[Qemu-devel] Re: sparc32 do_unassigned_access overhaul

[Artyom Tarasenko]

2010/1/15 Artyom Tarasenko <address@hidden>:
> 2010/1/15 Blue Swirl <address@hidden>:
>> On Fri, Jan 15, 2010 at 9:11 PM, Artyom Tarasenko
>> <address@hidden> wrote:
>>> 2010/1/15 Blue Swirl <address@hidden>:
>>>> On Fri, Jan 15, 2010 at 6:46 PM, Artyom Tarasenko
>>>> <address@hidden> wrote:
>>>>> According to pages 9-31 - 9-34 of "SuperSPARC & MultiCache Controller
>>>>> User's Manual":
>>>>>
>>>>> 1. "A lower priority fault may not overwrite the
>>>>>    MFSR status of a higher priority fault."
>>>>> 2. The MFAR is overwritten according to the policy defined for the MFSR
>>>>> 3. The overwrite bit is asserted if the fault status register (MFSR)
>>>>>   has been written more than once by faults of the same class
>>>>> 4. SuperSPARC will never place instruction fault addresses in the MFAR.
>>>>>
>>>>> Implementation of points 1-3 allows booting Solaris 2.6 and 2.5.1.
>>>>
>>>> Nice work! This also passes my tests.
>>>
>>> I'm afraid we still are not there yet though: Solaris 7 fails potentially 
>>> due to
>>> another bug in the MMU emulation, and the initial [missing-] RAM
>>> detection in OBP fails
>>> very probably due to a bug in in the MMU emulation.
>>
>> Some guesses:
>>  - Access to unassigned RAM area may be handled by the memory
>> controller differently (no faults, different faults etc.) than
>> unassigned access to SBus or other area.

You are right! It seems to be true for the area larger than max RAM though.
On a real SS-5 with 32M in the first bank, no fault is produced at
least for the areas
0-0x2fffffff, 0x70000000-0xafffffff (ha, this would solve problems
with SS-20 OBP
too) and 0xf0000000-0xf6ffffff.

Would you like to implement it?

That's how I tested it:

ok 8000000 map?
Virtual  : 0800.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.ec20  0000.0000 Invalid
ok 8000000 obmem 8000000 map-page
ok 8000000 map?
Virtual  : 0800.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.ec20  001f.b231
Segment  : @ 0.01fb.2300  001f.b221
Page     : @ 0.01fb.2200  0080.001e Access : rwx---
Physical : 0.0800.0000
ok 8000000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
 8000000  00 d1 e1 44 ff d1 e2 18  08 d1 e1 4e ff d1 e2 18  .QaV.Qb..QaV.Qb.
 8000010  00 d1 e1 44 ff d1 e2 18  08 d1 e1 4e ff d1 e2 18  .QaV.Qb..QaV.Qb.
ok
ok 10000000 map?
Virtual  : 1000.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.ec40  0000.0000 Invalid
ok 10000000 obmem 10000000 map-page
ok 10000000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
10000000  04 00 00 05 00 1f e0 00  04 00 00 05 00 1f e0 00  ......`.......`.
10000010  04 00 00 05 04 00 00 05  04 00 00 05 04 00 00 05  ................

ok 30000000 map?
Virtual  : 3000.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.ecc0  0000.0000 Invalid
ok 30000000 obmem 30000000 map-page
ok 30000000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
30000000  Data Access Error
ok 2fff0000 obmem 2fff0000 map-page
ok 2fff0000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
2fff0000  02 ff e1 44 ff d1 e2 18  2f d1 e1 4e ff d1 e2 18  .QaV.Qb..QaV.Qb.
2fff0010  00 d1 e1 44 ff d1 e2 18  2f d1 e1 4e ff d1 e2 18  .QaV.Qb..QaV.Qb.
ok
ok f0000000 map?
Virtual  : f000.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.efc0  0000.0000 Invalid
ok f0000000 obmem f0000000 map-page
ok f0000000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
f0000000  10 80 2f 66 a1 48 00 00  01 00 00 00 01 00 00 00  ../f!H..........
f0000010  29 1c 00 04 a8 15 20 d0  81 c5 00 00 a1 48 00 00  )...(. P.E..!H..
ok f7ff0000 map?
Virtual  : f7ff.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.efdc  0000.0000 Invalid
ok f7ff0000 obmem f7ff0000 map-page
ok f7ff0000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
f7ff0000  Data Access Error
ok f6ff0000 map?
Virtual  : f6ff.0000
Context  : @ 0.01ff.f000  001f.eec1 # 0
Region   : @ 0.01fe.efd8  0000.0000 Invalid
ok f6ff0000 obmem f6ff0000 map-page
ok f6ff0000 20 dump
          \/  1  2  3  4  5  6  7   8  9  a  b  c  d  e  f  v123456789abcdef
f6ff0000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ................
f6ff0010  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  ................

-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/