On Wed, Aug 04, 2010 at 11:17:28AM +0300, Avi Kivity wrote: > On 08/04/2010 10:56 AM, Gerd Hoffmann wrote: > > Hi, > > > >>>(1) -M somethingold. PCI devices don't have a pci rom bar then by > >>>default because they didn't not have one in older qemu versions, > >>>so we need some other way to pass the option rom to seabios. > >> > >>What did we do back then? before we had the fwcfg interface? > > > >Have qemu instead of bochs/seabios manage the vgabios/optionrom > >area (0xc8000 -> 0xe0000) and copy the roms to memory. Which > >implies the whole rom has to sit there as PMM can't be used then. > > Do we actually need PMM for isapc? Did PMM exist before pci? > > > > >>>(3) roms not associated with a PCI device: multiboot, extboot, > >>>-option-rom command line switch, vgabios for -M isapc. > >> > >>We could lay those out in high memory (4GB-512MB) and have the bios copy > >>them from there. > > > >Yea, we could. But it is pointless IMHO. > > > >$ ls -l *.bin > >-rwxrwxr-x. 1 kraxel kraxel 1536 Jul 15 15:51 extboot.bin* > >-rwxrwxr-x. 1 kraxel kraxel 1024 Jul 15 15:51 linuxboot.bin* > >-rwxrwxr-x. 1 kraxel kraxel 1024 Jul 15 15:51 multiboot.bin* > >-rwxrwxr-x. 1 kraxel kraxel 8960 Jul 15 15:51 vapic.bin* > > > >That are the ones we can't load via pci rom bar. Look how small > >they are. > > So they can just sit there? I'm confused, either there is enough > address space and we don't need to play games, or there isn't and we > do. > > 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. > We can do interface like that: guest enumerates available roms using fwcfg. Guest can tell host to map rom into guest specified IOMEM region. Guest copies rom from IOMEM region and tell host to unmap it. -- 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
