[PATCH v3 0/2] PSCI system off and reset for KVM ARM/ARM64

[Anup Patel]

On Wed, Dec 18, 2013 at 11:41 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> On Wed, Dec 18 2013 at 03:52:29 PM, Anup Patel <anup at brainfault.org> wrote:
>> On Wed, Dec 18, 2013 at 9:11 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
>>> Hi Anup,
>>>
>>> On Wed, Dec 18 2013 at 03:03:43 PM, Anup Patel <anup at brainfault.org> wrote:
>>>> On Wed, Dec 18, 2013 at 8:08 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
>>>>> Christoffer Dall <christoffer.dall at linaro.org> writes:
>>>>>
>>>>>> On Tue, Dec 17, 2013 at 05:05:34PM +0530, Anup Patel wrote:
>>>>>>> The Power State and Coordination Interface (PSCI) specification defines
>>>>>>> SYSTEM_OFF and SYSTEM_RESET functions for system poweroff and reboot.
>>>>>>>
>>>>>>> This patchset adds emulation of PSCI SYSTEM_OFF and SYSTEM_RESET functions
>>>>>>> in KVM ARM/ARM64 by forwarding them to user space (QEMU or KVMTOOL) using
>>>>>>> KVM_EXIT_SYSTEM_EVENT exit reason.
>>>>>>>
>>>>>>> To try this patch from guest kernel, we will need PSCI-based restart and
>>>>>>> poweroff support in the guest kenel for both ARM and ARM64.
>>>>>>>
>>>>>>> Rob Herring has already submitted patches for PSCI-based restart and
>>>>>>> poweroff in ARM kernel but these are not merged yet due unstable device
>>>>>>> tree bindings of kernel PSCI support. We will be having similar patches
>>>>>>> for PSCI-based restart and poweroff in ARM64 kernel.
>>>>>>> (Refer http://www.spinics.net/lists/arm-kernel/msg262217.html)
>>>>>>> (Refer http://www.spinics.net/lists/devicetree/msg05348.html)
>>>>>>
>>>>>> Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
>>>>>>
>>>>>> I can merge this series if Marc acks it as well.
>>>>>
>>>>> The patches themselves are mostly fine. One issue though: They implement
>>>>> part of the v0.2 spec, but keep on using the range of function IDs that
>>>>> we made up for v0.1.
>>>>>
>>>>> I just had a chat with the person responsible for the spec, and realized
>>>>> that the Function IDs mentionned in the v0.2 spec are not optional, and
>>>>> not using them would be in direct violation of the spec (the new numbers
>>>>> now come directly from the SMC calling convention).
>>>>
>>>> Should we emulate PSCI_VERSION call to help Guest determine
>>>> the spec version emulated by KVM (i.e. v0.1 or v0.2) ??
>>>
>>> I think that'd be a nice to have, but the guest is likely to get its
>>> information from the DT anyway. Plus I don't think the original PSCI
>>> spec specified PSCI_VERSION, which only make it useful for whatever
>>> comes after v0.2.
>>>
>>> So I think we need to:
>>> - Use the new range for PSCI v0.2 (while still supporting v0.1 and the
>>> old range)
>>
>> Does this mean we should have first isolate v0.2 ID range
>> from v0.1 ID range?
>
> Yes.

Are you planning to do it ?
OR
Do you expect me to do it because this patchset would depend on that?

>
>> And then...
>>
>> Rebase this patchset based on new v0.2 ID range?
>
> Indeed.
>
> Thanks,
>
>         M.
> --
> Jazz is not dead. It just smells funny.

Regards,
Anup