fixes QEMU abort in case it's started without memory
hotplug enabled.

as result of fix it will print following messages:
"
-device pc-dimm,id=d1,memdev=m1: memory hotplug is not enabled, enable it on startup
-device pc-dimm,id=d1,memdev=m1: Device 'pc-dimm' could not be initialized
"

Also fixup assert condition to detect hotplug address
space overflow.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reported-by: NHu Tao <hutao@cn.fujitsu.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

... allowing to get state of present memory devices.
Currently implemented only for PCDIMMDevice.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

- if slot property is not specified on -device/device_add command,
treat default value as request for assigning PCDIMMDevice to
the first free slot.

- if slot is provided with -device/device_add command, attempt to
use it or fail command if it's already occupied.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

- if 'addr' property is not specified on -device/device_add command,
treat the default value as request for assigning PCDIMMDevice to
the first free memory region.

- if 'addr' is provided with -device/device_add command, attempt to
use it or fail command if it's already occupied or falls inside
of an existing PCDIMMDevice memory region.

Note:
GCompareFunc(a, b) used by g_slist_insert_sorted() returns 'gint',
however it might be too small to fit difference between
2 addresses. So use 128bit to calculate the difference and normalize
result to -1/0/1 return values.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Tested-by: NAndrey Korolyov <andrey@xdel.ru>

MST: commit log tweaks

using the same memdev backend more than once will cause
assertion at MemoryRegion mapping time because it's already
mapped. Prevent it by checking that the associated MemoryRegion
is not mapped.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Acked-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

MST: tweak commit log

Each hotplug-able memory slot is a PCDIMMDevice.
A hot-add operation for a memory device:
- creates a new PCDIMMDevice and makes hotplug controller to map it into
  guest address space

Hotplug operations are done through normal device_add commands.
For migration case, all hotplugged memory devices on source should be
specified on target's command line using '-device' option with
properties set to the same values as on source.

To simplify review, patch introduces only PCDIMMDevice QOM skeleton that
will be extended by following patches to implement actual memory hotplug
and related functions.
Signed-off-by: NVasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>