[Qemu-ppc] commit 08521e2 breaks SLOF usb boot

[Nikunj A Dadhania]

Hi,

I have a working usb echi storage support for SLOF. I found that with
latest qemu HEAD, USB EHCI registers(HCSPARAMS) started appearing funnily
- in place of being LE it appeared BE. Bisecting it down I could get to
this zero to the following commit:


commit 08521e28c7e6e8cc1f53424a0f845f58d2ed9546
Author: Paolo Bonzini <address@hidden>
Date:   Fri May 24 12:54:01 2013 +0200

    memory: add big endian support to access_with_adjusted_size
    
    This will be used to split 8-byte access down to two four-byte accesses.
    
    Reviewed-by: Richard Henderson <address@hidden>
    Signed-off-by: Paolo Bonzini <address@hidden>


If I hack the above funniness in my USB EHCI driver, somewhere down the
qemu crashes at code introduced by this patch:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x00005555557a0ea4 in access_with_adjusted_size (address@hidden, 
address@hidden, address@hidden, access_size_min=<optimized out>, 
access_size_max=<optimized out>,
access=0x5555557a1f80 <memory_region_oldmmio_write_accessor>, 
opaque=0x5555567f8ab8) at /home/nikunj/work/power/code/qemu/memory.c:396
#2 0x00005555557a5ebb in memory_region_dispatch_write (size=1, data=0, addr=12, 
mr=0x5555567f8ab8) at /home/nikunj/work/power/code/qemu/memory.c:998

Reverting this, I can safely boot using a usb-storage device put on ehci 
controller.

Regards
Nikunj