Historically, user monitor arguments beginning with '-' (eg. '-f')
were passed as integers down to handlers.

I've maintained this behavior in the new monitor because we didn't
have a boolean type at the very beginning of QMP. Today we have it
and this behavior is causing trouble to QMP's argument checker.

This commit fixes the problem by doing the following changes:

1. User Monitor

   Before: the optional arg was represented as a QInt, we'd pass 1
           down to handlers if the user specified the argument or
           0 otherwise

   This commit: the optional arg is represented as a QBool, we pass
                true down to handlers if the user specified the
                argument, otherwise _nothing_ is passed

2. QMP

   Before: the client was required to pass the arg as QBool, but we'd
           convert it to QInt internally. If the argument wasn't passed,
           we'd pass 0 down

   This commit: still require a QBool, but doesn't do any conversion and
                doesn't pass any default value

3. Convert existing handlers (do_eject()/do_migrate()) to the new way

   Before: Both handlers would expect a QInt value, either 0 or 1

   This commit: Change the handlers to accept a QBool, they handle the
                following cases:

                   A) true is passed: the option is enabled
                   B) false is passed: the option is disabled
                   C) nothing is passed: option not specified, use
                                         default behavior
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

This changes the monitor eject_device() function to not check for
bdrv_is_inserted().

Example run where the bug manifests itself:

(output of 'info block' is stripped to include only the CD-ROM device)

  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 [not inserted]
  (qemu) change ide1-cd0 /dev/cdrom host_cdrom
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/cdrom ro=1 drv=host_cdrom encrypted=0
  (qemu) eject ide1-cd0
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/cdrom ro=1 drv=host_cdrom encrypted=0

  # at this point, a disk was inserted on the host CD-ROM drive

  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/cdrom ro=1 drv=host_cdrom encrypted=0
  (qemu) eject ide1-cd0
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 [not inserted]
  (qemu)

The first eject command didn't work because the is_inserted() check
failed.

I have no clue why the code had the is_inserted() check, as it doesn't matter
if there is a disk present at the host drive, when the user wants the virtual
device to be disconnected from the host device.

The is_inserted() check has another side effect: a memory leak if the "change"
command is used multiple times, as do_change() calls eject_device() before
re-opening the block device, but bdrv_close() is never called.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This is the list of drives defined with drive_init().  Hide it, so it
doesn't get abused.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

do_commit() and mux_proc_byte() iterate over the list of drives
defined with drive_init().  This misses host block devices defined by
other means.  Such means don't exist now, but will be introduced later
in this series.

Change them to use new bdrv_commit_all(), which iterates over all host
block devices.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

That's where they belong semantically (block device host part), even
though the actions are actually executed by guest device code.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Empty file used to create an empty drive (no media).  Since commit
9dfd7c7a, it's an error: "qemu: could not open disk image : No such
file or directory".  Older versions of libvirt can choke on this.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We should use 'dinfo->serial' length, 'serial' is a pointer, so
the serial number length is currently limited to the pointer size.

This fixes https://bugs.launchpad.net/qemu/+bug/584143 and is also
valid for stable.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Anything that moves hundreds of lines out of vl.c can't be all bad.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>