Re: [Qemu-devel] [PATCH] ahci: add port I/O index-data pair

[Daniel Verkamp]

(Sorry for the slow response, was on vacation)

On Thu, Sep 1, 2011 at 7:58 AM, Alexander Graf <address@hidden> wrote:
> On 08/30/2011 05:07 AM, Daniel Verkamp wrote:
>>
>> On Sun, Aug 28, 2011 at 11:48 AM, Alexander Graf<address@hidden>  wrote:
>>>
>>> On 27.08.2011, at 04:12, Daniel Verkamp wrote:
>>>
>>>> Implement an I/O space index-data register pair as defined by the AHCI
>>>> spec, including the corresponding SATA PCI capability and BAR.
>>>>
>>>> This allows real-mode code to access the AHCI registers; real-mode
>>>> code cannot address the memory-mapped register space because it is
>>>> beyond the first megabyte.
>>>
>>> Very nice patch! I'll check and compare with a real ICH-9 when I get
>>> back to .de, but I'd assume you also did that already ;). Once I checked
>>> that the IO region is set up similarly, I'll give you my ack.
>>
>> Please do double check against real hardware if you get the chance - I
>> don't have a real ICH-9 handy to test against.  This is all written
>> based on my reading of the spec and testing with an internal DOS
>> developer tool from work.
>>
>> I am mainly curious how the real thing handles writes to the index
>> register that aren't divisible by 4 or are beyond the end of the
>> register set (and how big that really is on ICH-9).  Judging by the
>> bits marked "RO" in the spec, I would guess writing 0x13 to the index
>> and then reading it back should give 0x10, but I haven't tested it on
>> real hw.
>
> Phew. So I finally got at least an ICH-9 system booting. This is what lspci
> -vvv tells me:
>
> 00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6
> port SATA AHCI Controller (rev 02) (prog-if 01 [AHCI 1.0])
>    Subsystem: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA AHCI
> Controller
>    Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
>    Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
>    Latency: 0
>    Interrupt: pin B routed to IRQ 26
>    Region 0: I/O ports at d000 [size=8]
>    Region 1: I/O ports at cc00 [size=4]
>    Region 2: I/O ports at c880 [size=8]
>    Region 3: I/O ports at c800 [size=4]
>    Region 4: I/O ports at c480 [size=32]
>    Region 5: Memory at ffaf9000 (32-bit, non-prefetchable) [size=2K]
>    Capabilities: [80] MSI: Enable+ Count=1/16 Maskable- 64bit-
>        Address: fee0f00c  Data: 4169
>    Capabilities: [70] Power Management version 3
>        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> PME(D0-,D1-,D2-,D3hot+,D3cold-)
>        Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
>    Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
>    Capabilities: [b0] Vendor Specific Information: Len=06 <?>
>    Kernel driver in use: ahci
>
> So BAR4 is where the IDP info should be. Offset is 4 into that IO space and
> the space is 32 bytes long. Do you have the ICH-9 implementation spec? I can
> try to dig something up if you don't have it around.
>

I'm not sure I understand what you mean, but I think everything is in
the right spot - compare with the real ICH-9 dump you provide
(relevant parts quoted below; full lspci dump from QEMU device at
end):

Real: Region 4: I/O ports at c480 [size=32]
QEMU: Region 4: I/O ports at c040 [size=32] (I/O address is different,
but that is ok)

Real: Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
QEMU: Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004 (identical)

> Please send me a small test program I can run on the machine to find out
> what happens for unaligned I/O accesses. That would be very helpful!
>

I will try to put something together in the next few days and send it along;
is a DOS test app suitable?

Thanks,
-- Daniel Verkamp


Here is the lspci -vvv -nn -x dump of the QEMU-emulated AHCI
controller with the patch applied:

00:04.0 SATA controller [0106]: Intel Corporation 82801IR/IO/IH
(ICH9R/DO/DH) 6 port SATA AHCI Controller [8086:2922] (rev 02)
(prog-if 01 [AHCI 1.0])
        Subsystem: Red Hat, Inc Device [1af4:1100]
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 24
        Region 4: I/O ports at c040 [size=32]
        Region 5: Memory at febf1000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
        Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
                Address: 00000000fee0100c  Data: 4149
        Kernel driver in use: ahci
00: 86 80 22 29 07 04 10 00 02 01 06 01 00 00 00 00
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
20: 41 c0 00 00 00 10 bf fe 00 00 00 00 f4 1a 00 11
30: 00 00 00 00 a8 00 00 00 00 00 00 00 0b 01 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 05 00 81 00 0c 10 e0 fe 00 00 00 00 49 41 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 40 00 3f 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 12 50 10 00 48 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00