It currently uses qerror_report(), but next commit will convert
the drive_del command to the QAPI and this requires using
error_set().
One particularity of qerror_report() is that it knows when it's
running on monitor context or command-line context and prints the
error message accordingly. error_set() doesn't do this, so we
have to be careful not to drop error messages.
qdev_unplug() has three kinds of usages:
1. It's called when hot adding a device fails, to undo anything
that has been done before hitting the error
2. It's called by function monitor functions like device_del(),
to unplug a device
3. It's used by xen_platform.c in a way that doesn't _seem_ to
be in monitor context
Only item 2 can print an error message to the user, this commit
maintains that.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
56f9107e43