qemu-system-FOO's main() acts on command line arguments in its own
idiosyncratic order.  There's not much method to its madness.
Whenever we find a case where one kind of command line argument needs
to refer to something created for another kind later, we rejigger the
order.

Block devices get created long after machine properties get processed.
Therefore, block device machine properties can be created, but not
set.  No such properties exist.  But the next commit will create some.
Time to rejigger again: create block devices earlier.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190308131445.17502-8-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
---
 vl.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/vl.c b/vl.c
index c22ca447fa..e9239d55ad 100644
--- a/vl.c
+++ b/vl.c
@@ -4274,6 +4274,13 @@ int main(int argc, char **argv, char **envp)
         exit(0);
     }
 
+    /*
+     * Note: we need to create block backends before
+     * machine_set_property(), so machine properties can refer to
+     * them.
+     */
+    configure_blockdev(&bdo_queue, machine_class, snapshot);
+
     machine_opts = qemu_get_machine_opts();
     qemu_opt_foreach(machine_opts, machine_set_property, current_machine,
                      &error_fatal);
@@ -4400,8 +4407,6 @@ int main(int argc, char **argv, char **envp)
     ram_mig_init();
     dirty_bitmap_mig_init();
 
-    configure_blockdev(&bdo_queue, machine_class, snapshot);
-
     qemu_opts_foreach(qemu_find_opts("mon"),
                       mon_init_func, NULL, &error_fatal);
 
-- 
2.17.2

Am 11.03.2019 um 23:08 hat Markus Armbruster geschrieben:
> qemu-system-FOO's main() acts on command line arguments in its own
> idiosyncratic order.  There's not much method to its madness.
> Whenever we find a case where one kind of command line argument needs
> to refer to something created for another kind later, we rejigger the
> order.
> 
> Block devices get created long after machine properties get processed.
> Therefore, block device machine properties can be created, but not
> set.  No such properties exist.  But the next commit will create some.
> Time to rejigger again: create block devices earlier.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Message-Id: <20190308131445.17502-8-armbru@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

This commit broke qemu-iotests 055. Looks like migration_object_init()
must come before configure_blockdev().

Kevin


(gdb) bt
#0  0x00007f7eb447853f in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1  0x00007f7eb4462895 in __GI_abort () at abort.c:79
#2  0x00007f7eb4462769 in __assert_fail_base
    (fmt=0x7f7eb45c9e90 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5589747e3e67 "current_migration", file=0x5589747e3d85 "migration/migration.c", line=187, function=<optimized out>) at assert.c:92
#3  0x00007f7eb44709f6 in __GI___assert_fail
    (assertion=assertion@entry=0x5589747e3e67 "current_migration", file=file@entry=0x5589747e3d85 "migration/migration.c", line=line@entry=187, function=function@entry=0x5589747e59b0 <__PRETTY_FUNCTION__.32386> "migrate_get_current") at assert.c:101
#4  0x0000558974513083 in migrate_get_current () at migration/migration.c:187
#5  0x000055897451634d in migrate_get_current () at migration/migration.c:1719
#6  0x000055897451634d in migrate_add_blocker (reason=<optimized out>, errp=errp@entry=0x7ffd901f4d10) at migration/migration.c:1715
#7  0x000055897459d941 in vmdk_open (bs=0x55897697a2c0, options=<optimized out>, flags=<optimized out>, errp=0x7ffd901f4d70) at block/vmdk.c:1019
#8  0x000055897458d466 in bdrv_open_driver
    (bs=bs@entry=0x55897697a2c0, drv=drv@entry=0x558974d6cfe0 <bdrv_vmdk>, node_name=<optimized out>, options=options@entry=0x55897697e560, open_flags=139266, errp=errp@entry=0x7ffd901f4e18) at block.c:1279
#9  0x0000558974590cc1 in bdrv_open_common (errp=0x7ffd901f4e18, options=0x55897697e560, file=0x5589769295a0, bs=0x55897697a2c0) at block.c:1537
#10 0x0000558974590cc1 in bdrv_open_inherit (filename=<optimized out>, 
    filename@entry=0x558976905490 "/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img", reference=reference@entry=0x0, options=0x55897697e560, 
    options@entry=0x5589768f4750, flags=<optimized out>, flags@entry=0, parent=parent@entry=0x0, child_role=child_role@entry=0x0, errp=0x7ffd901f50e0) at block.c:2889
#11 0x0000558974591ac1 in bdrv_open
    (filename=filename@entry=0x558976905490 "/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img", reference=reference@entry=0x0, options=options@entry=0x5589768f4750, flags=flags@entry=0, errp=errp@entry=0x7ffd901f50e0) at block.c:2982
#12 0x00005589745d6551 in blk_new_open
    (filename=filename@entry=0x558976905490 "/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img", reference=reference@entry=0x0, options=options@entry=0x5589768f4750, flags=flags@entry=0, errp=errp@entry=0x7ffd901f50e0) at block/block-backend.c:377
#13 0x000055897439f6b3 in blockdev_init
    (file=file@entry=0x558976905490 "/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img", bs_opts=bs_opts@entry=0x5589768f4750, errp=errp@entry=0x7ffd901f50e0)
    at blockdev.c:602
#14 0x00005589743a0524 in drive_new (all_opts=<optimized out>, block_default_type=<optimized out>, errp=0x558974dd6310 <error_fatal>) at blockdev.c:994
#15 0x00005589743aaba1 in drive_init_func (opaque=<optimized out>, opts=<optimized out>, errp=<optimized out>) at vl.c:1163
#16 0x000055897468db7a in qemu_opts_foreach (list=<optimized out>, func=0x5589743aab90 <drive_init_func>, opaque=0x558976869228, errp=0x558974dd6310 <error_fatal>)
    at util/qemu-option.c:1171
#17 0x0000558974235950 in configure_blockdev (snapshot=0, machine_class=0x558976869180, bdo_queue=0x7ffd901f5270) at vl.c:1230
#18 0x0000558974235950 in main (argc=<optimized out>, argv=0x7ffd901f53d8, envp=<optimized out>) at vl.c:4282



055 44s ...        [20:21:24] [20:21:52] [failed, exit status 1] - output mismatch (see 055.out.bad)
--- /home/kwolf/source/qemu/tests/qemu-iotests/055.out  2018-06-13 10:33:18.579269839 +0200
+++ /home/kwolf/source/qemu/tests/qemu-iotests/055.out.bad      2019-03-12 20:21:52.953410878 +0100
@@ -1,5 +1,83 @@
-..............................
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmp6q0miuno/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmp6q0miuno/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmppf_qfi2k/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmppf_qfi2k/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmpsoykllpm/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+WARNING:qemu:qemu received signal 6: /home/kwolf/source/qemu/tests/qemu-iotests/qemu -chardev socket,id=mon,path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/tmpsoykllpm/qemu-4146-monitor.sock -mon chardev=mon,mode=control -display none -vga none -qtest unix:path=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/qemu-4146-qtest.sock -machine accel=qtest -nodefaults -machine accel=qtest -drive if=virtio,id=drive0,file=blkdebug::/home/kwolf/source/qemu/tests/qemu-iotests/scratch/test.img,format=qcow2,cache=writeback -drive if=none,id=drive1,file=/home/kwolf/source/qemu/tests/qemu-iotests/scratch/blockdev-target.img,format=vmdk,cache=writeback
+E.E.E.........................
+======================================================================
+ERROR: test_complete_compress_blockdev_backup (__main__.TestDriveCompression)
+----------------------------------------------------------------------
+Traceback (most recent call last):
+  File "055", line 499, in test_complete_compress_blockdev_backup
+    target='drive1')
+  File "055", line 477, in do_test_compress_complete
+    self.do_prepare_drives(format['type'], format['args'], attach_target)
+  File "055", line 474, in do_prepare_drives
+    self.vm.launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 303, in launch
+    self._launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 330, in _launch
+    self._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qtest.py", line 107, in _post_launch
+    super(QEMUQtestMachine, self)._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 274, in _post_launch
+    self._qmp.accept()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 157, in accept
+    return self.__negotiate_capabilities()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 73, in __negotiate_capabilities
+    raise QMPConnectError
+qemu.qmp.QMPConnectError
+
+======================================================================
+ERROR: test_compress_cancel_blockdev_backup (__main__.TestDriveCompression)
+----------------------------------------------------------------------
+Traceback (most recent call last):
+  File "055", line 523, in test_compress_cancel_blockdev_backup
+    target='drive1')
+  File "055", line 502, in do_test_compress_cancel
+    self.do_prepare_drives(format['type'], format['args'], attach_target)
+  File "055", line 474, in do_prepare_drives
+    self.vm.launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 303, in launch
+    self._launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 330, in _launch
+    self._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qtest.py", line 107, in _post_launch
+    super(QEMUQtestMachine, self)._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 274, in _post_launch
+    self._qmp.accept()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 157, in accept
+    return self.__negotiate_capabilities()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 73, in __negotiate_capabilities
+    raise QMPConnectError
+qemu.qmp.QMPConnectError
+
+======================================================================
+ERROR: test_compress_pause_blockdev_backup (__main__.TestDriveCompression)
+----------------------------------------------------------------------
+Traceback (most recent call last):
+  File "055", line 563, in test_compress_pause_blockdev_backup
+    target='drive1')
+  File "055", line 526, in do_test_compress_pause
+    self.do_prepare_drives(format['type'], format['args'], attach_target)
+  File "055", line 474, in do_prepare_drives
+    self.vm.launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 303, in launch
+    self._launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 330, in _launch
+    self._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qtest.py", line 107, in _post_launch
+    super(QEMUQtestMachine, self)._post_launch()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/__init__.py", line 274, in _post_launch
+    self._qmp.accept()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 157, in accept
+    return self.__negotiate_capabilities()
+  File "/home/kwolf/source/qemu/tests/qemu-iotests/../../python/qemu/qmp.py", line 73, in __negotiate_capabilities
+    raise QMPConnectError
+qemu.qmp.QMPConnectError
+
 ----------------------------------------------------------------------
 Ran 30 tests

-OK
+FAILED (errors=3)
Failures: 055
Failed 1 of 1 tests

Kevin Wolf <kwolf@redhat.com> writes:

> Am 11.03.2019 um 23:08 hat Markus Armbruster geschrieben:
>> qemu-system-FOO's main() acts on command line arguments in its own
>> idiosyncratic order.  There's not much method to its madness.
>> Whenever we find a case where one kind of command line argument needs
>> to refer to something created for another kind later, we rejigger the
>> order.
>> 
>> Block devices get created long after machine properties get processed.
>> Therefore, block device machine properties can be created, but not
>> set.  No such properties exist.  But the next commit will create some.
>> Time to rejigger again: create block devices earlier.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> Message-Id: <20190308131445.17502-8-armbru@redhat.com>
>> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
>
> This commit broke qemu-iotests 055. Looks like migration_object_init()
> must come before configure_blockdev().

One of the slow tests not covered by make check-block...

I posted a proposed fix.  Thanks!

On 3/11/19 11:08 PM, Markus Armbruster wrote:
> qemu-system-FOO's main() acts on command line arguments in its own
> idiosyncratic order.  There's not much method to its madness.
> Whenever we find a case where one kind of command line argument needs
> to refer to something created for another kind later, we rejigger the
> order.
> 
> Block devices get created long after machine properties get processed.
> Therefore, block device machine properties can be created, but not
> set.  No such properties exist.  But the next commit will create some.
> Time to rejigger again: create block devices earlier.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Message-Id: <20190308131445.17502-8-armbru@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>   vl.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/vl.c b/vl.c
> index c22ca447fa..e9239d55ad 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4274,6 +4274,13 @@ int main(int argc, char **argv, char **envp)
>           exit(0);
>       }
>   
> +    /*
> +     * Note: we need to create block backends before
> +     * machine_set_property(), so machine properties can refer to
> +     * them.
> +     */
> +    configure_blockdev(&bdo_queue, machine_class, snapshot);
> +
>       machine_opts = qemu_get_machine_opts();
>       qemu_opt_foreach(machine_opts, machine_set_property, current_machine,
>                        &error_fatal);
> @@ -4400,8 +4407,6 @@ int main(int argc, char **argv, char **envp)
>       ram_mig_init();
>       dirty_bitmap_mig_init();
>   
> -    configure_blockdev(&bdo_queue, machine_class, snapshot);
> -
>       qemu_opts_foreach(qemu_find_opts("mon"),
>                         mon_init_func, NULL, &error_fatal);
>   
> 

Actually, there is more problems with this. Trying to run a guest with 
persistent reservations fails after this patch is applied (git bisect 
points me to this commit). My command line is:

qemu.git $ ./x86_64-softmmu/qemu-system-x86_64 \
-monitor stdio \
-object pr-manager-helper,id=pr-helper0,path=/tmp/pr-helper0.sock
-drive 
file=/dev/mapper/crypt,file.pr-manager=pr-helper0,format=raw,if=none,id=drive-scsi0-0-0-2 
\
-device 
scsi-block,bus=scsi0.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi0-0-0-2,id=scsi0-0-0-2

Honestly, I have no idea how to fix it, so I'm just raising this issue 
here. Do you want me to open a bug or something?

Thanks,
Michal

Michal Privoznik <mprivozn@redhat.com> writes:

> On 3/11/19 11:08 PM, Markus Armbruster wrote:
>> qemu-system-FOO's main() acts on command line arguments in its own
>> idiosyncratic order.  There's not much method to its madness.
>> Whenever we find a case where one kind of command line argument needs
>> to refer to something created for another kind later, we rejigger the
>> order.
>>
>> Block devices get created long after machine properties get processed.
>> Therefore, block device machine properties can be created, but not
>> set.  No such properties exist.  But the next commit will create some.
>> Time to rejigger again: create block devices earlier.
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> Message-Id: <20190308131445.17502-8-armbru@redhat.com>
>> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
>> ---
>>   vl.c | 9 +++++++--
>>   1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/vl.c b/vl.c
>> index c22ca447fa..e9239d55ad 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -4274,6 +4274,13 @@ int main(int argc, char **argv, char **envp)
>>           exit(0);
>>       }
>>   +    /*
>> +     * Note: we need to create block backends before
>> +     * machine_set_property(), so machine properties can refer to
>> +     * them.
>> +     */
>> +    configure_blockdev(&bdo_queue, machine_class, snapshot);
>> +
>>       machine_opts = qemu_get_machine_opts();
>>       qemu_opt_foreach(machine_opts, machine_set_property, current_machine,
>>                        &error_fatal);
>> @@ -4400,8 +4407,6 @@ int main(int argc, char **argv, char **envp)
>>       ram_mig_init();
>>       dirty_bitmap_mig_init();
>>   -    configure_blockdev(&bdo_queue, machine_class, snapshot);
>> -
>>       qemu_opts_foreach(qemu_find_opts("mon"),
>>                         mon_init_func, NULL, &error_fatal);
>>   
>>
>
> Actually, there is more problems with this. Trying to run a guest with
> persistent reservations fails after this patch is applied (git bisect
> points me to this commit). My command line is:
>
> qemu.git $ ./x86_64-softmmu/qemu-system-x86_64 \
> -monitor stdio \
> -object pr-manager-helper,id=pr-helper0,path=/tmp/pr-helper0.sock
> -drive
> file=/dev/mapper/crypt,file.pr-manager=pr-helper0,format=raw,if=none,id=drive-scsi0-0-0-2 
> \
> -device
> scsi-block,bus=scsi0.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi0-0-0-2,id=scsi0-0-0-2
>
> Honestly, I have no idea how to fix it, so I'm just raising this issue
> here. Do you want me to open a bug or something?

Let's skip the bug filing bureaucracy and go straight to debugging.

Actual and expected behavior of your reproducer, please :)

On 5/16/19 1:43 PM, Markus Armbruster wrote:
<snip/>

>> Actually, there is more problems with this. Trying to run a guest with
>> persistent reservations fails after this patch is applied (git bisect
>> points me to this commit). My command line is:
>>
>> qemu.git $ ./x86_64-softmmu/qemu-system-x86_64 \
>> -monitor stdio \
>> -object pr-manager-helper,id=pr-helper0,path=/tmp/pr-helper0.sock
>> -drive
>> file=/dev/mapper/crypt,file.pr-manager=pr-helper0,format=raw,if=none,id=drive-scsi0-0-0-2
>> \
>> -device
>> scsi-block,bus=scsi0.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi0-0-0-2,id=scsi0-0-0-2
>>
>> Honestly, I have no idea how to fix it, so I'm just raising this issue
>> here. Do you want me to open a bug or something?
> 
> Let's skip the bug filing bureaucracy and go straight to debugging.

Agreed.

> 
> Actual and expected behavior of your reproducer, please :)
> 

Actual is that qemu fails to parse cmd line:


qemu-system-x86_64: -drive 
file=/dev/mapper/crypt,file.pr-manager=pr-helper0,format=raw,if=none,id=drive-scsi0-0-0-2: 
No persistent reservation manager with id 'pr-helper0'


Which obviously is not correct, because pr-helper0 is specified.
Expected result is that qemu suceeds in parsing the cmd line and starts 
the guest. To test it you don't need /dev/mapper/* really, I mean, if 
qemu fails with a different error message (e.g. it can't open the disk 
or EPERM or whatever), it's a sign it got past the cmd line parsing 
successfuly.

Michal