Re: [PATCH] arm64: xen: Implement EFI reset_system callback

From: Juergen Gross
Date: Thu Apr 06 2017 - 04:37:40 EST


On 06/04/17 10:32, Julien Grall wrote:
> Hi Juergen,
>
> On 06/04/17 07:23, Juergen Gross wrote:
>> On 05/04/17 21:49, Boris Ostrovsky wrote:
>>> On 04/05/2017 02:14 PM, Julien Grall wrote:
>>>> The x86 code has theoritically a similar issue, altought EFI does not
>>>> seem to be the preferred method. I have left it unimplemented on x86
>>>> and
>>>> CCed Linux Xen x86 maintainers to know their view here.
>>>
>>> (+Daniel)
>>>
>>> This could be a problem for x86 as well, at least theoretically.
>>> xen_machine_power_off() may call pm_power_off(), which is
>>> efi.reset_system.
>>>
>>> So I think we should have a similar routine there.
>>
>> +1
>>
>> I don't see any problem with such a routine added, in contrast to
>> potential "reboots" instead of power off without it.
>>
>> So I think this dummy xen_efi_reset_system() should be added to
>> drivers/xen/efi.c instead.
>
> I will resend the patch during day with xen_efi_reset_system moved to
> common code and implement the x86 counterpart (thought, I will not be
> able to test it).

I'm rather sure it isn't hit very often. Otherwise there would be more
complaints about crashes during power off (in fact I do remember several
occasions where somebody claimed power off seemed to do a reboot only).


Juergen

>>
>>>> This should also probably be fixed in stable tree.
>>
>> Yes.
>
> I will CC stable.
>
> Thank you,
>