Re: [PATCH 4/4] hw/block/fdc: Extract SysBus floppy controllers to fdc-sysbus.c - Philippe Mathieu-Daudé

From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: John Snow <jsnow@redhat.com>, qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
	"Aleksandar Rikalo" <aleksandar.rikalo@syrmia.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
	"Mark Cave-Ayland" <mark.cave-ayland@ilande.co.uk>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"Max Reitz" <mreitz@redhat.com>,
	"Artyom Tarasenko" <atar4qemu@gmail.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Miroslav Rezanina" <mrezanin@redhat.com>,
	"Aurelien Jarno" <aurelien@aurel32.net>
Subject: Re: [PATCH 4/4] hw/block/fdc: Extract SysBus floppy controllers to fdc-sysbus.c
Date: Wed, 28 Apr 2021 14:30:40 +0200	[thread overview]
Message-ID: <3053142c-7588-92ea-00a2-96847c08c0e9@redhat.com> (raw)
In-Reply-To: <0812a48a-36c6-8152-e8f1-f97c755b9f55@redhat.com>

On 4/27/21 7:34 PM, John Snow wrote:
> On 4/15/21 6:23 AM, Philippe Mathieu-Daudé wrote:
>> Some machines use floppy controllers via the SysBus interface,
>> and don't need to pull in all the SysBus code.
>> Extract the SysBus specific code to a new unit: fdc-sysbus.c,
>> and add a new Kconfig symbol: "FDC_SYSBUS".
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> 
> LGTM, but again you'll want someone to review the Kconfig changes. It
> looks reasonable to me at a glance, but I just don't know what I don't
> know there.
> 
> I'm trusting you somewhat that you've audited the proper dependencies
> for each subsystem and that these have been accurately described via
> Kconfig -- my knowledge of non-x86 platforms is a bit meager, so I am
> relying on CI to tell me if this breaks anything I care about.

The way I test these Kconfig changes is configuring with
--without-default-devices, and build/test for each machine doing:

$ echo $MACHINE=y > default-configs/devices/$arch-softmmu.mak

(I overwrite because currently we don't support having a base
config different than the default-configs one).

For example for the SPARCbook machine:

$ echo CONFIG_SUN4M=y > default-configs/devices/sparc-softmmu.mak
$ ninja qemu-system-sparc
$ qemu-system-sparc -M SPARCbook -S

Or for the Jazz machine:

$ echo CONFIG_JAZZ=y > default-configs/devices/mips64el-softmmu.mak
$ echo CONFIG_SEMIHOSTING=y >> default-configs/devices/mips64el-softmmu.mak
$ ninja qemu-system-mips64el
$ ./qemu-system-mips64el -M pica61 -S

(The CONFIG_SEMIHOSTING is a particular kludge pending another series)

But unfortunately there are predating bugs breaking this testing.

I'll add this information in the respin's cover.

> Would love to get an ACK from Mark Cave-Ayland and Hervé Poussineau if
> possible, but if they're not available to take a quick peek, we'll try
> to get this in closer to the beginning of the dev window to maximize
> problem-finding time.

The sun4m maintainer is Artyom.

> Reviewed-by: John Snow <jsnow@redhat.com>

Thanks!

> 
>> ---
>>   hw/block/fdc-sysbus.c | 252 ++++++++++++++++++++++++++++++++++++++++++
>>   hw/block/fdc.c        | 220 ------------------------------------
>>   MAINTAINERS           |   1 +
>>   hw/block/Kconfig      |   4 +
>>   hw/block/meson.build  |   1 +
>>   hw/block/trace-events |   2 +
>>   hw/mips/Kconfig       |   2 +-
>>   hw/sparc/Kconfig      |   2 +-
>>   8 files changed, 262 insertions(+), 222 deletions(-)
>>   create mode 100644 hw/block/fdc-sysbus.c