Re: [Qemu-devel] Re: [PATCHv8 00/16] boot order specification

[Gleb Natapov <gleb@redhat.com>]

On Sat, Dec 11, 2010 at 08:02:23PM +0200, Gleb Natapov wrote:
> On Sat, Dec 11, 2010 at 05:19:01PM +0000, Blue Swirl wrote:
> > >>                                                 What should we do with
> > >> ata-2@600 vs drive@1?
> > > There is no available IDE OF binding spec, so I when with the way
> > > OpenBIOS reports ata on qemu-x86. I have no idea what 600 in ata-2@600
> > > may mean, but looking at g3_beige_300.html there is no such node there
> > > and looking at any other device tree in http://penguinppc.org/historical/dev-trees-html/
> > > I haven't found one that use this kind of addressing for pci-ata.
> > > http://penguinppc.org/historical/dev-trees-html/g3bw_400.html for
> > > instance has pci@80000000/pci-bridge@d/pci-ata@1/ata-4. ata-2@600 kind of
> > > addressing is used by devices on mac-io bus which I do not think we
> > > emulate in qemu. So it looks like OpneBIOS is wrong here.
> > 
> > We have PMAC IDE, but this device is CMD646, so mac-io bus addressing
> > rules should not be used.
> > 
> So you agree that OpenBIOS is wrong here?
> 
> > In this tree there are two disks connected to CMD646, named
> > /pci@80000000/pci-bridge@d/pci-ata@1/ata-4/disk and
> > /pci@80000000/pci-bridge@d/pci-ata@1/ata-4/disk@1:
> > http://penguinppc.org/historical/dev-trees-html/g4_pci_350.html
> You are saying that qemu creates paths like:
> /grackle@fec00000/ide@3/drive@1/disk@0
> /grackle@fec00000/ide@3/drive@1/disk@1
> 
> I do not understand why qemu creates node drive@1. It should be drive@0
> according to the code. I'll look at why unit-address is incorrect for
> the node. But assuming that this problem is fixed then paths created by
> qemu is very similar to the paths in g4_pci_350.html. It looks like in 
> g4_pci_350.html they omit unit address if it is zero.
> 
Ah the problem is that we have not qdevified mac io bus. Since first to
ide disks are automatically attached to mac-io bus device paths for them
are incorrect. Next two ide devices will be attached to CMD646 and qemu
will generate correct device paths for them:

qemu-system-ppc -drive if=none,id=hda,file=/dev/null -device ide-drive,drive=hda,bootindex=1
-drive if=none,id=cd,file=/dev/null -device ide-drive,drive=cd,bootindex=0 -nographic -drive
if=none,id=hdb,file=/dev/null -device ide-drive,drive=hdb,bus=ide.0,bootindex=2 -drive
if=none,id=hdc,file=/dev/null -device ide-drive,drive=hdc,bus=ide.0,bootindex=3
adding '/grackle@fec00000/ide@3/drive@1/disk@1' at index 0
adding '/grackle@fec00000/ide@3/drive@1/disk@0' at index 1
adding '/grackle@fec00000/ide@3/drive@0/disk@0' at index 2
adding '/grackle@fec00000/ide@3/drive@0/disk@1' at index 3

So the fix is to qdevify mac io bus.

--
			Gleb.