Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35?

[Gleb Natapov]

On Wed, Aug 04, 2010 at 02:22:29PM +0100, Richard W.M. Jones wrote:
> 
> On Wed, Aug 04, 2010 at 04:07:09PM +0300, Gleb Natapov wrote:
> > On Wed, Aug 04, 2010 at 08:04:09AM -0500, Anthony Liguori wrote:
> > > On 08/04/2010 03:17 AM, Avi Kivity wrote:
> > > >For playing games, there are three options:
> > > >- existing fwcfg
> > > >- fwcfg+dma
> > > >- put roms in 4GB-2MB (or whatever we decide the flash size is)
> > > >and have the BIOS copy them
> > > >
> > > >Existing fwcfg is the least amount of work and probably
> > > >satisfactory for isapc.  fwcfg+dma is IMO going off a tangent.
> > > >High memory flash is the most hardware-like solution, pretty easy
> > > >from a qemu point of view but requires more work.
> > > 
> > > The only trouble I see is that high memory isn't always available.
> > > If it's a 32-bit PC and you've exhausted RAM space, then you're only
> > > left with the PCI hole and it's not clear to me if you can really
> > > pull out 100mb of space there as an option ROM without breaking
> > > something.
> > > 
> > We can map it on demand. Guest tells qemu to map rom "A" to address X by
> > writing into some io port. Guest copies rom. Guest tells qemu to unmap
> > it. Better then DMA interface IMHO.
> 
> I think this is a fine idea.  Do you want me to try to implement
> something like this?  (I'm on holiday this week and next week at
> the KVM Forum, so it won't be for a while ...)
> 
I wouldn't do that without principal agreement from Avi and Anthony :)

--
                        Gleb.