Re: [PATCH v3 07/11] hw/sh4/r2d: Realize IDE controller before accessing it

[Thomas Huth <thuth@redhat.com>]

On 13/10/2024 06.53, Guenter Roeck wrote:
> On 10/12/24 07:06, Bernhard Beschow wrote:
>>
>>
>> Am 12. Oktober 2024 09:40:27 UTC schrieb Thomas Huth <thuth@redhat.com>:
>>> On 12/10/2024 00.48, Philippe Mathieu-Daudé wrote:
>>>> On 11/10/24 05:23, Thomas Huth wrote:
>>>>> On 03/05/2024 23.34, Guenter Roeck wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On Thu, Feb 08, 2024 at 07:12:40PM +0100, Philippe Mathieu-Daudé wrote:
>>>>>>> We should not wire IRQs on unrealized device.
>>>>>>>
>>>>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>>>>>> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>>>>>>> Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>
>>>>>>
>>>>>> qemu 9.0 fails to boot Linux from ide/ata drives with the sh4
>>>>>> and sh4eb emulations. Error log is as follows.
>>>>>>
>>>>>> ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100
>>>>>> ata1.00: 16384 sectors, multi 16: LBA48
>>>>>> ata1.00: configured for PIO
>>>>>> scsi 0:0:0:0: Direct-Access     ATA      QEMU HARDDISK    2.5+ PQ: 0 
>>>>>> ANSI: 5
>>>>>> sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
>>>>>> sd 0:0:0:0: [sda] Write Protect is off
>>>>>> sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't 
>>>>>> support DPO or FUA
>>>>>> ata1: lost interrupt (Status 0x58)
>>>>>>
>>>>>> [ and more similar errors ]
>>>>>>
>>>>>> qemu command line:
>>>>>>
>>>>>> qemu-system-sh4eb -M r2d -kernel arch/sh/boot/zImage \
>>>>>>      -snapshot -drive file=rootfs.ext2,format=raw,if=ide \
>>>>>>      -append "root=/dev/sda console=ttySC1,115200 noiotrap" \
>>>>>>      -serial null -serial stdio -monitor null -nographic -no-reboot
>>>>>>
>>>>>> Bisect points to this patch (see below). Reverting it fixes the problem.
>>>>
>>>> Sorry Guenter for missing your email :(
>>>>
>>>>>
>>>>>    Hi Philippe!
>>>>>
>>>>> Today I noticed that our sh4 test from tests/avocado/ 
>>>>> tuxrun_baselines.py is failing (which is not run by default, that's why 
>>>>> nobody noticed), and bisection took me to the same result that Guenter 
>>>>> already reported.
>>>>
>>>> "not run by default" because flaky.
>>>>
>>>> Having a quick look, the problem seems hw/ide/core.c uses non-QOM
>>>> shortcuts. In particular ide_bus_init_output_irq() expects a preset
>>>> IRQ. Not something trivial to fix.
>>>
>>> I wonder whether the other spots that use ide_bus_init_output_irq() or 
>>> similar constructs are broken now, too. Bernhard apparently already fixed 
>>> (reverted) one in commit 143f3fd3d8b51d6526c8ea80e8a2a085f6f01cdf.
>>>
>>> But what about fc432ba0f58343c8912b80e9056315bb9bd8df92 ?
>>
>> There is an indirection going on in pmac_ide_irq() which triggers 
>> real_*_irq. These get wired via sysbus API after realize() while 
>> ide_bus_init_output_irq() wires to pmac_ide_irq(). So 
>> fc432ba0f58343c8912b80e9056315bb9bd8df92 seems safe to me (haven't tested 
>> it though).
>>
> 
> Not sure if that answers the question, but booting from ide works
> for both mac99 and g3beige emulations.

Ok, thank you both, that sounds like we should be safe with macio IDE, indeed!

  Thomas