status' with variable sized type 'uas_iu' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end]
uas_iu status;
^
Reported-by: Ed Maste <emaste@FreeBSD.org>
Reported-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Reported-by: Han Han <hhan@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210120153522.1173897-4-philmd@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
For some reason the assert() added in commit ccb799313a
("hw/usb: avoid format truncation warning when formatting
port name") does not fix when building with GCC 10.
KISS and expand the buffer by 4 bytes to silent the following
error when using GCC 10.2.1 on Fedora 33:
hw/usb/hcd-xhci.c: In function 'usb_xhci_realize':
hw/usb/hcd-xhci.c:3309:54: error: '%d' directive output may be truncated writing between 1 and 8 bytes into a region of size 5 [-Werror=format-truncation=]
3309 | snprintf(port->name, sizeof(port->name), "usb2 port #%d", i+1);
| ^~~~~~~~~~~~~~~
hw/usb/hcd-xhci.c:3309:54: note: directive argument in the range [1, 89478486]
In file included from /usr/include/stdio.h:866,
from include/qemu/osdep.h:85,
from hw/usb/hcd-xhci.c:22:
/usr/include/bits/stdio2.h:70:10: note: '__builtin___snprintf_chk' output between 13 and 20 bytes into a destination of size 16
70 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
71 | __bos (__s), __fmt, __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hw/usb/hcd-xhci.c:3323:54: error: '%d' directive output may be truncated writing between 1 and 8 bytes into a region of size 5 [-Werror=format-truncation=]
3323 | snprintf(port->name, sizeof(port->name), "usb3 port #%d", i+1);
| ^~~~~~~~~~~~~~~
hw/usb/hcd-xhci.c:3323:54: note: directive argument in the range [1, 89478486]
In file included from /usr/include/stdio.h:866,
from include/qemu/osdep.h:85,
from hw/usb/hcd-xhci.c:22:
/usr/include/bits/stdio2.h:70:10: note: '__builtin___snprintf_chk' output between 13 and 20 bytes into a destination of size 16
70 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
71 | __bos (__s), __fmt, __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210118181115.313742-1-philmd@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Device code shouldn't mess with QOM property "realized" since we have
proper interfaces (merge commit 6675a653). Commit 8ddab8dd3d
"usb/hcd-xhci: Split pci wrapper for xhci base model" and commit
f00ff136ee "usb: hcd-xhci-sysbus: Attach xhci to sysbus device"
reintroduced two instances. Clean them up. Note that s->xhci is
a (bus-less) TYPE_XHCI device.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210119120151.53757-1-armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We should use printf format specifier "%u" instead of "%d" for
argument of type "unsigned int".
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Message-id: 20201119025751.45750-1-alex.chen@huawei.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
USBDEVFS_GET_SPEED is used since version 5.2.0 and
202d69a715
resulting in the following build failure with kernel < 5.0:
../hw/usb/host-libusb.c: In function 'usb_host_open':
../hw/usb/host-libusb.c:953:32: error: 'USBDEVFS_GET_SPEED' undeclared (first use in this function); did you mean 'USBDEVFS_GETDRIVER'?
int rc = ioctl(hostfd, USBDEVFS_GET_SPEED, NULL);
^~~~~~~~~~~~~~~~~~
USBDEVFS_GETDRIVER
A tentative was made to fix this build failure with
4969e697c1
However, the assumption that distros with old kernels also have old
libusb is just wrong so also add a check for defined(USBDEVFS_GET_SPEED)
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Message-id: 20201213213016.457350-1-fontaine.fabrice@gmail.com
[ kraxel: codestyle whitespace fixup ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is the result of running the timer-del-timer-free.cocci
script on the whole source tree.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201215154107.3255-4-peter.maydell@linaro.org
Commit 8118f0950f "migration: Append JSON description of migration
stream" needs a JSON writer. The existing qobject_to_json() wasn't a
good fit, because it requires building a QObject to convert. Instead,
migration got its very own JSON writer, in commit 190c882ce2 "QJSON:
Add JSON writer". It tacitly limits numbers to int64_t, and strings
contents to characters that don't need escaping, unlike
qobject_to_json().
The previous commit factored the JSON writer out of qobject_to_json().
Replace migration's JSON writer by it.
Cc: Juan Quintela <quintela@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-17-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
