Re: [RFC PATCH qemu] spapr: Kill SLOF

[Alexey Kardashevskiy]

On 07/01/2020 01:15, Daniel Henrique Barboza wrote:
> Hey,
> 
> On 1/5/20 8:38 PM, Alexey Kardashevskiy wrote:
>> Another version is coming, I'll start putting fewer people in the cc:
>> list, watch address@hidden for further updates if interested.
>> Thanks,
> 
> 
> Question: does Petitboot already replaces SLOF in every possible
> scenario for all
> the spapr machine features?

Petitboot kernel+initramdisk almost replaces SLOF + GRUB.

The difference here is that with SLOF + GRUB there is still OF client
interface; and with Petitboot the target system does not get OF just
because Petitboot kexec's to the target kernel which is a different
booting mode in Linux.


> Or is Petitboot 'good enough' to get the ball
> rolling and then we'll incrementally improve Petitboot/spapr code to add
> the
> missing bits?

For Linux guests it needs a bit more cleanup but in general it is quite
good to go.

However I seriously doubt if AIX and FreeBSD guests can be kexec'ed to
and if they could, they may require some OF client interface services
which a standard OF firmware (i.e. SLOF) provides and which I want to
avoid adding into QEMU, such as network/disk booting. Not many care
about this but it is not zero number of people either.


> I am asking because this "SLOF-less" feature is something we'll want to
> expose on
> Libvirt - users will sure enjoy enjoy the shorter boot time - and I want
> to brace
> for impact when users starts opening bugs about the SLOF-less machine
> missing stuff
> that the SLOF version does.

Too soon :)


-- 
Alexey