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

From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: qemu-devel@nongnu.org
Cc: John Snow <jsnow@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Eduardo Habkost <ehabkost@redhat.com>,
	Paul Durrant <paul@xen.org>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	kvm@vger.kernel.org, Stefano Stabellini <sstabellini@kernel.org>,
	Igor Mammedov <imammedo@redhat.com>,
	Anthony Perard <anthony.perard@citrix.com>,
	qemu-block@nongnu.org, Richard Henderson <rth@twiddle.net>,
	xen-devel@lists.xenproject.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sergio Lopez <slp@redhat.com>
Subject: Re: [PATCH 12/12] hw/i386/pc: Move PC-machine specific declarations to 'pc_internal.h'
Date: Fri, 13 Dec 2019 17:47:28 +0100	[thread overview]
Message-ID: <d9792ff4-bada-fbb9-301d-aeb19826235c@redhat.com> (raw)
In-Reply-To: <20191213161753.8051-13-philmd@redhat.com>

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".

[3] https://www.mail-archive.com/qemu-devel@nongnu.org/msg664627.html
[2] https://www.mail-archive.com/qemu-devel@nongnu.org/msg664765.html
[5] https://www.mail-archive.com/qemu-devel@nongnu.org/msg664754.html
[6] https://www.mail-archive.com/qemu-devel@nongnu.org/msg664766.html

> ---
>   hw/i386/pc_internal.h | 144 ++++++++++++++++++++++++++++++++++++++++++
>   include/hw/i386/pc.h  | 128 -------------------------------------
>   hw/i386/acpi-build.c  |   1 +
>   hw/i386/pc.c          |   1 +
>   hw/i386/pc_piix.c     |   1 +
>   hw/i386/pc_q35.c      |   1 +
>   hw/i386/pc_sysfw.c    |   1 +
>   hw/i386/xen/xen-hvm.c |   1 +
>   8 files changed, 150 insertions(+), 128 deletions(-)
>   create mode 100644 hw/i386/pc_internal.h