qemu-irix/hw/nvram
Laszlo Ersek 30929793b0 fw_cfg: unbreak migration compatibility for 2.4 and earlier machines
When I reviewed Marc's fw_cfg DMA patches, I completely missed that the
way we set dma_enabled would break migration.

Gerd explained the right way (see reference below): dma_enabled should be
set to true by default, and only true->false transitions should be
possible:

- when the user requests that with

    -global fw_cfg_mem.dma_enabled=off

  or

   -global fw_cfg_io.dma_enabled=off

  as appropriate for the platform,

- when HW_COMPAT_2_4 dictates it,

- when board code initializes fw_cfg without requesting DMA support.

Cc: Marc MarĂ­ <markmb@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Alexandre DERUMIER <aderumier@odiso.com>
Cc: qemu-stable@nongnu.org
Ref: http://thread.gmane.org/gmane.comp.emulators.qemu/390272/focus=391042
Ref: https://bugs.launchpad.net/qemu/+bug/1536487
Suggested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1455823860-22268-1-git-send-email-lersek@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit e6915b5f3a)

Conflicts:
	include/hw/compat.h

* remove cosmetic dep on c9c0afbb

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2016-03-17 17:33:59 -05:00
..
Makefile.objs hw: move NVRAM interfaces to hw/nvram/, configure with default-configs/ 2013-04-08 18:13:16 +02:00
ds1225y.c savevm: Remove all the unneeded version_minimum_id_old (rest) 2014-05-14 15:24:51 +02:00
eeprom93xx.c savevm: Remove all the unneeded version_minimum_id_old (x86) 2014-06-16 04:55:26 +02:00
fw_cfg.c fw_cfg: unbreak migration compatibility for 2.4 and earlier machines 2016-03-17 17:33:59 -05:00
mac_nvram.c macio-nvram: add to misc category 2015-10-23 12:35:18 +11:00
spapr_nvram.c spapr: Merge sPAPREnvironment into sPAPRMachineState 2015-07-07 17:44:50 +02:00