On Fri, Jan 22, 2021 at 06:01:57PM +0100, Greg Kurz wrote:
> It is currently not possible to perform a strict boot from USB storage:
> 
> $ qemu-system-ppc64 -accel kvm -nodefaults -nographic -serial stdio \
> 	-boot strict=on \
> 	-device qemu-xhci \
> 	-device usb-storage,drive=disk,bootindex=0 \
> 	-blockdev driver=file,node-name=disk,filename=fedora-ppc64le.qcow2
> 
> 
> SLOF **********************************************************************
> QEMU Starting
>  Build Date = Jul 17 2020 11:15:24
>  FW Version = git-e18ddad8516ff2cf
>  Press "s" to enter Open Firmware.
> 
> Populating /vdevice methods
> Populating /vdevice/vty@71000000
> Populating /vdevice/nvram@71000001
> Populating /pci@800000020000000
>                      00 0000 (D) : 1b36 000d    serial bus [ usb-xhci ]
> No NVRAM common partition, re-initializing...
> Scanning USB
>   XHCI: Initializing
>     USB Storage
>        SCSI: Looking for devices
>           101000000000000 DISK     : "QEMU     QEMU HARDDISK    2.5+"
> Using default console: /vdevice/vty@71000000
> 
>   Welcome to Open Firmware
> 
>   Copyright (c) 2004, 2017 IBM Corporation All rights reserved.
>   This program and the accompanying materials are made available
>   under the terms of the BSD License available at
>   http://www.opensource.org/licenses/bsd-license.php
> 
> 
> Trying to load:  from: /pci@800000020000000/usb@0/storage@1/disk@101000000000000 ...
> E3405: No such device
> 
> E3407: Load failed
> 
>   Type 'boot' and press return to continue booting the system.
>   Type 'reset-all' and press return to reboot the system.
> 
> 
> Ready!
> 0 >
> 
> The device tree handed over by QEMU to SLOF indeed contains:
> 
> qemu,boot-list =
> 	"/pci@800000020000000/usb@0/storage@1/disk@101000000000000 HALT";
> 
> but the device node is named usb-xhci@0, not usb@0.
> 
> This happens because the firmware names of PCI devices returned
> by get_boot_devices_list() come from pcibus_get_fw_dev_path(),
> while the sPAPR PHB code uses a different naming scheme for
> device nodes. This inconsistency has always been there but it was
> hidden for a long time because SLOF used to rename USB device
> nodes, until this commit, merged in QEMU 4.2.0 :
> 
> commit 85164ad4ed9960cac842fa4cc067c6b6699b0994
> Author: Alexey Kardashevskiy <aik@ozlabs.ru>
> Date:   Wed Sep 11 16:24:32 2019 +1000
> 
>     pseries: Update SLOF firmware image
> 
>     This fixes USB host bus adapter name in the device tree to match QEMU's
>     one.
> 
>     Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>     Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> 
> Fortunately, sPAPR implements the firmware path provider interface.
> This provides a way to override the default firmware paths.
> 
> Just factor out the sPAPR PHB naming logic from spapr_dt_pci_device()
> to a helper, and use it in the sPAPR firmware path provider hook.
> 
> Fixes: 85164ad4ed99 ("pseries: Update SLOF firmware image")
> Signed-off-by: Greg Kurz <groug@kaod.org>

Nice work.  Applied to ppc-for-6.0.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson