Re: [Qemu-arm] [Qemu-devel] [PATCH RFC] fw-cfg: support writeable blobs

[Gerd Hoffmann]

On Mo, 2016-02-22 at 22:12 +0200, Michael S. Tsirkin wrote:
> On Mon, Feb 22, 2016 at 03:26:56PM +0100, Gerd Hoffmann wrote:
> > On Mo, 2016-02-22 at 14:41 +0200, Michael S. Tsirkin wrote:
> > > Useful to send guest data back to QEMU.
> > 
> > Use case?
> > 
> > cheers,
> >   Gerd
> 
> VM GEN ID at least wants to pass address of some blob
> in guest memory to host.
> 
> Apparently, that's also useful for nvdimm.
> 
> A reasonable way to do that seems to be to write it into
> fw cfg file, this way it's also migrated automatically.

Both seem to be about acpi aml code talking to qemu backend.

Not sure fw_cfg files are reasonable for that, given that you have to
fetch the directory listing, parse it to figure the entry index, ...

I want see a patch actually using that before going to merge it.

cheers,
  Gerd