[Qemu-devel] [PATCH for-1.4 0/2] fix migration failure from 1.3 due to SeaBIOS size change

[Michael Roth]

Migration from 1.3 currently fails due to a mismatch between the expected size
of 256KB and the received size of 128KB for seabios. This series attempts to
fix the issue by allowing a resize function to be registered to handle resizing
memory blocks to accomodate the source's, and using that to re-initialize
"pc.bios" and "isa-bios" MemoryRegions based on the size of the incoming block.

There are also 2 potential alternatives to this patch set:

1) When I compile seabios 1.7.2 locally I end up with a 128KB binary. I'm not
   sure what options are needed to generate one matching the 256KB size
   currently in tree, but if those options are non-essential we could possibly
   just commit a smaller binary. Resizing may still become necessary in the
   future, but it would suffice for 1.4 at least.

2) We can begin checking in past versions of SeaBIOS and other roms and loading
   those according to selected machine type. This would be similar to be how
   we've dealt with similar issues regarding the default vram size changing for
   VGA, but might not scale well with ISPs.

I don't have any particular preference, but I think we should consider
committing one of these prior to the 1.4 release.

 arch_init.c                 |   28 +++++++++---
 hw/pc_sysfw.c               |  104 ++++++++++++++++++++++++++++++++-----------
 include/migration/vmstate.h |   14 ++++++
 savevm.c                    |   77 ++++++++++++++++++++++++++++++++
 4 files changed, 192 insertions(+), 31 deletions(-)