Re: [Qemu-devel] [PATCH v4.1] Add optionrom compatible with fw_cfg DMA version

[Gerd Hoffmann]

On Mo, 2016-04-04 at 16:21 +0100, Richard W.M. Jones wrote:
> On Mon, Apr 04, 2016 at 04:02:04PM +0100, Stefan Hajnoczi wrote:
> >   (1) initrd loading is broken, kernel complains it finds only gibberish:
> > 
> >   [    0.934582] Unpacking initramfs...
> >   [    1.166983] Initramfs unpacking failed: junk in compressed archive
> >   [    1.168458] Freeing initrd memory: 32812k freed
> 
> That's strange.  I certainly never saw anything like this.  I wonder
> if it's because your initrd is particularly large?

I've simply used /boot/initramfs-$version from the host.  It's 33M.  Not
exactly small, but given this is a standard RHEL-7 install I also
wouldn't rate this as unusual big.

> >   (2) going back to non-dma boot via -M pc-$old doesn't work, appearently
> >       fw_cfg dma is enabled even for old machine types.
> 
> IIRC there was a thread about how we accidentally added DMA to old
> machine types.  Does this matter?

That one should be fixed meanwhile.

cheers,
  Gerd