Re: [PATCH v26 00/20] i386 cleanup PART 2 - Philippe Mathieu-Daudé

From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: "Alex Bennée" <alex.bennee@linaro.org>,
	"Claudio Fontana" <cfontana@suse.de>,
	"Igor Mammedov" <imammedo@redhat.com>,
	"Thomas Huth" <thuth@redhat.com>
Cc: Laurent Vivier <lvivier@redhat.com>,
	Peter Maydell <peter.maydell@linaro.org>,
	Eduardo Habkost <ehabkost@redhat.com>,
	Richard Henderson <richard.henderson@linaro.org>,
	qemu-devel@nongnu.org, Markus Armbruster <armbru@redhat.com>,
	Roman Bolshakov <r.bolshakov@yadro.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v26 00/20] i386 cleanup PART 2
Date: Wed, 5 May 2021 14:24:34 +0200	[thread overview]
Message-ID: <7fd6ae36-6e12-676e-0484-43c1f9d04c6a@redhat.com> (raw)
In-Reply-To: <03b6b51e-71d7-a2c9-4d3d-db1ac77a1484@redhat.com>

On 5/5/21 2:15 PM, Philippe Mathieu-Daudé wrote:
> On 5/5/21 12:04 PM, Alex Bennée wrote:
>> Claudio Fontana <cfontana@suse.de> writes:
>>> On 3/8/21 3:02 PM, Alex Bennée wrote:
>>>> Claudio Fontana <cfontana@suse.de> writes:
>>>>
>>>>> Hi,
>>>>>
>>>>> anything else for me to do here?
>>>>
>>>> It looks to me that this series is looking pretty good. Every patch has
>>>> at least one review so I think it's just waiting on the maintainers to
>>>> pick it up.
>>>>
>>>> Paolo/Richard - are you intending to take the series as is or are you
>>>> waiting for something else? I'd like to see the patch delta reduced for
>>>> the ARM cleanup work which is still ongoing.
>>>
>>> I am a bit at a loss here, as this has been reviewed for a while, but nothing is happening.
>>> Rebasing is starting to become more and more draining;

> I didn't noticed the following patch had its content changed:
> Revert "target/arm: Restrict v8M IDAU to TCG"
> So now this is not a full revert, only the TYPE_IDAU_INTERFACE
> type is moved back.

Correcting myself. This is a plain revert, and I disagree with it
because if TCG is not available, TCG-specific devices/machines
shouldn't be loaded into QEMU. Cortex-M and v8M IDAU *are* TCG
specific and no such object should be built/registered, so the
interface shouldn't be there neither.

Below is a possible way to get there. Reverting the commit and
build Cortex-M devices in a non-TCG build is a kludge / shortcut
which allows Claudio to remove a big chunk of non-TCG code, so
is probably acceptable, and we can keep cleaning later.

> More generally I think more code should be automatically stripped
> out by Kconfig instead. In [1,2] I suggested to tie accel-specific
> Kconfig selectors:
> 
>   config ARM_V7R
>     bool
>     depends on TCG && ARM
> 
>   config ARM_V7M
>     bool
>     depends on TCG && ARM
>     select PTIMER
> 
>   config XLNX_ZYNQMP_ARM
>     bool
>     default y if TCG && AARCH64
> 
> But this can certainly be done on top of Claudio's work.
> 
> [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg777710.html
> [2] https://www.mail-archive.com/qemu-devel@nongnu.org/msg777719.html
> 