Re: [Qemu-devel] Release plan for 0.12.0

[Jordan Justen]

On Fri, Oct 2, 2009 at 06:29, Anthony Liguori <address@hidden> wrote:
> Jordan Justen wrote:
>>
>> On Thu, Oct 1, 2009 at 14:23, Anthony Liguori <address@hidden>
>> wrote:
>>
>>>
>>> I see a CSM as a pre-requisite for merging a uefi rom.  A user can
>>> already
>>> use a uefi rom by simply using the -bios parameter so there's nothing
>>> inhibiting testing.  My concern about introducing a new machine type is
>>> that
>>> it would require duplicate testing and force the selection of uefi up
>>> through the management tool stack.
>>>
>>
>> I understand your points.  You want to keep a single machine type and
>> try to support UEFI and legacy boots with that firmware.
>> Unfortunately, I don't know that we will be able to provide that via
>> OVMF.  There is no open source CSM for us to make use of.
>>
>> And, it is true that -bios can be used for OVMF by those with a
>> particular interest in UEFI.  But for a more general audience, I think
>> without the -M switch a Linux distribution couldn't package qemu in
>> such a way that both a legacy bios and the OVMF firmware would be
>> available.
>>
>
> My concern is that if we provide separate machine types, it doubles our
> testing since we have to test guests with both the BIOS firmware and the
> UEFI firmware.  It also hurts usability since a user now has to make the
> decision as to whether they want to use UEFI or not.  A user should not have
> to even know what EFI is.
>
> So I think the best way forward is to hold off on UEFI in mainline until we
> can provide a single unified stack.

Ok.  I understand if this is the way the QEMU project wants to
proceed.  I think it might delay UEFI support somewhat, but it
certainly would be better for the user if they did not have to provide
the correct command line to boot.

While it is true that a separate machine type could potentially be
viewed as increasing the testing requirements, I am not so sure.  If
QEMU has a UEFI+CSM solution, wouldn't we still have to test both UEFI
based OS boot and the CSM based legacy OS boot?

>>> OTH, uefi + a CSM based on SeaBIOS could be used as the default firmware.
>>>  I
>>> don't think it's a reasonable target for 0.12 but I think if someone
>>> actively worked on it, it would be possible for future releases.
>>>
>>
>> I don't know of any efforts to create an open source CSM.  Is someone
>> working on converting SeaBIOS to act as a CSM?
>>
>
> There are multiple parties that seem to be interested in uefi for guests.  I
> expect that one of those parties will end up doing the work if that's the
> requirement that we put down.
>
>> For tianocore.org & OVMF we would further be restricted by requiring a
>> BSD licensed CSM.  Of course, if there was a SeaBIOS based CSM, then
>> I'm sure OVMF could be modified to make use of it easily enough.  We
>> just wouldn't be able to have the SeaBIOS CSM on tianocore.org and
>> part of the normal tianocore.org OVMF releases.
>>
>
> I don't think that's a big problem for us.

Yes, I agree that this is would not be a problem for QEMU.  In fact,
I'd like to take back my opinion regarding how this may or may not be
usable by tianocore.org and OVMF.  Although we don't have GPL code
hosted within any of our tianocore.org projects at this time, maybe
this could change...

I do know that we don't intend to start an open source CSM project on
tianocore.org at this time.

But, if such a project was started, I think we would support
development via email on our edk2 dev list, and potentially even host
the project on tianocore.org.

So, I would invite anyone thinking of tackling such a task to join the
edk2 dev list to discuss your work.  Furthermore, if you'd like to
request the project to be hosted on tianocore.org, feel free to ask
our administrators.  (As mentioned previously, we usually deal with
the BSD license on tianocore.org, but please don't let this hold you
back from asking questions, or requesting hosting of your project.)

Thanks,

-Jordan