[SeaBIOS] [PATCH v17] Add pvpanic device driver

Laszlo Ersek lersek at redhat.com
Wed May 15 18:25:41 CEST 2013

(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,


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!)


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