Re: [Qemu-devel] [PATCH v3 11/14] ioport: Switch dispatching to memory core layer

From: Paolo Bonzini <pbonzini@redhat.com>
To: "Hervé Poussineau" <hpoussin@reactos.org>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Liu Ping Fan" <pingfank@linux.vnet.ibm.com>,
	"Mark Cave-Ayland" <mark.cave-ayland@ilande.co.uk>,
	qemu-devel <qemu-devel@nongnu.org>,
	"Alexander Graf" <agraf@suse.de>,
	"Blue Swirl" <blauwirbel@gmail.com>,
	"Jan Kiszka" <jan.kiszka@web.de>,
	"Anthony Liguori" <anthony@codemonkey.ws>,
	"Andreas Färber" <afaerber@suse.de>,
	"Aurelien Jarno" <aurelien@aurel32.net>
Subject: Re: [Qemu-devel] [PATCH v3 11/14] ioport: Switch dispatching to memory core layer
Date: Tue, 16 Jul 2013 19:12:33 +0200	[thread overview]
Message-ID: <51E57F01.9020309@redhat.com> (raw)
In-Reply-To: <51E57C09.5000000@reactos.org>

Il 16/07/2013 18:59, Hervé Poussineau ha scritto:
> Paolo Bonzini a écrit :
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> Il 16/07/2013 09:18, Jan Kiszka ha scritto:
>>> Sorry for sending out invitations and then being late to this party
>>> - vacation. What is the status now? Do we have a short-term plan to
>>> avoid the regression or is this better solved by cleaning up the
>>> whole endianess thing? Is anyone actively on it, or should I take a
>>> drink, sit down and join the discussion?
>>
>> Basically, we need testing.  The current state of the tree is before
>> Herve's patch, which means PREP is (should be) broken.
>>
>> Alexey posted a patch that reintroduces the DEVICE_LITTLE_ENDIAN and
>> removes the cpu_{in,out}{b,w,l} indirection.
>>
>> http://permalink.gmane.org/gmane.comp.emulators.qemu/222345
>>
>> We need to test platforms that used a cpu_{in,out}{b,w,l} indirection
>> (MIPS, PPC, SPARC) with and without Alexey's patch.
>>
>> The other occurrences of indirections are:
>>
>> - - hw/isa/i82378.c: This is PREP.  Again, removing the indirection
>> should be tested by Herve or Andreas on top of Alexey's patch.
> 
> For i82378, I have a big patch for it, which rewrites large parts of the
> emulation. Moreover, as i82378 is only used in PReP machine, this
> indirection can be ignored for now.

As you prefer.

>> - - hw/isa/isa_mmio: bamboo, g3beige and mac99 could be tested by Alex.
>>  I don't know about MIPS.  If anything is broken, the solution is to
>> replace isa_mmio_{setup,init} with an alias to get_system_io().  This
>> stops using isa_mmio altogether, so it can be done only on those
>> platforms where it's needed.
> 
> For MIPS Jazz, it is currently broken in SCSI emulation when installing
> Windows NT 4.0/MIPS. However, it seems quite a general problem on
> Windows NT 4, as Neozeed also reported the same freeze when running
> NT4/x86 on http://virtuallyfun.superglobalmegacorp.com/?p=3065 .

But this bug could even prevent VGA initialization, so it should happen
much earlier than that.  So the SCSI breakage would not block testing.

Paolo

>> - - hw/pci-host/apb.c: this is SPARC.  Perhaps Mark Cave-Ayland can test
>> it and see if it is broken---again with and without Alexey's patch.
>> There is a small difference.  This file uses DEVICE_NATIVE_ENDIAN and
>> does the byte swap itself in pci_apb_io{read,write}{b,w,l}.
>>
>> There is also Alpha.  It doesn't matter because it's little endian,
>> but anyway rth is removing the indirection.
> 
> Hervé
> 
> 