[Qemu-commits] [qemu/qemu] e6915b: fw_cfg: unbreak migration compatibility for 2.4 an...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: e6915b5f3a874a467a9a65f7ec1d6ef8d251a51a
      
https://github.com/qemu/qemu/commit/e6915b5f3a874a467a9a65f7ec1d6ef8d251a51a
  Author: Laszlo Ersek <address@hidden>
  Date:   2016-02-26 (Fri, 26 Feb 2016)

  Changed paths:
    M hw/nvram/fw_cfg.c
    M include/hw/compat.h

  Log Message:
  -----------
  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 Marí <address@hidden>
Cc: Gerd Hoffmann <address@hidden>
Cc: Alexandre DERUMIER <address@hidden>
Cc: address@hidden
Ref: http://thread.gmane.org/gmane.comp.emulators.qemu/390272/focus=391042
Ref: https://bugs.launchpad.net/qemu/+bug/1536487
Suggested-by: Gerd Hoffmann <address@hidden>
Signed-off-by: Laszlo Ersek <address@hidden>
Message-id: address@hidden
Signed-off-by: Gerd Hoffmann <address@hidden>


  Commit: 3ff430aa91f33388cce88d81edcad8b2ac5a7a9f
      
https://github.com/qemu/qemu/commit/3ff430aa91f33388cce88d81edcad8b2ac5a7a9f
  Author: Peter Maydell <address@hidden>
  Date:   2016-02-29 (Mon, 29 Feb 2016)

  Changed paths:
    M hw/nvram/fw_cfg.c
    M include/hw/compat.h

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/kraxel/tags/pull-fw-cfg-20160226-1' 
into staging

fw_cfg: unbreak migration compatibility for 2.4 and earlier machines

# gpg: Signature made Fri 26 Feb 2016 09:45:50 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <address@hidden>"
# gpg:                 aka "Gerd Hoffmann <address@hidden>"
# gpg:                 aka "Gerd Hoffmann (private) <address@hidden>"

* remotes/kraxel/tags/pull-fw-cfg-20160226-1:
  fw_cfg: unbreak migration compatibility for 2.4 and earlier machines

Signed-off-by: Peter Maydell <address@hidden>


Compare: https://github.com/qemu/qemu/compare/35227e6a09a2...3ff430aa91f3