On Wed, Aug 04, 2010 at 02:24:08PM +0100, Richard W.M. Jones wrote: > On Wed, Aug 04, 2010 at 08:15:04AM -0500, Anthony Liguori wrote: > > On 08/04/2010 08:07 AM, 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. > > > > That's what I thought too, but in a 32-bit guest using ~3.5GB of > > RAM, where can you safely get 100MB of memory to full map the ROM? > > If you're going to map chunks at a time, you are basically doing > > DMA. > > It's boot time, so you can just map it over some existing RAM surely? Not with current qemu. This is broken now. > Linuxboot.bin can work out where to map it so it won't be in any > memory either being used or the target for the copy. > -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
