Re: [Qemu-devel] [SeaBIOS] [PATCH v17] Add pvpanic device driver

[Paolo Bonzini]

Il 15/05/2013 18:25, Laszlo Ersek ha scritto:
> (Not sure why the CC list has grown this huge, but I'm adding Drew for
> good mesaure.)
> 
> On 05/15/13 09:27, Hu Tao wrote:
>> On Wed, May 15, 2013 at 09:21:54AM +0200, Laszlo Ersek wrote:
>>> On 04/05/13 09:17, Hu Tao wrote:
>>>
>>>> +            Method(RDPT, 0, NotSerialized) {
>>>> +                Store(PEPT, Local0)
>>>> +                Return (Local0)
>>>> +            }
>>>> +
>>>> +            Method(WRPT, 1, NotSerialized) {
>>>> +                Store(Arg0, PEPT)
>>>> +            }
>>>
>>> Please excuse my asking, I haven't been following this -- who's supposed
>>> to call these methods? The latest guest kernel patch I managed to find
>>> ([PATCH v7] kvm: notify host when the guest is panicked -- probably
>>> obsolete by now) appears to do a direct outl().
>>
>> An old version calls WRPT but is buggy, so you see the outl version.
>> This patch is in seabios before the outl version. If you think these
>> methods are needless, feel free to send a patch.
> 
> After Drew located the guest kernel commit for me,
> 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=8b10acd7
> 
> I can see this SeaBIOS patch *is* necessary -- even though the RDPT /
> WRPT methods are not used for port access, the port number itself is
> available from ACPI (\_SB.PCI0.ISA.PEVT._CRS, identified by the
> "QEMU0001" HID) to the kernel.
> 
> Hu, can you (and are you willing to) relicense this commit (seabios
> commit e9725dd7) under the 2-clause BSDL so I can port it to OVMF?
> 
> (Actually I'm somewhat confused because the first S-o-b is from Paolo.
> Since I share an employer with Paolo, getting permission from Paolo
> would be either quite easy or even unnecessary. Anyway it's better to ask!)

I and Hu did half of the patch each. :)

But I think it's simpler to avoid OVMF and wait for the time when QEMU
will produce the ACPI tables.

Paolo