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

[Anthony Liguori]

Michael Roth <address@hidden> writes:

> 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.

So do I on Fedora 18.  Unless someone has a reason why this is a bad
thing, I'll commit a 128kb binary and we can avoid this problem for 1.4.

Obviously, we need to figure it out but that at least buys us some time...

Regards,

Anthony Liguori

>    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(-)