Re: [PATCH 12/12] hw/i386/pc: Move PC-machine specific declarations to 'pc_internal.h'

From: Paolo Bonzini <pbonzini@redhat.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
	Sergio Lopez <slp@redhat.com>,
	Eduardo Habkost <ehabkost@redhat.com>,
	kvm@vger.kernel.org, Paul Durrant <paul@xen.org>,
	qemu-devel@nongnu.org, xen-devel@lists.xenproject.org,
	Anthony Perard <anthony.perard@citrix.com>,
	Igor Mammedov <imammedo@redhat.com>,
	qemu-block@nongnu.org, John Snow <jsnow@redhat.com>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [PATCH 12/12] hw/i386/pc: Move PC-machine specific declarations to 'pc_internal.h'
Date: Mon, 16 Dec 2019 16:41:27 +0100	[thread overview]
Message-ID: <90d54a3b-ae96-43ac-0f8e-268c1257f7d0@redhat.com> (raw)
In-Reply-To: <0d15c735-73b4-7875-ec0f-8c181508f0d4@redhat.com>

On 16/12/19 16:37, Philippe Mathieu-Daudé wrote:
> On 12/15/19 10:58 AM, Michael S. Tsirkin wrote:
>> On Fri, Dec 13, 2019 at 05:47:28PM +0100, Philippe Mathieu-Daudé wrote:
>>> On 12/13/19 5:17 PM, Philippe Mathieu-Daudé wrote:
>>>> Historically, QEMU started with only one X86 machine: the PC.
>>>> The 'hw/i386/pc.h' header was used to store all X86 and PC
>>>> declarations. Since we have now multiple machines based on the
>>>> X86 architecture, move the PC-specific declarations in a new
>>>> header.
>>>> We use 'internal' in the name to explicit this header is restricted
>>>> to the X86 architecture. Other architecture can not access it.
>>>>
>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>> ---
>>>> Maybe name it 'pc_machine.h'?
>>>
>>> I forgot to describe here (and in the cover), what's follow after this
>>> patch.
>>>
>>> Patch #13 moves PCMachineClass to
>>>
>>> If you ignore PCMachineState, "hw/i386/pc.h" now only contains 76
>>> lines, and
>>> it is easier to see what is PC machine specific, what is X86
>>> specific, and
>>> what is device generic (not X86 related at all):
>>>
>>> - GSI is common to X86 (Paolo sent [3], [6])
>>> - IOAPIC is common to X86
>>> - i8259 is multiarch (Paolo [2])
>>> - PCI_HOST definitions and pc_pci_hole64_start() are X86
>>> - pc_machine_is_smm_enabled() is X86 (Paolo sent [5])
>>> - hpet
>>> - tsc (Paolo sent [3])
>>> - 3 more functions
>>>
>>> So we can move half of this file to "pc_internal.h" and the other to
>>>
>>> One problem is the Q35 MCH north bridge which directly sets the PCI
>>> PCMachineState->bus in q35_host_realize(). This seems a QOM violation
>>> and is
>>> probably easily fixable.
>>>
>>> Maybe I can apply Paolo's patches instead of this #12, move X86-generic
>>> declarations to "hw/i386/x86.h", and directly git-move what's left of
>>> "hw/i386/pc.h" to "pc_internal.h".
>>
>> Yea that sounds a bit better.
> 
> OK, I'll wait for Paolo's next pull get in, then continue based on that,
> including Paolo's "x86: allow building without PC machine types" series.
> 
> (Thanks Paolo for picking most of this series!)

FWIW I don't think kvm_i8259_init should be in sysemu/kvm.h, since it's
x86-specific and that would be something like the same mistake already
done with hw/i386/pc.h.

Paolo