Re: [Qemu-devel] [PATCH RFC 1/3] memory: Add dump-pc-mem command for checkpointing

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Bohdan Trach (bohdan.trach@mailbox.tu-dresden.de) wrote:
> Hi David, thank you for the feedback!

No problem, sorry for the delay,

> On 11/16/2015 05:46 PM, Dr. David Alan Gilbert wrote:
> > * Bohdan Trach (bv.trach@gmail.com) wrote:
> >> From: Bohdan Trach <bohdan.trach@mailbox.tu-dresden.de>
> >>
> >> dump-pc-mem command is added for checkpointing guest memory to
> >> file. Only system RAM region is saved. This checkpoint is later used to
> >> recover unchanged pages.
> > 
> > Why not just use the 'dump_guest_memory' commands; they dump it in interesting
> > existing formats; they have headers in the files as well rather than just
> > a raw blob of data.
> > If you wanted to restrict to only certain RAM blocks, then I'd suggest adding
> > a feature to that existing command.
> > You might also find that you want other RAMBlocks as well, for example where
> > RAM is added using hot plu, those are separate RAM blocks.
> 
> We will try to rework these patches to use existing formats. Current
> format was used because it is extremely simple to work with. The
> restriction of saving only 'pc.ram' RAMBlock is just the consequence
> of this design choice.

I think the ELF one should actually turn out to be the easiest; there's
probably some existing ELF code you can find in the QEMU code base
to make it easier to parse, but once you find the start of the block
it should then be contiguous.

Dave


> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > 
> 
> -- 
> With best regards,
> Bohdan Trach
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK