[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-ppc] [Qemu-devel] [PATCH RFC] spapr: by-pass SLOF when -kernel
From: |
Nikunj A Dadhania |
Subject: |
Re: [Qemu-ppc] [Qemu-devel] [PATCH RFC] spapr: by-pass SLOF when -kernel is provided |
Date: |
Wed, 06 Jul 2016 13:32:49 +0530 |
User-agent: |
Notmuch/0.21 (https://notmuchmail.org) Emacs/25.0.94.1 (x86_64-redhat-linux-gnu) |
Alexey Kardashevskiy <address@hidden> writes:
> [ Unknown signature status ]
> On 06/07/16 11:35, David Gibson wrote:
>> On Tue, Jul 05, 2016 at 04:42:37PM +0200, Laurent Vivier wrote:
>>> As device-tree is now fully built by QEMU, we don't need SLOF
>>> anymore if the kernel is provided on the command line.
>>>
>>> In this case, don't load SLOF and boot directly into the
>>> kernel.
>>>
>>> This saves at least 5 seconds on the boot sequence.
>>>
>>> Signed-off-by: Laurent Vivier <address@hidden>
>>
>> I'm not comfortable applying this. We actually used to do this ages
>> ago, but changed to always running through SLOF, and there were
>> reasons for doing so.
>>
>> I don't remember exactly what they were, but I think it boiled down to
>> slight differences in state between booting from SLOF and booting
>> without SLOF leading to confusing errors from the guest kernel.
>>
>
> PCI resource allocation is still done by SLOF (however having them not set
> will trigger allocation in the guest but this is rather unexpected
> workaround than a feature);
I am not sure that works well, i had a work around in qemu for this to get
triggered in guest kernel.
> "client-architecture-support" won't work
> without SLOF either (i.e. compatibile PowerISA 2.0x CPUs).
Right.
Regards
Nikunj